Australia reports its first imported human case of H5N1 bird flu.

Image of H5N1 virus cell.

Health officials in Australia's Victoria state have reported the first human case of H5N1 avian/bird flu in the country. The case is a child who contracted the virus while on a visit to India and was ill in March.

In a statement, the Victoria Department of Health said the child had a severe infection but has fully recovered. Contact tracing revealed no evidence of transmission in Australia, and health officials said the risk is low, given that the virus usually does not spread easily among humans.

Meanwhile, the H5N1 strain that infected the child, is not the same as the one fueling outbreaks in the United States, health officials said, noting that the H5N1 virus has never been detected in animals or people in Australia before.

India continues to report sporadic H5N1 outbreaks in poultry, including recurrences in Andhra Pradesh and Maharashtra in February, according to a recent situation report from the World Organization for Animal Health.

Since January 2022 and through April 25, 2024, 26 sporadic human H5N1 cases have been reported from eight countries, however none of them from India, according to information supplied by the US Centers for Disease Control and Prevention (CDC). Fourteen cases of the illness were severe or critical, seven were fatal, four were mild, and eight were asymptomatic.

Most patients were exposed to sick or dead poultry. Eleven of the cases were thought to involve an older H5N1 clade (2.3.2.1c) circulating in Cambodia and Vietnam, with the others due to the newer clade (2.3.4.4b) circulating globally, including the United States.

The national health department also revealed that it is also supporting Agriculture Victoria in its response to an outbreak at a poultry farm, which is not related to the human case. In a separate press release from Australia's agriculture ministry, it was revealed that through testing, a highly pathogenic avian influenza outbreak caused by the subtype H7, was detected at a layer farm near the Victoria city of Meredith.

Agriculture secretary Murray Watt said in a statement Australia takes any incident involving highly pathogenic avian influenza seriously and expressed relief that the strain detected was not the same as the virus affecting other regions of the world such as the United States and Antarctica.

Australia experienced nine highly pathogenic avian/bird flu outbreaks in poultry between 1976 and 2021, according to Agriculture Victoria. In 2020 and early 2021, the state battled three different strains across three different local government areas, including highly pathogenic H7N7 at three layer farms, low pathogenic H5N2 at two turkey farms, and low pathogenic H7N6 at one emu farm.

References:

Clade - A clade is a grouping that includes a common ancestor and all the descendants (living and extinct) of that ancestor.