What is the chance of HIV infection after needle prick injury?: (A) 1/100, (B) 1/300, (C) 1/10000, (D) 1 in 1 Lakh
Answer is B. Needle prick injury: HIV transmission following skin puncture from a contaminated needle is 0.3 % and a mucous membrane exposure is 0.09%. The seroconversion rate for HIV is 1:300, or 0.3% from a hollow-bore needle stick injury. Antiretroviral drugs as postexposure prophylaxis decreases the risk of infection. Must know: In Hepatitis B, the seroconversion ranges from 23 to 62%, with higher rates associated with patients who are HBeAg positive, as compared to HBeAG negative. The seroconversion rate for Hepatitis C is 1.8%. For Hepatitis C no prophylactic treatment is available. HBV post exposure prophlylaxis with hepatitis B immunoglobulin and initiation of Hep B vaccine is 90%effective. Ref: Harrison's Principles of internal medicine, 16th edition, page 1081.