Monday, April 21, 2008

What interests you most?

My Sitemeter collects statistics on usage of this blog (don’t worry, you can’t be identified) including pages visited and referrals from search engines like Google and Yahoo.

I looked through some recent stats and found that the most common questions referred to the safety of chicken (by far the most frequent referral), unpasteurized milk, coliforms and how bacteria can get into food. There were one or two surprising enquiries, but I won’t go into those.

Over the next few posts I’ll visit some of the more popular questions, starting with a report from New Zealand on campylobacteriosis and poultry.

The March 2008 Monthly Surveillance Report from ESR makes for interesting reading.

The incidence of campylobacteriosis in the human population of New Zealand has fallen again. 450 campylobacteriosis cases were notified in March 2008 compared with 1145 cases notified in the same month of the previous year. The current 12 month rate* is 234 cases per 100,000 head of population, compared with 386 for the previous 12 months to March 2007 – a 39% reduction. Compared with the rates of other infectious diseases surveyed, this is a very significant achievement.

Though there is currently no direct evidence, at least some of this reduction must be because of the strenuous efforts made by the poultry industry to reduce the levels of contamination on fresh poultry and poultry products.

The Campylobacter surveillance data contain other interesting observations on the possible source of infection: of the cases where the information was recorded, 51% had eaten food from a food premise (I assume that means a restaurant or take-away); 38% had contact with farm animals; 22% had contact with other people showing symptoms of campylobacteriosis. Other possible links included pre-schools and childcare, drinking non-habitual or untreated water supply or contact with recreational water. A surprising 17% reported faecal contact, while a small proportion reported contact with a sick animal.

Obviously, this information is confounded and incomplete and doesn’t explain exactly how the patients contracted campylobacteriosis. However, it does point to the special nature of life in New Zealand and suggests that we need to look widely to find ways to control our high incidence of campylobacteriosis.

(For further information on Campylobacter, either select "search blog" using the keyword Campylobacter, or go to "So what is this Campylobacter thing?" posted Tuesday 21st November 2006 by clicking the Archive).

How do you know chicken is safe to eat? If you cook it yourself, use a meat thermometer to check the internal temperature reaches 74 C (165 F). The USDA suggests 160 F (71.1 C) for beef burgers. If you buy chicken ready-cooked for reheating, use the same temperatures. If you are going to eat pre-cooked chicken without further heating, make sure you trust the supplier.

* The 12 month rate is based on the cumulative total for the current year (12 months up to and including March 2008), expressed as cases per 100,000