An up-to-date timeline that documents

the years in which pandemics occurred over the past century, as well as the years in which bird flu strains made the jump to people.

Significant Dates in Influenza History

Major pandemic
The appearance of a new influenza strain in the human population

1918
Pandemic
“Spanish flu” H1N1
The most devastating flu pandemic in recent history, killing more than 500,000 people in the United States, and 20 million to 50 million people worldwide.

1957-58
Pandemic
“Asian flu” H2N2
First identified in China, this virus caused roughly 70,000 deaths in the United States during the 1957-58 season. Because this strain has not circulated in humans since 1968, no one under 30 years old has immunity to this strain.

1968-69
Pandemic
“Hong Kong flu” H3N2
First detected in Hong Kong, this virus caused roughly 34,000 deaths in the United States during the 1968-69 season. H3N2 viruses still circulate today.

1977
Appearance of a new influenza strain in humans

“Russian flu” H1N1
Isolated in northern China, this virus was similar to the virus that spread before 1957. For this reason, individuals born before 1957 were generally protected, however children and young adults born after that year were not because they had no prior immunity.

1997
Appearance of a new influenza strain in humans
H5N1
The first time an influenza virus was found to be transmitted directly from birds to people, with infections linked to exposure to poultry markets. Eighteen people in Hong Kong were hospitalized, six of whom died.

1999
Appearance of a new influenza strain in humans

H9N2
Caused illness in two children in Hong Kong, with poultry being the probable source.

2002
Appearance of a new influenza strain in humans

H7N2
Evidence of infection is found in one person in Virginia following a poultry outbreak.

2003
Appearance of a new influenza strain in humans

H5N1
Caused two Hong Kong family members to be hospitalized after a visit to China, killing one of them, a 33-year-old man. (A third family member died while in China of an undiagnosed respiratory illness.)

H7N7
Eighty-nine people in the Netherlands, most of whom were poultry workers, became ill with eye infections or flu-like symptoms. A veterinarian who visited one of the affected poultry farms died.

H7N2
Caused a person to be hospitalized in New York.

H9N2
Caused illness in one child in Hong Kong.

2004**
Appearance of a new influenza strain in humans

H5N1
Caused illness in 44 people in Thailand and Vietnam, 32 of whom died. Researchers are especially concerned because this flu strain, which is quite deadly, is becoming endemic in Asia.

H7N3
Caused illness in two poultry workers in Canada.

H10N7
Caused illness in two infants in Egypt. One child’s father is a poultry merchant.

** (through October 25)

Courtesy: National Institute of Allergy and Infectious Diseases

This entry was posted on Friday, October 14th, 2005 at 9:09 pm and is filed under Bird Flu, Avian Influenza, H5N1. Both comments and pings are currently closed.