Infectious Diseases Flashcards
(30 cards)
What are the three key enzymes involved in HIV pathogenesis?
Reverse Transcriptase, Integrase, Protease
Note: these are the targets of many HIV drugs
What CD4 count is needed to classify as AIDS?
<200
What diseases are HIV patients at risk of with a CD4 count of 200-500?
Oral hairy leukoplakia Shingles Thrush Skin infections TB
What is used to treat PCP?
Co-trimazole
What stain is used for microscopy of PCP?
Silver stain
What are the five classes of antiretroviral drugs used in HIV treatment?
Nucleoside/tide reverse transcriptase inhibitors (NRTIs)
Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
Protease inhibitors (PIs)
Integrase inhibitors (IIs)
Entry inhibitors (EIs)
What two opportunistic conditions cause ring lesions in the brain?
How can they be differentiated?
Lymphoma - One lesion
Toxoplasmosis - Multiple lesions
When do HIV antibodies become detectable?
What can be used before this point for diagnosis?
4 weeks after exposure
PCR can be used 1 week after exposure
What is used as PEP and PrEP for HIV? How often are they used
Truvada
PrEP - either taken daily or 12 hours before exposure
PEP - give after high risk exposure for 4 weeks
What diagnostic tests would you do in suspected malaria?
Blood films - thick and thin
or antigen detection test (dipstick) (Rapid Diagnostic Test)
What do thick and thin blood films show in malaria investigations?
Thick - How much
Thin - what type of parasite
Name four strains of malaria
Plasmodium falciparum
Plasmodium vivax
Plasmodium ovale
Plasmodium malariae
Which strains of malaria have a dormant liver stage?
Plasmodium vivax
Plasmodium ovale
What level of parasitaemia is considered severe?
What is the treatment?
> 2%
IV artesunate
Name 4 complications of malaria?
Cerebral malaria Acute respiratory distress syndrome Spontaneous bleeding and coagulopathy Septicaemia Severe anaemia (Haemolytic) Hypoglycaemia Metabolic acidosis Acute kidney injury Nephrotic syndrome Jaundice Splenic rupture
What prophylaxis can be used for malaria?
Doxycycline
Malarone (atovaquone/proguanil)
What is a Gohn focus?
The primary lesion in TB - it is a caseating granuloma
Once it calcifies it becomes a Ranke focus that is visible on x-ray
What is a Gohn complex?
Gohn focus plus pulmonary lymph node involvement
What investigations are done in suspected TB?
Sputum sample - Ziehl Neelson stain for acid fast bacilli OR aura amine phenol staining and detection with fluorescent microscopy
Broncheo-alveolar lavage
Mantoux (false positive if had bCG)
Interferon gamma release assay - Quantiferon
PCR
What is the treatment for TB? and a side effect of each drug?
Rifamicin - 6 months - Orange secretions
Isoniazid - 6 months - Peripheral neuropathy
Pyrazinamide - 2 months - Deranged LFTs, elevated uric acid, arthralgia
Ethambutol - 2 months - EYES, colour blindness, reduced visual acuity, optic neuritis
What is given to prevent side effects of Isoniazid?
Pyridoxine
What are the TB findings on chest x-ray?
Cavitation
Consolidation
Calcification
Fibrosis
What would be seen on an MRI head in CJD?
Cortical and basal ganglion changes
What are some features of measles?
Koplick spots (oral - red spots with white centre)
Dry cough
Conjunctivitis
Maculopapular rash starting in the hair line
