Highlights in the History of Avian Influenza (Bird Flu) Timeline – 1960 – 1999

1961

• An outbreak in wild birds (common tern) in South Africa suggests wild birds as a possible reservoir for avian influenza A viruses.

1967

• Researchers proposed a relationship between human and avian influenza A viruses after a study showed a relationship between the 1957 human pandemic influenza virus and an influenza A virus isolated from a turkey. The study raised the question, and triggered additional studies, on whether human influenza viruses are of avian origin.

1968

• The 1968 pandemic was caused by an influenza A (H3N2) virus comprised of two genes from an avian influenza A virus, including a new H3 hemagglutinin, but also contained the N2 neuraminidase from the 1957 H2N2 virus. In addition, the 1968 H3N2 pandemic virus was a reassortant virus between the seasonal human influenza A(H2N2) virus and a low pathogenic avian influenza A virus¹⁰. It was first detected in Hong Kong in July, and noted in the United States by September 1968^13,14,15. The estimated number of deaths was 1 million worldwide and about 100,000 in the United States.

• Though indications on the potential role of bird flu on the origin of human pandemics had been present for nearly a decade, it wasn’t until 1968 that avian influenza A virus infections in wild birds in the United States, Australia, and Russia were confirmed using blood tests^{16, 17, 18, 19, 20}.

1994

• In May 1994, a LPAI H5N2 virus was detected in chickens in Mexico²².
• Also in 1994, an outbreak of HPAI H7N3 virus occurred in poultry farms in Pakistan²³. In 2001, 2003 and 2004, viruses of low and high pathogenicity continued to emerge in birds.

1997

• In 1997, large HPAI H5N1 virus outbreaks were detected in poultry in Hong Kong, and zoonotic (animal to human) transmission led to 18 human infections with six deaths. These were the recognized first H5N1 human infections with fatal outcomes⁵.