Epidemiology of Campylobacteriosis in Castile and Leon, Spain,during the period 2008-2015

Objective: Campylobacter is considered the most frequent agent of gastroenteritis in humans all around the world. The aim of this study was to know the incidence, trend and seasonality of notified campylobacteriosis cases in Castile and Leon, Spain, from 2008 to 2015. In addition, to describe the type of case and source of notification, and study the influence of age, sex and Campylobacter species on the hospitalization of cases.

Methods: Retrospective cross-sectional study with a time series analysis. Data on notified campylobacteriosis cases were collected from the Epidemiological Surveillance System of Castile and Leon (2008-2015). Incidence rates and incidence rate ratios by age, sex and year of notification were calculated. In order to estimate trend and seasonality, a time series analysis was performed using a multiplicative method and adjusted to a linear and exponential model.

Results: From 4,330 cases analyzed, 49.4% of children aged under 5 were affected. The ratio of men to women was 1.43 and 61.8% of cases were notified from secondary care. C. jejuni was isolated from 72.3% of samples (n=2,593). Incidence rate ranged from 11.42 cases per 100,000 inhabitants in 2008 to 33.53 in 2015. The seasonality range was from 71.97% (13th four-week period) to 125.54% (9th four-week period). Hospitalization reached 62.5% for people aged 60 or over.

Conclusions: A growing trend of notified campylobacteriosis cases is observed in Castile and Leon (2008-2015), mainly in children aged under 5, with a peak in summer months. Males are more affected than females and hospitalization increases with age.