The medicine does not replace standard praziquantel for older children and adults. Instead, it closes a longstanding gap in schistosomiasis treatment by giving health systems a dispersible, easier-to-administer option for children who are often exposed to contaminated water early in life but have been left outside mass treatment campaigns.
Why this schistosomiasis treatment matters for preschoolers
The breakthrough is no longer theoretical. In March 2025, Merck and the Pediatric Praziquantel Consortium said Uganda became the first country to treat a preschool-aged child with arpraziquantel, turning a long-running pediatric drug project into an actual treatment event. Soon after, WHO’s TDR program outlined rollout preparations in Senegal, underscoring that many children in high-prevalence settings are infected before they ever reach school age.
The path to this point took several years. In 2022, WHO updated its schistosomiasis guidance to expand preventive chemotherapy to all people in need, including preschool-aged children. In December 2023, the European Medicines Agency issued a positive scientific opinion on arpraziquantel, saying it was the first medicine formulated for the needs of preschool-aged children. By May 2024, the treatment had reached WHO prequalification, a milestone that helps countries and procurement agencies move closer to adoption.
From approvals to delivery: schistosomiasis treatment enters the field
Now the story is shifting from approvals to access. In Tanzania, health authorities and partners launched an 18-month Lake Zone pilot in February 2026 aimed at reaching more than 25,000 preschool-aged children, while also testing how arpraziquantel can fit into routine services and future national scale-up. That launch followed Tanzania’s 2025 distinction as the first country to grant regulatory approval for the medicine.
That practical phase matters. A medicine can win scientific backing and still stall if countries cannot register it, buy it, distribute it and explain it to families. Arpraziquantel’s slow arrival shows how neglected tropical disease innovation often works in practice: first the evidence, then policy change, then regulatory progress, and finally the harder task of getting treatment into health centers close to where children live.
What comes next for schistosomiasis treatment
Early rollout does not mean the access problem is solved. Endemic countries will still need financing, supply security, training and community trust to turn pilot programs into broad coverage. But for the first time, schistosomiasis treatment for preschoolers is no longer only a missing tool discussed in reports and conferences. It is beginning to exist inside real health systems.
That is why arpraziquantel matters beyond its formulation. It gives control programs a chance to align treatment with the way schistosomiasis actually behaves: early exposure, repeated reinfection and damage that can begin long before a child is old enough to join a school-based campaign. For countries trying to reduce transmission and protect children sooner, that is a meaningful breakthrough.
