Use of laboratory tests and clinical symptoms for identification of primary HIV infection.
OBJECTIVE
To determine the sensitivity and specificity of symptoms, three HIV-1 RNA assays, a p24 antigen EIA and a third-generation enzyme immunoassay (EIA) antibody test for diagnosis of primary HIV infection (PHI).


METHODS
Prospective cohort in a university research program.


METHODS
Of 258 eligible persons screened for PHI, 40 had primary/early infection (22 preseroconversion, 18 within 6 months of seroconversion) and 218 did not. Seven participants with preseroconversion HIV-1 from a second center were added for evaluating laboratory tests.


METHODS
PHI, defined as a negative or indeterminate antibody test with subsequent conversion. Symptom analysis also included persons with antibody conversion of less than 6 months' duration.


RESULTS
The symptoms most strongly associated with PHI in multivariate analysis were fever [odds ratio (OR) 5.2; 95% confidence interval (CI) 2.3-11.7] and rash (OR 4.8; 95% CI 2.4-9.8). The sensitivity and specificity, respectively, for detecting preseroconversion HIV infection were: p24 antigen, 79% and 99%; third-generation EIA, 79% and 97%; HIV-1 RNA by branched chain DNA 100% and 95%; HIV-1 RNA by polymerase chain reaction 100% and 97%; HIV-1 RNA by transcription-mediated amplification testing, 100% and 98%. False-positive HIV-1 RNA tests were not reproducible and had values < 3000 copies/ml, while only one person with confirmed PHI was in this range.


CONCLUSIONS
Rash and fever indicated the highest risk of PHI. HIV-1 RNA tests are very sensitive for PHI but false-positive results occur. False-positive results can be reduced through duplicate testing and considering tests < 5000 copies/ml as indeterminate results requiring additional testing. p24 antigen was more specific than HIV-1 RNA testing but less sensitive.
Hecht
Frederick M
FM
Positive Health Program HIV Section at San Francisco General Hospital, tUniversity of California at San Francisco, 94110, USA.
Busch
Michael P
MP
Rawal
Bhupat
B
Webb
Marcy
M
Rosenberg
Eric
E
Swanson
Melinda
M
Chesney
Margaret
M
Anderson
Jennifer
J
Levy
Jay
J
Kahn
James O
JO
D000328:Adult; D015331:Cohort Studies; D005076:Exanthema; D005189:False Positive Reactions; D005260:Female; D005334:Fever; D015483:HIV Antibodies / Q000032:analysis; D016655:HIV Core Protein p24 / Q000032:analysis; D015658:HIV Infections / Q000175:diagnosis* / Q000503:physiopathology; D006679:HIV Seropositivity; D015497:HIV-1 / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012367:RNA, Viral / Q000032:analysis*; D012680:Sensitivity and Specificity
D015483:HIV Antibodies; D016655:HIV Core Protein p24; D012367:RNA, Viral