Use of fourth-generation rapid combined antigen and antibody diagnostic tests for the detection of acute HIV infection in a community centre for men who have sex with men, between 2016 and 2019.

OBJECTIVE: To assess the use of fourth-generation rapid diagnostic tests in identifying acute infection of Human Immunodeficiency Virus (HIV). METHODS: BCN Checkpoint promotes sexual health among men who have sex with men (MSM), with a focus on diagnosing HIV early, initiating combined antiretroviral treatment (cART) promptly, and recommending regular repeat testing for those who have tested negative. This cross-sectional study included all test results obtained at the centre between 25 March 2016 and 24 March 2019. The Alere™ HIV Combo (now rebranded to Determine™ HIV Ultra, from Abbott) was used to detect p24 antigen (p24 Ag) and/or immunoglobulin M (IgM) and G (IgG) antibodies to HIV-1/HIV-2 (HIV Ab). Rapid polymerase chain reaction (PCR) confirmatory testing and Western blot (WB) were performed for clients with a positive rapid test result. Confirmed HIV cases were promptly referred to the HIV unit for care and cART prescription. RESULTS: A total of 12,961 clients attended BCN Checkpoint during the study and 27,298 rapid tests were performed. 450 tests were found to be reactive, of which 430 confirmed as HIV-positive, representing a prevalence of 3.32%. Four confirmed cases (0.93%) were detected as "p24 Ag only", nine (2.09%) as "both p24 and HIV Ab" and 417 (96.98%) as "HIV Ab only". The "p24 Ag only" group had a 1-log higher viral load than the other groups and initiated treatment on the following working day. Overall, there were 20 false-positive results (0.07% and 4.44% of total and reactive tests, respectively), of which 10 positive for "p24 Ag only" and 10 for "HIV Ab only". CONCLUSIONS: Four Acute HIV Infections (AHI), with very high viral loads, have been detected with the "p24 Ag only" while the HIV Ab were still absent. Referral to the HIV unit and initiation of cART on the following working day contributed to improving persons' health and to reduce HIV transmission chain.

Falling HIV incidence in a community clinic cohort of men who have sex with men and transgender women in Barcelona, Spain.

In Barcelona, Spain prior to 2006, HIV testing was mostly limited to formal healthcare facilities with no incidence data reported. A community-based organization (BCN Checkpoint) was established to increase HIV testing in a peer-led community location to generate incidence data in men who have sex with men and transgender women. Three community engagement interventions were conducted between 2009 and 2017 as follows: 2009-2011 (peer-led point-of-care testing for HIV), 2012-2014 (12-monthly HIV testing with an emphasis on testing in partnerships), 2015-2017 (three-monthly HIV testing with rapid referral for antiretroviral initiation). Between 2009 and 2017 a predominantly cisgender male (99.4%) and Spanish national (62.4%) population with mean age of 34.8 years had 49,630 visits. Mean visit number increased from 1.69 in the first to 2.07 in the last three-year period. HIV incidence fell from 4.17 (95% confidence interval [CI]: 3.53-4.93) per 100 person-years in 2009-2011 to 1.57 (95% CI: 1.30-1.89) per 100 person-years in 2015-2017. This represents a 62% reduction (incidence rate ratio: 0.38, 95% CI: 0.29-0.48) between the first and third study period (p < 0.001). These early interventions may have contributed to the reduction seen in HIV incidence in this cohort.