•The earliest possible Kenyan patients come from a region where Chinese nationals were building roads in 2019 and last year.
•In total, blood samples donated by 582 people from Kisumu and Kericho between January and March, last year, were tested, and 19 had Covid-19 antibodies.
Testing has found possible Covid-19 infections in Kenya dating back to January last year.
This provides evidence more people were infected probably months before Brenda Cherutich and Brian Orinda were confirmed Kenya’s first Covid-19 patients on March 12.
The country’s first patients could instead have been three adults in Western Kenya, according to antibody tests on stored blood from Kisumu and Kericho.
They are a 69-year-old man, a 46-year-old man, and a 47-year-old woman, all of who had no symptoms when they submitted their blood samples in January last year.
“If participants in our study did have an asymptomatic infection, then such cases could have contributed to early undetected spread of the pandemic in Kenya,” researchers who tested the blood said.
Their findings, titled “SARS-CoV-2 Antibody Prevalence in People with and without HIV in Rural Western Kenya, January to March 2020”, are published in the Aids journal this month.
The researchers said it is not unusual that these cases are away from Nairobi and Mombasa where SARS-CoV-2, the virus that causes Covid-19, was believed to have been introduced into Kenya.
The Kenyan adults come from a region where Chinese nationals were building roads in 2019 and last year.
“Some of the earliest known cases of Covid-19 in Africa were imported by manufacturing workers who travelled from China to Egypt and it is possible that SARS-CoV-2 could have reached the otherwise remote region of our study similarly via construction workers,” they said.
In total, the researchers tested blood samples donated by 582 people from Kisumu and Kericho between January and March last year.
Antibodies in the blood are taken as evidence of coronavirus infection and can be detected as early as two weeks after a person is first infected.
Nineteen people had SARS-Cov-2 antibodies, with the three adults being the earliest in January.
However, it can be difficult to distinguish antibodies that neutralize SARS-CoV-2 from antibodies that fight other coronaviruses, including some that cause the common cold.
Tests on the Kenyan samples are therefore not definitive, and the results may represent cross-reactivity from other infections.
“These may represent cross-reactivity or asymptomatic infections that predated the first reported Covid-19 cases in Kenya,” the researchers said.
However, data from other countries also suggest that SARS-CoV-2 was circulating weeks or months before initial cases were detected.
“Further research is needed to distinguish the two possible explanations for detectable SARS-CoV-2 antibodies in our study,” the researchers added.
They are Jonah Maswai, John Owuoth, Ibrahim Daud, Valentine Sing’oei and Fred Sawe from the Henry Jackson Foundation Medical Research International stations in Kericho and Kisumu.
Others are Trevor Crowell, Michelle Imbach, Nicole Dear, Leigh Anne Eller, Christina Polyak, and Julie Ake from the Walter Reed Army Institute of Research, and Henry M. Jackson Foundation for the Advancement of Military Medicine, Maryland.
The blood was donated at Kericho District Hospital, AIC Litein Mission Hospital, Kapkatet District Hospital, Tenwek Mission Hospital, Kapsabet County Hospital, Nandi Hills County Hospital, and Kisumu West County Hospital.
It was principally donated for the ongoing African Cohort Study, a project of the US military HIV research programme in Kisumu and Kericho.
The pandemic coronavirus emerged in Wuhan, China in late 2019.
By January 30, last year, cases had also been confirmed in Taiwan and Thailand, Australia, Malaysia, Singapore, France, Japan, South Korea, the United States, Vietnam, Canada and Nepal.
Edited by Kiilu Damaris