TY - JOUR AU - Viboud, Cécile AU - Boëlle, Pierre-Yves AU - Pakdaman, Khashayar AU - Carrat, Fabrice AU - Valleron, Alain-Jacques AU - Flahault, Antoine T1 - Influenza Epidemics in the United States, France, and Australia, 1972–1997 T2 - Emerging Infectious Disease journal PY - 2004 VL - 10 IS - 1 SP - 32 SN - 1080-6059 AB - Influenza epidemics occur once a year during the winter in temperate areas. Little is known about the similarities between epidemics at different locations. We have analyzed pneumonia and influenza deaths from 1972 to 1997 in the United States, France, and Australia to examine the correlation over space and time between the three countries. We found a high correlation in both areas between France and the United States (correlation in impact, Spearman’s ρ = 0.76, p < 0.001, and test for synchrony in timing of epidemics, p < 0.001). We did not find a similar correlation between the United States and Australia or between France and Australia, when considering a systematic half-year lead or delay of influenza epidemics in Australia as compared with those in the United States or France. These results support a high correlation at the hemisphere level and suggest that the global interhemispheric circulation of epidemics follows an irregular pathway with recurrent changes in the leading hemisphere. KW - influenza/epidemiology/mortality KW - pneumonia/epidemiology/mortality KW - comparative study KW - seasons KW - United States/epidemiology KW - Australia/epidemiology KW - France/epidemiology KW - statistical models KW - Australia KW - France KW - United States DO - 10.3201/eid1001.020705 UR - https://wwwnc.cdc.gov/eid/article/10/1/02-0705_article ER - End of Reference