In 2010, based on the experience gained in the 2009 influenza pandemic, the surveillance is strengthened with the implementation of the hospital surveillance of SARI.
Objective To determine the epidemiological characteristics and etiological agents of ILI and SARI.
Methodology All cases from sentinel sites in the period from January to October 2010 were included. The analysed variables were: hospitalisations by epidemiological week, age, sex, entrance to ICU, death, presence of comorbidity, risk factors, and identification of the causative agent.
Results Sentinel Surveillance of ILI detected 799 patients. The most affected age group was young adults (15–39 years of age) with 55.82% (446/799). Only 11% (83/781) had some co morbidity and/or risk factor. Regarding SARI hospital surveillance, 1692 notifications were recorded. Of these, 10.17% (172/1692) required treatment in intensive care unit (ICU), 53 patients died (specific lethality for SARI 3.13%). The distribution by age groups showed an increased risk in children under 5 and older than 60, with rates of 51% (868/1692) and 16% (274/1692), respectively. Nearly 30% (479/1692) of patients had comorbidity and/or risk factors. Samples were taken in 71.3% of cases (1206/1692) and positivity was 22.6% (273/1206). The most frequently identified viruses were RSV, 39% (106/273), Influenza A H3, 18% (49/273) and influenza A H1N1, 15% (41/273).
Conclusions With the incorporation of the SARI surveillance, respiratory viruses have been better characterised. The Influenza A H1N1 virus had a similar pattern to the seasonal respiratory viruses.