A retrospective analysis of human cystic echinococcosis in Sardinia (Italy), an endemic Mediterranean region, from 2001 to 2005.

To assess the current impact of human CE in Sardinia (Italy) and to monitor the changes over time, a survey has been carried out for the period 2001-2005 using hospital inpatient discharge reports (HDR) as information source, supplementing data wherever possible with additional information retrieved directly from medical records. The total of 726 admissions with "Echinococcosis" as primary diagnosis (annual rate of 8.9 per 100,000 inhabitants) concerned 540 CE cases with an annual mean incidence rate of 6.62 per 100,000 inhabitants. Male-to-female ratio was 1.36, suggesting a marked risk associated with traditional male occupations. Age-specific incidence showed increasing rates of clinical CE with age for both genders. The liver was found to be the most common localization, affecting 72% of patients, while pulmonary CE was more frequent in males than in females. CE risk was unevenly distributed in the island. The more pastoral areas had the highest probability of humans becoming infected, with an incidence rate of clinical cases of approximately 14.0 per 100,000 for areas with sheep/inhabitants index of >6. Compared to the past, incidence rates appear to be decreasing both for pulmonary and hepatic localizations, while there is a reversal of the CE "urbanization" trend resulting in "ruralization", accompanied by a greater degree of parasite ecological "isolation" and focus-points of infection risk. In spite of this decrease, the cost of hospital care alone (approximately 4 million euros) suggests that the monetary plus non-monetary costs of CE are still very high but not fully recognised.