Prevalence rate and risk factors of human cystic echinococcosis: A cross-sectional, community-based, abdominal ultrasound study in rural and urban north-central Chile

Abstract

Background Cystic echinococcosis (CE) caused by Echinococcus granulosus sensu lato (s.l.) is a neglected and underdiagnosed parasitic zoonosis that has a significant socioeconomic impact on rural communities relying on livestock farming. CE is endemic across Latin America, including Chile, where the Coquimbo region exhibits a relatively high record of hospital-based human cases and infected animals. However, the incidence of hospitalized CE cases may underestimate the real burden of infection in a population, since the majority of cases never reach medical attention or official disease records. Methodology/Principal findings In 2019, a cross-sectional, community-based study was conducted with the objectives of estimating for the first time the prevalence of human abdominal CE using abdominal ultrasound (US) screening in volunteers residing in urban and rural localities of the Monte Patria municipality located in Limarí province, Coquimbo region, Chile, and identifying the risk factors associated with human infection. Pre-screening activities included a 16-h lecture/hands-on training aimed at rural physicians that focused on the diagnosis of CE by US, based on current WHO recommendations. A total of 2,439 (~8% of municipality inhabitants) people from thirteen target localities were screened by abdominal US in June-July 2019. We found an overall CE prevalence of 1.6% (95% CI 1.1–2.2) with a significantly higher likelihood of infection in rural localities, older age classes and people drinking non-potable water; 84.6% of infected volunteers were newly diagnosed with CE. Cysts were either in active or inactive stages in equal proportions; active cysts were detected in all age classes, while 95.7% of inactive cysts occurred in >40 years-old subjects. Conclusions/Significance This is the first US survey aimed at detecting human infection caused by Echinococcus granulosus s.l. in Chile. Our findings indicate a high CE prevalence in the area, and contribute to define the demographic and behavioral risk factors promoting the transmission of the parasitic infection within target communities. Our results support the implementation of cost-effective strategies for the diagnosis, treatment and control of CE, and the need to improve the epidemiological surveillance system in Chile.

Africa-wide meta-analysis on the prevalence and distribution of human cystic echinococcosis and canine Echinococcus granulosus infections

“…The finding of higher prevalence in women concurs reports from Argentina [ 29 ] and Iran [ 24 ]. Our finding however contradicts the reports of Andrabi et al [ 25 ] from India and Acosta-Jamett et al [ 40 ] from Chile who reported higher prevalence of HCE in men compared to women. The higher prevalence observed in adults (≥ 18 years) compared to children (≤ 17 years) is in line with the report of Uchiumi et al [ 30 ] from Argentina and could be attributable to the chronic nature of the disease.…”

Liver cystic echinococcosis: A retrospective study on the demographics and clinical profile of patients managed at a single tertiary institution in central Eastern Cape Province, South Africa

“…Dogs feeding on infected offal in the vicinity further perpetuate the life cycle and transmission of the parasite to the environment. [20,21] Similarly, Ngcobo et al [26] noted that the majority of pulmonary CE cases in their study were from rural areas of KwaZulu-Natal and Eastern Cape provinces.…”

“…The traditional role of women in rural regions means that they are typically responsible for household duties, thereby increasing their exposure to potential sources of tapeworm eggs such as dogs, polluted water, soil and vegetables, and makes females more vulnerable than males. [17][18][19][20][21][22] CE can affect individuals of all age groups, but patients typically experience symptoms and indicators of the disease at a relatively late stage, [3,18] because the cysts in the liver grow slowly (at a rate of 1 -5 mm per year). [3,18] In terms of geographical location, the majority of our patients lived in Amathole district.…”

Cystic Echinococcosis in the Early 2020s: A Review

“…The first ultrasound-focused survey that focused on determining the prevalence rate of CE in Chile was published in 2022 [ 39 ]. The research identified the prevalence rate within the studied population as 1.6% (CI 95%, 1.1–2.2), while also concluding that the risk factors associated with the infection were rural areas, old age, and the drinking of non-potable water.…”