1 in 3 people in Nairobi has been infected with Covid-19, says researchers


A trader wears a protective facemask as Nairobi County health workers fumigate City Market on March 24, 2020. A German shipment of 6 million facemasks on transit through Kenya is missing. [Elvis Ogina, Standard]


At least one in every three people living in Nairobi has been infected with coronavirus, a new study shows.

The survey which analysed antibodies shows seroprevalence (the level of a pathogen in a population as measured in blood serum) for the virus in Nairobi stands at 35 per cent.

Seroprevalence is a way of identifying the number of people in a given population who have developed antibodies to diseases such as SARS-CoV-2, herpes simplex and HIV, following an infection.

Antibodies are Y-shaped proteins that bind to the body’s foreign invaders and signal the immune system to get to work. They bind like a lock-and-key to the invaders — whether they are viruses, bacteria, fungi or parasites.

The number of infections in Nairobi, according to the research done by Kenya Medical Research Institute (Kemri), University of Nairobi and Washington State University, is the highest compared to what is documented in countries that have recorded the highest deaths.

Lead researcher Erick Osoro told The Standard after the report was released on Tuesday that the US and countries in Europe have reported one infection in every 20 or 25 people.

“Half of the households in Nairobi had at least one person who had been infected. However, in most cases, the remaining people in the households had no evidence of past infection,” reads the report.

Biggest caseload

Osoro, who works with Washington State University Global Health-Kenya, said research was still ongoing to determine how long the antibodies stay in one’s body. The report says three in every 10,000 people infected in Nairobi died. Infections were also found to be higher in those between ages 20 and 45 compared to children.

Tea room bus stage in Nairobi on January 05, 2020 after learners resumed in-class learning countrywide after a nine month disruption caused by the Covid-19 pandemic. [Stafford Ondego, Standard]

“Persons aged 20-49 were 2.5 times more likely to have been infected with Covid-19 compared to children less than 10 years. Children under 10 and persons over 60 had the lowest infection levels,” says the report.

The study involved 1,164 participants from 17 sub-counties of Nairobi, and was conducted last year between November 2 and 23.

The study found Embakasi West to have most of the infections in the capital, accounting for 60 per cent. Mathare was second with 53 per cent, Ruaraka (46), Kibra (45) while Embakasi North had 45 per cent. Others were Dagoretti North (42 per cent), Starehe (26), Langata (23), Westlands (19), Kasarani (16) and Roysambu (13).

Nairobi County has had the biggest case load of Covid-19, with more than a third of all reported deaths nationally.

Reports by the Ministry of Health reveal that Nairobi has the highest attack rates of the virus, at 974.8, compared to 210.4 per 100,000 nationally.

The January 27 Covid-19 status report showed that Kenya had a total of 100,323 confirmed cases. Nairobi was leading in the number of infections, with 43,014 cases, followed by Mombasa with 9,019 while Kiambu had 6,392 and Nakuru  4,785 cases.