How common is Campylobacter infection?
Campylobacter species represent one of the most common causes of bacterial diarrheal illness worldwide. According to the Centers for Disease Control and Prevention (CDC), there are about 1.3 million cases of Campylobacter infection each year in the United States alone. Campylobacter is, therefore, the most common cause of bacterial foodborne illness, ahead of Salmonella species.
In 2019, 9,731 confirmed cases of Campylobacter infection were reported to the CDC through FoodNet, which represented an incidence rate of 19.5 cases for every 100,000 persons in the United States. These numbers represent a 13% increase in incidence compared to data from 2016-2018 and an approximate 70% increase compared to 2006. This drastic increase in confirmed cases may be due to the widespread use of new detection methods and increased tracking. Although the nature and degree of underreporting is subject to dispute, all agree that the confirmed cases represent just the tip of the iceberg. Indeed, one study estimates the annual incidence rate for Campylobacter to be around 1,000 cases per 100,000 persons.
Campylobacteriosis follows a pattern of seasonality, with more cases occurring in summer months than winter months. The majority of cases of illness caused by Campylobacter are independent from recognized outbreaks; however, some research shows that the peak of illness in the warmer months is more significant when looking at cases which are part of outbreaks rather than total overall cases.