Nigerian scientists have confirmed the country’s first Omicron virus variant cases, with at least one case occurring in October.
Tests confirmed two cases of the variant among travelers from South Africa who arrived in Nigeria in the last week, the Nigeria Center for Disease Control (NCDC) said in a statement.
Retrospective sequencing of previously confirmed cases among other travelers also identified the variant among samples collected in October, officials said.
No other samples anywhere in the world have been confirmed to date back to October.
Botswana and South Africa were the only African countries to confirm Omicron cases before Dec. 1, when Nigeria and Ghana announced detected cases.
Canada’s first detected cases were both among individuals who had recently traveled from Nigeria.
South Africa and Botswana have said their samples date back to early November.
Experts say the number of mutations the variant has indicates it could be more transmissible and could evade the protection people enjoy from vaccines and prior infection, although they also caution that little is known yet about the strain.
Countries around the world curbed travel from southern Africa in recent days. Cases of Omicron have since been seen in some two dozen countries, including Canada, Israel, and the Netherlands.
Dutch officials said on Nov. 30 that the variant was found in samples from Nov. 19 and Nov. 23, signaling it was present in Europe earlier than previously believed.
“It is not clear yet whether these people have visited southern Africa,” the Dutch National Institute for Public Health said in a statement.
Preliminary findings from countries that identified Omicron cases earlier show “there is insufficient evidence to suggest that symptoms associated with Omicron are different from other variants,” Dr. Ifedayo Adetifa, director-general of the NCDC, said in a statement. “However, it may be more transmissible.”
It’s safe to assume the variant is “widespread globally,” Adetifa said. “Therefore, it is a matter of when, not if, we will identify more cases.”
Nigeria has updated its travel advisory. All travelers hoping to enter the country are now required to present a negative COVID-19 test before boarding a plane, a restriction also imposed by some other nations. Nigerians were encouraged to get a vaccine and follow mitigation measures such as social distancing and wearing masks.
South African doctors have said the variant hasn’t yet caused symptoms more severe than those caused by other strains.
“There is nothing much that we see beyond what we have seen with Delta variant,” Dr. Mvuyisi Mzukwa, vice chair of the South African Medical Association, said on CNN’s “New Day.”
Many of the patients don’t require hospitalization, he said.
