What Could Explain the Lower COVID-19 Burden in Africa despite Considerable Circulation of the SARS-CoV-2 Virus?

The differential spread and impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing Coronavirus Disease 2019 (COVID-19), across regions is a major focus for researchers and policy makers. Africa has attracted tremendous attention, due to predictions of catastrophic impacts that have not yet materialized. Early in the pandemic, the seemingly low African case count was largely attributed to low testing and case reporting. However, there is reason to consider that many African countries attenuated the spread and impacts early on. Factors explaining low spread include early government community-wide actions, population distribution, social contacts, and ecology of human habitation. While recent data from seroprevalence studies posit more extensive circulation of the virus, continuing low COVID-19 burden may be explained by the demographic pyramid, prevalence of pre-existing conditions, trained immunity, genetics, and broader sociocultural dynamics. Though all these prongs contribute to the observed profile of COVID-19 in Africa, some provide stronger evidence than others. This review is important to expand what is known about the differential impacts of pandemics, enhancing scientific understanding and gearing appropriate public health responses. Furthermore, it highlights potential lessons to draw from Africa for global health on assumptions regarding deadly viral pandemics, given its long experience with infectious diseases.

Child coverage with mosquito nets and malaria treatment from population-based surveys in african countries: a baseline for monitoring progress in roll back malaria.

We assessed the proportion of febrile children less than five years old with prompt effective antimalarial treatment and the proportion of those less than five years old sleeping under insecticide-treated nets (ITNs) or any mosquito net the preceding night in African malarious countries. Data were reviewed from 23 Multiple Indicator Cluster Surveys and 13 Demographic and Health Surveys conducted between 1998 and 2002. A median of 53% of febrile children received antimalarial treatment. A median of 84% of these treatments, however, involved chloroquine, and the proportion of treatments given within two days of onset of symptoms was unknown in most surveys. Median coverages of those less than five years old with any net and ITNs were 15% and 2%, respectively. Use of nets, and especially ITNs, was consistently lower in rural than in urban areas. At the outset of intensified malaria control under Roll Back Malaria, coverage with principal interventions was far below the target of 60% set for Africa in 2005.

Monitoring mosquito net coverage for malaria control in Africa: possession vs. use by children under 5 years.

OBJECTIVES: To investigate the strengths and weaknesses of the indicators 'proportion of households possessing mosquito net(s)' and 'proportion of children under 5 years of age who slept under a net the preceding night' for monitoring malaria control. METHODS: Review of data from household surveys including demographic and health surveys in sub-Saharan African countries. RESULTS: Net possession ranged among 14 surveyed regions from 0.1% to 28.5% for insecticide-treated nets (ITNs) and among 69 regions from 3.6% to 79.7% for any net. Reported use during the preceding night by children under 5 years of age was between 0% and 16% for ITNs and between 0.7% and 74.5% for any net. On average, in households owning ITN(s), 55% of children slept under it (R2 = 0.97, P < 0.001). For any net, use was -4.2% + 0.875 x possession (R2 = 0.89, P < 0.001); the use of nets, however, also varied somewhat among the surveyed countries (P = 0.003). In-depth surveys suggested that use was lower than possession because: (i). nets were scarce (mean 1.8 per possessing household); (ii). nets were not always used for children and (iii). use was lower during hot, dry months than during cool rainy months, and many surveys had been conducted in the dry season. CONCLUSIONS: Not all mosquito nets owned by African households are being used for young children. Household education on the consistent use of nets for this vulnerable group is called for in malaria control programmes. Regular, district-level rapid assessments of household possession of nets should complement ongoing in-depth surveys. Data on 'use during the preceding night' must be interpreted taking the survey season into account.