Gauteng is no longer insulated

COVID: FIRST TWO LOCKDOWNS PROTECTED PROVINCE

➜ Comparatively low antibody levels found among blood donors there.

Gauteng may well have escaped serious consequences of the first and second waves thanks to lockdowns. This is according to preliminary results released by the South African National Blood Service (SANBS) in partnership with the Western Cape Blood Service, the department of science and innovation and the South African Centre of Excellence in Epidemiological Modelling and Analysis (Sacema), based at Stellenbosch University.

The results came from the analysis of data from a survey of blood donors in all provinces, conducted to determine the prevalence of antibodies (seroprevalence) against Sars-CoV-2, the virus causing the Covid-19 disease.

Preliminary results, reporting on seroprevalence in the Eastern Cape, Northern Cape, Free State and KwaZulu-Natal were previously released. The updated analysis presents estimates from the Western Cape, North West, Limpopo, Mpumalanga and Gauteng.

Sacema research professor Alex Welte said: “Sampling was spread out between January and May, so there are subtleties which make it tricky to speak precisely about an overall national estimate at any particular point in time.

“Given this was largely the time between the second and third waves, it is still useful to produce a nationally weighted average.

“We took into account the variation of prevalence by race within each province and the population size estimates produced by Statistics South Africa; we are not just naively interpreting the prevalence among donors as the prevalence in the wider population.”

SANBS medical director Dr Karin van den Berg said: “Interestingly, we saw comparatively very low antibody levels among donors ... in Gauteng as compared to other provinces, especially when you consider population density.

“This could indicate that Gauteng was more insulated from the initial waves and may in part explain the devastating spread of the virus through Gauteng.

“However, the role of the different variants, especially the delta variant, must also be considered.

“Further investigation would be required.”