Infectious diseases Flashcards
How to manage red man syndrome with vancomycin?
Stop the vancomycin infusion until symptoms resolve and then re start at a slower rate
What is a rapid plasma reagin test?
useful to monitor disease activity and reinfection. It is written as the number of times a sample containing syphilis needs to be diluted before it becomes undetectable. Therefore, 1 in 2 means it needs to be diluted twice, whereas 1 in 32 means it needs to be diluted 32 times (meaning disease activity is higher in the latter). A rise by 4-fold or more in a previously infected patient either indicates no treatment response or reinfection.
What stains with india ink?
Cryptococcus neoformans
Management of cerebral toxoplasmosis?
pyrimethamine plus sulphadiazine for at least 6 weeks
Gram positive rods mneumonic
ABCD L
Actinomyces
Bacillus anthracis (anthrax)
Clostridium
Diphtheria: Corynebacterium diphtheriae
Listeria monocytogenes
Gram negative rods?
Escherichia coli
Haemophilus influenzae
Pseudomonas aeruginosa
Salmonella sp.
Shigella sp.
Campylobacter jejuni
Management of pneumocytitis jiroveci pneumonia?
co-trimoxazole
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)
First line for syphilis?
intramuscular benzathine penicillin
What is the Jarisch-Herxheimer reaction
fever, rash, tachycardia after the first dose of antibiotic
Standard for diagnosis and screening of 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
First line for gonorrhoea?
IM ceftriazone
Monitoring for terbinafine?
LFTs checked before commencing terbinafine and 4-6 weeks into treatment
What is trichomonas vaginalis?
highly motile, flagellated protozoan parasite. Trichomoniasis is a sexually transmitted infection (STI).
What is giardiasis?
flagellate protozoan Giardia lamblia. It is spread by the faeco-oral route.
Complications of mycoplasm 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 is kaposi’s sarcoma caused by?
Human herpes virus 8
Live attenuated vaccines
BCG
MMR
oral polio
yellow fever
oral typhoid
Features of giardiasis?
often asymptomatic
non-bloody diarrhoea- steatorrhoea
bloating, abdominal pain
lethargy
flatulence
weight loss
malabsorption and lactose intolerance can occur
adverse effects of metronisazole?
disulfiram-like reaction with alcohol
increases the anticoagulant effect of warfarin
Progressive multifocal leukoencephalopathy (PML)
widespread demyelination
due to infection of oligodendrocytes by JC virus (a polyoma DNA virus)
What pneumonia cause is associated with cold sores?
Streptococcus pneumoniae
IV antibiotic in 3 months-50 YO with meningococcal meningitis?
cefotaxime (or ceftriaxone)
If over 50 first abx in meningococcal meningitis?
cefotaxime (or ceftriaxone) + amoxicillin (or ampicillin) for adults
What is HIV seroconversion?
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
WHat does legionaella typically colonise?
typically colonizes water tanks and hence questions may hint at air-conditioning systems or foreign holidays
Legionella manaegement
Treat with erythromycin/clarithromycin
What is Q fever caused by?
Coxiella burnetii
Features of Q fever?
typically prodrome: fever, malaise
causes pyrexia of unknown origin
transaminitis
atypical pneumonia
endocarditis (culture-negative)
Management of Q fever?
Doxycyline
Features of enteric fever?
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
Features of herpes simplex virus?
primary infection: may present with a severe gingivostomatitis
cold sores
painful genital ulceration
Live attenuated vaccine mneumonic?
Mi Booty
MMR
Influenza (intranasal)
BCG
Oral polio
Oral rotavirus
Typhoid
Yellow Fever
Investigation of choice for chlamydia?
Nucleic acid amplification tests (NAATs)
TB management inital phase?
irst 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)
What is gonorrhea caused by?
Gram-negative diplococcus Neisseria gonorrhoea
First line for management of meningitis contacts?
oral ciprofloxacin or rifampicin
What are clue cells seen in?
BV
Amstel’s criteria state that 3 out of 4 of the following should be present for a diagnosis of BV:
Thin, white, homogeneous discharge.
Vaginal fluid pH >4.5.
Clue cells on microscopy of wet mount.
Release of a fishy odour on adding alkali (potassium hydroxide).
Severe cellulitis treatment?
Only say the C word if its a SEVERE situation
Cellulitis Mx = Co-amox / Cefuroxime / Clindamycin / Ceftriaxone
Features of trichomonas vafinalis?
vaginal discharge: offensive, yellow/green, frothy
vulvovaginitis
strawberry cervix
pH > 4.5
in men is usually asymptomatic but may cause urethritis
Treartment of trichmonas vaginalis?
Oral metronidazole
First line for animal bites?
Co-amoxiclav
Typical presentation of bacillus cerus infection?
Two types of illness are seen
vomiting within 6 hours, stereotypically due to rice
diarrhoeal illness occurring after 6 hours
Diptheria presentation
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
First line for syphilis?
intramuscular benzathine penicillin is the first-line management
Are the herpes ulcers painful or painless?
Painful
What is leptospirosis caused by?
Leptospira interrogans
Pneumonia cause commonly after influenza infection
Staphylococcus aureus
Immunocompromised patients with toxoplasmosis are treated with what?
pyrimethamine plus sulphadiazine
What does clostridium perfringes produce?
produces α-toxin, a lecithinase, which causes gas gangrene (myonecrosis) and haemolysis
Causes of false-negative Mantoux test
immunosuppression (miliary TB, AIDS, steroid therapy)
sarcoidosis
lymphoma
extremes of age
fever
hypoalbuminaemia, anaemia
Gonorrhea treatment if dont want IM cefitraxone?
oral cefixime + oral azithromycin
Why should nitrofuratonin be avoided during breast feeding?
small amounts in milk but can cause haemolysis in G6PD infants.
patients with ovale or vivax malaria should be given what folowing acute treatment?
Primaquine
How does parvovirus B19 present in pregnant women?
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)
Incubation periods of different diarroheal illnessses
1-6 hrs: Staphylococcus aureus, Bacillus cereus*
12-48 hrs: Salmonella, Escherichia coli
48-72 hrs: Shigella, Campylobacter
> 7 days: Giardiasis, Amoebiasis
UTI towards end of pregnancy?
Amoxicillin or cefalexin
Management of suspected/confirmed lyme disease?
doxycycline if early disease. Amoxicillin is an alternative if doxycycline is contraindicated
Pneumocystis jiroveci penumonia is treated with what?
Co-trimaxazole
Adverse effects of tetracyclines?
discolouration of teeth: therefore should not be used in children < 12 years of age
photosensitivity
angioedema
black hairy tongue
What is chancroid?
tropical disease caused by Haemophilus ducreyi.
Chancroid makes du cry (painful ulcer, painful lymph node)
HSV 1 and 2 which ones is mouth and which is genital herpes?
1 is mouth and 2 is genital herpes
HSV1 and 2. You got one mouth and two baws.
HSV 1 and 2 which ones is mouth and which is genital herpes?
1 is mouth and 2 is genital herpes
HSV1 and 2. You got one mouth and two baws.
Medication for acute epiglottisi?
Haemophilus influenza type B
Bacterial causes of otitis externa?
Pseudomonas aeruginosa
Incubatio period for ebola?
2 to 21 days
What is the most common opportunistic infection in AIDS?
PCP
Investigation findings in PCP?
CXR: typically shows bilateral interstitial pulmonary infiltrates but can present with other x-ray findings e.g. lobar consolidation. May be normal
exercise-induced desaturation
sputum often fails to show PCP, bronchoalveolar lavage (BAL) often needed to demonstrate PCP (silver stain shows characteristic cysts)
Viral meningitis treatment?
IV ceftriaxone
IV amoxicillin is also used if immunocomprimised
HPV types caused by genital warts?
HPV 6 and 11
What is Jarisch-Herxheimer reaction?
Complication of syphilis treatment, or other spirochete infections, with antibiotics and is associated with flushing, nausea, tachycardia, and headaches. It is managed supportively and antibiotics should continue. In the context of the symptoms and management suggesting syphilis, as well as the timing of the symptom onset, this is the most likely answer.
Management of a soliatary keratinised wart?
Cryotherapy
Management of multiple non-keratinised warts?
Topical podophyllum
Most common cause of primary syphillis?
Treponema pallium
First line for BV?
Metronidazole
First line for human bite?
Co-amoxiclav
First line for campylobacter?
Clarithromycin
Management of infectious mononucleosis?
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
TB medication memory aid?
RifamPEEcin
E for ethambutol, e for eyes
IsoNERVEzid
Pyrazinamide - p for pain
CT findings in toxoplasmosis?
usually single or multiple ring enhancing lesions, mass effect may be seen
What accounts for 50% of cerebral lesions in patient’s with HIV?
Toxoplasmosis
s prophylaxis for contacts of patients with meningococcal meningitis
Oral ciprofloxacin or rifampicin
Mangement of cerebral toxoplasmosis?
pyrimethamine plus sulphadiazine for at least 6 weeks
antibiotic of choice for cellulitis in pregnancy if the patient is penicillin allergic?
Erythromycin
What should be monitoried in syphillis to assess the response?
nontreponemal (RPR/VDRL) titres should be monitored after treatment to assess the response
LP should be delayed in the following circumstances in bacterial meningitis?
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
Most common organism found in central line infections
Staphylococcus epidermis
Returning traveller with fever, RUQ pain? Think what?
Amoebic liver abscess
Pneumonia in an alcoholic? Think what?
Klebsiella mneumonia
most common cause of community-acquired pneumonia
Streptoccus pneumonia
Exacerbations of chronic bronchitis abx management
Amoxicillin or tetracycline or clarithromycin
Abx Management of Uncomplicated community-acquired pneumonia
Amoxicillin (Doxycycline or clarithromycin in penicillin allergic, add flucloxacillin if staphylococci suspected e.g. In influenza)
Abx management of Pneumonia possibly caused by atypical pathogens
Clarithromycin
Abx management of hospital acquired pneumonia?
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)
Abx of Lower UTI?
Trimethoprim or nitrofurantoin. Alternative: amoxicillin or cephalosporin
Abx management of acute pyelonephritis?
Broad-spectrum cephalosporin or quinolone
Abx management of acute prostatits?
Quinolone or trimethoprim
Abx management of impetigo?
Topical hydrogen peroxide, oral flucloxacillin or erythromycin if widespread
Abx management of cellulitis?
Flucloxacillin (clarithromycin, erythromycin or doxycycline if penicillin-allergic)
Abx management of cellulitis near the eyes or nose?
Co-amoxiclav (clarithromycin, + metronidazole if penicillin-allergic)
Management of eryiplesa?
Flucloxacillin* (clarithromycin, erythromycin or doxycycline if penicillin-allergic)
Management of animal or human bite?
Co-amoxiclav (doxycycline + metronidazole if penicillin-allergic)
Management of mastitis during breastfeeding?
Flucloxacillin
Abx Management of throat infections?
Phenoxymethylpenicillin (erythromycin alone if penicillin-allergic)
Abx Management of sinusitis
Phenoxymethylpenicillin
Abx management of otitis media?
Amoxicillin (erythromycin if penicillin-allergic)
Abx management of otitis externa?
Flucloxacillin (erythromycin if penicillin-allergic)
Abx management of peridontal abscess?
Amoxicillin
Abx management of gingivitis?
Metronidazole
Abx management of gonorrhea
Intramuscular ceftriaxone