Infectious diseases Flashcards
What are gram +ve cocci?
staphylococci + streptococci (including enterococci)
What are 3 gram -ve cocci?
Neisseria meningitidis + Neisseria gonorrhoeae, also Moraxella catarrhalis
Name 5 gram postive rods
ABCD L
Actinomyces Bacillus anthracis (anthrax) Clostridium Diphtheria: Corynebacterium diphtheriae Listeria monocytogenes
Name 6 gram -ve rods
Escherichia coli
Haemophilus influenzae
Pseudomonas aeruginosa
Salmonella sp.
Shigella sp.
Campylobacter jejuni
What 5 agents can cause CAP?
What is seen in alcoholics?
Streptococcus pneumoniae (accounts for around 80% of cases)
Haemophilus influenzae
Staphylococcus aureus: commonly after influenza infection
atypical pneumonias (e.g. Due to Mycoplasma pneumoniae)
viruses
Klebsiella is seen in alcoholics
What is the most common cause of CAP?
Streptococcus pneumoniae (pneumococcus) is the most common cause of community-acquired pneumonia
Give 4 characteristic features of pneumococcal pneumonia?
Characteristic features of pneumococcal pneumonia
rapid onset high fever pleuritic chest pain herpes labialis (cold sores)
What are the two types of pnuemococcal vaccine currently in use?
There are two type of pneumococcal vaccine currently in use:
pneumococcal conjugate vaccine (PCV) pneumococcal polysaccharide vaccine (PPV)
Who is routinely offered the pneumococcal vaccine?
The PCV is given to children as part of their routine immunisations (at 3 and 12-13 months).
The PPV is offered to all adults over the age of 65 years, to patients with chronic conditions such as COPD and to those who have had a splenectomy (see below).
What 9 groups of people should be given the pneumococcal vaccine?
Groups who should be vaccinated:
asplenia or splenic dysfunction
chronic respiratory disease: COPD, bronchiectasis, cystic fibrosis, interstitial lung disease. Asthma is only included if ‘it requires the use of oral steroids at a dose sufficient to act as a significant immunosuppressant’
chronic heart disease: ischaemic heart disease if requiring medication or follow-up, heart failure, congenital heart disease. Controlled hypertension is not an indication for vaccination
chronic kidney disease
chronic liver disease: including cirrhosis and chronic hepatitis
diabetes mellitus if requiring medication
immunosuppression (either due to disease or treatment). This includes patients with any stage of HIV infection
cochlear implants
patients with cerebrospinal fluid leaks
Adults usually require just one dose but those with asplenia, splenic dysfunction or chronic kidney disease need a booster every 5 years.
How is influenza vaccine given to children? when is this given? is this a live vaccine?
it is given intranasally
the first dose is given at 2-3 years, then annually after that
it is a live vaccine (cf. injectable vaccine below)
Why would a child be given an injectable influenza vaccine? is this effective?
children who were traditionally offered the flu vaccine (e.g. asthmatics) will now be given intranasal vaccine unless this is inappropriate, for example if they are immunosuppressed. In this situation the inactivated, injectable vaccine should be given
only children aged 2-9 years who have not received an influenza vaccine before need 2 doses
it is less effective than the intranasal vaccine
What are 7 contraindications of influenza vaccine in children?
Contraindications
immunocompromised aged < 2 years current febrile illness or blocked nose/rhinorrhoea current wheeze (e.g. ongoing viral-induced wheeze/asthma) or history of severe asthma (BTS step 4) egg allergy pregnancy/breastfeeding if the child is taking aspirin (e.g. for Kawasaki disease) due to a risk of Reye's syndrome
What are 4 side effects of the influenza vaccine?
Side-effects
blocked-nose/rhinorrhoea headache anorexia
What groups of adults get the flu vaccine due to personal health?
The Department of Health recommends annual influenza vaccination for all people older than 65 years, and those older than 6 months if they have:
chronic respiratory disease (including asthmatics who use inhaled steroids) chronic heart disease (heart failure, ischaemic heart disease, including hypertension if associated with cardiac complications) chronic kidney disease chronic liver disease: cirrhosis, biliary atresia, chronic hepatitis chronic neurological disease: (e.g. Stroke/TIAs) diabetes mellitus (including diet controlled) immunosuppression due to disease or treatment (e.g. HIV) asplenia or splenic dysfunction pregnant women adults with a body mass index >= 40 kg/m²
What groups of people get the flu vaccine due to personal circumstance i.e. occupationally
Other at risk individuals include:
health and social care staff directly involved in patient care (e.g. NHS staff) those living in long-stay residential care homes carers of the elderly or disabled person whose welfare may be at risk if the carer becomes ill (at the GP's discretion)
The influenza vaccine
-is this live?
-How should this be stored?
-What is a contraindication?
-is this effective?>
-How long does this take to work?
The influenza vaccine
it is an inactivated vaccine, so cannot cause influenza. A minority of patients however develop fever and malaise which may last 1-2 days should be stored between +2 and +8ºC and shielded from light contraindications include hypersensitivity to egg protein. in adults the vaccination is around 75% effective, although this figure decreases in the elderly it takes around 10-14 days after immunisation before antibody levels are at protective levels
What treatment is used for Exacerbations of chronic bronchitis
Amoxicillin or tetracycline or clarithromycin
What treatment is used for Uncomplicated community-acquired pneumonia
Amoxicillin (Doxycycline or clarithromycin in penicillin allergic, add flucloxacillin if staphylococci suspected e.g. In influenza)
What treatment is added if you are considering atypical pneumonia?
Clarithromycin
What treatment is used for HAP?
Within 5 days of admission: co-amoxiclav or cefuroxime
More than 5 days after admission: piperacillin with tazobactam OR a broad-spectrum cephalosporin (e.g. ceftazidime) OR a quinolone (e.g. ciprofloxacin)
Describe the primary infection of TB
A non-immune host who is exposed to M. tuberculosis may develop a primary infection of the lungs. A small lung lesion known as a Ghon focus develops. The Ghon focus is composed of tubercle-laden macrophages. The combination of a Ghon focus and hilar lymph nodes is known as a Ghon complex
In immunocompetent people, the initial lesion usually heals by fibrosis. Those who are immunocompromised may develop disseminated disease (miliary tuberculosis).
Describe the secondary infection of TB? what can lead to this?
If the host becomes immunocompromised the initial infection may become reactivated. Reactivation generally occurs in the apex of the lungs and may spread locally or to more distant sites. Possible causes of immunocompromise include:
immunosuppressive drugs including steroids HIV malnutrition
Where can secondary infection of TB occur?
The lungs remain the most common site for secondary tuberculosis. Extra-pulmonary infection may occur in the following areas:
central nervous system (tuberculous meningitis - the most serious complication) vertebral bodies (Pott's disease) cervical lymph nodes (scrofuloderma) renal gastrointestinal tract
Describe the standard treatment of TB
The standard therapy for treating active tuberculosis is:
Initial phase - first 2 months (RIPE)
Rifampicin Isoniazid Pyrazinamide Ethambutol (the 2006 NICE guidelines now recommend giving a 'fourth drug' such as ethambutol routinely - previously this was only added if drug-resistant tuberculosis was suspected)
Continuation phase - next 4 months
Rifampicin Isoniazid
What is the treatment of latent TB?
The treatment for latent tuberculosis is 3 months of isoniazid (with pyridoxine) and rifampicin OR 6 months of isoniazid (with pyridoxine)
What is the treatment for meningeal TB?
Patients with meningeal tuberculosis are treated for a prolonged period (at least 12 months) with the addition of steroids
Who would warrant directly observed therapy for TB?
Directly observed therapy with a three times a week dosing regimen may be
indicated in certain groups, including:
homeless people with active tuberculosis patients who are likely to have poor concordance all prisoners with active or latent tuberculosis
What is immune reconstitution disease in the treatment of TB?
Immune reconstitution disease
occurs typically 3-6 weeks after starting treatment often presents with enlarging lymph nodes
Which drug side effects?
potent liver enzyme inducer
hepatitis, orange secretions
flu-like symptoms
Rifampicin
Which drug side effects?
peripheral neuropathy: prevent with pyridoxine (Vitamin B6)
hepatitis, agranulocytosis
liver enzyme inhibitor
isoniazid
Which drug side effects?
hyperuricaemia causing gout
arthralgia, myalgia
hepatitis
Pyrazinamide
What has to be checked before starting ethambutol?
optic neuritis: check visual acuity before and during treatment
What 8 groups of people get a BCG
all infants (aged 0 to 12 months) living in areas of the UK where the annual incidence of TB is 40/100,000 or greater
all infants (aged 0 to 12 months) with a parent or grandparent who was born in a country where the annual incidence of TB is 40/100,000 or greater. The same applies to older children but if they are 6 years old or older they require a tuberculin skin test first
previously unvaccinated tuberculin-negative contacts of cases of respiratory TB
previously unvaccinated, tuberculin-negative new entrants under 16 years of age who were born in or who have lived for a prolonged period (at least three months) in a country with an annual TB incidence of 40/100,000 or greater
healthcare workers
prison staff
staff of care home for the elderly
those who work with homeless people
What does the BCG vaccine contain? What else does this offer protection against?
The vaccine contains live attenuated Mycobacterium bovis. It also offers limited protection against leprosy.
Describe the administration of the BCG vaccine
any person being considered for the BCG vaccine must first be given a tuberculin skin test. The only exceptions are children < 6 years old who have had no contact with tuberculosis
given intradermally, normally to the lateral aspect of the left upper arm
BCG can be given at the same time as other live vaccines, but if not administered simultaneously there should be a 4 week interval
What are 5 contraindications to the BCG vaccine? what age is this not given to?
Contraindications
previous BCG vaccination a past history of tuberculosis HIV pregnancy positive tuberculin test (Heaf or Mantoux)
The BCG vaccine is not given to anyone over the age of 35, as there is no evidence that it works for people of this age group.
Mycoplasma pneumonia:
-what is this a cause of?
-what is this assoc. with?
-Is this common?
Mycoplasma pneumoniae is a cause of atypical pneumonia which often affects younger patients. It is associated with a number of characteristic complications such as erythema multiforme and cold autoimmune haemolytic anaemia. Epidemics of Mycoplasma pneumoniae classically occur every 4 years. It is important to recognise atypical pneumonia as it may not respond to penicillins or cephalosporins due to it lacking a peptidoglycan cell wall.
What are 3 features of mycoplasma pneumoniae?
Features
the disease typically has a prolonged and gradual onset flu-like symptoms classically precede a dry cough bilateral consolidation on x-ray
What are 7 complications of mycoplasma pneumoniae?
cold agglutins (IgM): may cause an haemolytic anaemia, thrombocytopenia
erythema multiforme, erythema nodosum
meningoencephalitis, Guillain-Barre syndrome and other immune-mediated neurological diseases
bullous myringitis: painful vesicles on the tympanic membrane
pericarditis/myocarditis
gastrointestinal: hepatitis, pancreatitis
renal: acute glomerulonephritis
What investigations are used for mycoplasma pneumoniae?
Investigations
diagnosis is generally by Mycoplasma serology positive cold agglutination test → peripheral blood smear may show red blood cell agglutination
What is the management of mycoplasma pneumoniae?
Management
doxycycline or a macrolide (e.g. erythromycin/clarithromycin)
What is legionnaires disease caused by? where does this typically colonise? can you get person-person transmission?
Legionnaire’s disease is caused by the intracellular bacterium Legionella pneumophilia. It typically colonizes water tanks and hence questions may hint at air-conditioning systems or foreign holidays. Person-to-person transmission is not seen
Give 8 features of legionnaires disease?
Features
flu-like symptoms including fever (present in > 95% of patients) dry cough relative bradycardia confusion lymphopaenia hyponatraemia deranged liver function tests pleural effusion: seen in around 30% of patients
What is the diagnostic testof choice for legionnaireS? what is seen on CXR?
Investigations
diagnositic test of choice:urinary antigen
chest x-ray findings are non-specific but may include:
a mid-to-lower zone predominance of patchy consolidation
pleural effusions in around 30%
What is the management of legionnaires disease?
Management
treat with erythromycin/clarithromycin
What is the treatment for Throat infections
Phenoxymethylpenicillin (erythromycin alone if penicillin-allergic)
What is infectious mononucleosis? what is this caused by?
Infectious mononucleosis (glandular fever) is caused by the Epstein-Barr virus (EBV, also known as human herpesvirus 4, HHV-4) in 90% of cases. Less frequent causes include cytomegalovirus and HHV-6. It is most common in adolescents and young adults.
What is the classic triad of infectious mononucleosis?
The classic triad of sore throat, pyrexia and lymphadenopathy is seen in around 98% of patients:
sore throat lymphadenopathy: may be present in the anterior and posterior triangles of the neck, in contrast to tonsillitis which typically only results in the upper anterior cervical chain being enlarged pyrexia
What are 6 features outwith the triad that are seen in glandular fevers?
Other features include:
malaise, anorexia, headache palatal petechiae splenomegaly - occurs in around 50% of patients and may rarely predispose to splenic rupture hepatitis, transient rise in ALT lymphocytosis: presence of 50% lymphocytes with at least 10% atypical lymphocytes haemolytic anaemia secondary to cold agglutins (IgM)
What happens if you treat glandular fevers with amoxicillin?
a maculopapular, pruritic rash develops in around 99% of patients who take ampicillin/amoxicillin whilst they have infectious mononucleosis
How long do symptoms last for in glandular fever?
Symptoms typically resolve after 2-4 weeks.
What is the diagnosis of glandular fever?
Diagnosis
heterophil antibody test (Monospot test)
NICE guidelines suggest FBC and Monospot in the 2nd week of the illness to confirm a diagnosis of glandular fever.
What is the management of glandular fever?
Management is supportive and includes:
rest during the early stages, drink plenty of fluid, avoid alcohol simple analgesia for any aches or pains consensus guidance in the UK is to avoid playing contact sports for 4 weeks after having glandular fever to reduce the risk of splenic rupture
What is mumps caused by?
Mumps is a caused by RNA paramyxovirus and tends to occur in winter and spring
Describe the spread and the pathophysiology of mumps? what is the incubation period?
Spread
by droplets respiratory tract epithelial cells → parotid glands → other tissues infective 7 days before and 9 days after parotid swelling starts incubation period = 14-21 days
What are 3 features of mumps?
Clinical features
fever
malaise, muscular pain
parotitis ('earache', 'pain on eating'): unilateral initially then becomes bilateral in 70%
What is the prevention of mumps?
Prevention
MMR vaccine: the efficacy is around 80%
What is the management of mumps?
Management
rest paracetamol for high fever/discomfort notifiable disease
What are 4 complications of mumps?
Complications
orchitis - uncommon in pre-pubertal males but occurs in around 25-35% of post-pubertal males. Typically occurs four or five days after the start of parotitis hearing loss - usually unilateral and transient meningoencephalitis pancreatitis
What does Respiratory syncytial virus cause?
bronchiolitis
What does Parainfluenza virus cause?
croup
What does Rhinovirus cause?
common cold
what does Haemophilus influenzae cause?
COPD exac, Community-acquired pneumonia
Most common cause of bronchiectasis exacerbations
Acute epiglottitis
What does staph., aureus cause in the respiratory tract?
Pneumonia, particularly following influenza
What is given for sinusitis?
Phenoxymethylpenicillin
What is given for otitis media?
Amoxicillin (erythromycin if penicillin-allergic)
What is given for otitis externa?
Flucloxacillin (erythromycin if penicillin-allergic)
What is given for Periapical or periodontal abscess
Amoxicillin
What is given for Gingivitis: acute necrotising ulcerative
metronidazole
What is given for impetigo?
Topical hydrogen peroxide, oral flucloxacillin or erythromycin if widespread
What is cellulitis most commonly caused by?
Cellulitis is most commonly caused by infection with Streptococcus pyogenes or less commonly Staphylcoccus aureus. The majority of cases resolve with oral antibiotics.
How is cellulitis diagnosed?
The diagnosis of cellulitis is clinical. No further investigations are required in primary care. Bloods and blood cultures may be requested if the patient is admitted and septicaemia is suspected.
What classification system is used to guide how cellulitis is managed?
Eron classification
Class Features
I There are no signs of systemic toxicity and the person has no uncontrolled co-morbidities
II The person is either systemically unwell or systemically well but with a co-morbidity (for example peripheral arterial disease, chronic venous insufficiency, or morbid obesity) which may complicate or delay resolution of infection
III The person has significant systemic upset such as acute confusion, tachycardia, tachypnoea, hypotension, or unstable co-morbidities that may interfere with a response to treatment, or a limb-threatening infection due to vascular compromize
IV The person has sepsis syndrome or a severe life-threatening infection such as necrotizing fasciitis
Who should be admitted for IV antibiotics to treat cellulitis? 6
They recommend the following that we admit for intravenous antibiotics the following patients: CKS
Has Eron Class III or Class IV cellulitis. Has severe or rapidly deteriorating cellulitis (for example extensive areas of skin). Is very young (under 1 year of age) or frail. Is immunocompromized. Has significant lymphoedema. Has facial cellulitis (unless very mild) or periorbital cellulitis.
What is the management of eron class 1 cellulitis?
Eron Class I
oral antibiotics NICE oral flucloxacillin as first-line treatment for mild/moderate cellulitis oral clarithromycin, erythromycin (in pregnancy) or doxycycline is recommended in patients allergic to penicillin
what is the treatment of eron class III-IV cellulitis?
Eron Class III-IV
admit NICE recommend: oral/IV co-amoxiclav, oral/IV clindamycin, IV cefuroxime or IV ceftriaxone
What is the management of animal bites?
The majority of bites seen in everyday practice involve dogs and cats. These are generally polymicrobial but the most common isolated organism is Pasteurella multocida.
Management
cleanse wound. Puncture wounds should not be sutured closed unless cosmesis is at risk current BNF recommendation is co-amoxiclav if penicillin-allergic then doxycycline + metronidazole is recommended
What are the common bacteria found in human bites? what is the treatment?
Human bites commonly cause multimicrobial infection, including both aerobic and anaerobic bacteria.
Common organisms include:
Streptococci spp. Staphylococcus aureus Eikenella Fusobacterium Prevotella
Co-amoxiclav is recommended, as for animal bites.
The risk of viral infections such as HIV and hepatitis C should also be considered.
what is cat scratch disease caused by? what are 4 features?
Cat scratch disease is generally caused by the Gram negative rod Bartonella henselae
Features
fever history of a cat scratch regional lymphadenopathy headache, malaise
What is the treatment of Cellulitis (near the eyes or nose)
Co-amoxiclav (clarithromycin, + metronidazole if penicillin-allergic)
What is the treatment of Erysipelas?
Flucloxacillin* (clarithromycin, erythromycin or doxycycline if penicillin-allergic)
Who would benefit from post-exposure prophylaxis to chicken pox? what is given?
The following criteria should be met to determine who would benefit from active post-exposure prophylaxis:
1. significant exposure to chickenpox or herpes zoster
e.g. exposure to limited, covered-up shingles may not warrant post-exposure prophylaxis
2. a clinical condition that increases the risk of severe varicella; this includes immunosuppressed patients, neonates and pregnant women
e.g. long-term steroids, methotrexate and other common immunosuppressants
3. no antibodies to the varicella virus
ideally all at-risk exposed patients should have a blood test for varicella antibodies
this should not, however, delay post-exposure prophylaxis past 7 days after initial contact
Patients who fulfill the above criteria should be given varicella-zoster immunoglobulin (VZIG).
Bed bugs
-What is this caused by?
-How is this managed?
-How can this be controlled/prevented?
Bed bugs describes a variety of clinical problems including itchy skin rashes, bites and allergic symptoms secondary to infestation with Cimex hemipteru.
Bedbug infestation seems to be an increasingly common presentation within UK general practice. Bedbugs thrive in mattresses or fabrics, and can be extremely difficult to eradicate. Topical hydrocortisone is suitable to control itch, but definitive management is through a pest management company and fumigation of the house.
Bed bug numbers may be controlled by hot-washing bed linen and using mattress covers.
What is lyme disease caused by?
Lyme disease is caused by the spirochaete Borrelia burgdorferi and is spread by ticks.
Describe erythema migrans seen in lyme disease? what other systemic features occur within 30 days?
Early features (within 30 days)
erythema migrans
'bulls-eye' rash is typically at the site of the tick bite
typically develops 1-4 weeks after the initial bite but may present sooner
usually painless, more than 5 cm in diameter and slowlly increases in size
present in around 80% of patients.
systemic features
headache
lethargy
fever
arthralgia
What are 5 later features of lyme disease? (after 30 days)
Later features (after 30 days)
cardiovascular
heart block
peri/myocarditis
neurological
facial nerve palsy
radicular pain
meningitis
What investigations are recommended for lyme disease?
Investigation
NICE recommend that Lyme disease can be diagnosed clinically if erythema migrans is present
erythema migrans is therefore an indication to start antibiotics
enzyme-linked immunosorbent assay (ELISA) antibodies to Borrelia burgdorferi are the first-line test
if negative and Lyme disease is still suspected in people tested within 4 weeks from symptom onset, repeat the ELISA 4-6 weeks after the first ELISA test. If still suspected in people who have had symptoms for 12 weeks or more then an immunoblot test should be done
if positive or equivocal then an immunoblot test for Lyme disease should be done
What is the management of asymptomatic tick bites?
Management of asymptomatic tick bites
tick bites can be a relatively common presentation to GP practices, and can cause significant anxiety if the tick is still present, the best way to remove it is using fine-tipped tweezers, grasping the tick as close to the skin as possible and pulling upwards firmly. The area should be washed following. NICE guidance does not recommend routine antibiotic treatment to patients who've suffered a tick bite
What is the manageemnt of suspected/confirmed lyme disease? What reaction can be seen after initiating therapy?
Management of suspected/confirmed Lyme disease
doxycycline if early disease. Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy)
people with erythema migrans should be commenced on antibiotic without the need for further tests
ceftriaxone if disseminated disease
Jarisch-Herxheimer reaction is sometimes seen after initiating therapy: fever, rash, tachycardia after first dose of antibiotic (more commonly seen in syphilis, another spirochaetal disease)
What is given to treat lower UTI?
Trimethoprim or nitrofurantoin. Alternative: amoxicillin or cephalosporin
When is urine culture sent in UTI
send a urine culture if:
aged > 65 years visible or non-visible haematuria
How is UTI managed in a symptomatic pregnant lady?
-what is first line?
-what is second line?
if the pregnant woman is symptomatic:
a urine culture should be sent in all cases should be treated with an antibiotic for first-line: nitrofurantoin (should be avoided near term) second-line: amoxicillin or cefalexin trimethoprim is teratogenic in the first trimester and should be avoided during pregnancy
How is asymptomatic bacteruria treated in pregnant women?
asymptomatic bacteriuria in pregnant women:
a urine culture should be performed routinely at the first antenatal visit Clinical Knowledge Summaries recommend an immediate antibiotic prescription of either nitrofurantoin (should be avoided near term), amoxicillin or cefalexin. This should be a 7-day course the rationale of treating asymptomatic bacteriuria is the significant risk of progression to acute pyelonephritis a further urine culture should be sent following completion of treatment as a test of cure
How is UTI treated in men?
Men
an immediate antibiotic prescription should be offered for 7 days as with non-pregnant women, trimethoprim or nitrofurantoin should be offered first-line unless prostatitis is suspected a urine culture should be sent in all cases before antibiotics are started NICE Clinical Knowledge Summaries state: 'Referral to urology is not routinely required for men who have had one uncomplicated lower urinary tract infection (UTI).'
What is given to treat acute pyelonephritis>
Broad-spectrum cephalosporin or quinolone
What is given to treat prostatitis?
Quinolone or trimethoprim
What is the treatment of gonorrhoea?
IM ceftriaxone
What is gonorrhoea caused by? what is the incubation period?
Gonorrhoea is caused by the Gram-negative diplococcus Neisseria gonorrhoeae. Acute infection can occur on any mucous membrane surface, typically genitourinary but also rectum and pharynx. The incubation period of gonorrhoea is 2-5 days
What are the features of gonorrhoea in males? in females?
Features
males: urethral discharge, dysuria females: cervicitis e.g. leading to vaginal discharge rectal and pharyngeal infection is usually asymptomatic
Describe the management of gonorrhoea?
-first line
-if sensitivities are known
-if the partient has refused first line treatment
Management
ciprofloxacin used to be the treatment of choice. However, there is increased resistance to ciprofloxacin (around 36% in the UK) and therefore cephalosporins are now more widely used there was a change in the 2019 British Society for Sexual Health and HIV (BASHH) guidelines. Previously the first-line treatment was IM ceftriaxone + oral azithromycin. The new first-line treatment is a single dose of IM ceftriaxone 1g (i.e. no longer add azithromycin). If sensitivities are known (and the organism is sensitive to ciprofloxacin) then a single dose of oral ciprofloxacin 500mg should be given if ceftriaxone is refused (e.g. needle-phobic) then oral cefixime 400mg (single dose) + oral azithromycin 2g (single dose) should be used
What are the complications of gonorrhoea?
-what is the triad of symptoms?
-What are later complications?
Disseminated gonococcal infection (DGI) and gonococcal arthritis may also occur, with gonococcal infection being the most common cause of septic arthritis in young adults. The pathophysiology of DGI is not fully understood but is thought to be due to haematogenous spread from mucosal infection (e.g. Asymptomatic genital infection). Initially there may be a classic triad of symptoms: tenosynovitis, migratory polyarthritis and dermatitis. Later complications include septic arthritis, endocarditis and perihepatitis (Fitz-Hugh-Curtis syndrome)
What are three key features of disseminated gonococcal infection
Key features of disseminated gonococcal infection
tenosynovitis migratory polyarthritis dermatitis (lesions can be maculopapular or vesicular)
What is the treatment of chlamydia?
Doxycycline or azithromycin
what causes chlamydia?
-is this common?
-what is the incubation period?
Chlamydia is the most prevalent sexually transmitted infection in the UK and is caused by Chlamydia trachomatis, an obligate intracellular pathogen. Approximately 1 in 10 young women in the UK have Chlamydia. The incubation period is around 7-21 days, although it should be remembered a large percentage of cases are asymptomatic
What is LGV? how is this treated?
Lymphogranuloma venereum (LGV) is caused by Chlamydia trachomatis. Typically infection comprises of three stages
stage 1: small painless pustule which later forms an ulcer stage 2: painful inguinal lymphadenopathy stage 3: proctocolitis
LGV is treated using doxycycline.
What are the features of gonorrhoea is women? in men?
Features
asymptomatic in around 70% of women and 50% of men women: cervicitis (discharge, bleeding), dysuria men: urethral discharge, dysuria
What are 7 potential complications of chlamydia?
Potential complications
epididymitis pelvic inflammatory disease endometritis increased incidence of ectopic pregnancies infertility reactive arthritis perihepatitis (Fitz-Hugh-Curtis syndrome)
Describe the investigations for chlamydia? what is first line investigation for women vs men? when should chlamydia testing be carried out?
Investigation
traditional cell culture is no longer widely used nuclear acid amplification tests (NAATs) are now the investigation of choice urine (first void urine sample), vulvovaginal swab or cervical swab may be tested using the NAAT technique for women: the vulvovaginal swab is first-line for men: the urine test is first-line Chlamydiatesting should be carried out two weeks after a possible exposure
Describe the screening for chlamydia
Screening
in England the National Chlamydia Screening Programme is open to all men and women aged 15-24 years the 2009 SIGN guidelines support this approach, suggesting screening all sexually active patients aged 15-24 years relies heavily on opportunistic testing
What is the first line treatment of chlamydia?
doxycycline (7 day course) if first-line
this is now preferred to azithromycin due to concerns about Mycoplasma genitalium. This infection is often coexistant in patients with Chlamydia and there is evidence of rising levels of macrolide resistance, hence why doxycycline is preferred if doxycycline is contraindicated / not tolerated then either azithromycin (1g od for one day, then 500mg od for two days) should be used
What is the treatment of chlamydia if pregnant?
if pregnant then azithromycin, erythromycin or amoxicillin may be used. The SIGN guidelines suggest azithromycin 1g stat is the drug of choice ‘following discussion of the balance of benefits and risks with the patient’
who should be offered a choice of provider for initial partner notification for chlamydia? who should be contacted?
patients diagnosed with Chlamydia should be offered a choice of provider for initial partner notification - either trained practice nurses with support from GUM, or referral to GUM
for men with urethral symptoms: all contacts since, and in the four weeks prior to, the onset of symptoms
for women and asymptomatic men all partners from the last six months or the most recent sexual partner should be contacted
contacts of confirmed Chlamydia cases should be offered treatment prior to the results of their investigations being known (treat then test)
What is the treatment for PID?
Oral ofloxacin + oral metronidazole or intramuscular ceftriaxone + oral doxycycline + oral metronidazole
What is the treatment for syphilis?
Benzathine benzylpenicillin or doxycycline or erythromycin
What is syphilis caused by? how many stages of infection can occur? what is the incubation period?
Syphilis is a sexually transmitted infection caused by the spirochaete Treponema pallidum. Infection is characterised by primary, secondary and tertiary stages. The incubation period is between 9-90 days
Describe the primary features of syphilis?
Primary features
chancre - painless ulcer at the site of sexual contact local non-tender lymphadenopathy often not seen in women (the lesion may be on the cervix)
What are the secondary features of syphilis? when does this occur?
Secondary features - occurs 6-10 weeks after primary infection
systemic symptoms: fevers, lymphadenopathy rash on trunk, palms and soles buccal 'snail track' ulcers (30%) condylomata lata (painless, warty lesions on the genitalia )
What are the tertiary features of syphilis?
Tertiary features
gummas (granulomatous lesions of the skin and bones) ascending aortic aneurysms general paralysis of the insane tabes dorsalis Argyll-Robertson pupil
what are 5 features of congenital syphilis?
Features of congenital syphilis
blunted upper incisor teeth (Hutchinson's teeth), 'mulberry' molars rhagades (linear scars at the angle of the mouth) keratitis saber shins saddle nose deafness
What is the treatment of BV?
Oral or topical metronidazole or topical clindamycin
What is BV? what happens to vaginal pH?
Bacterial vaginosis (BV) describes an overgrowth of predominately anaerobic organisms such as Gardnerella vaginalis. This leads to a consequent fall in lactic acid producing aerobic lactobacilli resulting in a raised vaginal pH.
What is the criteria used for diagnosis of BV? how many points should be present for diganosis?
Amsel’s criteria for diagnosis of BV - 3 of the following 4 points should be present
thin, white homogenous discharge clue cells on microscopy: stippled vaginal epithelial cells vaginal pH > 4.5 positive whiff test (addition of potassium hydroxide results in fishy odour)
What is the management of BV in an asymptomatic woman?
Management
if the woman is asymptomatic, treatment is not usually required CKS
e.g. picked up on a swab done for different reasons
exceptions include if a woman is undergoing a termination of pregnancy
What is the management of BV in a symptomatic woman? what is the cure rate? what is the relapse rate?
if symptomatic: oral metronidazole for 5-7 days CKS
70-80% initial cure rate relapse rate > 50% within 3 months a single oral dose of metronidazole 2g may be used if adherence may be an issue the BNF suggests topical metronidazole or topical clindamycin as alternatives
What is the management of BV in pregnancy?
if pregnant CKS
results in an increased risk of preterm labour, low birth weight and chorioamnionitis, late miscarriage it was previously taught that oral metronidazole should be avoided in the first trimester and topical clindamycin used instead. Recent guidelines however recommend that oral metronidazole is used throughout pregnancy if asymptomatic: discuss with the woman's obstetrician if treatment is indicated if symptomatic: either oral metronidazole for 5-7 days or topical treatment. The higher, stat dose of metronidazole mentioned above is not recommended
What is trichomonas vaginalis?
Trichomonas vaginalis is a highly motile, flagellated protozoan parasite. Trichomoniasis is a sexually transmitted infection (STI).
What are the 5 features of trichomonas?
Features
vaginal discharge: offensive, yellow/green, frothy vulvovaginitis strawberry cervix pH > 4.5 in men is usually asymptomatic but may cause urethritis
What is done in the investigation of trichomonas?
Investigation
microscopy of a wet mount shows motile trophozoites
What is the management of trichomonas?
Management
oral metronidazole for 5-7 days, although the BNF also supports the use of a one-off dose of 2g metronidazole
What is non-gonococcal urethritis? describe a typical case?
Non-gonococcal urethritis (NGU, sometimes referred to as non-specific urethritis) is a term used to describe the presence of urethritis when a gonococcal bacteria are not identifiable or the initial swab. A typical case would be a male who presented to a GUM clinic with a purulent urethral discharge and dysuria. A swab would be taken in clinic, microscopy performed which showed neutrophils but no Gram-negative diplococci (i.e. no evidence of gonorrhoea). Clearly, this patient requires immediate treatment prior to waiting for the Chlamydia test to come back and hence an initial diagnosis of NGU is made.
What can cause non-gonococcal urethritis?
No cause is found in around half of cases. Possible causative organisms include:
Chlamydia trachomatis
most common cause
Mycoplasma genitalium
thought to cause more symptoms than Chlamydia
less common causes
Ureaplasma urealyticum
Trichomonas vaginalis
Escherichia coli
What is the management of non-gonococcal urethritis?
Management
contact tracing the BNF and British Association for Sexual Health and HIV (BASHH) both recommend either oral azithromycin or doxycycline
What is chancroid? what does this cause?
Chancroid is a tropical disease caused by Haemophilus ducreyi. It causes painful genital ulcers associated with unilateral, painful inguinal lymph node enlargement. The ulcers typically have a sharply defined, ragged, undermined border.
How many strains of HSV exist? what do these cause?
There are two strains of the herpes simplex virus (HSV) in humans: HSV-1 and HSV-2. Whilst it was previously thought HSV-1 accounted for oral lesions (cold sores) and HSV-2 for genital herpes it is now known there is considerable overlap
What are three features of HSV?
Features
primary infection: may present with a severe gingivostomatitis cold sores painful genital ulceration
What is the management of HSV:
-gingivostomatitis
-cold sores
-genital
Management
gingivostomatitis: oral aciclovir, chlorhexidine mouthwash cold sores: topical aciclovir although the evidence base for this is modest genital herpes: oral aciclovir. Some patients with frequent exacerbations may benefit from longer term aciclovir
What is the management of HSV in pregnancy?
Pregnancy
elective caesarean section at term is advised if a primary attack of herpes occurs during pregnancy at greater than 28 weeks gestation women with recurrent herpes who are pregnant should be treated with suppressive therapy and be advised that the risk of transmission to their baby is low
What does HPV cause? what can this predispose to?
Genital warts (also known as condylomata accuminata) are a common cause of attendance at genitourinary clinics. They are caused by the many varieties of the human papillomavirus HPV, especially types 6 & 11. It is now well established that HPV (primarily types 16,18 & 33) predisposes to cervical cancer.
6 & 11: causes genital warts 16 & 18: linked to a variety of cancers, most notably cervical cancer
What are the features of HPV?
Features
small (2 - 5 mm) fleshy protuberances which are slightly pigmented may bleed or itch
What is the management of HPV?
Management
topical podophyllum or cryotherapy are commonly used as first-line treatments depending on the location and type of lesion
multiple, non-keratinised warts are generally best treated with topical agents
solitary, keratinised warts respond better to cryotherapy
imiquimod is a topical cream that is generally used second line
genital warts are often resistant to treatment and recurrence is common although the majority of anogenital infections with HPV clear without intervention within 1-2 years
Who is offered the HPV vaccine?
The UK has an HPV immunisation programme that provides protection against both the main oncogenic HPV strains (16 & 18) as well as the strains that commonly cause genital warts (6 & 11). The immunisation programme is aimed primarily at 12-13 years olds, both girls and boys but the vaccine is also offered to gay, bisexual, and other men who have sex with men (GBMSM) to protect against anal, throat and penile cancers.
How is the HPV vaccine given to 12 and 13 year old girls?
All 12- and 13-year-olds (girls AND boys) in school Year 8 are offered the human papillomavirus (HPV) vaccine.
the vaccine is normally given in school information given to parents and available on the NHS website make it clear that the child may receive the vaccine against parental wishes since September 2023 one dose is now given instead of two. This change followed evidence from large studies that one dose provided equivalent protection
How are:
-eligible GBMSM under age 25
-eligible GBMSM age 25-45
-eligible individuals who are immunosuppressed or those known to have HIV
Given HPV vaccien
Other groups
eligible GBMSM under the age of 25 also receive 1-dose, offered through sexual health clinics eligible GBMSM aged 25 to 45 years receive a 2-dose schedule, offered through sexual health clinics eligible individuals who are immunosuppressed or those known to be HIV-positive receive a 3-dose schedule
What si hepatitis B? how is this spread? what is the incubation period?
Hepatitis B is a double-stranded DNA hepadnavirus and is spread through exposure to infected blood or body fluids, including vertical transmission from mother to child. The incubation period is 6-20 weeks.
What are 3 features of hep B?
-what are 6 complications of hep B infection?
The features of hepatitis B include fever, jaundice and elevated liver transaminases.
Complications of hepatitis B infection
chronic hepatitis (5-10%). 'Ground-glass' hepatocytes may be seen on light microscopy fulminant liver failure (1%) hepatocellular carcinoma glomerulonephritis polyarteritis nodosa cryoglobulinaemia
Immunisation against hep B
-who is given as a child?
-who are at risk workers who should be vaccinated?
-
Immunisation against hepatitis B (please see the Greenbook link for more details)
children born in the UK are now vaccinated as part of the routine immunisation schedule. This is given at 2, 3 and 4 months of age at risk groups who should be vaccinated include: healthcare workers, intravenous drug users, sex workers, close family contacts of an individual with hepatitis B, individuals receiving blood transfusions regularly, chronic kidney disease patients who may soon require renal replacement therapy, prisoners, chronic liver disease patients
What does the hep B vaccine contain? Does everybody respond?
Contains HBsAg adsorbed onto aluminium hydroxide adjuvant and is prepared from yeast cells using recombinant DNA technology
around 10-15% of adults fail to respond or respond poorly to 3 doses of the vaccine. Risk factors include age over 40 years, obesity, smoking, alcohol excess and immunosuppression
Who is tested for anti-HbS
testing for anti-HBs is only recommended for those at risk of occupational exposure (i.e. Healthcare workers) and patients with chronic kidney disease. In these patients anti-HBs levels should be checked 1-4 months after primary immunisation
What does each Anti-HBs level indicate:
>100
10-100
<10§
Anti-HBs level (mIU/ml) Response
> 100 Indicates adequate response, no further testing required. Should still receive booster at 5 years
10 - 100 Suboptimal response - one additional vaccine dose should be given. If immunocompetent no further testing is required
< 10 Non-responder. Test for current or past infection. Give further vaccine course (i.e. 3 doses again) with testing following. If still fails to respond then HBIG would be required for protection if exposed to the virus
What is the management of Hep B?
Management of hepatitis B
pegylated interferon-alpha used to be the only treatment available. It reduces viral replication in up to 30% of chronic carriers. A better response is predicted by being female, < 50 years old, low HBV DNA levels, non-Asian, HIV negative, high degree of inflammation on liver biopsy whilst NICE still advocate the use of pegylated interferon firstl-line other antiviral medications are increasingly used with an aim to suppress viral replication (not in a dissimilar way to treating HIV patients) examples include tenofovir, entecavir and telbivudine (a synthetic thymidine nucleoside analogue)
Hepatitis C - who is at risk? is this common?
Hepatitis C is likely to become a significant public health problem in the UK in the next decade. It is thought around 200,000 people are chronically infected with the virus. At risk groups include intravenous drug users and patients who received a blood transfusion prior to 1991 (e.g. haemophiliacs).
What kind of virus is Hep C? what is the incubation period?
hepatitis C is a RNA flavivirus
incubation period: 6-9 weeks
What is the risk of transmission for hep c
-during needlestick injury
-vertical transmission
-breastfeeding
-sexual intercourse
Transmission
the risk of transmission during a needle stick injury is about 2% the vertical transmission rate from mother to child is about 6%. The risk is higher if there is coexistent HIV breastfeeding is not contraindicated in mothers with hepatitis C the risk of transmitting the virus during sexual intercourse is probably less than 5% there is no vaccine for hepatitis C
What are clinical features assoc with exposure to hep. C virus?
After exposure to the hepatitis C virus only around 30% of patients will develop features such as:
a transient rise in serum aminotransferases / jaundice fatigue arthralgia
What investigations are used for hep C? what is the natural course of the disease?
Investigations
HCV RNA is the investigation of choice to diagnose acute infection whilst patients will eventually develop anti-HCV antibodies it should be remembered that patients who spontaneously clear the virus will continue to have anti-HCV antibodies
Outcome
around 15-45% of patients will clear the virus after an acute infection (depending on their age and underlying health) and hence the majority (55-85%) will develop chronic hepatitis C
How is chronic hep C defined? what are 7 complications of chronic hep C?
Chronic hepatitis C may be defined as the persistence of HCV RNA in the blood for 6 months.
Potential complications of chronic hepatitis C
rheumatological problems: arthralgia, arthritis eye problems: Sjogren's syndrome cirrhosis (5-20% of those with chronic disease) hepatocellular cancer cryoglobulinaemia: typically type II (mixed monoclonal and polyclonal) porphyria cutanea tarda (PCT): it is increasingly recognised that PCT may develop in patients with hepatitis C, especially if there are other factors such as alcohol abuse membranoproliferative glomerulonephritis
What is the management of chronic infection hep C?
Management of chronic infection
treatment depends on the viral genotype - this should be tested prior to treatment the management of hepatitis C has advanced rapidly in recent years resulting in clearance rates of around 95%. Interferon based treatments are no longer recommended the aim of treatment is sustained virological response (SVR), defined as undetectable serum HCV RNA six months after the end of therapy currently a combination of protease inhibitors (e.g. daclatasvir + sofosbuvir or sofosbuvir + simeprevir) with or without ribavirin are used
What are 3 side effects of ribavirin?
ribavirin - side-effects: haemolytic anaemia, cough. Women should not become pregnant within 6 months of stopping ribavirin as it is teratogenic
What are 5 side effects of interferon alpha?
interferon alpha - side-effects: flu-like symptoms, depression, fatigue, leukopenia, thrombocytopenia
Hepatitis D
-what is this
- how is this transmitted?
Hepatitis D is a single stranded RNA virus that is transmitted parenterally. It is an incomplete RNA virus that requires hepatitis B surface antigen to complete its replication and transmission cycle.
It is transmitted in a similar fashion to hepatitis B (exchange of bodily fluids) and patients may be infected with hepatitis B and hepatitis D at the same time.
What is a hepatitis D co-infection vs a super-infection?
Hepatitis D terminology:
Co-infection: Hepatitis B and Hepatitis D infection at the same time. Superinfection: A hepatitis B surface antigen positive patient subsequently develops a hepatitis D infection.
Superinfection is associated with high risk of fulminant hepatitis, chronic hepatitis status and cirrhosis.
What is the diagnosis and management of Hep D?
Diagnosis is made via reverse polymerase chain reaction of hepatitis D RNA. Interferon is currently used as treatment, but with a poor evidence base.
Hep A
-what type of virus is this?
-what is the incubation period?
-What is the transmission?
-Does hep A cause chronic disease?
Hepatitis A is typically a benign, self-limiting disease, with a serious outcome being very rare.
Overview
incubation period: 2-4 weeks RNA picornavirus transmission is by faecal-oral spread, often in institutions doesn't cause chronic disease
What are the features of hep A infection? 5
Features
flu-like prodrome abdominal pain: typically right upper quadrant tender hepatomegaly jaundice deranged liver function tests
Are there complications of hep A?
Complications
complications are rare and there is no increased risk of hepatocellular cancer
Is there a vaccine available for hep A?
Immunisation
an effective vaccine is available after the initial dose a booster dose should be given 6-12 months later
What 6 people should receive hep A immunisation?
Who should be vaccinated? (Based on the Green book guidelines)
people travelling to or going to reside in areas of high or intermediate prevalence, if aged > 1 year old people with chronic liver disease patients with haemophilia men who have sex with men injecting drug users individuals at occupational risk: laboratory worker; staff of large residential institutions; sewage workers; people who work with primates
Hep E
-What kind of virus?
-how is this spread?
-What is the incubation period?
RNA hepevirus
spread by the faecal-oral route
incubation period: 3-8 weeks
Hep E
-Where is this found in the world?
-What illness does this cause? Is there a mortality assoc?
common in Central and South-East Asia, North and West Africa, and in Mexico
causes a similar disease to hepatitis A, but carries a significant mortality (about 20%) during pregnancy
Hep E
-Is there complications?
-is there a vaccine?
does not cause chronic disease or an increased risk of hepatocellular cancer
a vaccine is currently in development, but is not yet in widespread use
Is HIV seroconversion symptomatic? how does this present? is this assoc. with prognosis? when does this occur?
HIV seroconversion is symptomatic in 60-80% of patients and typically presents as a glandular fever type illness. Increased symptomatic severity is associated with poorer long term prognosis. It typically occurs 3-12 weeks after infection
Give some features of HIV seroconversion? 7
Features
sore throat lymphadenopathy malaise, myalgia, arthralgia diarrhoea maculopapular rash mouth ulcers rarely meningoencephalitis
What are the two tests that can be done for diagnosis of HIV? when are these indicated?
HIV antibodies
may not be present in early infection, but most people develop antibodies to HIV at 4-6 weeks but 99% do by 3 months
usually consists of both a screening ELISA (Enzyme Linked Immuno-Sorbent Assay) test and a confirmatory Western Blot Assay
p24 antigen
a viral core protein that appears early in the blood as the viral RNA levels rise
usually positive from about 1 week to 3 - 4 weeks after infection with HIV
combination tests (HIV p24 antigen and HIV antibody) are now standard for the diagnosis and screening of HIV
if the combined test is positive it should be repeated to confirm the diagnosis
some centres may also test the viral load (HIV RNA levels) if HIV is suspected at the same time
How should HIV testing in an asymptomatic patient be done?
testing for HIV in asymptomatic patients should be done at 4 weeks after possible exposure
after an initial negative result when testing for HIV in an asymptomatic patient, offer a repeat test at 12 weeks
What does antiretroviral treatment for HIV involve? When is treatment initiated?
Antiretroviral therapy (ART) involves a combination of at least three drugs, typically two nucleoside reverse transcriptase inhibitors (NRTI) and either a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI). This combination both decreases viral replication but also reduces the risk of viral resistance emerging
Following the 2015 BHIVA guidelines it is now recommended that patients start ART as soon as they have been diagnosed with HIV, rather than waiting until a particular CD4 count, as was previously advocated.
What does an entry inhibitor do in HIV treatment and can you give an example?
Entry inhibitors
maraviroc (binds to CCR5, preventing an interaction with gp41), enfuvirtide (binds to gp41, also known as a 'fusion inhibitor') prevent HIV-1 from entering and infecting immune cells
Name 3 Nucleoside analogue reverse transcriptase inhibitors (NRTI) and give their adverse effects
tenofovir: used in BHIVAs two recommended regime NRTI. Adverse effects include renal impairment and ostesoporosis
zidovudine: anaemia, myopathy, black nails
didanosine: pancreatitis
Give 2 examples of Non-nucleoside reverse transcriptase inhibitors and give the side effects
Non-nucleoside reverse transcriptase inhibitors (NNRTI)
examples: nevirapine, efavirenz side-effects: P450 enzyme interaction (nevirapine induces), rashes
Give some examples of protease inhibitors 4
-what are the side effects?
Protease inhibitors (PI)
examples: indinavir, nelfinavir, ritonavir, saquinavir side-effects: diabetes, hyperlipidaemia, buffalo hump, central obesity, P450 enzyme inhibition indinavir: renal stones, asymptomatic hyperbilirubinaemia ritonavir: a potent inhibitor of the P450 system
What do integrase inhibitors do when treating HIV? give some examples
Integrase inhibitors
block the action of integrase, a viral enzyme that inserts the viral genome into the DNA of the host cell examples: raltegravir, elvitegravir, dolutegravir
What is advised on mode of delivery for pregnant ladies with HIV?
Mode of delivery
vaginal delivery is recommended if viral load is less than 50 copies/ml at 36 weeks, otherwise caesarian section is recommended a zidovudine infusion should be started four hours before beginning the caesarean section
what is used for neonatal antiretroviral therapy?
Neonatal antiretroviral therapy
zidovudine is usually administered orally to the neonate if maternal viral load is <50 copies/ml. Otherwise triple ART should be used. Therapy should be continued for 4-6 weeks.
Should HIV positive mothers breastfeed?
Infant feeding
in the UK all women should be advised not to breast feed
Diarrhoea in HIV
-Is this common?
-What are the possible causes? 4
Diarrhoea is common in patients with HIV. This may be due to the effects of the virus itself (HIV enteritis) or opportunistic infections
Possible causes
Cryptosporidium + other protozoa (most common) Cytomegalovirus Mycobacterium avium intracellulare Giardia
What is the most common infective cause of diarrhoea in HIV patients? what is the incubation period? what is used to diagnosis? what is the rteatement?
Cryptosporidium is the most common infective cause of diarrhoea in HIV patients. It is an intracellular protozoa and has an incubation period of 7 days. Presentation is very variable, ranging from mild to severe diarrhoea. A modified Ziehl-Neelsen stain (acid-fast stain) of the stool may reveal the characteristic red cysts of Cryptosporidium. Treatment is difficult, with the mainstay of management being supportive therapy
What can be the cause of diarrhoea in HIV positive patients with a CD4 count below 50? how is diagnosis made? what are typical features? what is the treatment?
Mycobacterium avium intracellulare is an atypical mycobacteria seen with the CD4 count is below 50. Typical features include fever, sweats, abdominal pain and diarrhoea. There may be hepatomegaly and deranged LFTs. Diagnosis is made by blood cultures and bone marrow examination. Management is with rifabutin, ethambutol and clarithromycin
Kaposi sarcoma in HIV
-what is this caused by?
-how does this present?
-how can respiratory involvement be affected?
-What is the treatment?
Kaposi’s sarcoma
caused by HHV-8 (human herpes virus 8) presents as purple papules or plaques on the skin or mucosa (e.g. gastrointestinal and respiratory tract) skin lesions may later ulcerate respiratory involvement may cause massive haemoptysis and pleural effusion radiotherapy + resection
What is the most common cause of oesophagitis in patients with HIV? what is the treatment?
Oesophageal candidiasis is the most common cause of oesophagitis in patients with HIV. It is generally seen in patients with a CD4 count of less than 100. Typical symptoms include dysphagia and odynophagia. Fluconazole and itraconazole are first-line treatments.
Toxoplasmosis in HIV
-What are the symptoms?
-what is seen on CT?
-What is the management
Toxoplasmosis
accounts for around 50% of cerebral lesions in patients with HIV constitutional symptoms, headache, confusion, drowsiness CT: usually single or multiple ring enhancing lesions, mass effect may be seen management: sulfadiazine and pyrimethamine
Thallium spect negative
Primary CNS lymphoma in HIV
-what virus is this assoc. with?
-What is seen on CT?
-What is the treatment?
Thallium spect?
Primary CNS lymphoma
accounts for around 30% of cerebral lesions associated with the Epstein-Barr virus CT: single or multiple homogenous enhancing lesions treatment generally involves steroids (may significantly reduce tumour size), chemotherapy (e.g. methotrexate) + with or without whole brain irradiation. Surgical may be considered for lower grade tumours
Thallium spect positive
Encephalitis in HIV
-Caused by what?
-what is seen on CT?
Encephalitis
may be due to CMV or HIV itself HSV encephalitis but is relatively rare in the context of HIV CT: oedematous brain
What is the most common fungal infection of the CNS in HIV?
-what are the features
Cryptococcus
most common fungal infection of CNS headache, fever, malaise, nausea/vomiting, seizures, focal neurological deficit
What is seen on LP in cryptococcal CNS infection in HIV?
CSF
high opening pressure
elevated protein
reduced glucose
normally a lymphocyte predominance but in HIV white cell count many be normal
India ink test positive
What is seen on CT in cryptococcal CNS infection in HIV
CT: meningeal enhancement, cerebral oedema
meningitis is typical presentation but may occasionally cause a space-occupying lesion
PML in HIV
-What is this caused by?
-What does this cause?
-What are the clinical features?
-What are the investigations?
Progressive multifocal leukoencephalopathy (PML)
widespread demyelination due to infection of oligodendrocytes by JC virus (a polyoma DNA virus) symptoms, subacute onset : behavioural changes, speech, motor, visual impairment CT: single or multiple lesions, no mass effect, don't usually enhance. MRI is better - high-signal demyelinating white matter lesions are seen
AIDS dementia complex
-What is this?
-What is seen on CTB?
AIDS dementia complex
caused by HIV virus itself symptoms: behavioural changes, motor impairment CT: cortical and subcortical atrophy
What is the commonest bacterial cause of infectious intestinal disease in the uk? how is this spread? what is the incubation period?
Campylobacter is the commonest bacterial cause of infectious intestinal disease in the UK. The majority of cases are caused by the Gram-negative bacillus Campylobacter jejuni. It is spread by the faecal-oral route and has an incubation period of 1-6 days.
Give 3 features of campylobacter
Features
prodrome: headache malaise diarrhoea: often bloody abdominal pain: may mimic appendicitis
Describe the management of campylobacter
Management
usually self-limiting the BNF advises treatment if severe or the patient is immunocompromised. Clinical Knowledge summaries also recommend antibiotics if severe symptoms (high fever, bloody diarrhoea, or more than eight stools per day) or symptoms have last more than one week the first-line antibiotic is clarithromycin ciprofloxacin is an alternative although the BNF states that 'Strains with decreased sensitivity to ciprofloxacin isolated frequently'
Give 5 complications of campylobacter
Complications
Guillain-Barre syndrome may follow Campylobacter jejuni infections reactive arthritis septicaemia, endocarditis, arthritis
What is the most common protozoal cause of diarrhoea? who is this most common in?
Cryptosporidiosis is the commonest protozoal cause of diarrhoea in the UK. Two species, Cryptosporidium hominis and Cryptosporidium parvum account for the majority cases.
Cryptosporidiosis is more common in immunocompromised patients (e.g. HIV) and young children.
What are 4 features of cryptosporidium diarrhoea?
Features
watery diarrhoea abdominal cramps fever in immunocompromised patients, the entire gastrointestinal tract may be affected resulting in complications such as sclerosing cholangitis and pancreatitis
what is the diagnosis of cryptosporidium?
Diagnosis
stool: modified Ziehl-Neelsen stain (acid-fast stain) of the stool may reveal the characteristic red cysts of Cryptosporidium
what is the management of cryptosporidium?
Management
is largely supportive for immunocompetent patients if the patient has HIV and is not on antiretroviral therapy then this should be started and often will be enough to resolve the infection nitazoxanide may be used for immunocompromised patients rifaximin is also sometimes used for immunocompromised patients/patients with severe disease
What is the treatment of c. diff?
First episode: oral vancomycin
Second or subsequent episode of infection: oral fidaxomicin
What is travellers diarrhoea defined as? What is the most common cause?
Travellers’ diarrhoea may be defined as at least 3 loose to watery stools in 24 hours with or without one of more of abdominal cramps, fever, nausea, vomiting or blood in the stool. The most common cause is Escherichia coli.
E.Coli
-Who is this most common in?
-what 3 clinical features are seen?
Common amongst travellers
Watery stools
Abdominal cramps and nausea
Describe what is seen in giardiasis diarrhoea?
Prolonged, non-bloody diarrhoea
Describe the clinical features of cholera
Profuse, watery diarrhoea
Severe dehydration resulting in weight loss
Not common amongst travellers
Describe the clinical features of shigella
Bloody diarrhoea
Vomiting and abdominal pain
What are 2 clinical features of s. aureus gastroenteritis
Severe vomiting
Short incubation period
What two types of illness are seen in bacillus cereus gastroenteritis?
Two types of illness are seen
vomiting within 6 hours, stereotypically due to rice diarrhoeal illness occurring after 6 hours
Describe the clinical features of amoebiasis
Gradual onset bloody diarrhoea, abdominal pain and tenderness which may last for several weeks
ncubation period
Staphylococcus aureus, Bacillus cereus* ?
Salmonella, Escherichia coli
Shigella, Campylobacter
Giardiasis, Amoebiasis
ncubation period
1-6 hrs: Staphylococcus aureus, Bacillus cereus* 12-48 hrs: Salmonella, Escherichia coli 48-72 hrs: Shigella, Campylobacter > 7 days: Giardiasis, Amoebiasis
What is the treatment of salmonella (non-typhoid)?
Ciprofloxacin
What is the treatment of shigella?
Ciprofloxacin
What is giardiasis caused by? What are 3 risk factors?
Giardiasis is caused by the flagellate protozoan Giardia lamblia. It is spread by the faeco-oral route.
Risk factors
foreign travel swimming/drinking water from a river or lake male-male sexual contact
What are 7 features of giardiasis?
Features
often asymptomatic
non-bloody diarrhoea
steatorrhoea
bloating, abdominal pain
lethargy
flatulence
weight loss
malabsorption and lactose intolerance can occur
What investigations are carried out for giardiasis?
Investigations
stool microscopy for trophozoite and cysts: sensitivity of around 65% stool antigen detection assay: greater sensitivity and faster turn-around time than conventional stool microscopy methods PCR assays are also being developed
What is the treatment of giardiasis?
Treatment is with metronidazole.
What is enteric fever? what is this caused by?
The Salmonella group contains many members, most of which cause diarrhoeal diseases. They are aerobic, Gram-negative rods which are not normally present as commensals in the gut.
Typhoid and paratyphoid are caused by Salmonella typhi and Salmonella paratyphi (types A, B & C) respectively. They are often termed enteric fevers, producing systemic symptoms such as headache, fever, arthralgia.
How is typhoid transmitted?
Pathophysiology
typhoid is transmitted via the faecal-oral route (also in contaminated food and water)
Describe features of enteric fever? 5
Features
initially systemic upset as above relative bradycardia abdominal pain, distension constipation: although Salmonella is a recognised cause of diarrhoea, constipation is more common in typhoid rose spots: present on the trunk in 40% of patients, and are more common in paratyphoid
Give 5 complications of enteric fever
Possible complications include
osteomyelitis (especially in sickle cell disease where Salmonella is one of the most common pathogens) GI bleed/perforation meningitis cholecystitis chronic carriage (1%, more likely if adult females)
What is the diagnosis of norovirus?
Diagnosis
Clinical history and stool culture viral PCR (polymerase chain reaction).
How does salmonella differ from norovirus?
Salmonella infection has an incubation period of 6 - 72 hours and is often the result of contact with contaminated animal products, for example, unpasteurized eggs or milk. Unlike norovirus, salmonella gastroenteritis can cause bloody diarrhoea and patients often have a high fever.
How does rotavirus differ from norovirus?
Rotavirus gastroenteritis causes symptoms very similar to those of norovirus, but predominantly affects children under the age of 5 years.
How does e.coli gastroenteritis differ from norovirus?
E. coli infection, like Norovirus, causes vomiting and diarrhoea but has a longer incubation period (between 3-4 days but can be up to 10 days following pathogen exposure) and unlike Norovirus, E Coli infection commonly causes severe abdominal cramping and frequently causes bloody diarrhoea.
How is norovirus managed?
Resolution and Potential Complications
The infection is self-limiting in immunocompetent patients and symptoms generally resolve within 72 hours Dehydration and electrolyte imbalances may arise as a result of vomiting and diarrhoea, leading to significant morbidity and mortality and patients should be managed supportively with rehydration and electrolyte supplementation where necessary.
Where is brucellosis most commonly found in?
Brucellosis is a zoonosis more common in the Middle East and in farmers, vets and abattoir workers. Four major species cause infection in humans: B. melitensis (sheep), B. abortus (cattle), B. canis and B. suis (pigs). Brucellosis has an incubation period 2 - 6 weeks.
Give 3 features of brucellosis and 4 complications? what is found on blood tests?
Features
non-specific: fever, malaise hepatosplenomegaly sacroiliitis: spinal tenderness may be seen complications: osteomyelitis, infective endocarditis, meningoencephalitis, orchitis leukopenia often seen
What is the diagnosis of brucellosis?
Diagnosis
the Rose Bengal plate test can be used for screening but other tests are required to confirm the diagnosis Brucella serology is the best test for diagnosis blood and bone marrow cultures may be suitable in certain patients, but these tests are often negative
What is the management of brucellosis?
Management
doxycycline and streptomycin
What is cutaneous lava migrans? how is this transmitted?
Cutaneous larva migrans is a dermatological condition prevalent in tropical and subtropical regions, largely attributable to cutaneous penetration and subsequent migration of nematode larvae, primarily from the Ancylostoma genus (e.g. Ancyclostoma braziliense). Typically, the transmission vectors are faecal-contaminated soil or sand, posing significant risks to individuals with a history of barefoot beach visits or direct soil contact.
Describe the clinical presentation of cutaneous lava migrans
The clinical presentation typically involves an intensely pruritic, ‘creeping’, serpiginous, erythematous cutaneous eruption that advances over time. Symptoms can last for weeks to months, potentially leading to secondary bacterial infection due to excessive scratching. Diagnosis is typically clinical, based on exposure history and characteristic skin manifestations.
What is the management of cutaneous lava migrans?
Treatment options revolve around anthelmintic agents, such as ivermectin or albendazole. Topical therapy with thiabendazole can also be effective, although it’s generally less preferred due to a lower efficacy rate and higher side effect profile.
Describe prevention strategies for cutaneous lava migrans
Prevention strategies largely involve patient education about appropriate protective measures, particularly avoiding direct skin contact with potentially contaminated soil. Given the zoonotic nature of cutaneous larva migrans, public health measures for animal defecation control can also contribute to reducing the prevalence of this condition.
What is dengue fever? what can it progress to? how is it transmitted? what is the incubation period
Dengue fever is a viral infection that can progress to viral haemorrhagic fever (other examples include yellow fever, Lassa fever, Ebola).
Aetiology
dengue virus is a RNA virus of the genus Flavivirus transmitted by the Aedes aegypti mosquito incubation period of 7 days
How is dengue fever classified?
Patients with dengue fever can be classified as follows:
dengue fever:
without warning signs
with warning signs
severe dengue (dengue haemorrhagic fever)
What are warning signs of dengue fever?
‘warning signs’ include:
abdominal pain hepatomegaly persistent vomiting clinical fluid accumulation (ascites, pleural effusion)
what are 7 clinical features of dengue fever?
Dengue fever
fever
headache (often retro-orbital)
myalgia, bone pain and arthralgia ('break-bone fever')
pleuritic pain
facial flushing (dengue)
maculopapular rash
haemorrhagic manifestations e.g. positive tourniquet test, petechiae, purpura/ecchymosis, epistaxis
What is severe dengue and what can this result in?
Severe dengue (dengue haemorrhagic fever)
this is a form of disseminated intravascular coagulation (DIC) resulting in:
thrombocytopenia
spontaneous bleeding
around 20-30% of these patients go on to develop dengue shock syndrome (DSS)
What is found on blood tests in dengue fever? what are diagnostic tests?
Investigations
typically blood results
leukopenia, thrombocytopenia, raised aminotransferases
diagnostic tests
serology
nucleic acid amplification tests for viral RNA
NS1 antigen test
What is the treatment of dengue fever?
Treatment
entirely symptomatic e.g. fluid resuscitation, blood transfusion etc no antivirals are currently available
What is diphtheria? what is the pathophysiology?
Diphtheria is caused by the Gram positive bacterium Corynebacterium diphtheriae
Pathophysiology
releases an exotoxin encoded by a β-prophage exotoxin inhibits protein synthesis by catalyzing ADP-ribosylation of elongation factor EF-2
What are 5 clinical features of dengue fever? what does diptheria toxin cause?
Diphtheria toxin commonly causes a ‘diphtheric membrane’ on tonsils caused by necrotic mucosal cells. Systemic distribution may produce necrosis of myocardial, neural and renal tissue
Possible presentations
recent visitors to Eastern Europe/Russia/Asia
sore throat with a 'diphtheric membrane' - grey, pseudomembrane on the posterior pharyngeal wall
bulky cervical lymphadenopathy
may result in a 'bull neck' appearanace
neuritis e.g. cranial nerves
heart block
What investigations are used for dengue?
Investigations
culture of throat swab: uses tellurite agar or Loeffler's media
What is the management of dengue?
Management
intramuscular penicillin diphtheria antitoxin
What is leishmaniasis caused by? what 3 forms are seen?
Leishmaniasis is caused by the intracellular protozoa Leishmania, which are spread by the bites of sandflies. Cutaneous, mucocutaneous leishmaniasis and visceral forms are seen
Cutaneous leishmaniasis
-what is this caused by?
-what is seen at the site of the bite?
-how is this diagnosed?
-what is the management?
Cutaneous leishmaniasis
caused by Leishmania tropica or Leishmania mexicana crusted lesion at the site of bite there may be an underlying ulcer it is typically diagnosed by doing a punch biopsy from the edge of the lesion allowing for both histology and culture cutaneous leishmaniasis acquired in South or Central America merits treatment due to the risk of mucocutaneous leishmaniasis whereas disease acquired in Africa or India can be managed more conservatively
Mucocutaneous leishmaniasis
-what is this caused by
-how does this differ from cutaneous leishmaniasis?
Mucocutaneous leishmaniasis
caused by Leishmania braziliensis skin lesions may spread to involve mucosae of nose, pharynx etc
Visceral leishmaniasis
-what is this caused by?
-where does this occur?
-What clinical features are seen? 8
-What is seen on blood tests?
-what is the gold standard for diagnosis?
Visceral leishmaniasis (kala-azar)
mostly caused by Leishmania donovani
occurs in the Mediterranean, Asia, South America, Africa
fever, sweats, rigors
massive splenomegaly. hepatomegaly
poor appetite*, weight loss
occasionally patients may report increased appetite with paradoxical weight loss
grey skin - 'kala-azar' means black sickness
pancytopaenia secondary to hypersplenism
the gold standard for diagnosis is bone marrow or splenic aspirate
Leptospirosis
-what is this caused by?
-when is this usually seen?
Leptospirosis is caused by the spirochaete Leptospira interrogans (serogroup L. icterohaemorrhagiae), classically being spread by contact with infected rat urine.
Epidemiology
leptospirosis is commonly seen in questions referring to sewage workers, farmers, vets or people who work in an abattoir however, on an international level, leptospirosis is far more common in the tropics so should be considered in the returning traveller
Describe the early phase of leptospirosis
The early phase is due to bacteraemia and lasts around a week
may be mild or subclinical fever flu-like symptoms subconjunctival suffusion (redness)/haemorrhage
Describe the second immune phase of leptospirosis. what can this lead to?
second immune phase may lead to more severe disease (Weil’s disease)
acute kidney injury (seen in 50% of patients) hepatitis: jaundice, hepatomegaly aseptic meningitis
Describe the investigations of leptospirosis
Investigation
serology: antibodies to Leptospira develop after about 7 days
PCR
culture
growth may take several weeks so limits usefulness in diagnosis
blood and CSF samples are generally positive for the first 10 days
urine cultures become positive during the second week of illness
What is the management of leptospirosis?
Management
high-dose benzylpenicillin or doxycycline
What are the general features of non-falciparum malaria?
-what fever does plasmodium vivax/ovale cause?
-what fever does plamodium malariae cause?
-what is associated with plasmodium malariae?
Features
general features of malaria: fever, headache, splenomegaly Plasmodium vivax/ovale: cyclical fever every 48 hours. Plasmodium malariae: cyclical fever every 72 hours Plasmodium malariae: is associated with nephrotic syndrome
What is the treatment of non-falciparum malaria?
Treatment
in areas which are known to be chloroquine-sensitive then WHO recommend either an artemisinin-based combination therapy (ACT) or chloroquine in areas which are known to be chloroquine-resistant an ACT should be used ACTs should be avoided in pregnant women patients with ovale or vivax malaria should be given primaquine following acute treatment with chloroquine to destroy liver hypnozoites and prevent relapse
Atovaquone + proguanil (Malarone) (malaria prophylaxis)
-side effects
-when to start
-when to stop
GI upset
1 - 2 days
7 days
Chloroquine (malaria prophylaxis)
-what is the side effect
-what is this contraindicated in?
-how often is this taken
-when to start
-when to stop
Headache
Contraindicated in epilepsy
Taken weekly
1 week
4 weeks
Doxycyline
-side effects
-when to start
-when to stop
Photosensitivity
Oesophagitis
1 - 2 days
4 weeks
Mefloquine (Lariam)
-what arethe side effects
-what is this contraindicated in?
-how often is this taken
-when to start
-when to stop
Dizziness
Neuropsychiatric disturbance
Contraindicated in epilepsy
Taken weekly
2 - 3 weeks
4 weeks
Proguanil (Paludrine)
Proguanil + chloroquine
-when to start
-when to stop
1 week
4 weeks
Malaria prophylaxis in pregnancy
-chloroquine
-malarone
-mefloquine
-doxycyline
can any of these be taken?
chloroquine can be taken
proguanil: folate supplementation (5mg od) should be given
Malarone (atovaquone + proguanil): the BNF advises to avoid these drugs unless essential. If taken then folate supplementation should be given
mefloquine: caution advised
doxycycline is contraindicated
What should be given to children travelling to malaria endemic countries?
It is again advisable to avoid travel to malaria endemic regions with children if avoidable. However, if travel is essential then children should take malarial prophylaxis as they are more at risk of serious complications.
diethyltoluamide (DEET) 20-50% has been shown to repel up to 100% of mosquitoes if used correctly. It can be used in children over 2 months of age* doxycycline is only licensed in the UK for children over the age of 12 years
What is schistosomiasis caused by? what are the three main species?
Schistosomiasis, or bilharzia, is a parasitic flatworm infection. The three main species of schistosome are S. mansoni, S. japonicum and S. haematobium.
what acute manifestations of schistosomiasis exist?
Acute manifestations may include:
swimmers' itch
acute schistosomiasis syndrome (Katayama fever)
fever
urticaria/angioedema
arthralgia/myalgia
cough
diarrhoea
eosinophilia
Schistosoma haematobium
-what can these worm do?
-what is seen on xray?
-what can this cause?\
-how canthis present and what is this a risk factro for?
Schistosoma haematobium
These worms deposit egg clusters (pseudopapillomas) in the bladder, causing inflammation. The calcification seen on x-ray is actually calcification of the egg clusters, not the bladder itself.
Depending on the site of these pseudopapillomas in the bladder, they can cause an obstructive uropathy and kidney damage.
This typically presents as a ‘swimmer’s itch’ in patients who have recently returned from Africa. Schistosoma haematobium is a risk factor for squamous cell bladder cancer.
What are the features of schistosoma haematobium?
Features
frequency haematuria bladder calcification
what are the investigations and management of schistosoma haematobium?
nvestigation
for asymptomatic patients serum schistosome antibodies are generally preferred for symptomatic patients the gold standard for diagnosis is urine or stool microscopy looking for eggs
Management
single oral dose of praziquantel
What do Schistosoma mansoni and Schistosoma japonicum cause? what complications from these exist?
These worms mature in the liver and then travel through the portal system to inhabit the distal colon. Their presence in the portal system can lead to progressive hepatomegaly and splenomegaly due to portal vein congestion.
These species can also lead to complications of liver cirrhosis, variceal disease and cor pulmonale.
Schistosoma intercalatum and Schistosoma mekongi - what can these cause?
Schistosoma intercalatum and Schistosoma mekongi
These are less prevalent than the other three forms, but are both attributed to intestinal schistosomiasis.
What is strongyloides stercoralis? how do these gain access to the body? what illness does this cause?
Strongyloides stercoralis is a human parasitic nematode worm. The larvae are present in soil and gain access to the body by penetrating the skin. Infection with Strongyloides stercoralis causes strongyloidiasis.
strongyloidiasis
-What are 5 features canthiis cause?
Features
diarrhoea abdominal pain/bloating papulovesicular lesions where the skin has been penetrated by infective larvae e.g. soles of feet and buttocks larva currens: pruritic, linear, urticarial rash if the larvae migrate to the lungs a pneumonitis similar to Loeffler's syndrome may be triggered
What is the treatment of strongyloidiasis?
Treatment
ivermectin and albendazole are used
What are the two main forms of trypanosomiasis?
Two main form of this protozoal disease are recognised - African trypanosomiasis (sleeping sickness) and American trypanosomiasis (Chagas’ disease).
How many forms of african trypanosomiasis are seen? how are these spread? what are 4 clinical features?
Two forms of African trypanosomiasis, or sleeping sickness, are seen - Trypanosoma gambiense in West Africa and Trypanosoma rhodesiense in East Africa. Both types are spread by the tsetse fly. Trypanosoma rhodesiense tends to follow a more acute course. Clinical features include:
Trypanosoma chancre - painless subcutaneous nodule at site of infection intermittent fever enlargement of posterior cervical lymph nodes later: central nervous system involvement e.g. somnolence, headaches, mood changes, meningoencephalitis
What is the management of african trypanosomiasis?
Management
early disease: IV pentamidine or suramin later disease or central nervous system involvement: IV melarsoprol
What is american trypanosomiasis caused by? what are the clinical features? what are the compliactions?
American trypanosomiasis, or Chagas’ disease, is caused by the protozoan Trypanosoma cruzi. The vast majority of patients (95%) are asymptomatic in the acute phase although a chagoma (an erythematous nodule at site of infection) and periorbital oedema are sometimes seen. Chronic Chagas’ disease mainly affects the heart and gastrointestinal tract
myocarditis may lead to dilated cardiomyopathy (with apical atophy) and arrhythmias gastrointestinal features includes megaoesophagus and megacolon causing dysphagia and constipation
What is the management of chagas disease?
Management
treatment is most effective in the acute phase using azole or nitroderivatives such as benznidazole or nifurtimox chronic disease management involves treating the complications e.g., heart failure
Zika virus
-How is this transmitted?
Zika is a mosquito-borne infection caused by Zika virus, a member of the genus flavivirus and family Flaviviridae. It was first isolated from a monkey in the Zika forest in Uganda in 1947.
Transmission is usually via the bite of an infected Aedes mosquito, although a small number of cases of sexual transmission have been reported. There is increasing evidence of transmission via the placenta from mother to fetus.
What are the clinical symptoms of zika virus?
The majority of people infected with Zika virus have no symptoms. For those with symptoms, Zika virus tends to cause a mild, short-lived (2 to 7 days) febrile disease. Signs and symptoms suggestive of Zika virus infection may include a combination of the following:
fever rash arthralgia/arthritis conjunctivitis myalgia headache retro-orbital pain pruritus
Give some warning signs of meningitis
Senior review if any warning signs are present (please see the Meningitis Research Foundation algorithm link for the full list). Examples include:
rapidly progressive rash poor peripheral perfusion respiratory rate < 8 or > 30 / min or pulse rate < 40 or > 140 / min pH < 7.3 or WBC< 4 *109/L or lactate > 4 mmol/L GCS < 12 or a drop of 2 points poor response to fluid resuscitation
When should LP be delayed in the management of meningitis?4
Lumbar puncture should be delayed in the following circumstances
signs of severe sepsis or a rapidly evolving rash
severe respiratory/cardiac compromise
significant bleeding risk
signs of raised intracranial pressure
focal neurological signs
papilloedema
continuous or uncontrolled seizures
GCS ≤ 12
What is the treatment of meningitis?
IV antibiotics
3 months - 50 years: BNF recommends cefotaxime (or ceftriaxone) > 50 years: BNF recommends cefotaxime (or ceftriaxone) + amoxicillin (or ampicillin) for adults
IV dexamethasone
the BNF recommend to 'consider adjunctive treatment with dexamethasone (particularly if pneumococcal meningitis suspected in adults), preferably starting before or with first dose of antibacterial, but no later than 12 hours after starting antibacterial; avoid dexamethasone in septic shock, meningococcal septicaemia, or if immunocompromised, or in meningitis following surgery'
What is the treatment in each below situation in meningitis:
Initial empirical therapy aged < 3 months
Initial empirical therapy aged 3 months - 50 years
Initial empirical therapy aged > 50 years
Meningococcal meningitis
Pneumococcal meningitis I
Meningitis caused by Haemophilus influenzae
Meningitis caused by Listeria
Initial empirical therapy aged < 3 months IVcefotaxime + amoxicillin (or ampicillin)
Initial empirical therapy aged 3 months - 50 years IV cefotaxime (or ceftriaxone)
Initial empirical therapy aged > 50 years IV cefotaxime (or ceftriaxone) + amoxicillin (or ampicillin)
Meningococcal meningitis IV benzylpenicillin or cefotaxime (or ceftriaxone)
Pneumococcal meningitis IV cefotaxime (or ceftriaxone)
Meningitis caused by Haemophilus influenzae IV cefotaxime (or ceftriaxone)
Meningitis caused by Listeria IV amoxicillin (or ampicillin) + gentamicin
What is the treatment for meningitis if pen-allergy/cephalosporin allergy?
If the patient has a history of immediate hypersensitivity reaction to penicillin or to cephalosporins the BNF recommends using chloramphenicol.
Who is prophylaxis offered to for meningitis?
Prophylaxis needs to be offered to households and close contacts of patients affected with meningococcal meningitis. Prophylaxis should also be offered to people who have been exposed to respiratory secretion, regardless of the closeness of contact. The risk to contacts is highest in the first 7 days but persists for at least 4 weeks.
What is used for meningitis prophylaxis? is vaccianation given? when is no prophylaxis needed?
people who have been exposed to a patient with confirmed bacterial meningitis should be given prophylactic antibiotics if they have close contact within the 7 days before onset
oral ciprofloxacin or rifampicin may be used. The Health Protection Agency (HPA) guidelines now state that whilst either may be used ciprofloxacin is the drug of choice as it is widely available and only requires one dose
meningococcal vaccination should be offered to close contacts when serotype results are available, including booster doses to those who had the vaccine in infancy
for pneumococcal meningitis, no prophylaxis is generally needed. There are however exceptions to this. If a cluster of cases of pneumococcal meningitis occurs the HPA have a protocol for offering close contacts antibiotic prophylaxis. Please see the link for more details
Body fluid spillages
-what is used?
-how is this used?
Generally speaking hypochlorite (chlorine in oxidation state +1) is recommend for the management of body fluid spillage. It is often used in the granular or powder form which is then spread over the affected area.
Chlorine-releasing agents can be a hazard especially if used in large volumes in confined spaces or if mixed with urine. Ensuring adequate ventilation to the area is therefore important.
Other points
personal protective equipment (plastic aprons, gloves, mask, eye protection) is recommended for staff cleaning up body fluids mops should not be used
What is used for suppression of MRSA?
Suppression of MRSA from a carrier once identified
nose: mupirocin 2% in white soft paraffin, tds for 5 days skin: chlorhexidine gluconate, od for 5 days. Apply all over but particularly to the axilla, groin and perineum
What is mumps caused by?
-How is this spread?
-what is the incubation period?
Mumps is a caused by RNA paramyxovirus and tends to occur in winter and spring
Spread
by droplets respiratory tract epithelial cells → parotid glands → other tissues infective 7 days before and 9 days after parotid swelling starts incubation period = 14-21 days
What are 4 clinical features of mumps?
Clinical features
fever
malaise, muscular pain
parotitis ('earache', 'pain on eating'): unilateral initially then becomes bilateral in 70%
What is the management of mumps?
Management
rest paracetamol for high fever/discomfort notifiable disease
What are 4 complications of mumps?
omplications
orchitis - uncommon in pre-pubertal males but occurs in around 25-35% of post-pubertal males. Typically occurs four or five days after the start of parotitis hearing loss - usually unilateral and transient meningoencephalitis pancreatitis
What is orf?
Orf is generally a condition found in sheep and goats although it can be transmitted to humans. It is caused by the parapox virus.
What does orf cause in animals?
In animals
'scabby' lesions around the mouth and nose
What does orf cause in humans?
n humans
generally affects the hands and arms initially small, raised, red-blue papules later may increase in size to 2-3 cm and become flat-topped and haemorrhagic
How does parvovirus B19 affect pregnant women? what should a pregnant women do if she is exposed? How is this spread? when is a person i=nfectious?
Be aware that the virus can affect an unborn baby in the first 20 weeks of pregnancy. If a woman is exposed early in pregnancy (before 20 weeks) she should seek prompt advice from whoever is giving her antenatal care as maternal IgM and IgG will need to be checked. It is spread by the respiratory route and a person is infectious 3 to 5 days before the appearance of the rash. Children are no longer infectious once the rash appears and there is no specific treatment.
What are 4 clinical features of rabies?
Features
prodrome: headache, fever, agitation hydrophobia: water-provoking muscle spasms hypersalivation Negri bodies: cytoplasmic inclusion bodies found in infected neurons
What is the management of an animal bite in at-risk countries for rabies?
There is now considered to be ‘no risk’ of developing rabies following an animal bite in the UK and the majority of developed countries. Following an animal bite in at-risk countries:
the wound should be washed if an individual is already immunised then 2 further doses of vaccine should be given if not previously immunised then human rabies immunoglobulin (HRIG) should be given along with a full course of vaccination. If possible, the dose should be administered locally around the wound
Rubella
-what is this caused by?
-what can happen if contracted during pregnancy?
Rubella, also known as German measles, is a viral infection caused by the togavirus. Following the introduction of the MMR vaccine, it is now very rare (typically less than 5 cases in the UK per year). If contracted during pregnancy there is a risk of congenital rubella syndrome
When are rubella outbreaks most common?
-What is the incubation period?
-when are individuals infectious in rubella?
Basics
outbreaks more common around winter and spring the incubation period is 14-21 days individuals are infectious from 7 days before symptoms appear to 4 days after the onset of the rash
What are 3 clinical features of rubella?
Features
prodrome, e.g. low-grade fever rash: maculopapular, initially on the face before spreading to the whole body, usually fades by the 3-5 day lymphadenopathy: suboccipital and postauricular
What are 4 complications of rubella?
Complications
arthritis thrombocytopaenia encephalitis myocarditis
What 4 infections are individuals more susceptable to following splenecotmy?
Following a splenectomy patients are particularly at risk from pneumococcus, Haemophilus, meningococcus and Capnocytophaga canimorsus* infections
What vaccinations are given to individuals with splenectomy?
Vaccination
if elective, should be done 2 weeks prior to operation Hib, meningitis A & C annual influenza vaccination pneumococcal vaccine every 5 years
What antibiotics prophylaxis is given to those with splenectomy?
Antibiotic prophylaxis
penicillin V: unfortunately clear guidelines do not exist of how long antibiotic prophylaxis should be continued. It is generally accepted though that penicillin should be continued for at least 2 years and at least until the patient is 16 years of age, although the majority of patients are usually put on antibiotic prophylaxis for life
Describe changes on blood film following splenectomy
Post-splenectomy changes
Platelets will rise first (therefore in ITP, transufsion should be given after splenic artery clamped) Blood film will change over following weeks, Howell-Jolly bodies will appear Other blood film changes include target cells and Pappenheimer bodies Increased risk of post-splenectomy sepsis, therefore prophylactic antibiotics and pneumococcal vaccine should be given.
sulfonamides
-How do these work?
-Give 2 examples
-are there non-antibiotic sulfonamides?
Sulfonamides are a class of drug that work by inhibiting dihydropteroate synthetase.
Antibiotic sulfonamides:
sulfamethoxazole
+ co-trimoxazole is a combination of sulfamethoxazole + trimethoprim that is used in the management of Pneumocystis jiroveci pneumonia
sulfadiazine sulfisoxazole
There are also examples of non-antibiotic sulfonamides:
sulfasalazine sulfonylureas
Give 3 adverse effects of co-trimoxazole
Adverse effects of co-trimoxazole include:
hyperkalaemia headache rash (including Steven-Johnson Syndrome)
What is the mechanism of action of tetracycline antibiotics? what is the mechanism of resistance?
Examples
doxycycline tetracycline
Mechanism of action
protein synthesis inhibitors binds to 30S subunit blocking binding of aminoacyl-tRNA
Mechanism of resistance
increased efflux of the bacteria by plasmid-encoded transport pumps, ribosomal protection
Give 4 adverse effects of tetracyclines
Notable adverse effects
discolouration of teeth: therefore should not be used in children < 12 years of age photosensitivity angioedema black hairy tongue
What is the mechanism of action of trimethoprim?
Mechanism of action
interferes with DNA synthesis by inhibiting dihydrofolate reductase
may, therefore, interact with methotrexate, which also inhibits dihydrofolate reductase
Give 2 adverse effects of trimethoprim?
Adverse effects
myelosuppression
transient rise in creatinine: trimethoprim competitively inhibits the tubular secretion of creatinine resulting in a temporary increase which reverses upon stopping the drug
trimethoprim blocks the ENaC channel in the distal nephron, causing a hyperkalaemic distal RTA (type 4). It also inhibits creatinine secretion, often leading to an increase in creatinine by around 40 points (but not necessarily causing AKI)
How does metronidazole work and what are 2 adverse effects?
Metronidazole is a type of antibiotic that works by forming reactive cytotoxic metabolites inside the bacteria.
Adverse effects
disulfiram-like reaction with alcohol increases the anticoagulant effect of warfarin
How do you define a ‘clean wound’
Wounds less than 6 hours old, non-penetrating with negligible tissue damage
How do you define a tetanus prone wound?
puncture-type injuries acquired in a contaminated environment e.g. gardening injuries
wounds containing foreign bodies
compound fractures
wounds or burns with systemic sepsis
certain animal bites and scratches
How do you define a high-risk tetanus prone wound?
heavy contamination with material likely to contain tetanus spores e.g. soil, manure
wounds or burns that show extensive devitalised tissue
wounds or burns that require surgical intervention
How do you treat a patient with any wound if they have had a full course of tetanus vaccine with the last dose <10yrs ago?
Patient has had a full course of tetanus vaccines, with the last dose < 10 years ago
no vaccine nor tetanus immunoglobulin is required, regardless of the wound severity
How do you treat a wound if a patient has had a full course of tetanus vaccines with the last dose >10 yrs ago?
Patient has had a full course of tetanus vaccines, with the last dose > 10 years ago
if tetanus prone wound: reinforcing dose of vaccine high-risk wounds (e.g. compound fractures, delayed surgical intervention, significant degree of devitalised tissue): reinforcing dose of vaccine + tetanus immunoglobulin
How do you treat a wound if a patient’s vaccination history is unknown?
If vaccination history is incomplete or unknown
reinforcing dose of vaccine, regardless of the wound severity for tetanus prone and high-risk wounds: reinforcing dose of vaccine + tetanus immunoglobulin
what 7 vaccines are live attenuated 7
BCG
measles, mumps, rubella (MMR)
influenza (intranasal)
oral rotavirus
oral polio
yellow fever
oral typhoid
what 3 vaccines are inactivated?
rabies
hepatitis A
influenza (intramuscular)
What 3 vaccines are toxoid vaccines?
tetanus
diphtheria
pertussis
what are 5 subunit and conjugate vaccines?
pneumococcus (conjugate)
haemophilus (conjugate)
meningococcus (conjugate)
hepatitis B
human papillomavirus
