Household transmission of SARS-CoV-2 in a well-characterized African cohort

COVID-19 poses unique risks to communities in resource-limited regions of sub-Saharan Africa (SSA). So far, little is known about the incidence, risk factors or outcomes of COVID-19 in SSA, or how these might differ from other areas with different resources, household structures and cultural practices. Elsewhere, COVID-19 is strongly associated with increasing age, male sex, and medical problems. Unexpectedly, children rarely get severe COVD-19 and do not appear to major contributors to spreading the infection, unlike with other respiratory viruses. Detailed household transmission studies of SARS-CoV-2 have the potential to reveal invaluable insights into how SARS-CoV-2 is transmitted, and have been recommended by the World Health Organization. We will take advantage of a CIHR-funded prospective cohort of 210 households in Nairobi, Kenya, which began in early 2019 and was designed to study the transmission of other viruses, to determine the local patterns of SARS-CoV-2 transmission among children and adults. Serum samples were collected from women (half of whom have HIV) who were enrolled during pregnancy, their newborn infants, and all other household members (895 people total), before the pandemic began. Blood collected every 3 months will be tested by different methods to detect SARS-CoV-2 antibodies to see how often infection occurred. Weekly saliva, urine and stool samples are also collected from 100 of the households, which will be tested for SARS-CoV-2 to see how the virus is spread. Because we have all the approvals to do the work and the cohort is already being followed, this study is a highly efficient way to study SARS-CoV-2 transmission in an African setting, where age-structure, household and community practices, and rates of HIV and other co-infections differ from other parts of the world. Thus, this work will provide timely insight into the global COVID-19 pandemic, and guide public health interventions in resource-limited settings.