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.
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Background: Corticosteroids are recommended for management of patients with severe COVID-19 who require supplemental oxygen. Despite limited evidence on their benefits in sub-Saharan Africa, corticosteroids were adopted as part of COVID-19 management guidelines by many African countries, including Zambia. We report on the use of corticosteroids and related clinical outcomes among hospitalized patients in Zambia. Methods: Patients with SARS-CoV-2 infection who were admitted in one of nine COVID-19 treatment centers across Zambia between March 2020 and September 2021 were included. Patient demographic and clinical information were collected, including corticosteroid use and in-patient disposition (discharged or died). Severe COVID-19 at admission was defined as having an oxygen saturation <90%, respiratory rate >30 breaths/minute, or a need for oxygen therapy. Primary outcomes for the study were prolonged hospitalization (i.e., ≥5 days in the treatment center among patients who were discharged) and in-hospital mortality. We used mixed-effects logistic regression to assess associations between corticosteroid use and primary outcomes among patients with severe COVID-19 at admission. Models were adjusted for age, sex, number of comorbid conditions, and COVID-19 treatment center. Results: The study included 2,630 patients, 1,751 (67%) of whom had severe COVID-19 at admission. Of those, 1,587 (91%) received corticosteroids with 1,470 (93%) initiating at or before treatment center admission. The median duration of treatment with corticosteroids was 3 days (interquartile range: 1-6) and 95% of patients received dexamethasone. Regression analyses indicated that receiving corticosteroids was associated with prolonged hospitalization for discharged patients (adjusted odds ratio (aOR): 2.98;95% confidence interval (CI): 1.78-5.22), but not with in-hospital mortality (aOR: 1.14;95% CI: 0.76-1.75)). Conclusion: Use of corticosteroids was common among admitted patients with severe COVID-19, but not associated with improved COVID-19 outcomes. While our study was not designed to assess the effectiveness of corticosteroids, these results suggest a need to both comprehensively assess their use relative to national guidelines and investigate their benefits in the African context. Important differences in epidemiology and healthcare system capacity could modify the effect of corticosteroids in Zambia relative to countries where the evidence for their use was generated.
ABSTRACT
Background: Multiple vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have demonstrated high effectiveness for reducing severe COVID-19 and mortality. However, vaccine effectiveness data from the African region, where COVID-19 epidemiology and SARS-CoV-2 vaccine coverage differs from other regions, are limited. This study aimed to assess vaccine effectiveness in preventing in-hospital COVID-19 mortality in Zambia. Methods: The study included patients hospitalized with SARS-CoV-2 infection at eight COVID-19 treatment centers across Zambia between May 1, 2021, and October 27, 2021, coinciding with the period of SARS-CoV-2 vaccine availability in Zambia. Patient's demographic and clinical information was collected, including vaccination status and in-patient disposition (discharged or died). The study used mixed-effects logistic regression to assess the odds of in-hospital mortality by vaccination status, adjusted for age, sex, number of comorbid conditions, disease severity, and COVID-19 treatment center (random-effects term). Vaccine effectiveness was defined as 1 minus the adjusted odds ratio (aOR) times 100%. Results: During the study period for Zambia, 729 patients ≥18 years being treated in one of the participating COVID-19 treatment centers had data describing their hospitalization course and SARS-CoV-2 vaccination status. Forty-eight (6.6%) patients had received ≥1 vaccine dose at the time they were admitted to the hospital. Forty-two (87.5%) received AstraZeneca, three (6.3%) received Janssen, and three (6.3%) were unknown vaccine type. Only five (11.9%) of AstraZeneca recipients had received two vaccine doses. The age and sex of vaccinated patients was not different than unvaccinated patients (median age 60 years vs. 57 years, respectively, p=0.6;50.0% females vs. 42.9% females, respectively, p=0.4). In-hospital mortality was 16.7% for patients reporting ≥1 vaccine dose and 32.0% for unvaccinated patients (aOR: 0.3 [95% confidence interval (CI): 0.1-0.7). SARS-CoV-2 vaccine effectiveness for in-hospital mortality was 65.8% (95% CI: 25.9-85.9%). Conclusion: Consistent with evidence from other countries, vaccinated patients demonstrated lower odds of in-hospital mortality than those who were unvaccinated in Zambia. The low vaccine coverage in Zambia and among patients in this study likely impacted the precision of the estimate for the odds of in-hospital mortality. Vaccination is a critical tool for reducing the consequences of the SARS-CoV-2 epidemic in Zambia.
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.
ABSTRACT
Background: Zambia-where HIV prevalence is 11.5% - is experiencing widespread transmission of COVID-19. Studies of clinical outcomes of COVID-19 among HIV-infected individuals have shown mixed results of the impact of HIV status on disease severity or mortality. However, unlike Zambia, most of these studies originated from countries with low prevalence of HIV, with the HIV-infected individuals comprising a small fraction of the overall COVID-19 patient population. We describe the clinical outcomes of patients with SARSCoV2 infections who were admitted in COVID-19 treatment facilities in Zambia. Specifically, we assessed associations between HIV infection and COVID-19 severity and mortality. Methods: We collected demographic and clinical information from all adult patients admitted with SARS-CoV2 infection across five inpatient facilities in Zambia from July to October 2020. Logistic regression was utilized to examine the association between HIV status and COVID-19 severity, defined as the need for supplemental oxygen at any point during admission;and survival analyses were employed to explore the relationship between HIV status and 28-day mortality. Regression analyses were adjusted for age, sex, and facility. Results: There were 182 cases of severe COVID-19 among 271 enrolled patients. Overall, 66 (24%) patients were HIV-infected, 146 (54%) were male, and 53 (20%) were >60 years. Most HIV-infected patients (87%) were on antiretroviral therapy (ART) and among those with viral load results, 86% were virally suppressed (<1000 cp/ml). Compared to HIV-uninfected patients, those who were HIV-infected had lower BMI (mean: 26.0 vs. 28.0, p=0.05), and were less likely to be hypertensive (34.8% vs. 47.4%, p=0.01). HIV infection was not a significant predictor of severe disease (adjusted odds ratio: 1.71, 95% CI: 0.88 - 3.46), nor was it associated with 28-day mortality (adjusted hazard ratio: 0.87, 95% CI: 0.39 - 1.94). Conclusion: In this study from a sub-Saharan African (SSA) country with a generalized HIV epidemic, HIV had no statistically significant impact on COVID-19 severity or mortality. Most of the HIV-infected population in this study were virally suppressed and this may indicate that with optimal ART and achievement of HIV viral suppression, the risk of severe disease or mortality from COVID-19 among people living with HIV (PLHIV) can be minimized. Additional studies that assess impact of COVID-19 on PLHIV not on ART are needed, as this group continues to make up a large portion of PLHIV in SSA.