Telling signs of a fourth wave in Kenya

A country which has experienced three COVID-19 waves can bank on modelling experience as a periscope to sneak a peek at the character and peak of a new wave lurking around the corner.

The easier part of scholarship is to understand the complex as one acquires knowledge. The harder part is to move from the complex to the simple, so as to provide and explain practical solutions in ways similar to the beaten path of nature’s efficiency.

COVID-19 has made modelling the talk of the moment. Not to waste the crisis, learners can utilise the disruptive opportunities of the pandemic to relate more meaningfully with how models use data abundance to support policy and strategic planning. This short article does that. It uses the familiar data on COVID-19 cases and shows how a country which has experienced three waves already can bank on modelling experience as a periscope to sneak a peek at the character and peak of a fourth wave lurking around the corner.

Key Highlights

• Africa’s population-normalised testing rate remains lower than the global average but the probability of dying of COVID-19 and developing severe cases is higher in Africa, a finding that is attributable to the challenged health system on the continent.
• The surest signs of a surging trend is to watch the trajectory of the COVID curves with respect to business-as-usual trends. A persistent surge above the trend line for several days with positivity rates sustained above 5% is a red signal for worsening trends.
• Registering a mean of new daily cases exceeding 437 between June 16 and July 4, reaching more than 184,500 cases (with 130 severe cases at 0.07% probability) on July 4, 2021 would signal a significant surge towards a more viscous fourth wave in Kenya.

Global Overview

The global case fatality rate has been stable at 2.2% with a marginally increasing recovery rate going past 91%, recording a total of more than 177.5 million cases as of June 16, 2021. At 493 deaths per million as of June 16, the figure is likely to reach 500 deaths per million by August 2021.

Africa’s case fatality rate has been stable at 2.7% with a marginally increasing recovery rate going past 89%, recording a total of more than 5.1 million cases as of June 16, 2021. In Kenya, the seventh country in Africa in leading COVID-19 cases, there were 176,622 cases as of June 16, 2021.

Explaining Africa’s Comparative Performance

Africa’s share of the global population is currently 17% but her share of global COVID-19 cases has been stable at 2.9%, though posting a higher share of 3.7% of global active cases and 3.5% of global deaths and global severe cases. The probability of developing severe cases in Africa has been steady around 0.055%, more than the global probability of 0.050%. In Kenya, the probability has recently been 0.065%. Kenya’s share of Africa’s population is 4% but her share of Africa’s COVID-19 cases has been stable at 3.4% with 2.5 % of Africa’s COVID-19 deaths, but it is posting a higher share of 12–14% of Africa’s active cases and 4% of Africa’s severe cases. The foremost plausible interpretation is that Africa’s population-normalised testing rate remains lower than the global average but the probability of dying of COVID-19 and developing severe cases is higher in Africa, a finding that is attributable to the challenged health system on the continent.

In Kenya, the proportional metrics confirm a much higher share of Africa’s active cases despite her relatively low population-normalised testing rate stagnating at about 74 tests per million people per day, which is 30% of Rwanda’s performance on this normalised metric. The slow vaccination rate in Kenya and supply constraints, even affecting the more exposed health workers as has been witnessed lately as the Indian Delta variant ravages the western part of the country, can only worsen the outcomes for this East Africa’s most outstanding economic power.

What are the Signs of a New Wave? In Kenya?

The surest sign of a surging trend is to watch the trajectory of the COVID curves with respect to business-as-usual trends. A persistent surge above the trend line for several days with positivity rates sustained above 5% is a red signal for worsening trends. With daily tests averaging lower than 6000, and worse still if the testing is not population-targeted but driven by the need to test the people with symptoms, such a surge is telling of a potentially explosive new wave. The all-time daily average tests in Kenya is still below 4,000.

The model below shows the recent developments in COVID-19 cases in Kenya since May 19, 2021. This was a few weeks after the confirmation of the more contagious Indian Delta variant in Kisumu. It can be seen that the presumptive peaking of the cases along the “green line of hope” on June 12 at 172,354 was missed out by an excess of 1.6% in actual cases on that date.

Assuming an optimistic scenario for Kenya as observed between June 7 and June 12, there should, theoretically, be a peak of 180,957 (+/- 2%) cases on July 4, 2021. The implication is that reaching more than 184,500 cases (with 130 severe cases at 0.07% probability) on July 4, 2021 would signal a significant surge towards a more viscous new wave in Kenya. Registering a mean of new daily cases exceeding 437 between June 16 and July 4 is the simpler way of predicting the likelihood of a surge leading to a more viscous fourth wave in Kenya.

Delta Variant Disrupting the COVID-19 Map of Kenya

Spatially, the fast spread of the virus in western Kenya following the confirmation of the Indian Delta variant shifts the greater burden of care to the affected devolved units in charge of healthcare in the region, hence the counties of Kisumu and her neighbors. As shown in the status maps of March 25 and June 15 below, the shares of COVID-19 cases out of the national tally have been rising in the western region, where the Indian Delta variant was first confirmed. Since the western part of Kenya and the currently ravaged Uganda are contiguous, effective containment measures must be coordinated across the national borders as well, giving the challenge a political and diplomatic angle.

Containment Recommendations

1. Adequate preparedness against the new waves of COVID-19 requires long-term strategies, critical parts of which are data-driven modelling, disciplined adaptation, and collective response across national borders.
2. In Kenya, the latest trend in COVID-19 cases signals the possibility of a vicious fourth wave, with July 4, 2021 being a critical juncture for gauging the likely surge based on a threshold of 184,500 total cases by then — a figure that projects some 130 severe cases (serious or critical) to be catered for based on the established probability of 0.07%.
3. Vaccination and protective equipment for the most exposed groups, hence health workers, must take precedence in planning and preparing adequately to contain the resurgent pandemic.
4. Tighter policy enforcement through the routine containment measures remains relevant as the resurgent waves of the pandemic have shown. Greater civic and political duty is necessary to remain adaptive to the waves.