Schistosomiasis in children: a major public health problem

Schistosomiasis is one of the most prevalent parasitic diseases worldwide, and a very important one in terms of public health burden and economic impact. At present, the group of preschool-age children is left untreated due to lack of clinical data and a missing appropriate child-friendly formulation of the drug praziquantel. 

Schistosomiasis (also known as bilharzia) is one of the most prevalent parasitic diseases. It is a poverty-related disease that leads to chronic illness. The threat posed by schistosomiasis is substantial: the WHO estimates that at least 218 million people worldwide required treatment in 2015, of which more than 90% live in Africa.1 Schistosomiasis affects a large proportion of children under 14 years of age, including an estimated 28 million preschool-age children. In these very young children, prevalence of infection may exceed 60%.2

Schistosomiasis is acquired when people come into contact with fresh water infested with the larval forms (cercariae) of parasitic blood flukes, known as schistosomes. The microscopic adult worms live in the veins draining the urinary tract and intestines. Most of the eggs they lay are trapped in the tissues and the body’s reaction to them can cause massive damage. Left untreated, schistosomiasis can lead to anemia, stunted growth, reduced learning ability and chronic inflammation of the organs, which can be fatal in the most serious cases.

As efforts focus on morbidity control and elimination, there is a pressing need to treat preschool-age children (under 6 years old). No suitable drug formulation is made available for this high-risk group, which accounts for about 10% of the 258 million people already infected. The age group of preschool-age children is strategically important: they play a role in local disease transmission and an active infection acquired at an early age might aggravate the clinical significance of schistosomiasis in later-life.

The existing drug of choice for the treatment of schistosomiasis is praziquantel (PZQ), which was developed in the 1970s. A WHO-recommended global strategy to control schistosomiasis already exists; preventive chemotherapy involves yearly administration of PZQ to entire populations at risk. Tablets (usually 600 mg) are given as single oral doses, but the prophylactic treatment is suitable only for adults and school-aged children. Younger children usually cannot swallow the existing tablets because of their large size and bitter taste. More importantly, clinical data for the treatment of very young children are scarce and an appropriate pediatric drug to treat schistosomiasis does not exist, therefore a large young population remains untreated.

The Pediatric Praziquantel Consortium is developing a PZQ formulation that is more suitable for younger children, including infants and toddlers. The formulation should be smaller, orally dispersible, and have improved taste properties compared to the approved 600 mg tablet.

Learn more about our pediatric formulation technology and our development program, or visit our timeline to find out where we stand.

1WHO Schistomiasis Fact Sheet (accessed 20 July 2017)
2WHO Report of a meeting to review the results of studies on the treatment of schistosomiasis in preschool-age children