The viruses that infected two people in Cambodia with H5N1 avian influenza were identified as an endemic clade of bird flu circulating in the nation.
Concerns were raised this week that the infections were caused by a new strain of H5N1, clade 18.104.22.168b, which arose in 2020 and has caused a record number of deaths among wild birds and farmed poultry in recent months.
Reuters reports that according to a statement by the US Centers for Disease Control and Prevention (CDC), preliminary genetic sequencing carried out in Cambodia led its health ministry to identify the viruses as H5 clade 22.214.171.124c, which has circulated in Cambodia among birds and poultry for many years and has sporadically caused infections in people.
“Yes, this is an older clade of avian influenza that had been circulating around the region for a number of years and while it has caused human infections in the past, it has not been seen to cause human-to-human transmission. However, that doesn’t mean that the threat is any less,” said Erik Karlsson, Director of the National Influenza Center of Cambodia and acting Head of Virology at the Institut Pasteur du Cambodge, which sequenced the virus.
He went on to say that the response has to be coordinated and quick in order to minimize further spread and restrict exposure to any common cause.
Cambodia tested at least 12 people for the H5N1 strain last week, following the death of an 11-year-old girl from the virus in the country’s first documented human transmission in nearly a decade.