The final week

I now have some idea of what sorts of things come up regularly, and also what I need constant reminders about. For example, medicine.

I’m going to post stories/summaries I found helpful, and turn them into proper diagrams after MRCP. These are NOT comprehensive summaries. They are overviews to trigger my memory.

Toxoplasmosis

Toxoplasma gondii = an intracellular protozoan parasite. It lives in the cat.

In most people, it doesn’t do much. Occassionally it causes a couple of lymph nodes to enlarge, esp cervical/occipital. If you are really unlucky and the cat gave you an evil eye, you get chorioretinitis.

In pregnant women , the baby may get congenital toxoplasmosis, especially if mum is infected in the first 10 weeks. Watch out for CHC: Intracranial calcification, Hydrocephalus and Chorioretinitis.

In immunofail people, cerebral toxo is the big issue. Multiple, ring enhancing lesions, best seen on MRI.

IgG stays positive for life. Maybe you can use the affinity of IgG to work out if there’s an acute infection. Or maybe you could ask the Vengeful Cat God if they are infected, bringing a suitable supply of mice as an offering. IgM rises acutely, but returns to normal when it feels like it.

Cerebrospinal fluid (CSF) amplification DNA for toxoplasmosis gives the confirmatory diagnosis

Tx is co-trim for AIDS, and pyrido/sulfid for others.

Acute HIV

About 70% of people with HIV infection experience symptoms during seroconversion. It starts 2-6 weeks after exposure.

Think of Infectious Mononucelosis, but with more emphasis on a maculopapular rash that affects the upper body plus mouth/genital ulcers. Almost like a marriage between IM and Behcets.

FBC may show low platelets.

Ix: Bite the bullet and order HIV antibody and p24 antigen tests once the patient has been counselled and consented. The window period is now just one month with this cool 4th gen approach. Don’t use viral load for the initial test as you risk false positives. Get some confirmation assays if these are positive, and establish if its HIV-1 or HIV-2.

http://www.bhiva.org/documents/Guidelines/Testing/GlinesHIVTest08.pdf