High SARS-CoV-2 Exposure in Rural Southern Mozambique After Four Waves of COVID-19: Community-Based Seroepidemiological Surveys.

BACKGROUND: Mozambique was one of many African countries with limited testing capacity for SARS-CoV-2. Serosurveys, an alternative to estimate the real exposure to understand the epidemiology and transmission dynamics, have been scarce in Mozambique. Herein, we aimed to estimate the age-specific seroprevalence of SARS-CoV-2 in the general population of the Manhiça District, at four time points, for evaluating dynamics of exposure and the impact of vaccination. METHODS: We conducted four community-based seroepidemiological surveys separated by 3 months between May 2021 and June 2022 to assess the prevalence of SARS-CoV-2 antibodies. An age-stratified (0-19, 20-39, 40-59, and ≥ 60 years) sample of 4810 individuals was randomly selected from demographic surveillance database, and their blood samples were analyzed using WANTAI SARS-CoV-2 IgG + IgM ELISA. Nasopharyngeal swabs from a subsample of 2209 participants were also assessed for active infection by RT-qPCR. RESULTS: SARS-CoV-2 seroprevalence increased from 27.6% in the first survey (May 2021) to 63.6%, 91.2%, and 91.1% in the second (October 2021), third (January 2022), and fourth (May 2022) surveys, respectively. Seroprevalence in individuals < 18 years, who were not eligible for vaccination, increased from 23.1% in the first survey to 87.1% in the fourth. The prevalence of active infection was below 10.1% in all surveys. CONCLUSIONS: A high seroprevalence to SARS-CoV-2 was observed in the study population, including individuals not eligible for vaccination at that time, particularly after circulation of the highly transmissible Delta variant. These data are important to inform decision making on the vaccination strategies in the context of pandemic slowdown in Mozambique.

Challenges and needs for social behavioural research and community engagement activities during the COVID-19 pandemic in rural Mozambique.

After the Ebola outbreaks the world is again facing a challenge in which human behaviours and contact history play crucial roles in determining the trends in disease spreading within and across communities. With the onset of the recent coronavirus disease (COVID-19) pandemic, several issues related to conducting social behavioural sciences research and related community engagement activities arise, especially in rural areas of low-income countries, where the coverage of information and communication technologies (ICTs) is limited and their application on field-based research would imply a biased selection of relatively more privileged minorities with access to on-line and other communication platforms not requiring physical contact. This article enumerates and discusses the different technical challenges that social behavioural sciences research and community engagement activities face in times of public health emergencies caused by pandemics such as COVID-19. It also highlights the possibility of using alternative approaches to maintain the engagement with members of rural communities in research and social action activities, as well as the ethical challenges arising from such approaches.