Epidemiological and virological surveillance of the prevention of mother-to-child transmission of HIV among pregnant women in Togo.

BACKGROUND: In 2015, Togo introduced the "test-and-treat" strategy for the prevention of mother-to-child transmission (PMTCT) of HIV. Pediatric HIV infection remains a public health problem in Togo, with a mother-to-child transmission (MTCT) rate of 3.6% in 2020. This study aimed to estimate cases of HIV seroconversion during pregnancy and to identify pregnant women at high risk of transmitting HIV to their children in Lomé, Togo. METHODS: A descriptive cross-sectional study was carried out from 18 March to 22 May 2022 among women who had given birth in five maternity units providing PMTCT services in Lomé. Umbilical cord blood samples were taken from the maternal side by midwives after delivery. HIV serology was performed in the laboratory using the Alere™ HIV Combo SET and First Response HIV 1-2. Card Test version 2.0. A sample was considered positive if both tests were positive. The HIV-1 viral load in HIV-1-positive samples was measured using Cobas/Roche 4800 equipment. Information on the women was extracted from maternal antenatal records and antenatal consultation registers. RESULTS: A total of 3148 umbilical cord blood samples (median maternal age: 28 years (interquartile range [24-32]) were collected. Among them, 99.3% (3145/3148) had presented for at least one antenatal clinic visit before giving birth, and 78.7% (2456/3122) had presented for at least four visits. One hundred and twenty-one (121) cord samples were HIV-1 positive, representing a seroprevalence of 3.8% (95% CI = [3.2-4.6]). Among them, 67.8% (82/121) were known HIV-positive before the current pregnancy, 29.7 (36/121) were diagnosed as HIV-positive at the antenatal visits and 2.5% (3/121) were diagnosed as HIV-positive in the delivery room. Of the HIV-positive women, 85.9% (104/121) were on ARV treatment before delivery. The viral load was < 1000 copies/ml in 97.5% (118/121) cases. CONCLUSION: This study explored the virologic and epidemiological aspects of HIV among pregnant women in Togo. The results show significant viral suppression at delivery in women ART. Surveillance based on umbilical cord blood specimen screening is an interesting approach for monitoring the effectiveness of PMTCT programmes.

Challenges of scale-up to dolutegravir-based regimens in sub-Saharan Africa.

OBJECTIVE: Evaluate the potential effectiveness of the implementation of dolutegravir (DTG)-based regimens in patients on failing current antiretroviral treatment (ART) given the high levels of nucleoside reverse transcriptase inhibitor (NRTI) resistance in Togo. DESIGN: Patients on ART attending health facilities for routine follow-up visits and for whom HIV viral load test was performed were consecutively included. METHODS: Protease, reverse transcriptase and integrase fragments were sequenced and analyzed for presence of drug resistance mutations for patients with viral load more than 1000 copies/ml. RESULTS: Among 1681 patients, 320 (19.04%) had viral load more than 1000 copies/ml and 200 were tested for drug resistance mutations. Reverse transcriptase gene was successfully sequenced for 181/200 (90.5%) patients; 140/181 (77.4%) were resistant to NRTIs and non-NRTIs, 4/181 (2.2%) to NRTIs only and 18/181 (9.9%) to non-NRTIs only. Many viral strains accumulated mutations predicting resistance to NRTIs recommended in first and second-line DTG-based ART regimens. ART switch to a DTG-based regimen after viral load testing (viral load >1000 copies/ml) or blind switch without prior viral load testing to a new DTG-based first line, estimated 31% and 47.6% of patients to be potentially on functional DTG monotherapy respectively. CONCLUSION: Overall, our results predict that, at the scale of sub-Saharan Africa a significant proportion of patients could be on functional monotherapy. To achieve the third 90 of UNAIDS objectives, implementation of DTG-based regimens should be accompanied with an accelerated scaling up of access to viral load. Studies designed to quantify the implications of use of suboptimal DTG-based regimens are also needed.