Foodborne Campylobacteriosis in New Zealand Evidence rather than prejudice Donald Campbell Principal Advisor (Public Health) Science Group

Statistics are the triumph of the quantitative method, and the quantitative method is the victory of sterility and death. Hillaire Belloc

The burden of acute gastro- intestinal disease pyramid

Human disease surveillance in New Zealand Ministry of Health Environmental Services and Research Ltd Public Health Units New Zealand Food Safety Authority

Disease Investigations Enteric Purpose Disease Control Attribution Monitoring Methods Outbreaks Sporadic Foodborne Detecting, controlling and preventing outbreaks Priorities / setting policy for control (risk assessment) Estimating burden of disease Identifying emerging issues Data source Evaluation and monitoring

Campylobacteriosis 2006 Cases 15, /100,000 Hospitalisations 677 (969) 7.3% Mortality 1

Campylobacteriosis Jan 03 - May 07

Notification Rates

Campylobacter 2005

Disease Notifications

Monthly Campylobacteriosis

Enteric Outbreaks 2006 No of outbreaks % of outbreaks No of cases % of cases Norovirus Campylobacteriosis Giardia Cryptosporidium Salmonella C perfringens Others Unidentified

Case-case Analysis 2006 (%) Food premise Untreated drinking water Recreational water Farm Animal Overseas Travel Campylobacteriosis Cryptosporidiosis Giardiasis Salmonellosis Shigellosis Yersiniosis

Case-control studies MAGIC 1997 PAR chicken 50%+ Home protective Christchurch 1994 Poultry outside home Auckland 1996 Barbecued, undercooked chicken

Published campylobacteriosis investigation reports Likely CauseNo. of Outbreak Reports Likely foodborne2 Limited for foodborne2 Likely waterborne5 Limited for waterborne1 Possibly food or water2 Unclear1 Total13

Overall evidence for causality in New Zealand Foodborne transmission Evidence of association Strength of association Biologic gradient Consistency Biological plausibility Coherence Temporality Food dominant cause

The government is very keen on amassing statistics. They collect them, add them, raise them to the nth power, take the cube root and prepare wonderful diagrams. But you must remember that every one of these figures comes in the first instance from the Chowty Dar who just puts down what he damn well pleases. Sir Josiah Stamp 1929

Good surveillance does not necessarily ensure the making of right decisions but it reduces the chances of making wrong ones. Alexander Langmuir 1963