Prevalence and seasonality of campylobacter infections in the Primorsko - Goranska County (Croatia) during 2007

Aim To investigate the prevalence of campylobacter infections in the Primorsko-Goranska County(Croatia) and find out possible connection between the prevalence and environmental factors (the averagemonthly temperature and rainfall).Methods The data (number of stool samples examined, age and sex of the patients, monthly distributionof isolates and distribution of isolates according to the species) from the Laboratory for Diagnostics ofEnteric Infections of the Teaching Institute of Public Health of the Primorsko-Goranska County for theyear 2007 were analysed retrospectively. Meteorological data were obtained from the Croatian Meteorologicaland Hydrological Service and demographical data from the Republic of Croatia - CentralBureau of Statistics.Results During that year 7,105 stool samples were examined for Campylobacter spp. Campylobacterswere found in 561 samples (7.89%) but first isolates were identified in 310 cases and among themCampylobacter jejuni was found in 279 (90%) and C. coli in 31 (10%) cases. The patients were mostlychildren under four years of age (with the incidence of 669.21 cases/100,000) and young adults (20 - 29years) what resulted in the incidence of 116.24 cases/100,000. The highest numbers of Campylobacterspp. isolates were seen in July and August but the isolations were still frequent in September and October,which was in a positive correlation with the average monthly temperature (p=0.028), but there wasno correlation with the rainfall (p=0.61).Conclusions Our findings show bimodal age distribution of patients typical for developed countries.Seasonal variation is also noticed but it is not completely consistent with climate factors. Further investigationsof the incidence of campylobacteriosis and connection with the routes of transmission inhumans as well as the causes of seasonality are necessary.