The second wave now underway in the Western Cape

A second wave of SARS-CoV-2 infections is now clearly underway in the Western Cape as evidenced by the increase in COVID-19 hospital admissions. The steepness of the increase in the hospital admissions curve is similar to the gradient that was witnessed in May. The second wave is already at half the height of the first wave in the Western Cape and we are left guessing when the peak will be reached.

The graph below analyses the COVID-19 hospital admissions in the Western Cape as reported by the NICD to 2 December. The lines in the graph are generated by the NMG model.


The second wave in the Eastern Cape shows no clear signs of slowing down and is two-thirds of the height of the first wave recorded for this province. The graph below analyses the COVID-19 hospital admissions in the Eastern Cape measured to 2 December .


The NMG model predicts that some 55% of the population in the Eastern Cape will have been infected with the SARS-CoV-2 virus assuming the second wave peaks at its current levels. If these seroprevalence levels are repeated in the other provinces, then there is considerable scope for a second waves of infections to overwhelm us over the festive season.

3 December 2020



Comments

Post a Comment

Popular posts from this blog

Update on COVID 19 tracking in SA

Image
An analysis of the weekly deaths from natural causes as reported by the SA Medical Research Council (SAMRC) shows evidence of elevated excess deaths over the winter months of 2022. The graph below shows the weekly deaths reported by SAMRC in excess of the average weekly deaths reported between 1 January 2020 and 15 March 2020.  The COVID-19 hospital deaths as reported by the National Institute for Communicable Diseases (NICD) would appear to follow a similar pattern to that shown by the SAMRC excess deaths but with a more muted 5th wave. Anecdotally, the number of COVID-19 cases appear to be on the rise in South Africa although COVID-19 cases are no longer reported on a regular basis (outside of a hospital setting).  The above graphs show that the COVID-19 disease severity is certainly not near the levels experienced in the first three waves. 4 November 2022
Read more

Time to consider the 4th wave?

Image
We have updated the NMG model to consider various scenarios for the 4th wave of COVID-19 infections for South Africa. You can access the model at  https://nmg-covid-19.sctechnology.co.za/ It will take a sustained viral propagation above a threshold speed to generate a noticeable 4th wave. The first 4th wave scenario is displayed below assuming a viral propagation speed of Rt = 3.0 for a period of 100 days starting on 15 October 2021.  The second scenario shows the impact of a viral propagation speed of Rt = 4.0 for the 4th wave. It is important to note that to reach Rt = 4.0 in the current South African population would require a viral strain with a basic reproduction number of over 12 (some four times the speed of the original SARS-CoV-2 virus). This calculation is based on the NMG model, where some 67.5% of the South African population is assumed to have built up immunity to reinfection due to infection over the first three waves.  A material 4th wave could be caused by...
Read more

Is the third wave less deadly?

Image
KwaZulu Natal has overtaken both Gauteng and the Western Cape in the number of reported COVID-19 deaths. However, the deaths in KwaZulu Natal are still well off the peak experienced in the second wave.  The modeling done by NMG shows that the reported COVID-19 deaths are still lagging way behind what is projected for the third wave based on the reported infections. This would indicate that the likelihood of dying if infected in the third wave has not been as high as for the first two waves. This may be due to greater levels of prior exposure to the virus of those infected due to either vaccination or prior infection. It could also be the result of more effective medical treatment. 19 August 2021
Read more