Ultrasound-based population survey for abdominal cystic echinococcosis in Albania: Results from the NDTND project

BACKGROUND: Albania is considered endemic for cystic echinococcosis (CE). Recent data on prevalence and incidence of CE in Europe suggests that the Balkan region is the epicentre of this neglected parasitic disease in Europe. In Albania, a retrospective study has estimated a mean incidence of 1.49 cases/100,000 people. We aimed to assess the prevalence of CE in eight municipalities across the country. METHODOLOGY/PRINCIPAL FINDINGS: We enrolled participants aged >5 years in an ultrasound (US)-based screening for CE in 23 villages in eight municipalities from three prefectures. Participants were enrolled in the study after signing an informed consent and underwent a complete abdominal US. CE cysts were classified according to the WHO-IWGE ultrasound classification. A total of 3,710 participants were included in the study, of whom 2,685 (72.4%) were female. The median age of participants was 55 years (interquartile range, 42-64). Six confirmed CE cases were identified by US with cysts in the liver (1 CE2, 2 CE3a, 1 CE4 and 2 CE5). The crude prevalence of CE detected by US was 0.16% (95% CI 0.06-0.35), with a standardized prevalence of 0.11% (95% CI 0.02-0.21) according to the reference rural population 2023 in Albania. We calculated that the number of individuals who might currently be infected with CE in the rural area of this country was 908 (95% CI 138-1,678). CONCLUSIONS: This was the first population-based US field survey on CE conducted in Albania. Our screening yielded a lower prevalence than expected. However, the presence of active cysts points to ongoing transmission. Our study had several limitations including the use of a convenience sample that limited the attendance of males and children. In the future, surveillance activities for CE should be strengthened in Albania to better characterize the epidemiology of the disease.