Temporal trends in rate of hospitalization for rotavirus gastroenteritis in the pediatric population in Italy: cross sectional study utilizing national Hospital Discharge Database

Study design. This was a retrospective observational study, conducted using hospitalization data from national Hospital Discharge Database (HDD) available on the website of the Italian Ministry of Health. Objective The primary objectives were to estimate the frequency of hospitalization for Rotavirus gastroenteritis (RVGE) for the period 2002-2005 in children aged 0-14 years in the different regions of Italy, and to analyze temporal trends of hospitalization rates (HR) for geographical location. Methods. In Italy there are no specific surveillance systems for RV disease in place, so HDD are one mean by which diseases trends among hospitalizations may be observed. Cases of RVGE were identified using ICD9-CM code 00861. Three aged groups are studied: 0-1, 1-4 , and 5-14 years. In order to estimate HR, we used population for each study year published by the National Institute of Statistic website. Data analysis was performed using STATA 12. The nptrend command was used to examine for significant trends in temporal HR (p<0.05), based on the Wilcoxon rank-sum method. Results. In the study period, a total of 21,300 RVGE diagnosis were collected in children. The following HR for rotavirus were recorded: 71/100,000 residents in 2002, 49/100,000 in 2003, 51/100,000 in 2004 and 66/100.000 in 2005. RVGE accounted for the highest percentage of admission in children of 1-4 years of age. The respective HR were found to be: 2002:181/100,000; 2003:157/100,000; 2004:161/100,000; 2005: 204/100,000. The region with higher HR is Trentino Alto Adige while Calabria, while Valle D'Aosta and Sardegna present the lowest values. The analysis of temporal trends by geographical location shows that in the North, the average HR reached a peak in 2002, before declining in 2003 and 2004 and return to a high value in 2005. A similar trend, was observed for the Centre. In the South and Islands observed a different trend, indeed the HR varies from 39/100,000 in 2002 to 31/100,000 in 2003. In the following years, HR substantially increases, going to 48/100,000 residents. The analysis of temporal trend in the HR in the four years examined showed no statistically significant differences (p>0.05). Conclusions. The highest HR observed in the Northern compared to the rest of Italy could reflect actual geographic variability in incidence of rotavirus infection or disease, or could be due to differences in the sensitivity of the hospital discharge databases for detecting RVGE.