Bird flu scare came back again in state after two cases of human infections of the avian influenza caused by two variants H5N1 and H9N2 respectively were reported.

The WHO on Wednesday has pressed the alarm button and confirmed about one case of human infection of bird flu in a child in West Bengal.

With the two cases reported in the state, India recorded the third human infection of bird flu caused by the H9N2 virus since 2019, when the first one was reported in the country.

The child has recovered and was discharged from hospital, according to the global health body.

“On 22 May, the International Health Regulations (IHR) National Focal Point (NFP) for India reported to WHO a case of human infection with avian influenza A (H9N2) virus detected in a child resident of West Bengal state in India,” a media release issued by the WHO said on Wednesday.

The first case of human infection of bird flu caused by H9N2 virus was detected in a two-and-a-half-year-old baby of Indian origin in January. The baby who was diagnosed with the bird flu virus in the city has already gone back to Australia, sources in the state health department said.

According to the sources in the state health department at Swasthya Bhaban, the four and a half-year-old child is a resident of Manikchak in Malda district. The child fell ill showing symptoms of abdominal pain, breathlessness, respiratory tract infections with fever and cough during January. The child was diagnosed with bird flu caused by H9N2 virus and admitted to a hospital.

However, on 3 March, with a recurrence of severe respiratory distress, she was referred to another government hospital in Kolkata and was admitted to the pediatric ICU and incubated.

On 5 March, a nasopharyngeal swab sample was tested positive for influenza A in a laboratory in the city.

The same sample was sent to the National Institute of Virology (NIV) in Pune for sub-typing and the test confirmed it was a case of influenza A.

A team of public health experts of the state government and WHO are likely to visit Manikchak on Thursday to take stock of the situation there, it’s learnt.

Bird flu in humans caused by a novel influenza A virus subtype is an event that has the potential for high public health impact and must be notified to the WHO, as per international norms.

Most human cases of infection with avian influenza A (H9N2) viruses are exposed to the virus through contact with infected poultry or contaminated environments, the WHO said.

“Human infection tends to result in mild clinical illness,” the WHO release said.

Sources in the health department also said that the state animal resource and development department has already tested samples of around 29,000 poultry birds so far but no cases of bird flu has been confirmed.