A patient comes to hospital with a history of sore throat, diarrhea and sexual contact 2 weeks before. The best investigation to rule out HIV is:
Ans. is 'a' i.e., p. 24 antigen assay (Ref: Ananthanarayan, 9th/e, p. 577 - 578 and 8th/e, p. 576)* p24 antigen is the earliest virus marker to appear in blood and is the one tested for.* It may be detectable in blood after about 2 weeks.Remember: Nucleic acid tests (RT - PCR, BONA, PCR) are the earliest test to become positive (even before p24 antigen detection).TestPositive after infectionNucleic acid test12 daysp24 antigen test16 daysAntibodies test22 days
p24 antigen assay
ELISA
Western blot
Lymph node biopsy
Human Immunodeficiency Virus