Measuring Oral Pre-exposure Prophylaxis (PrEP) Continuation Through Electronic Health Records During Program Scale-Up Among the General Population in Zambia.

HIV pre-exposure prophylaxis (PrEP) is being scaled-up in Zambia, but PrEP continuation data are limited by paper-based registers and aggregate reports. Utilization of Zambia's electronic health record (EHR) system, SmartCare, may address this gap. We analyzed individuals aged ≥ 15 years who initiated PrEP between October 2020 and September 2021 in four provinces in Zambia in SmartCare versus aggregate reports. We measured PrEP continuation using Kaplan-Meier survival analysis and Cox proportional hazards models. SmartCare captured 29% (16,791/58,010) of new PrEP clients; 49% of clients continued at one month, and 89% discontinued PrEP by February 2022. Women were less likely than men to discontinue PrEP (adjusted hazard ratio [aHR]: 0.89, 95% CI 0.86-0.92, z = - 6.99, p < 0.001), and PrEP clients aged ≥ 50 years were less likely to discontinue PrEP compared to clients 15-19 years (aHR: 0.53, 95% CI 0.48-0.58, z = - 13.04, p < 0.001). Zambia's EHR is a valuable resource for measuring individual-level PrEP continuation over time and can be used to inform HIV prevention programs.

Trends in SARS-CoV-2 seroprevalence among pregnant women attending first antenatal care visits in Zambia: A repeated cross-sectional survey, 2021-2022.

SARS-CoV-2 serosurveys help estimate the extent of transmission and guide the allocation of COVID-19 vaccines. We measured SARS-CoV-2 seroprevalence among women attending ANC clinics to assess exposure trends over time in Zambia. We conducted repeated cross-sectional SARS-CoV-2 seroprevalence surveys among pregnant women aged 15-49 years attending their first ANC visits in four districts of Zambia (two urban and two rural) during September 2021-September 2022. Serologic testing was done using a multiplex bead assay which detects IgG antibodies to the nucleocapsid protein and the spike protein receptor-binding domain (RBD). We calculated monthly SARS-CoV-2 seroprevalence by district. We also categorized seropositive results as infection alone, infection and vaccination, or vaccination alone based on anti-RBD and anti-nucleocapsid test results and self-reported COVID-19 vaccination status (vaccinated was having received ≥1 dose). Among 8,304 participants, 5,296 (63.8%) were cumulatively seropositive for SARS-CoV-2 antibodies from September 2021 through September 2022. SARS-CoV-2 seroprevalence primarily increased from September 2021 to September 2022 in three districts (Lusaka: 61.8-100.0%, Chongwe: 39.6-94.7%, Chipata: 56.5-95.0%), but in Chadiza, seroprevalence increased from 27.8% in September 2021 to 77.2% in April 2022 before gradually dropping to 56.6% in July 2022. Among 5,906 participants with a valid COVID-19 vaccination status, infection alone accounted for antibody responses in 77.7% (4,590) of participants. Most women attending ANC had evidence of prior SARS-CoV-2 infection and most SARS-CoV-2 seropositivity was infection-induced. Capturing COVID-19 vaccination status and using a multiplex bead assay with anti-nucleocapsid and anti-RBD targets facilitated distinguishing infection-induced versus vaccine-induced antibody responses during a period of increasing COVID-19 vaccine coverage in Zambia. Declining seroprevalence in Chadiza may indicate waning antibodies and a need for booster vaccines. ANC clinics have a potential role in ongoing SARS-CoV-2 serosurveillance and can continue to provide insights into SARS-CoV-2 antibody dynamics to inform near real-time public health responses.