Cystic Echinococcosis in Children: Addressing Research Needs, Filling Knowledge Gaps

Abstract

Cystic Echinococcosis (CE) is a common neglected disease in many communities around the world, causing substantial costs on the endemic communities. CE has been considered a disease of adulthood, mostly affecting age groups within 20-59 years. However, CE can be seen in early life even in patients younger than 5 years. While the disease is frequently reported from children in the endemic areas across the globe, children CE is even more neglected and under-represented in the literature. Here we present an overview on this topic, summarizing main features of pediatric CE, current findings, existing knowledge and information gaps and research needs on this issue. In adults the lungs are involved in less than 30% of CE cases, however in children, pulmonary hydatid disease has been reported to be up to 67%. Different patterns of hydatid cyst and multiple organ involvement have been frequently observed in children, probably due to the immature filtering mechanisms of the liver and lungs during infancy and childhood and the role of intestinal lymphatic channels in dissemination of the parasite. It is believed that children immune system is less responsive to hydatid cysts, therefore serological assays of CE in children are likely to result in more false negative outcomes. As the proportion of internal organs occupied by the cyst is much greater in children than the adult patients, CE in children is more likely to be symptomatic than adults. Another peculiar aspect of pediatric CE is that the disease has been more frequently observed in boys than girls. According to the data recently published by the European Register of Cystic Echinococcosis the contribution of male patients is more than the females in children and adolescents. While males constitute 65% of the CE patients in 0-9 years age group, the proportion decreased to 50% and 45% in 30-39 and 70-79 years age groups, respectively. Considerable gaps of knowledge exist in pediatric echinococcosis and further investigations are required on this topic. Major information gaps in children CE include the lack of age-specific data, natural history, detailed clinical picture, clinical trials of non-surgical approaches, genotype data, specific guidelines for diagnosis and treatment and WHO ultrasound classification.