tetano
Editor, Senior Moderator
Jpn J Infect Dis. 2018 Feb 28. doi: 10.7883/yoken.JJID.2017.401. [Epub ahead of print]
[h=1]Geographic spread of influenza under the influence of community population size, which was different from that of measles and rubella.[/h] Yoshikura H[SUP]1[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] The influenza season was defined as the period from week 36 of the year to week 20 of the next year in this report. The population size of prefectures (x) and number of the patients per prefecture
were initially uncorrelated but became correlated as the season advanced. The correlation with correlation coefficient >0.7 emerged earlier and earlier over time; it was week 5 of the next year in 2001/2002 but it was week 47 of the same year in 2014/2015. Once x and y became correlated, plots of y in the vertical axis against x in the horizontal axis fell on a straight line, y=Cx[SUP]s[/SUP], where s was the slope of the plots and C a constant. The slope was steep (s>1) initially but became flat (s<1) later, indicating that influenza spread first to populated prefectures and then nationwide involving less populated prefectures. This spread pattern was the same for the seasonal influenza and AH1pdm2009, though the progression of the latter was much faster. For measles and rubella epidemics, the number of patients per prefecture was proportional to the square of the population size from the start to the end of the season.
[h=4]KEYWORDS:[/h] disease spread; influenza; measles; population size; rubella
PMID: 29491244 DOI: 10.7883/yoken.JJID.2017.401
[h=1]Geographic spread of influenza under the influence of community population size, which was different from that of measles and rubella.[/h] Yoshikura H[SUP]1[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] The influenza season was defined as the period from week 36 of the year to week 20 of the next year in this report. The population size of prefectures (x) and number of the patients per prefecture
were initially uncorrelated but became correlated as the season advanced. The correlation with correlation coefficient >0.7 emerged earlier and earlier over time; it was week 5 of the next year in 2001/2002 but it was week 47 of the same year in 2014/2015. Once x and y became correlated, plots of y in the vertical axis against x in the horizontal axis fell on a straight line, y=Cx[SUP]s[/SUP], where s was the slope of the plots and C a constant. The slope was steep (s>1) initially but became flat (s<1) later, indicating that influenza spread first to populated prefectures and then nationwide involving less populated prefectures. This spread pattern was the same for the seasonal influenza and AH1pdm2009, though the progression of the latter was much faster. For measles and rubella epidemics, the number of patients per prefecture was proportional to the square of the population size from the start to the end of the season.[h=4]KEYWORDS:[/h] disease spread; influenza; measles; population size; rubella
PMID: 29491244 DOI: 10.7883/yoken.JJID.2017.401