Use of a robust health information system to improve accuracy of recent HIV infection testing in Bangkok, Thailand, 2020-2021


BACKGROUND: Based on the Asia Epidemic Model, Bangkok has the highest number of estimated new HIV infections in Thailand. We integrated HIV recent infection testing into routine HIV testing services to monitor recent infection trends and accelerate efforts to ending AIDS in Bangkok.
METHODS: HIV recency testing was integrated in 16 facilities in Bangkok. Blood from consenting newly diagnosed adults with HIV (PLHIV) collected during October 2020'November 2021 was tested with a rapid test for recent infection (RTRI). Because PLHIV who have suppressed viral load (VL) can produce false recent results, we tested RTRI-recent specimens with VL (recent infection testing algorithm [RITA]); specimens with VL1,000 copies/ml were defined as RITA-recent, <1,000 copies/ml as RITA-long term (LT). Cross-checking clinical history data with the national AIDS database (NAD) and electronic medical records was conducted for all RTRI-recent cases to enhance the validity and accuracy of results. Logistic regression was used to identify associations between recent infection and demographic variables (sex, age, population).
RESULTS: 694/1,291 (53.8%) newly diagnosed PLHIV provided consent and were tested for recent infection: 59 (8.5%) tested RTRI-recent and, after VL testing, 54 (7.8%) tested RITA-recent and 5 tested RITA-LT. After cross-checking with NAD, 4/5 RITA-LT cases were among 21-25 year old men who had a history of pre-exposure prophylaxis, antiretroviral treatment (ART) <28 days at the time of RTRI testing or no ART history, and no previous HIV diagnosis, suggesting potential misclassification. Young clients aged 15-19 were more likely to test RITA-recent than other age groups (OR=2.5, p<.05).

Demographic% RITA recent infection (n/total)ORp-value
Age15-19 years16% (7/44)2.50.04
20-29 years8% (23/302)1.10.75
>30 years7% (24/345)1Ref
SexFemale9% (14/164)1Ref
Male8% (40/532)0.90.67
Population groupGeneral6% (23/356)1Ref
MSM10% (27/267)1.60.10
Other4% (4/73)0.80.75

CONCLUSIONS: While 15-19 year-olds showed a high proportion of RITA positives, recent HIV infections were diagnosed in all age groups, sexes and populations, warranting continued surveillance of HIV-1 recent infections in Bangkok. Cross-checking the clinical history with other records through a robust national health information system can be used to improve the accuracy of tests for recent infection.