Infectious Diseases

Question 1

What is are the components of HAART in HIV infection?

Answer 1

• Either a non-nucleoside reverse transcriptase inhibitor (NNRTI), a protease inhibitor (PI) or an integrase inhibitor depending on childs age. Plus a dual-nucleotide/nucleoside reverse transcritpase inhibitor (NRTI)

Question 2

What sort of antibiotic resistance does Klebsiella demonstrate?

Answer 2

ESBL

Question 3

What is Neisseria gonnorhoeae?

Answer 3

A gram negative diplococcus.

Question 4

What is empiric treatment for brain abscess?

Answer 4

Cefotaxime/ceftriaxone + metronidazole.

Question 5

How do you differentiate acute Hep B infection from chronic/vaccination response?

Answer 5

• Hepatitis B surface antigen (HBsAg) - detectable in acute and chronic infection. Presence means a person is infectious.
• Total hepatitis B core antigen (anti-HBc) appears at onset of symptoms and persists for life, indicates previous or current infection.
• IgM antibody to hepatitis B core antigen (IgM anti HBc) indicates acute infection (<6m).
• Hepatitis B surface antibody (anti-HBs) indicates immunity to HBV.

Question 6

Which malaria species cause cerebral malaria?

Answer 6

• P. falciparum inly.
• Also parasites create rings in blood cells (knowlesi also).
• RBC are not enlarged.

Question 7

What is the mechanism of penicillin resistance in pneumococcal infection?

Answer 7

• Decreased affinity of penicillin binding proteins.

- Resistant pneumococci make altered cell walls.

Question 8

Which influenza virus is most likely to cause rhabdomyolysis?

Answer 8

• Influenza B.

- Flu A can also but less commonly.

Question 9

What are features of congenital syphilis?

Answer 9

• Usually appear by 3m, most often by 5w.
• 60-90% asymptomatic at birth.
• Hepatomegaly, jaundice, nasal discharge, rash, generalised lymphadenopathy, skeletal abnormalities (destruction of medial tibia) known as Wimberger sign.
• Hutchinsons teeth.

Question 10

What differentiates Group B Strep and Strep pneumoniae in the laboratory?

Answer 10

• Both gram positive cocci that form long chains.
• GBS has b-haemolytic activity which gives coplete clearing on plate.
• Strep pneumonae has a-haemolytic activity which gives a green discolouration.