Abstract:
BACKGROUND : We describe the epidemiology of COVID-19 in South Africa following importation and during
implementation of stringent lockdown measures.
METHODS : Using national surveillance data including demographics, laboratory test data, clinical presentation,
risk exposures (travel history, contacts and occupation) and outcomes of persons undergoing COVID-19 testing
or hospitalised with COVID-19 at sentinel surveillance sites, we generated and interpreted descriptive
statistics, epidemic curves, and initial reproductive numbers (Rt).
FINDINGS : From 4 March to 30 April 2020, 271,670 SARS-CoV-2 PCR tests were performed (462 tests/100,000
persons). Of these, 7,892 (2.9%) persons tested positive (median age 37 years (interquartile range 28 49
years), 4,568 (58%) male, cumulative incidence of 13.4 cases/100,000 persons). Hospitalization records were
found for 1,271 patients (692 females (54%)) of whom 186 (14.6%) died. Amongst 2,819 cases with data, 489/
2819 (17.3%) travelled internationally within 14 days prior to diagnosis, mostly during March 2020 (466
(95%)). Cases diagnosed in April compared with March were younger (median age, 37 vs. 40 years), less likely
female (38% vs. 53%) and resident in a more populous province (98% vs. 91%). The national initial Rt was 2.08
(95% confidence interval (CI): 1.71 2.51).
INTERPRETATION : The first eight weeks following COVID-19 importation were characterised by early predominance
of imported cases and relatively low mortality and transmission rates. Despite stringent lockdown
measures, the second month following importation was characterised by community transmission and
increasing disease burden in more populous provinces.
