Is New Zealand's recent increase in campylobacteriosis due to changes in laboratory procedures? A survey of 69 medical laboratories

Abstract

Aims: To evaluate the contribution of changing procedures in microbiology laboratories over the previous 5 years to the increase in campylobacteriosis notifications. To assess whether regional differences in notification rates are due to variations in laboratory procedures.

Methods: A questionnaire was sent to 69 New Zealand medical laboratories, requesting data on their identification procedures for enteric pathogens, including campylobacter.

Results: Changes over the last 5 years in laboratory techniques were insufficient to account for a marked increase in campylobacter isolations. On the basis of data provided by 12 laboratories, the number of specimens that grew campylobacter increased by 49% between 1992 and 1993. Differences in laboratory methods do not explain regional differences in campylobacter notification rates.

Conclusion: Changes in laboratory methodologies over the last 5 years do not appear to account for the recent national increase in campylobacteriosis notifications.