infectious diseases and STIs 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)
what is the cause of typhoid and paratyphoid?
salmonella typhi and paratyphi (types A, B &C)
features of typhoid
systemic upset: fever, arthralgia, h/a
relative bradycardia
abdo pain, distention, constipation
Rose spots are pathognomonic (blanching pink, macular 2-3mm on trunk)
features of Brucellosis
how is it Dx?
Mx?
malaise and fever, hepatosplenomegaly, sacroiliitis
brucella serology test
doxy and streptomycin
what is the organism that causes syphilis
treponema pallidum
mode of action of aciclovir
inhibits viral DNA polymerase
target of the monoclonal antibodies: rituximab infliximab trastuzumab cetuximab
rituximab - anti CD20 (Non-hodgkin’s and RA)
infliximab - anti TNF (RA and Crohns)
trastuzumab (Herceptin) - anti HER2 (breast ca)
cetuximab - epidermal GFr antagonist (met colorectal ca and h&n ca)
Mx of trypanosomiasis?
Early: IV pentamidine or surine
If CNS involvement: melarsoprol
what is the microscopic structure of gonorrhoea
gram negative diplococci
what percentage of men and women are symptomatic with gonorrhoea?
90-95% of men
50% of women
what is the Ix and Mx of gonorrhoea?
1st past urine NAAT (nuclear acid amplification test)
Mx IM ceftriaxone 500mg and azithromycin 1g PO, contact tracing, retest in 2 weeks.
What contact tracing is needed for gonorrhoea?
symptomatic - sexual partners from last 2 weeks
asymptomatic - 3 months
What is the most common STI
chlamydia, 2nd gonorrhoea.
what percentage of men and women are symptomatic with chlamydia?
men 50%
women 20%
complications of chlamydia
men: epididymitis, epididymo-orchitis
women: PID, tubal infertility, ectopic pregnancy
Mx of chlamydia
single dose 1g azithromycin (erythromycin if preg) or 7 days 100mg doxycycline
Ix and Mx of lyme disease
serology tests for antibodies to Borrelia burgdorferi
Mx: doxy if early, ceftriaxone if disseminated
Can have Jarish-Herxheimer reaction after starting Rx - fever rash tachy. also seen in syphillis.
features and Mx of cutaneous anthrax
black eschar, marked oedema, typically painless and non tender
Mx:ciprofloxacin
gram positive cocci
staph and strep (including entero)
gram negative cocci
N.meningitis, N.gonorrhoea, moraxella
what medication do you give for malaria prophylaxis?
atovaquone + proguanil (Malarone)
risk of Hep B infection from needlestick of Hep B infected pt
Mx
20-30%
if had vaccine, give booster,
if not had vaccine - Hep B IG and vaccine
Treatment of shigella
ciprofloxacin
features of Dengue fever
Mx
h/a, fever,
low platelets, raised ALT
Mx: symptomatic
Mx of toxoplasmosis in HIV patients
treat if CD4 count is <200
sulfadiazine and pyrimethamine
Ix for malaria
3 x blood films
raised platelets
normochromic normocytic anaemia
normal WCC
Features of loiasis
painful swellings of the limbs - angioedema with paraesthesia
leukocytosis and hypereosinophilia
conjunctival spread (eye worm)
Filarial infection caused by Loa Loa (central and western Africa)
prevention of loiasis
weekly diethylcarbamazine citrate for prevention
Most common skin condition in HIV pts
Eosinophilic folliculitis
Occurs when CD4 <300
Itchy papules and pustules on chest and arms
Organism, symptoms and treatment of schistosomiasis
Schistosoma Haematobium
dysuria, frequency, haematuria (occasionally haemospermia), incontinence
Rx: oral praziquantel
Features of HIV seroconversion illness
Ix
fever, malaise, arthritis
rash, sore throat
diarrhoea, lymphadenopathy
meningo-encephalaitis
Seroconversion period 2-3 weeks to 3 months.
Ix: P24 antigen and HIV RNA PCR.
Amoebic dysentry:
features
Ix
Mx
fever (rarely high temps) abdo pain and diarrhoea. Stool may have blood or mucus in.
Ix: stool cultures and microscopy
Mx: oral metronidazole for 5 days then diloxanide furoate to destroy gut cysts.
Mx of hookworm
Most common feature is iron deficiency anaemia
Mx with albendazole or mebendazole (antihelmintic)
