Food poisoning cases spike
A spike in the number of people struck down by a foodborne illness in the MidCentral District Health Board region is most likely the result of cross contamination from poultry meat.
New figures from the Institute of Environmental Science and Research for December show a high number of campylobacteriosis cases, with 49 notified in the MidCentral region.
It is a significant increase compared to previous months, which typically have about 20 to 30 cases.
Campylobacteriosis is the most frequently notified foodborne illness in New Zealand. Its symptoms include abdominal pain, fever, and diarrhoea.
Massey University Infectious Disease Research Centre director Nigel French said the "urban campylobacter season" was in full swing and was generally when most cases of cross contamination from poultry meat occurred. "There are a whole lot of possible reasons why you might see an increase but November to February is the time when you see most cases of campylobacteriosis in urban areas," he said.
"In rural areas you tend to see more cases in spring, particularly associated with calving season."
Prof French said cross contamination of meat was a common way for people to get infected with the illness.
"At this time of year there are a lot of risk factors associated with increases in infections - the barbecue season is an important time of year where particularly raw meat comes into contact with salad vegetables. You can imagine a barbecue where you've got raw chicken and salad next to it and before the chicken has a chance to cook, it can contaminate the salad - that's how people can pick up infection," he said.
Prof French said the two most common sources of the campylobacter bacteria in the Manawatu region were chicken and ruminants - cows and sheep.
"About half of the cases in the region are attributable to chicken and half to ruminants, most likely cattle," he said. "The distinction is that most of the chicken cases come from the urban areas and most of the cattle cases come from the rural areas. Whereas the chicken cases are most likely to be foodborne, in rural areas it is most likely to be direct contact with cattle faecal material and contamination of the environment, and many of the cases from the rural area are young children, in particular."
The Infectious Disease Research Centre is working on a report of case origins in the region from last year for the Ministry of Health.