Kjell Olof Hedlund at the Institute for Infectious Disease told Swedish news agency TT that he thinks there’s a connection with our vulnerability during the darker and colder part of the year. He believes that we may be less likely to withstand infection around this time due to lack of sunlight and as the weather makes us stay in closer vicinity to others.
This year the increase in cases is starting later than usual – something which may be connected to the Swine Flu pandemic.
“It could be due to people being more careful about their hand hygiene at present,” Hedlund told TT.
Winter vomiting disease can strike at any time of the year, but generally the larger outbreaks in Sweden occur around late autumn.