London flu


In December 1972 reports began to circulate of cases of 'London flu' throughout the United States. 'London flu' was a particular form of influenza caused by an influenza virus which had apparently first been identified in India in 1971, but was first identified as a distinct strain in England early in 1972.

Progression within the United States

On 14 December it was reported by the federal Center for Disease Control that there were cases in five states: Memphis, Kansas City, Baltimore, Anchorage and Seattle. By 22 December, it was described as a variant of Hong-Kong flu, 'A-England 72' with outbreaks in 2 colleges in South Massachusetts.
By 29 December it was reported as present in 14 states, with 'thousands' of cases, with San Francisco Bay the latest to be hit. On the next day a further state was reported to be affected.
A TV report on 8 January 1973 announced that 18 states were affected, and in the United Kingdom there had been over 1,000 deaths. On 13 January the New York Times announced that the CDC considered that the outbreak exceeded epidemic level, with California particularly hard hit.
On 3 February, London flu deaths in the US reached 1,027, according to the National Center for Disease Control, nearing the previous year's death toll for Hong Kong flu.

International reports

The World Health Organization reported outbreaks also in the Soviet Union, the Netherlands, Switzerland, Morocco and Lebanon, with localised outbreaks in four other countries.

Analysis

Subsequent statistical analysis indicated that by the following season, influenza type B was predominating over type A strains by a factor approaching 4:1.