Evidence suggests that all influenza viruses in mammals, including humans, derived from viruses in wild ducks and other waterfowl. Some of these viruses could have been acquired by humans thousands of years ago. But medical historians know of no clearly identifiable influenza epidemics until large-scale outbreaks occurred in Europe in 1510, 1557, and 1580. The 1580 outbreak also spread into Africa and Asia, making it the first known pandemic. Pandemics have occurred periodically ever since. Major pandemics took place in 1729-1730, 1732-1733, 1781-1782, 1830-1831, 1833, and 1889-1890. The last of these, called the Russian flu because it reached Europe from the east, was the first pandemic for which detailed records are available.
In the 20th century, major pandemics occurred in 1918-1919, 1957-1958, and 1968-1969. The 1918-1919 pandemic was the most destructive in recorded history. It started as World War I (1914-1918) was ending and caused 20 million deaths—twice as many deaths as the war itself. When and where the pandemic began is uncertain, but because Spain experienced the first major outbreak, the disease came to be called the Spanish flu. The virus was exceptionally lethal; many of the deaths were among young adults age 20 to 40, a group usually not severely affected by influenza.
In 1957 a flu outbreak occurred in Guizhou, a province in southwestern China. Within six months, most areas of the world were battling what became known as Asian flu. Before the 1957-1958 pandemic subsided, an estimated 10 to 35 percent of the world’s population had been affected. The overall mortality rate, however, was comparatively low.
About a decade later, a variant of the virus that caused the 1957-1958 pandemic originated in either Guizhou or Yunnan province in southern China. The variant was first isolated and identified in Hong Kong in July 1968. Within a few months, cases of this Hong Kong flu appeared around the world. Hardest hit by the pandemic were children under age 5 and adults aged 45 to 64. In the United States, an estimated 30 million people were infected and there were some 33,000 influenza-related deaths.
No additional pandemics occurred during the 20th century, but public health experts expect that there will be more pandemics in coming years. While scientists do not yet know how to accurately predict flu outbreaks, they have established an international network to track and monitor outbreaks so that health officials can take immediate preventive measures to avoid pandemics. The international network, called FluNet, consists of about 110 influenza centers in more than 80 countries and several World Health Organization (WHO) centers, all linked electronically.
In the 20th century, major pandemics occurred in 1918-1919, 1957-1958, and 1968-1969. The 1918-1919 pandemic was the most destructive in recorded history. It started as World War I (1914-1918) was ending and caused 20 million deaths—twice as many deaths as the war itself. When and where the pandemic began is uncertain, but because Spain experienced the first major outbreak, the disease came to be called the Spanish flu. The virus was exceptionally lethal; many of the deaths were among young adults age 20 to 40, a group usually not severely affected by influenza.
In 1957 a flu outbreak occurred in Guizhou, a province in southwestern China. Within six months, most areas of the world were battling what became known as Asian flu. Before the 1957-1958 pandemic subsided, an estimated 10 to 35 percent of the world’s population had been affected. The overall mortality rate, however, was comparatively low.
About a decade later, a variant of the virus that caused the 1957-1958 pandemic originated in either Guizhou or Yunnan province in southern China. The variant was first isolated and identified in Hong Kong in July 1968. Within a few months, cases of this Hong Kong flu appeared around the world. Hardest hit by the pandemic were children under age 5 and adults aged 45 to 64. In the United States, an estimated 30 million people were infected and there were some 33,000 influenza-related deaths.
No additional pandemics occurred during the 20th century, but public health experts expect that there will be more pandemics in coming years. While scientists do not yet know how to accurately predict flu outbreaks, they have established an international network to track and monitor outbreaks so that health officials can take immediate preventive measures to avoid pandemics. The international network, called FluNet, consists of about 110 influenza centers in more than 80 countries and several World Health Organization (WHO) centers, all linked electronically.
