[Predicting spread of new pandemic swine-origin influenza A (H1N1) in local mid-size city: evaluation of hospital bed shortage and effectiveness of vaccination].
OBJECTIVE
On April 24th, 2009, a new swine-origin influenza A (H1N1) was first reported in Mexico. Japan confirmed cases of the flu on May 9th, and the pandemic in Japan has become full-scale. The Ministry of Health, Labor and Welfare of Japan announced that the first peak of this pandemic was predicted to occur in October, 2009. Therefore, it is most important to predict the progress of this pandemic to be able to use medical resources effectively in Japan.


METHODS
We used a modified susceptible-exposed-infected-recovered (SEIR) model to calculate the number of infected people and hospital bed shortage during this pandemic. In this model, available medical resources were investigated on the basis of four vaccination scenarios.


RESULTS
Our model showed that it would take a further six months for the pandemic to peak than was predicted by the Ministry of Health, Labor and Welfare of Japan. Without vaccination, at the peak of the pandemic 23,689 out of 400,000 people would be infected and the hospital bed shortage would reach 7,349 in total.


CONCLUSIONS
We suggest that mathematical models are strong tools to predict the spread of infectious diseases. According to our model, it is possible to prevent hospital bed shortage by vaccination.
Takeuchi
Shouhei
S
Department of Public Health, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan. shouhei-t@umin.net
Kuroda
Yoshiki
Y
D004196:Disease Outbreaks; D005544:Forecasting; D006295:Health Resources / Q000706:statistics & numerical data; D006742:Hospital Bed Capacity / Q000706:statistics & numerical data*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000453:epidemiology* / Q000517:prevention & control*; D007564:Japan / Q000453:epidemiology; D032541:Mass Vaccination; D015233:Models, Statistical; D008962:Models, Theoretical
D007252:Influenza Vaccines