ABSTRACT
Background: Confirmed COVID-19 case counts underestimate SARS-CoV-2 infections, particularly in countries with limited testing capacity. Pregnant women attending antenatal care (ANC) clinics have served as healthy population surrogates to monitor diseases like HIV and malaria. We measured SARS-CoV-2 seroprevalence among women attending ANC clinics to assess infection trends over time in Zambia. Method(s): We conducted repeated cross-sectional surveys among pregnant women aged 15-49 years attending their first ANC visits in 3 districts of Zambia during September 2021-September 2022. Up to 200 women per district were enrolled each month, completing a standardized questionnaire. Dried blood spot samples were collected for serologic testing for prior infection using the Tetracore FlexImmArrayTM SARS-CoV-2 Human IgG Antibody Test and HIV testing according to national guidelines. We calculated odds ratios (ORs) for SARS-CoV-2 seroprevalence by demographic characteristics, adjusting for the district. Result(s): A total of 5,351 women were enrolled at 29 study sites between September 2021 and September 2022. Participants' median age was 25 years (interquartile range: 21-30), 530 (9.9%) tested positive for HIV, and 101 (1.9%) reported a prior positive COVID-19 test. Overall, SARS-CoV-2 seroprevalence was 67%, and rose from 49% in September 2021 to 85% in September 2022 (Figure 1). The greatest increase in seroprevalence occurred during the 4th wave caused by the Omicron variant (48% in December 2021 to 63% in January 2022). Seroprevalence was significantly higher among women living in urban districts (Chipata and Lusaka) compared to rural Chongwe District (Chipata OR: 1.2, 95% confidence interval [CI]: 1.1-1.4;Lusaka OR: 1.7, 95% CI: 1.5-2.0). The age group was not significantly associated with seroprevalence after adjusting for the district (aOR: 1.1, 95% CI: 1.0-1.2). Seroprevalence was significantly lower among women living with HIV than women living without HIV (aOR: 0.8, 95% CI: 0.6-0.9). Conclusion(s): Overall, two-thirds of women in the three surveyed districts in Zambia had evidence of SARS-CoV-2 exposure, rising to 85% after the Omicron variant spread throughout the country. ANC clinics have a potential role in ongoing SARS-CoV-2 serosurveillance and can continue to provide insights into SARS-CoV-2 infection dynamics. Furthermore, they provide a platform for focused SARS-CoV-2 prevention messaging and COVID-19 management in pregnant women at higher risk of severe disease. (Figure Presented).
ABSTRACT
Background: Reliable serologic assays are needed to accurately measure prevalence of prior exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, several countries in Africa have reported apparent SARS-CoV-2 assay cross-reactivity with other non-coronavirus pathogens. We used 3 SARS-CoV-2 serologic assays to assess positivity in archived serum specimens collected in Zambia prior to the COVID-19 pandemic and explored seropositivity associations with participant characteristics. Methods: SARS-CoV-2 antibody seropositivity was measured using serum specimens collected from pregnant women aged 15-49 years enrolled in an HIV and syphilis sentinel surveillance study in 26 sites across Zambia during 2017-2018. Of 9,508 participants with archived specimens, 1,500 (16%) were selected using stratified random sampling (by study site). SARS-CoV-2 antibody seroprevalence was measured using the Panbio IgM/IgG lateral flow assay, Euroimmun spike IgG enzyme-linked immunosorbent assay (ELISA), and the Wantai pan-Ig ELISA. HIV and syphilis testing followed the national testing algorithms. We compared age group and HIV and syphilis status with SARS-CoV-2 antibody seropositivity using chi-square test. Results: Among the 1,500 female participants, 1,297 (86%) had specimens available for testing. Participants' median age was 25 years (interquartile range: 21-30 years). HIV and syphilis prevalence were 16% and 6%, respectively. SARS-CoV-2 antibody seropositivity was 14% on the Panbio assay, 7% on the Euroimmun assay, and 2% on the Wantai assay. There was no concordance of positive results between the 3 assays, and no association between SARS-CoV-2 antibody seropositivity and age group, HIV status, or syphilis status on all 3 assays (p>0.05 for all comparisons). Conclusion: Three SARS-CoV-2 serologic assays showed antibody positivity in pre-pandemic specimens, possibly indicating cross-reactivity with antibodies to other coronaviruses or other non-coronavirus pathogens. Panbio and Euroimmun assays yielded more false positives than would be expected based on manufacturer-reported specificities. Although there was no association of SARS-CoV-2 antibody seropositivity with HIV or syphilis, testing for other pathogens could provide information about the identities of cross-reacting antibodies with these assays. Assessing for virus neutralizing capability of cross-reacting antibodies in SARS-Cov-2 antibody positive specimens could provide information about possible pre-existing SARS-CoV-2 immunity.
ABSTRACT
Background: The WHO recommends enhanced adherence counseling (EAC) before regimen switch for HIV-positive, antiretroviral therapy (ART)-treated individuals with non-suppressed viral loads (VL). However, there is a paucity of data, especially within a clinical trial setting, on the determinants of viral suppression (VS) following EAC among those failing ART. We thus evaluated predictors of VS among adults failing ART who had undergone EAC in the VISEND clinical trial. Methods: Our trial is a randomized 144 week open label non-inferiority study with adults failing (VL≧ 1000 copies/mL) ART of tenofovir disoproxil fumarate (TDF), lamivudine (3TC) plus efavirenz (EFV) or nevirapine (NVP), switched to 1) TDF,3TC,DTG or 2) tenofovir alafenamide (TAF), emtricitabine (FTC),DTG or 3) lopinavir/ritonavir (LPV/r) or atazanavir/r (ATV/r), zidovudine (ZDV),3TC. Viral loads and other biomarkers were collected at weeks 12, 24, 48, 72, 96 and 144. Adults with VL≧ 1000 copies/mL at each of these time points underwent EAC involving 3 sessions over a period of 3 months according to existing guidelines. We calculated proportions of individuals who achieved VS post EAC and analyzed factors (demographic and clinical) independently associated with VS post EAC. Using multivariable log regression models, associations were analyzed as crude risk ratios (CRR) and adjusted risk ratios (ARR). Results: The overall VS rates following EAC among individuals with virologic failure was 66%;broken down as follows: TAF,FTC,DTG (78%), TDF,3TC,DTG (71%), ZDV,3TC,ATV/r (62%), and ZDV,3TC,LPV/r (53%). Compared to adults with no formal education, those having primary (ARR 1.55 [1.32-1.81], P<0.001) or secondary level education (ARR 1.93 [1.65-2.27], P<0.001) were more likely to achieve VS. Those less likely to suppress post EAC were individuals on ART for > 5 years (ARR 0.75 [0.75-0.75], P<0.001), VL > 10,000 copies/mL at time of failure (0.48 [0.48-0.48], P<0.001), presence of comorbidities (ARR 0.77 [0.66-0.90], P=0.001) and those taking concomitant medications (ARR 0.67 [0.58-0.79], P<0.001). Having suffered from COVID-19 infection had no association with VS post EAC (ARR 0.59 [0.22-1.58], P=0.30). Consistent results are in Table 1. Conclusion: In the VISEND trial, EAC led to VS rates near the WHO target of 70% with disparities in outcomes according to gender, education, and other factors. There is a need to routinely incorporate EAC into clinical trials and practice before regimen switch in order to maximize outcomes.
ABSTRACT
The effect of HIV infection on COVID-19 outcomes remains an urgent question in sub-Saharan Africa, where many countries are experiencing dual HIV and COVID-19 epidemics, and capacity to treat severe COVID-19 is limited. Using data from patients with probable or confirmed COVID-19 admitted to specialized treatment centers during March-December 2020 in Zambia, the Zambian Ministry of Health and CDC assessed the relationship between HIV infection and severe COVID-19 and COVID-19-associated death. Among 443 patients included in the study, 122 (28%) were HIV-positive, and of these, 91 (89%) were receiving ART at the time of hospitalization. HIV status alone was not significantly associated with severe COVID-19 at admission or during hospitalization or with COVID-19-associated death. However, among HIV-positive persons, those with severe HIV disease were more likely to develop severe COVID-19 and were at increased risk for COVID-19-associated death. Ensuring that persons maintain HIV disease control, including maintaining ART continuity and adherence, achieving viral suppression, and addressing and managing underlying medical conditions, could help reduce COVID-19-associated morbidity and mortality in sub-Saharan Africa.