MRCP Infectious diseases/STI Flashcards
How long after HIV infection does seroconversion occur?
2-4 weeks
Describe symptoms of HIV seroconversion
Viral illness similar to glandular fever:
fever, myalgia, pharyngitis, erythematous maculopapular rash
Diagnosing HIV serovoncersion
HIV RNA (viral load) & p24 antigen (ELISA)
Investigation of choice for HIV infection: HIV antibody serology (3 month window from infection to this test becoming positive -> false negative. hence seroconversion do the above tests)
Markers of infection activity in HIV
Viral load (RNA) & CD4 count
Post-splenectomy sepsis common organisms
Encapsulated organisms: - H influenza type b - S pneumoniae (most concerning) - N meningitidis Receive vaccines for the above
Multiple painful genital ulcers & tender lymphadenopathy
Herpes simples virus
First-line investigation suspected meningococcal infection
If no rash/raised ICP: LP & CSF microscopy.
If rash/raised ICP/uncooperative: Blood cultures & PCR
Cream coloured retina, overlying haemorrhages. ‘pizza pie appearance’
CMV retinitis
Occurs in up to 25% of untreated AIDS
Test for latent TB (irrespective of vaccination status)
asymptomatic, contact with TB positive
Mantoux test
Symptoms of primary TB infection
Often asymptomatic ;)
Cough/wheeze/erythema nodosum. Reactivation presents with typical symptoms.
Most severe malaria species
Plasmodium falciparum
Malaria species which have ‘hypnozoite’ stage - parasites remain dormant in liver and can cause relapse months or years later
P ovale, P vivax
Give primaquine as well as chloroquine to cure hynozoites
Gold-standard investigation for malaria
Malaria blood film (microscopy)
- x3 thick and thin blood films over 24-48h
- thick identifies parasite, thin identifies parasite load
Treatment for severe falciparum malaria
IV artesunate
2nd line: IV quinine (5 days) then second agent eg doxycycline for 7 days
What vaccination is never indicated in HIV positive people? (irrespective of CD4 count)
BCG
Risk of developing clinical TB
List the live-attenuated vaccines (8)
BCG, MMR oral polio, oral typhoid, oral rotavirus intranasal influenza yellow fever shingles & chickenpox
Malignancies associated with EBV infection (5)
- Burkitt’s lymphoma
- Hodgkin’s lymphoma
- Nasopharyngeal carcinoma
- HIV-associated CNS lymphomas
- Gastric cancer
Jarisch-Herxheimer reaction as associated with which conditions?
Spirochete infections:
- Syphilis
- Lyme disease
- Leptospirosis
Describe Jarisch-Herxheimer reaction
Fever, tachycardia, hypotension & rash after first dose of antibiotics, within 24h.
Likely due to toxin release following rapid bacterial death
CSF staining with India ink
Cryptococcal meningitis
Sabouraud dextrose agar
Sporothrix schenckii infection
- fungal, enters via cut in skin
- non-tender maculopapular lesion, progressive increase in number along lymphatic lines
How is coxiella burnetii spread?
Between animals via infected ticks
Animal to human by inhalation of infected dusts and aerosols, and unpasteurised milk of infected cows
Treatment for trichomonas vaginalis
PO metronidazole
Anti-HBe antibodies implies what?
Active hep B infection
