Early transmission characteristics of influenza A(H1N1)v in Australia: Victorian state, 16 May – 3 June 2009

Abstract

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Seroprevalence to Influenza A(H1N1) 2009 Virus—Where Are We?

“…The larger volume and distribution of the studies has provided us with a greater confidence in the results than looking only at the very few early studies. Overall, school-aged children played an especially important role in the transmission of influenza, and this was also shown in this 2009 pandemic (24). The pandemic 2009 virus has characteristics broadly similar to those of the seasonal H1N1 influenza viruses in terms of viral shedding, clinical illness, and transmissibility (10).…”

Choosing pandemic parameters for pandemic preparedness planning: A comparison of pandemic scenarios prior to and following the influenza A(H1N1) 2009 pandemic

“…This yielded 21 articles eligible for the review (Fig. 2) [3,4,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]. By reference checking and studying policy documents from the European Centre for Disease Prevention and Control (ECDC), the Centers of Disease Control and Prevention (CDC), and the World Health Organization (WHO), 15 additional articles or documents were found [46][47][48][49][50][51][52][53][54][55][56][57][58][59][60].…”

“…Boëlle et al have based their value on a combination of three projective models using a range of 2.2-3.1, but state that the model with a R e of 2.6 should be favoured [55]. Boni [41]. Finally, an article describing the early outbreak of influenza A(H1N1) in Japan yielded a value of 2.3, which the authors described as possibly reflecting the existence of few highly connected clusters of cases in high school students [52].…”

Pandemic Influenza H1N1

“…Large numbers of imported cases can distort estimates of the reproduction number, 19,30,31 especially when infected travelers are not typical of community-acquired cases (for example, the age structure of imported vs. local cases 32 ). Changes in reporting rates can lead to inaccuracies in estimates of the reproduction number, 10,14,33 and when the reproduction number is close to one, the stochastic nature of the early stages of an outbreak can cause it to be overestimated. 34 Finally, differences in infectivity or susceptibility between population groups can lead to differences in estimates of the reproduction number if the disease is largely confined to one group.…”