Testing algorithm detected acute HIV infections missed by antibody testing alone
SEATTLE — Immunoassays, nucleic acid tests and antibody tests may detect acute HIV infections that would be missed by antibody-only testing, according to data presented at CROI 2015.
Researchers examined the outcomes and reporting characteristics of routine HIV testing data in Massachusetts, Maryland and Michigan state public health laboratories. A CDC algorithm with nucleic acid testing conducted by a referral laboratory was used by public health laboratories in Massachusetts and Michigan, while Maryland used a modified system. Yield of acute outcomes, result reporting time and costs were analyzed in each laboratory.
Of the 7,914 specimens from Massachusetts, 6,069 from Michigan and 36, 266 from Maryland, eight, one and 19 acute infections were identified, respectively, by the laboratories. One specimen was identified as HIV-2 positive in both Maryland and Massachusetts.
The median time from the receipt of the specimen by the facility to the reporting of test results for acute infections was 7 days for Massachusetts and Maryland, and 11 days for Michigan. For HIV-1 antibody-confirmed infections, the median was 3 days for Massachusetts and Maryland, and 2 days for Michigan. The cost of each positive specimen was $336 in Massachusetts, $281 in Michigan and $221 in Maryland.
“Fourth-generation immunoassays, coupled with antibody tests and nucleic acid test, detected acute infections in public health laboratories that may have been missed if an antibody-only test such as the Western Blot had been used as a confirmatory test,” the researchers wrote. “Promotion of the CDC HIV testing algorithm, with quicker reporting of acute infections, will facilitate public health intervention to interrupt transmission.”
Nasrullah M, et al. Abstract #613. Acute Infections, Cost and Time to Reporting of HIV Test Results in US State Public Health Laboratories. Presented at: Conference on Retroviruses and Opportunistic Infections; Feb. 23-26, 2015; Seattle.
Disclosure: The researchers report no relevant financial disclosures