First wave of contagion is probably over

A man undergoes Covid-19 testing.

Photo credit: File | Nation Media Group

What you need to know:

  • At the peak of the pandemic, special beds set aside for those infected were occupied to a large extent, especially in Nairobi and Mombasa.
  • The only plausible explanation for consistently low positivity rates over several days and weeks is that the number of currently infected people in the population is reducing.

Over the past weeks, the government has struggled with Covid-19 testing, with the Ministry of Health officials lamenting over lack of testing kits.

While the government has argued that the shortage is a global phenomenon, the same has been difficult to believe given relative ease of access to the kits by private laboratories.

While the absolute numbers of people being tested daily have actually dropped significantly due to the government’s inability to do proper testing and contact tracing, another interesting phenomenon has emerged.

The proportion of those testing positive has been dropping gradually over the past couple of weeks, even dipping below the magical 5 per cent in the past few days.

While many will be justifiably sceptical of any pronouncements based on our Covid-19 numbers, the statistics in fact tell an optimistic story. Other than the positivity rate, there are several other markers one may use to assess the stage of a pandemic such as Covid-19.

Intensive care

At the peak of the pandemic, special beds set aside for those infected were occupied to a large extent, especially in Nairobi and Mombasa. Further, intensive care units were full of patients with respiratory distress and other complications.

Finally, even with low numbers of daily testing, a large percentage of those tested were being found to be positive.

Now, as a result of our administrative failings, we do not really know what proportion of our population has been infected with Covid-19 since it landed in the country, and we can therefore not use the absolute numbers announced daily to gauge the extent of its spread.

However, even with most skewed testing strategy possible, it is not easy to maintain a low positivity rate over a prolonged period of time.

The only plausible explanation for consistently low positivity rates over several days and weeks is that the number of currently infected people in the population is reducing. This is further borne out by the fact that numbers of hospitalised patients with Covid-19 have also dropped significantly over the past few weeks.

In countries that had a robust science-driven prevention response, such a dip in positivity rates would be evidence that the strategy has worked and a majority of the population have been kept away from the infection.

Severe illness

The other explanation, more likely in our setting, would be that as we dithered and bickered, a large proportion of our population got infected and recovered, or suffered more severe illness away from the public glare and without knowing it was Covid-19. A test several days or weeks after recovery would be negative in this case.

If indeed a majority of Kenyans have already been infected and recovered, the low positivity rates would mean that we have crested the peak of the pandemic, and one would now hope that those infected have acquired a measure of protective immunity.

We can now only hope that there shall be no second wave, or that we will be better prepared with a vaccine or a cure should it show up again in the future.

lukoye@gmail.com