ABSTRACT
Background. The B.1.1.529 (Omicron) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in the fourth COVID-19 pandemic wave across the southern African region, including Malawi. The seroprevalence of SARS-CoV-2 antibodies and their association with epidemiological trends of hospitalisations and deaths are needed to aid locally relevant public health policy decisions. Methods. We conducted a population-based serosurvey from December 27, 2021 to January 17, 2022, in 7 districts across Malawi to determine the seroprevalence of SARS-CoV-2 antibodies. Primary sampling units (PSU) were selected using probability proportionate to the number of households based on the 2018 national census, followed by second-stage sampling units that were selected from listed households. A random systematic sample of households was selected from each PSU within the 7 districts. Serum samples were tested for antibodies against SARS-CoV-2 receptor binding domain using WANTAI SARS-CoV-2 Receptor Binding Domain total antibody commercial enzyme-linked immunosorbent assay (ELISA). We also evaluated COVID-19 epidemiologic trends in Malawi, including cases, hospitalizations and deaths from April 1, 2021 through April 30, 2022, collected using the routine national COVID-19 reporting system. Results. Serum samples were analysed from 4619 participants (57% female; 65% aged 14 to 50 years), of whom 1018 (22%) had received a COVID-19 vaccine. The overall assay-adjusted seroprevalence was 86.3% (95% confidence interval (CI), 85.1% to 87.5%). Seroprevalence was lowest among children <13 years of age (66%) and highest among adults 18 to 50 years of age (82%). Seroprevalence was higher among vaccinated compared to unvaccinated participants (96% vs. 77%; risk ratio, 6.65; 95% CI, 4.16 to 11.40). Urban residents were more likely to test seropositive than those living in rural settings (91% vs. 78%; risk ratio, 2.81; 95% CI, 2.20 to 3.62). National COVID-19 data showed that at least a two-fold reduction in the proportion of hospitalisations and deaths among the reported cases in the fourth wave compared to the third wave (hospitalization, 10.7% (95% CI, 10.2 to 11.3) vs 4.86% (95% CI, 4.52 to 5.23), p<0.0001; deaths, 3.48% (95% CI, 3.18 to 3.81) vs 1.15% (95% CI, 1.00 to 1.34), p<0.0001). Conclusion. We report reduction in proportion of hospitalisations and deaths from SARS-CoV-2 infections during the Omicron variant dominated wave in Malawi, in the context of high SARS-CoV-2 seroprevalence but low COVID-19 vaccination coverage. These findings suggest that COVID-19 vaccination policy in high seroprevalence settings may need to be amended from mass campaigns to targeted vaccination of at-risk populations.
Subject(s)
Coronavirus Infections , Severe Acute Respiratory Syndrome , Death , COVID-19ABSTRACT
Background Global experts estimate that in the absence of intervention, Coronavirus disease 2019 (COVID-19) will result into 40 million deaths globally and this burden is likely to be more pronounced in low-income settings. The knowledge, attitudes and practices of people during this pandemic is pivotal to uptake of recommended preventative strategies. This paper describes the Malawian knowledge, attitudes and practices related to COVID-19 and associated public health measures.Methods This was a multi-site cross-sectional survey where qualitative data was collected in nine Malawian districts over 3 weeks (5–25 October 2020), 6 months after the first confirmed COVID-19 case. A total of 521 participants (> 18 years) were enrolled to answer a questionnaire delivered through interviews.Results We found that all respondents were aware of the ongoing COVID-19 pandemic with the majority using the Radio as their main information-source. 75% of participants displayed knowledge of all key symptoms of COVID-19 (cough, fever and shortness of breath) and in addition to this knowledge, the majority of participants (97%) knew enough to take some sort of intervention (calling a COVID hotline or visiting the nearest hospital) if they developed symptoms. Participants also demonstrated a high perception of risk of COVID-19, where > 60% of participants believed to be susceptible to the coronavirus under the current preventative measures and > 50% believed they would die from infection. Communities displayed a high perceived effectiveness of all preventative measures, with “hand hygiene using soap and water” being perceived as effective by the majority of respondents. Although the majority of the participants (> 80%) were willing to self-isolate at home, various barriers to home-isolation were raised which would ultimately influence their ability to do so.Conclusion Baseline community psychosocial and behavioral information which influences the adoption of new COVID-19 public health measures in Malawi has been highlighted alongside recommendations for best practices.