Abstract
To investigate the effects of weather conditions on bacterial food poisoning, the relations of seven indices of weather, viz. maximal, minimal and mean air temperature, mean vapor pressure, minimum and mean relative humidity, and global solar radiation, to daily outbreaks of food poisoning from Vibrio parahaemolyticus, Staphylococcus and Salmonella in Tokyo were examined by multiple logistic regression analysis, during 1981-86 and 1987-91, respectively. By factor analysis, the seven weather indices were summarized into two factors, viz. temperature/vapor pressure, to which maximal, minimal and mean air temperature and mean vapor pressure were positively related, and humidity/solar radiation, to which minimal and mean humidity were positively related, while global solar radiation was negatively related.
The outbreak of Vibrio parahaemolyticus food poisoning was positively related to minimal temperature three days before the outbreak for both of the time periods investigated (p<0.05, multiple logistic regression analysis). Similarly, the outbreak of Staphylococcus food poisoning was positively related to temperature/vapor pressue three days before the outbreak (p<0.05). However, none of the weather indices were significantly related to the outbreak of Salmonella food poisoning in either period (p>0.05).
It is suggested that a high temperature/vapor pressure factor three days before outbreaks of Vibrio parahaemolyticus and Staphylococcus food poisoning had the most significant effect on the outbreaks of these two types of food poisoning.
