Influenza is a seasonal disease in temperate regions. Most
cases in Thailand occur during the rainy months between July
and September. Fig. 4 shows the time distribution of the
influenza outbreak in humans in Thailand [3-18]. The disease
activity starts at the beginning of the rainy season (July), peak
in August. Most of the influenza outbreaks is in Trang
province (average mean from 1997-2013). Trang province is
in the south region of Thailand.