Infectious Disease Flashcards
Organisms splenectomy patients are at risk from
pneumococcus, haemophilus, meningococcus and Capnocytophaga canimorsus (usually from dog bites)
splenectomy vaccinations needed and prophylactic Abx
Hib,
meningitis A and C
annual influenza
pneumococcal vaccine every 5 yrs
penicillin V
Leishmaniasis - type of organism involved, mode of spread, forms of the disease
intracellular protazoa sand fly cutaneous (mexicana) mucocutaneous (brasiliensis) visceral (donovani)
multiple ring enhancing lesions seen on CT of HIV+ pt. Dx? Mx?
toxoplasmosis
most common neurological infection in HIV pts
Mx - pyrimethamine and sulfadiazine
features of severe malaria
schizonts on blood film temp >39 parasitaemia >2% severe anaemia hypoglycaemia cerebral malaria - seizures, coma acute renal failure ARDS DIC
main organism responsible for bacterial vaginosis
gardnerella vaginosis (anaerobic)
Mx of bacterial vaginosis
oral metronidazole for 5-7 days,
more than half relapse in 3 months
topical metronidazole or clindamycin as alternatives
when do you start PCP prophylaxis in HIV pts?
when CD4 <200 (oral co-trimoxazole)
Antibiotic therapies for meningitis: at GP hospital setting hospital >50 and <3/12 pen allergic
IM benzylpenicillin - dont delay transport to hosp
IV cefotaxime
IV cefotaxime and amoxicillin
chloramphenicol
Management of meningitis contacts
offer prophylaxis to close contacts and housemates
oral rifampicin or ciprofloxacin
offer vaccine afterwards.
TB meds side effects Rifampicin Isoniazid pyrazinamide ethambutol
Rifampicin - hepatitis, flu-like Sx,
isoniazid - peripheral neuropathy, hepatitis, agranulocytosis, Pellagra (B3 def)
pyrazinamide - hyperuricaemia –> gout, hepatitis
ethambutol - optic neuritis - check VA before and during treatment.
Listeria monocytogenes - typical spread, dangerous to who, management
multiply at low temperatures
typically spread via contaminated food
particularly dangerous to pregnant women - can lead to miscarriage
Mx: BCULT, Rx with amoxicillin/ampicillin
Management of tetanus
supportative inc muscle relaxants
IM human tetanus immunoglobulin for high risk wounds
IV metronidazole
symptoms of chlamydia
asymptomatic in 70% women and 50% of men
women: cervicitis (discharge, bleeding), dysuria
men: urethral discharge, dysuria
Ix and Mx of chlamydia
nuclear acid amplification tests (NAATs) - 1st pass urine, vulvovaginal/cervical swab
7 days doxycycline or single dose azithromycin, erythromycin if preg.
who do you contact if pt is found to have chlamydia
and what do you offer?
symptomatic men - partners in last 4 weeks
asymptomatic men and all women - partners from last 6 months
Test and treat prior to knowledge of results.
most common cause of infective diarrhoea in HIV pts
Ix
Mx
cryptosporidium (protozoa)
acid fast stain shows red cysts
Supportative management
what are the features of African trypanosomiasis (sleeping sickness)?
mode of spread?
trypanosoma chancre - painless nodule at site of infection
intermittent fever
posterior cervical chain LN enlargement
later CNS involvement - somnolence, headaches, meningoencephalitis
Tsetse fly
whats is Chagas’ diease?
features
trypanosoma cruzi protozoa infection
95% asymptomatic in acute phase
chronic infection causes myocarditis (HF and arrhythmias) and megaoesophagus and megacolon (dysphagia and constipation)
key features of:
trichomonas vaginalis
BV
candida
offensive yellow/green frothy discharge, vulvovaginitis
offensive thin grey fishy discharge
“cottage cheese” discharge, itchy
what type of hypersensitivity occurs in scabies infections
type IV - delayed cell mediated response
Mx of scabies infection
1st line: permethrin, repeat in 7 days
pruritis can persist for 4-6 weeks
treat all contacts and wash bed linen and towels on day 1
features of Lyme disease
early
late
borrelia burgdorferi
early: erythema chronicum migrans (papule at site of tick bite -> annular lesion with central clearing)
systemic symptoms: malaise, fever, arthralgia
late:
cardio: myocarditis, heart block
neuro: CN palsies, meningitis
polyarthritis
hep B serology seen in a previously infected pt (>6months ago)
anti HBs+ now immune. negative in chronic disease
anti HBc+ positive in current or previous infection
HBsAg - no current infection and not infectious (positive in HB carriers)