What rainy season means for coronavirus

As Kenya heads into the long rains season, what could this mean for the spread of Coronavirus?

According to the meteorological department, temperatures are expected to slowly fall toward the end of this month, while rains increase.

"It is noted that day-time temperatures decreased over most parts of the country," says head of the meteorological department Stella Aura, regarding the March 9-15 week.

In Kenya, the rainy and cold season tends to be when people get sick from colds and flu and there is fear the same might hold for coronavirus disease, also called Covid-19.

However, infectious diseases specialist at Aga Khan University Hospital Prof Rodney Adam told the Star it is not yet known what role weather plays on the spread of Sars-CoV-2, the virus that causes the coronavirus.

"There is no reason to believe that the rainy season will affect the spread of Covid-19. Whether there is a role for climate we don't know that yet," he said. 

"The best environment for the virus is 37-40 degrees so all they need is to jump from from one human host to another."

Covid-19 was first reported to the World Health Organisation as a pneumonia of unknown cause in Wuhan, on December  31, 2019.

By yesterday, 225,253 infections and 9,276 deaths had been reported, mostly along the northern hemisphere, which is currently in winter. 

At least 85,826 or 90 per cent of all patients have recovered fully, according to the WHO. 

The mechanism that causes influenza and colds to spread faster in the winter is not perfectly understood, says Prof Adam.

"Even for influenza it is not conclusively understood why it is more prevalent in the cold season," he told the Star.

Scientists theorize it relates to the way virus particles can stay active on surfaces such as matatu seat handles, lift buttons and door handles for longer in cold weather.

It could also be down to the tendency ofv people to congregate in warm, close conditions where diseases spread easily during cold weather. 

Head of the meteorological department Stella Aura says a few parts of Kenya will receive morning and evening rains this weekend. 

Aura says until Monday, rainfall is likely to continue over parts of the Lake Victoria basin, the Rift Valley highlands, central Kenya including Nairobi, the Coast and Ukambani.

"A few areas within the Northeast and the Northwest may also receive some rainfall," she said. 

The rains will increase in April and end in May or June. However, Mets says this year the temperatures will remain higher than usual.

Some viruses may have a temperature range where they can survive for longer.

 Sars coronaviruses are usually stable at low temperature and low humidity environment. 

But much less is known about the behaviour of SARS-CoV-2 in warm outdoor environments.