Infectious diseases Flashcards
What are the Eron classifications
criteria were used to guide how cellulitis is managed.
class 1 no signs of systemic toxicity
class 2 pt systematically well or unwell but has co-morbidity which may complicate or delay the resolution of infection
class 3 acute morbidity that may interfere with the treatment of cellulitis or limb-threatening infection due to vascular compromise
class 4 sepsis or life-threatening infection such as necrotizing fasciitis
MGT of cellulitis
Mild to moderate –> Flucloxacillin (1st line)
Severe –> co-amoxiclav/ cefuroxime/ clindamycin/ ceftriaxone
Bacterial vaginosis
+ causative organism
+ Amsel’s criteria
+ MGT
overgrowth of anaerobic organisms such as Gardnerella vaginalis
Amsel’s criteria for diagnosis of BV - 3 out of 4
- 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)
MGT
- 5-7 days of metronidazole
- topical metronidazole or topical clindamycin as alterntives
Bacterial vaginosis vs Trichomonas
both have
- offensive vaginal discharge
- high ph >4.5
- treatment with metronidazole
BV
- white discharge
- clue cells under microscope
- fishy smell
Trichomonas
- Frothy, yellow-green discharge
- vulvovaginitis
- strawberry cervix
- wet mount shows motile trophozoties
Metronidazole adverse effects
- Reaction with alcohol -> because of a disulfiram-like reaction
- increases the anticoagulant effect of warfarin
STI ulcers: causes
Genital herpes- painful
Syphilis- painless
Chancroid- Painful ulcers caused by Haemophilus ducreyi
Lymphogranuloma venereum (chlamydia)- painless
Behcet’s disease- painful
other causes
Carcinoma
Granuloma inguinale
Influenza vaccine
- timing
- how is children’s vaccine given
- contraindications
given btwn sep and early november
Three things about child vaccine
- given intranasally
- first dose at 2-3 yrs then annually
- it is a live vaccine (inactivated given IM)
contraindications
immuno-compromise/ less than 2 years/ febrile or wheeze illness/ egg allergy/ pregnancy or breastfeeding/ aspirin due to risk of reye’s syndrome
SE of live vaccine given intranasally
headache/ anorexia/ blocked nose or rhinorrhea
SE of inactivated vaccine given intramusculary
Fever and malaise
takes 10-14 days before antibody levels are protective
Listeria
- feature
- diagnosis
- management
- complications in pregnant women
Features
diarrhea, flu-like illness, pneumonia, meningoencephalitis, ataxia, and seizures
Dx only blood cultures
MGT
- amoxicillin/ampicillin (cephalosporins usually inadequate)
- Listeria meningitis should be treated with IV amoxicillin/ampicillin and gentamicin
Pregnant women are most vulnerable (20 times)
complications
- miscarriage
- premature labour
- stillbirth
- chorioamnionitis
UTI in pregnancy
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
Herpes simplex virus
HSV1 - oral lesions
HSV2 - genital sores
but there is an overlap
features
- primary infection- gingivostomatitis
- cold sores
- painful genital ulcers
MGT
aciclovir
MGT of lower UTI
non-pregnant women
pregnant women
men
catheterized patients
non-pregnant women
-> trimethoprim or nitrofurantoin for 3 days
pregnant women treat for 7 days (send urine culture before and after abx therapy)
–> avoid trimethoprim during pregnancy
–> avoid nitrofurantoin near term but is the first line
–> amoxicillin or cefalexin second line
men
–> trimethoprim or nitrofurantoin for 7 days
catheterised patients
–> send cultures
–> treat for 7 days only if symptomatic
When do you need to send for culture
send a urine culture if:
aged > 65 years
visible or non-visible haematuria
pregnant
men
notifiable dx in the UK
Acute encephalitis
Acute infectious hepatitis
Acute meningitis
Acute poliomyelitis
Anthrax
Botulism
Brucellosis
Cholera
COVID-19
Diphtheria
Enteric fever (typhoid or paratyphoid fever)
Food poisoning
Haemolytic uraemic syndrome (HUS)
Infectious bloody diarrhoea
Invasive group A streptococcal disease
Legionnaires Disease
Leprosy
Malaria
Measles
Meningococcal septicaemia
Mumps
Plague
Rabies
Rubella
Severe Acute Respiratory Syndrome (SARS)
Scarlet fever
Smallpox
Tetanus
Tuberculosis
Typhus
Viral haemorrhagic fever (VHF)
Whooping cough
Yellow fever
MSRA
Methicillin-resistant Staphylococcus aureus
MGT - for carrier
MGT - for infection
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
MRSA infections:
vancomycin
teicoplanin
linezolid
MSRA
Methicillin-resistant Staphylococcus aureus
MGT - for carrier
MGT - for infection
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
MRSA infections:
vancomycin
teicoplanin
linezolid
Lyme disease
causative organism
spirochaete Borrelia burgdorferi and is spread by ticks.
Features of lyme disease
Early and late
Early features (within 30 days)
erythema migrans
- ‘bulls-eye’ rash at the site of the tick bite
- develops 1-4 weeks after the initial bite but may present sooner
- usually painless, more than 5 cm in diameter and slowly increases in size
- present in around 80% of patients.
systemic features
headache
lethargy
fever
arthralgia
Later features (after 30 days)
cardiovascular: heart block, peri/myocarditis
neurological: facial nerve palsy, radicular pain, meningitis
Diagnosis of Lyme disease
clinically rash (erythema migrans) is present
or serologically
enzyme-linked immunosorbent assay (ELISA) antibodies to Borrelia burgdorferi are the first-line test
–> next test is immunobolt
MGT of confirmed lyme disease (clinically with rash only or serologically)
doxycycline if early disease. Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy)
ceftriaxone if disseminated disease
Jarisch-Herxheimer reaction is sometimes seen after initiating therapy: fever, rash, tachycardia after the first dose of antibiotic (more commonly seen in syphilis, another spirochaetal disease)
MGT of confirmed lyme disease (clinically with rash only or serologically)
doxycycline if early disease. Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy)
ceftriaxone if disseminated disease
Jarisch-Herxheimer reaction is sometimes seen after initiating therapy: fever, rash, tachycardia after the first dose of antibiotic (more commonly seen in syphilis, another spirochaetal disease)
Treatment of
- invasive diarrhea (causing bloody diarrhea and fever)
- non-invasive diarrhea
- traveler’s diarrhea
invasive diarrhea –> ciprofloxacin
non-invasive –> most resolve on their own, if needed use metronidazole
traveller diarrhea –> metronidazole
Causative organisms for typhoid and paratyphoid (Enteric fever)
Salmonella typhi and Salmonella paratyphi (types A, B & C)
features of enteric fever (typhoid/ paratyphoid caused by salmonella group)
headache, fever, arthralgia
initially systemic upset as above
relative bradycardia
abdominal pain, distension
constipation
rose spots: present on the trunk in 40% of patients, and are more common in paratyphoid
complications of typhoid
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)
Investigating herpes simplex
nucleic acid amplification tests (NAAT) is the investigation of choice in genital herpes and are now considered superior to viral culture
HSV serology may be useful in certain situations such as recurrent genital ulceration of unknown cause
Tetanus management of wounds
classify wound first (clean/ tetanus prone/high-risk tetanus prone)
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
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
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
Gonorrhoea (Neisseria gonorrhoeae)
- features
- complications
- MGT
gonorrhea is a gram -ve diplococcus
in females (cervicitis –> vaginal discharge)
in males - urethral discharge
reinfection is common
complications
- urethral strictures
- epididymitis
- salpingitis
- infertility
- Disseminated gonococcal infection (DGI)
MGT
-The first-line treatment is a single dose of IM ceftriaxone 1g
- if ceftriaxone is refused (e.g. needle-phobic) then oral cefixime 400mg (single dose) + oral azithromycin 2g (single dose) should be used
Disseminated gonococcal 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)
MGT of Kaposi sarcoma
radiotherapy and resection
what is chancroid?
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.
Live attenuated vaccine
- may pose a risk for immunocompromised patients
BCG
measles, mumps, rubella (MMR)
influenza (intranasal)
oral rotavirus
oral polio
yellow fever
oral typhoid
Malaria prophylaxis
Atovaquone+ proguanil (SE GI upset)
Cholorquine (SE headache)
* contraindicated in epilepsy
Doxycycline (SE photosensitivity +oesophagitis)
*contraindicated in pregnancy
Mefloquine (SE neuropsychiatric disturbance)
* contraindicated in epilepsy
Proguanil
Proguanil + chloroquine
Malaria prophylaxis
Atovaquone+ proguanil (SE GI upset)
Cholorquine (SE headache)
* contraindicated in epilepsy
Doxycycline (SE photosensitivity +oesophagitis)
*contraindicated in pregnancy
Mefloquine (SE neuropsychiatric disturbance)
* contraindicated in epilepsy
Proguanil
Proguanil + chloroquine
malaria prophylaxis in pregnancy
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
MGT of animal and human bites
(bites are usually polymicrobial)
Animal bite
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
Human Bites
co-amoxiclav
consider risk of HIV and hepatitis
Rifampicin - adverse effects
potent CYP450 liver enzyme inducer
hepatitis
orange secretions
flu-like symptoms
MGT of toxoplasmosis (toxoplasma gonaii is an obligate intracellualr protozoan)
in immunocompetent pts
- most are asymptomatic
- no treatment needed
in immunosuppresed pts
pyrimethamine plus sulphadiazine for at least 6 weeks
Antibiotic guidance (respiratory)
- Exacerbation of chronic bronchitis
- Uncomplicated CAP
- Pneumonia with atypcial pathogen
- HAP
- Exacerbation of chronic bronchitis (Amoxicillin/ tetracycline/ clarithromycin)
- Uncomplicated CAP (Amoxicillin if pen allergic - doxycycline or clarithromycin) if staph infection suspected in influenza then add fluclox
- Pneumonia with an atypical pathogen (clarithromycin)
- HAP (within five days - co-amoxiclav or cefuroxime/ more than five days tazocin/ceftazidime/ciprofloxacin)
Antibiotics guidance (urinary tract)
- lower UTI
- Acute pyelonephritis
- Acute prostatitis
- lower UTI (Trimethoprim or nitrofurantoin. Alternative: amoxicillin or cephalosporin)
- Acute pyelonephritis (Broad-spectrum cephalosporin or quinolone)
- Acute prostatitis (Quinolone or trimethoprim)
Antibiotics guidance (urinary tract)
- lower UTI
- Acute pyelonephritis
- Acute prostatitis
- lower UTI (Trimethoprim or nitrofurantoin. Alternative: amoxicillin or cephalosporin)
- Acute pyelonephritis (Broad-spectrum cephalosporin or quinolone)
- Acute prostatitis (Quinolone= ciprofloxacin or trimethoprim)
Antibiotics guidance (skin)
- Impetigo
- Cellulitis
- Cellulitis near the eye or the nose
- Erysipelas
- Aminal or human bite
- Mastitis during breastfeeding
- Impetigo (Topical hydrogen peroxide, oral flucloxacillin or erythromycin if widespread)
- Cellulitis (Flucloxacillin or alternatives clarithromycin, erythromycin or doxycycline)
- Cellulitis near the eye or the nose (Co-amoxiclav (clarithromycin, + metronidazole if penicillin-allergic)
- Erysipelas (Flucloxacillin* (clarithromycin, erythromycin or doxycycline if penicillin-allergic)
- Aminal or human bite- co-amoxiclav (doxycycline + metronidazole if penicillin-allergic)
- Mastitis during breastfeeding- Flucloxacillin
Antibiotics guidance (ENT)
- Throat infection
- Sinusitis
- Otitis media
- Otitis externa
- Periapical or periodontal abscess
- Gingivitis
- Throat infection (phenoxymethylpenicillin or erythromycin if allergic)
- Sinusitis (phenoxymethylpenicillin)
- Otitis media- Amoxicillin
- Otitis externa- Flucloxacillin
- Periapical or periodontal abscess- Amoxicillin
- Gingivitis - metronidazole
abx for GI infections
- Clostridioides difficile
- Salmonella (non-typhoid)
- Shigellosis
- Campylobacter
- Clostridioides difficile (first vancomycin / other episodes fidaxomicin)
- Salmonella (non-typhoid)- cipro
- Shigellosis- cipro
- Campylobacter jejuni (commonest GI infective cause)- clarithroymicn is first line / cipro is an alternative
Treatment of gonorreha
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
CAP organism common in alcoholics
Characteristic features of pneumococcal pneumonia
rapid onset
high fever
pleuritic chest pain
herpes labialis (cold sores)
Do you manage people with asymptomatic tick bites
NICE guidance does not recommend routine antibiotic treatment to patients who’ve suffered a tick bite
Jarisch Herxheimer reaction
common after initiating therapy for spirochaetal disease (syphilis and lyme disease)
Fever
Rash
Tachycardia
all occur after the first dose of the antibiotic
Jarisch Herxheimer reaction
common after initiating therapy for spirochaetal disease (syphilis and lyme disease)
Fever
Rash
Tachycardia
all occur after the first dose of the antibiotic
Antibiotics guidance (GUS)
- Gonorrhea
- Chalmydia
- PID
- Syphilis
- Gonorrhea : Intramuscular ceftriaxone
- Chalmydia: Doxycycline or azithromycin
- PID: Oral ofloxacin + oral metronidazole or intramuscular ceftriaxone + oral doxycycline + oral metronidazole
- Syphilis: Benzathine benzylpenicillin or doxycycline or erythromycin
overview of HIV treatments
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
Nucleoside analogue reverse transcriptase inhibitors (NRTI)
examples: zidovudine (AZT), abacavir, emtricitabine, didanosine, lamivudine, stavudine, zalcitabine, tenofovir
general NRTI side-effects: peripheral neuropathy
Non-nucleoside reverse transcriptase inhibitors (NNRTI)
examples: nevirapine, efavirenz
side-effects: P450 enzyme interaction (nevirapine induces), rashes
Protease inhibitors (PI)
examples: indinavir, nelfinavir, ritonavir, saquinavir
side-effects: diabetes, hyperlipidaemia, buffalo hump, central obesity, P450 enzyme inhibition
integrase inhibitors
examples: raltegravir, elvitegravir, dolutegravir
Complications of Campylobacter jejuni?
- GBS
- Reactive arthritis
- sepsis
- endocarditis
- arthritis
The incubation period for gastroenteritis
Incubation period
1-6 hrs: Staphylococcus aureus, Bacillus cereus*
12-48 hrs: Salmonella, Escherichia coli
48-72 hrs: Shigella, Campylobacter
> 7 days: Giardiasis, Amoebiasis
MGT of active 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
The complication of TB treatment
(R)ifampicin
potent liver enzyme inducer
hepatitis, oRange secretions
flu-like symptoms
iso(N)iazid
peripheral Neuropathy: prevent with pyridoxiNe (Vitamin B6)
hepatitis, agraNulocytosis
liver enzyme inhibitor
pyrazinamide
hyperuricaemia causing gout
arthralgia, myalgia
hepatitis
ethambut(O)l
Optic neuritis: check visual acuity before and during treatment
Antimalarials contraindicated in epilepsy
Choloroquine - Taken weekly
Mefloquine - taken weekely
When do you stop antimalarial prophylaxis generally and what is the exception?
prophylaxis stops after 4 weeks
except for Atovaquone +proguanil (malarone)
When do you stop antimalarial prophylaxis generally and what is the exception?
prophylaxis stops after 4 weeks
except for Atovaquone +proguanil (malarone)
When do you stop antimalarial prophylaxis generally and what is the exception?
prophylaxis stops after 4 weeks
except for Atovaquone +proguanil (malarone)
Diarrhea in HIV patients
It is very common
This may be due to the effects of the virus itself (HIV enteritis) or opportunistic infections
Possible causes
Cryptosporidium + other protozoa (most common) –> supportive management
Cytomegalovirus
Mycobacterium avium intracellulare
- Rifabutin/ ethambutol/ Clarithromycin
Giardia
Diarrhea in HIV patients
It is very common
This may be due to the effects of the virus itself (HIV enteritis) or opportunistic infections
Possible causes
Cryptosporidium + other protozoa (most common) –> supportive management
Cytomegalovirus
Mycobacterium avium intracellulare
- Rifabutin/ ethambutol/ Clarithromycin
Giardia
Rabies
- features
- management
it is a viral disease that can cause acute encephalitis
Features
prodrome: headache, fever, agitation
hydrophobia: water-provoking muscle spasms
hypersalivation
Negri bodies: cytoplasmic inclusion bodies found in infected neurons
Following animal bites in an at-risk country
wash the wound
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
If untreated it is nearly always fatal
Epstein-Barr virus-associated conditions
Malignancies associated with EBV infection
Burkitt’s lymphoma*
Hodgkin’s lymphoma
nasopharyngeal carcinoma
HIV-associated central nervous system lymphomas
The non-malignant condition hairy leukoplakia is also associated with EBV infection.
*EBV is currently thought to be associated with both African and sporadic Burkitt’s
Epstein-Barr virus-associated conditions
Malignancies associated with EBV infection
Burkitt’s lymphoma*
Hodgkin’s lymphoma
nasopharyngeal carcinoma
HIV-associated central nervous system lymphomas
The non-malignant condition hairy leukoplakia is also associated with EBV infection.
*EBV is currently thought to be associated with both African and sporadic Burkitt’s
MGT of early Lyme disease
14-21 days of oral doxycycline
Parvovirus B19 (erythema infectiosum/ fifth disease/ Slapped cheek syndrome)
Presentations
asymptomatic
Fever and rash in children
pancytopaenia in immunosuppressed patients
aplastic crises e.g. in sickle-cell disease
hydrops fetalis
parvovirus B19 in pregnant women can cross the placenta in pregnant women
this causes severe anaemia due to viral suppression of fetal erythropoiesis → heart failure secondary to severe anaemia → the accumulation of fluid in fetal serous cavities (e.g. ascites, pleural and pericardial effusions)
treated with intrauterine blood transfusions
the organism most likely to cause pneumonia in pts with cystic fibrosis (pts develop bronchiectasis early in their life)
Pseudomonas aeruginosa is an important organism causing LRTI in cystic fibrosis patients
the organism also causes
- skin infections after burn
- otitis externa in DM –> malignant otitis externa
- UTI
Tx
- if pt well await results of sputum culture
- However, an anti-pseudomonal agent such as piperacillin with tazobactam or ciprofloxacin should be used as part of empirical treatment for sepsis in cystic fibrosis patients.
Bacterial CAP that follows influenza infection
Staph aureus
Most common cause of pneumonia in patients with COPD
Haemophilus influenza
The most common cause of pneumonia in malnourished alcoholics
Klebsiella
Legionella pneumonia
- features
- diagnosis
- MGT
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
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
Diagnosis
urinary antigen
Management
treat with erythromycin/clarithromycin
Sepsis 6
- Administer oxygen: Aim to keep saturations > 94% (88-92% if at risk of CO2 retention e.g. COPD)
- Take blood cultures
- Give broad-spectrum antibiotics
- Give intravenous fluid challenges
NICE recommend a bolus of 500ml crystalloid over less than 15 minutes - Measure serum lactate
- Measure accurate hourly urine output
Sepsis red flag criteria (NICE)
Responds only to voice or pain/ unresponsive
Acute confusional state
Systolic B.P <= 90 mmHg (or drop >40 from normal)
Heart rate > 130 per minute
Respiratory rate >= 25 per minute
Needs oxygen to keep SpO2 >=92%
Non-blanching rash, mottled/ ashen/ cyanotic
Not passed urine in last 18 h/ UO < 0.5 ml/kg/hr
Lactate >=2 mmol/l
Recent chemotherapy
Hepatitis C (note there is no vaccine for hepatitis C)
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
Chronic Hepatitis C- MGT
treatment depends on the viral genotype - this should be tested prior to treatment
A combination of protease inhibitors (e.g. daclatasvir + sofosbuvir or sofosbuvir + simeprevir) with or without ribavirin are used
Complications of treatment
ribavirin - side-effects: haemolytic anaemia, cough. Women should not become pregnant within 6 months of stopping ribavirin as it is teratogenic
interferon alpha - side-effects: flu-like symptoms, depression, fatigue, leukopenia, thrombocytopenia
Respiratory pathogens and associated condition
Respiratory syncytial virus Bronchiolitis
Parainfluenza virus Croup
Rhinovirus Common cold
Influenza virus Flu
Streptococcus pneumoniae CAP (most common cause)
Haemophilus influenzae CAP/ most common cause of bronchiectasis exacerbations/ Acute epiglottitis
Staphylococcus aureus Pneumonia, particularly following influenza
Mycoplasma pneumoniae Atypical pneumonia
- Flu-like symptoms classically precede a dry cough.
- Complications include haemolytic anaemia and erythema multiforme
Legionella pneumophilia Atypical pneumonia
- Classically spread by air-conditioning systems, causes dry cough. - Lymphopenia, deranged liver function tests and hyponatraemia may be seen
Pneumocystis jiroveci Common cause of pneumonia in HIV patients. Typically patients have few chest signs and develop exertional dyspnoea
Mycobacterium tuberculosis Causes tuberculosis. A wide range of presentations from asymptomatic to disseminated disease are possible. Cough, night sweats and weight loss may be seen
How many doses on tetanus vaccine provide long term protection
Tetanus vaccine is currently given in the UK as part of the routine immunisation schedule at:
2 months
3 months
4 months
3-5 years
13-18 years
HPV immunisation
All 12- and 13-year-olds (girls AND boys) in school Year 8 are offered the human papillomavirus (HPV) vaccine.
information given to parents and available on the NHS website make it clear that the daughter may receive the vaccine against parental wishes
given as 2 doses - girls have the second dose between 6-24 months after the first, depending on local policy
HPV vaccination should also be offered to men who have sex with men under the age of 45 to protect against anal, throat and penile cancers.
Injection site reactions are particularly common with HPV vaccines.
How to manage contacts of those with meningitis (meningococcal meningitis and pneumococcal meningitis)
prophylaxis to household and close contacts of patients with meningococcal meningitis and those exposed to respiratory secretion
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 or may be used.
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.
Antibiotics for meningitis
Initial empirical therapy aged < 3 months
- IV cefotaxime + 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
- Intravenous benzylpenicillin or cefotaxime (or ceftriaxone)
Pneuomococcal meningitis
- Intravenous cefotaxime (or ceftriaxone)
Meningitis caused by Haemophilus influenzae
- Intravenous cefotaxime (or ceftriaxone)
Meningitis caused by Listeria
- Intravenous amoxicillin (or ampicillin) + gentamicin
MGT of pneumocystis jiroveci penumonia
features
dyspnoea
dry cough
fever
very few chest signs
treated with co-trimoxazole, which is a mix of trimethoprim and sulfamethoxazole
IV pentamidine in severe cases
aerosolized pentamidine is an alternative treatment for Pneumocystis jiroveci pneumonia but is less effective with a risk of pneumothorax
steroids if hypoxic (if pO2 < 9.3kPa then steroids reduce risk of respiratory failure by 50% and death by a third)
MGT of necrotizing fasciitis
Management
urgent surgical referral debridement
intravenous antibiotics
Prognosis
average mortality of 20%
Post-exposure prophylaxis
Hep A
Hep B
Hep C
HIV
VZV
Hep A- can use Human normal IGs or Hep A vaccine
Hep B
HBsAg positive source
- exposure to known responder to the HBV vaccine then a booster dose should be given
- if they are a non-responder (anti-HBs < 10mIU/ml 1-2 months post-immunisation) they need to have hepatitis B immune globulin (HBIG) and a booster vaccine
- unknown source
for known responders the HBV vaccine the Green Book advises considering a booster dose of HBV vaccine
for known non-responders HBIG + vaccine should be given whilst those in the process of being vaccinated should have an accelerated course of HBV vaccine
Hep C- monthly PCR - if seroconversion then interferon +/- ribavirin
HIV
a combination of oral antiretrovirals (e.g. Tenofovir, emtricitabine, lopinavir and ritonavir) as soon as possible (i.e. Within 1-2 hours, but may be started up to 72 hours following exposure) for 4 weeks
serological testing at 12 weeks following completion of post-exposure prophylaxis
VZV
VZIG for IgG negative pregnant women/immunosuppressed
Post-exposure prophylaxis
Hep A
Hep B
Hep C
HIV
VZV
Hep A- can use Human normal IGs or Hep A vaccine
Hep B
HBsAg positive source
- exposure to known responder to the HBV vaccine then a booster dose should be given
- if they are a non-responder (anti-HBs < 10mIU/ml 1-2 months post-immunisation) they need to have hepatitis B immune globulin (HBIG) and a booster vaccine
- unknown source
for known responders the HBV vaccine the Green Book advises considering a booster dose of HBV vaccine
for known non-responders HBIG + vaccine should be given whilst those in the process of being vaccinated should have an accelerated course of HBV vaccine
Hep C- monthly PCR - if seroconversion then interferon +/- ribavirin
HIV
a combination of oral antiretrovirals (e.g. Tenofovir, emtricitabine, lopinavir and ritonavir) as soon as possible (i.e. Within 1-2 hours, but may be started up to 72 hours following exposure) for 4 weeks
serological testing at 12 weeks following completion of post-exposure prophylaxis
VZV
VZIG for IgG negative pregnant women/immunosuppressed
Features of an aspergilloma infection (a fungus ball or mycetoma composed of aspergillus hyphae along with cellular debris and mucus)
usually asymptomatic but can present with cough and haemoptysis
INV for aspergilloma
chest x-ray containing a rounded opacity. A crescent sign may be present
high titres Aspergillus precipitins
Spinal epidural abscess
- most common causative organism
- presentation
- INV
- Rx
most common causative organism- Staph aureus
presentation
- fever/ back pain/ focal neurological deficits
INV
- bloods/ blood cultures/ infection screen (CXR, urine MSU)/ MRI of whole spine
Rx
Long term abx
+/- surgical evacuation of the abscess
Clostridia bacteria
What are four species
Clostridia are gram-positive, obligate anaerobic bacilli.
C. perfringens
produces α-toxin, a lecithinase, which causes gas gangrene (myonecrosis) and haemolysis
features include tender, oedematous skin with haemorrhagic blebs and bullae. Crepitus may present on palpation
C. botulinum
typically seen in canned foods and honey
prevents acetylcholine (ACh) release leading to flaccid paralysis
C. difficile
causes pseudomembranous colitis, typically seen after the use of broad-spectrum antibiotics
produces both an exotoxin and a cytotoxin
C. tetani
produces an exotoxin (tetanospasmin) that prevents the release of glycine from Renshaw cells in the spinal cord causing a spastic paralysis
what is the organism causing the majority of erysipelas?
Streptococcus pyogenes, a beta-haemolytic group A streptococci and the rash is caused by an endotoxin rather than the bacteria itself.
Gram -ve on an endocervical swab
Gonorrhoea
features of glandular fever/ infectious mononucleosis - caused by EBV
The classic triad of sore throat, pyrexia and lymphadenopathy is seen
Other features :
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)
a maculopapular, pruritic rash develops in around 99% of patients who take ampicillin/amoxicillin whilst they have infectious mononucleosis
Gastroentritis - Incubation period
1-6 hrs: Staphylococcus aureus, Bacillus cereus*
12-48 hrs: Salmonella, Escherichia coli
48-72 hrs: Shigella, Campylobacter
> 7 days: Giardiasis, Amoebiasis
Infective diarrhoea
E coli- travellers diarrhoea/ Watery stools/ Abdominal cramps and nausea
Giardiasis Prolonged, non-bloody diarrhoea/ common in travellers but not as much as Ecoli
Cholera- Profuse, watery diarrhoea/ Severe dehydration resulting in weight loss
Shigella- Bloody diarrhoea/ Vomiting and abdominal pain
S aureus- Severe vomiting/ Short incubation period
C Jujeni- A flu-like prodrome is usually followed by crampy abdominal pains, fever and diarrhoea which may be bloody
May mimic appendicitis
Complications include Guillain-Barre syndrome
Bacillus cereus Two types of illness are seen: vomiting within 6 hours, stereotypically due to rice Or diarrhoeal illness occurring after 6 hours
Amoebiasis Gradual onset bloody diarrhoea, abdominal pain and tenderness which may last for several weeks
URTI symptoms + amoxicillin → rash
A rash develops in around 99% of patients who take amoxicillin whilst they have infectious mononucleosis. Her treatment should be supportive
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
Mycoplasma pneumonia
flu-like symptoms classically precede a dry cough
bilateral consolidation on x-ray
complications may occur as below
Complications
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
Mycoplasma pneumonia vs legionella
both
have flu-like symptoms
Dry cough
Deranged LFTs
Macrolides (erythromycin)
Legionella
Lymphopenia
Hyponatremia
Dx urinary antigen
Mycoplasma
Haemolytic anaemia/ ITP
Erythema multiforme
Encephalitis/ GBS
Myocarditis
Dx Serology
MGT of chlamydia in pregnancy vs not in pregnancy
doxycycline as first leint
- alternative –> azithromycin
in pregnancy
- azithromycin, erythromycin or amoxicillin
causative organism for leptospirosis
spirochaete Leptospira interrogans (serogroup L. icterohaemorrhagiae), classically being spread by contact with infected rat urine.
Commonly seen in questions referring to sewage workers, farmers, vets or people who work in an abattoir
Features/ INV/ MGT of
Leptospirosis
Features
fever
flu-like symptoms
subconjunctival suffusion (redness)/haemorrhage
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
Investigation
serology
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
Management
high-dose benzylpenicillin or doxycycline
MGT of chickenpox in at-risk groups
significant exposure + person is at risk + test for antibodies is -ve
if all three present then you should give varicella-zoster immunoglobulin (VIZG)
MGT of syphilis
IM benzathine penicillin is the first-line
management
alternatives: doxycycline
the Jarisch-Herxheimer reaction is sometimes seen following treatment
fever, rash, tachycardia after the first dose of antibiotic
in contrast to anaphylaxis, there is no wheeze or hypotension
it is thought to be due to the release of endotoxins following bacterial death and typically occurs within a few hours of treatment
No treatment is needed other than antipyretics if required
MGT of latent TB
Latent tuberculosis treatment options:
3 months of isoniazid (with pyridoxine) and rifampicin, or
6 months of isoniazid (with pyridoxine)
Chlamydia - when is a test of cure needed?
A TOC should be performed 6 weeks post infection in pregnant women as recommended by the BASHH guidelines. If a TOC is performed earlier than 6 weeks there is a possibility that nonviable Chlamydia DNA will still be present on the NAAT, giving a false positive result.
A TOC is not routinely required in uncomplicated chlamydia infection in men and non- pregnant women.
Chlamydia - when is a test of cure needed?
A TOC should be performed 6 weeks post infection in pregnant women as recommended by the BASHH guidelines. If a TOC is performed earlier than 6 weeks there is a possibility that nonviable Chlamydia DNA will still be present on the NAAT, giving a false positive result.
A TOC is not routinely required in uncomplicated chlamydia infection in men and non- pregnant women.
Chlamydia- partner notification
Chlamydia - partner notification:
symptomatic men: all partners from the 4 weeks prior to the onset of symptoms
women + asymptomatic men: all partners from the last 6 months or the most recent sexual partner
Diphtheria
(Gram-positive bacterium Corynebacterium diphtheriae)
Features
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 blockDiphtheria 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
Diphtheria
(Gram-positive bacterium Corynebacterium diphtheriae)
Features
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 blockDiphtheria 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
Diphtheria INV + MGT
culture of throat swab: uses tellurite agar or Loeffler’s media
Management
intramuscular penicillin
diphtheria antitoxin
What is Fitz-Hugh-Curtis syndrome?
Fitz-Hugh-Curtis syndrome is a complication of pelvic inflammatory disease in which the liver capsule becomes inflamed causing right upper quadrant pain. This leads to scar tissue formation and peri-hepatic adhesions. It usually occurs in women who have either chlamydia or gonorrhoea.
Treatment is through eradication of the responsible organism although laparoscopy is required in some patients to perform lysis of adhesions that have formed.
Dx and screening for HIV
Combination tests (HIV p24 antigen and HIV antibody) are now standard for the diagnosis and screening of HIV
MGT of Hep B
First line is pegylated interferon-alpha
examples include tenofovir, entecavir and telbivudine (a synthetic thymidine nucleoside analogue)
Interpreting Hep B results
Treatment of genital warts
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
Syphilis
- Primary
- Seconday
- Tertiary
- Congenital
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)
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 )
Tertiary features
gummas (granulomatous lesions of the skin and bones)
ascending aortic aneurysms
general paralysis of the insane
tabes dorsalis
Argyll-Robertson pupil
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
