BackgroundIn the Philippines, the Department of Health (DOH) is the governing agency for the health system and is mandated to provide national policy direction and develop national plans, technical standards, and guidelines on health. Under the Local Government Code of 1991, local government units (LGUs) were granted autonomy and responsibility for provision of health services. This decentralisation has posed challenges in terms of capacity and coordination. Here, we describe the War on Worms (WOW) campaign, which was developed and implemented to provide technical support to DOH and LGUs in the prevention and control of helminth infections in the Philippines. MethodsIn 2012, the WOW Campaign was implemented in Davao del Norte, Philippines. Advocacy fora were conducted to forge partnerships between different sectors and solicit support of local officials. Health workers received training and resources, and social mobilisation activities were conducted in the community to raise awareness of helminth control. With the endorsement of the Department of Education (DepEd), children in schools aged 5–12 years were given anthelmintics via school-based, teacher-assisted mass drug administration (MDA). Combined MDA for soil-transmitted helminthiasis (STH) and schistosomiasis was eventually implemented in schistosomiasis-endemic sites to simplify and increase efficiency of treatment for both infections. Parasite assessment using the Kato-Katz technique was conducted in sentinel sites at the beginning of the project to provide baseline helminth status in the area. After MDA, we monitored coverage rates, and adherence to the programme. Follow-up parasitological assessment after four rounds of MDA was also conducted to monitor outcomes of the deworming programme. FindingsIn its 5 years of implementation, the WOW Campaign has generated evidence for policy formulation to improve control of intestinal helminthiasis. The combined MDA among school-aged children showed a marked increase from the 31% coverage rate in 2013 to 69% in 2014. This increasing trend continued with the 75% and 90% combined MDA coverage rates in 2015 and 2016, respectively. The baseline and follow-up parasitological assessments conducted in 2012 and 2015, respectively, showed reductions in the prevalence of STH and schistosomiasis. In 2012, the baseline parasitological assessment in school children showed a cumulative STH prevalence and moderate-to-heavy intensity STH prevalence of 14·7% and 0·5%, respectively, with 3·1% schistosomiasis prevalence. In 2015, the follow-up parasitological assessment showed a decrease in the prevalence of STH and moderate-to-high intensity STH to 4·2% and 0·3%, respectively. Schistosomiasis prevalence also showed a reduction to 0·3%, meeting WHO target schistosomiasis prevalence of <1%. Lessons from the WOW Campaign, such as the school-based teacher-assisted combined MDA, increased coverage rates, and decreased prevalence rates, contributed in the formulation of policies for the National School Deworming Day (NSDD), National School Deworming Month (NSDM), and Harmonized Schedule and Combined Mass Drug Administration (HSCMDA). Likewise, a memorandum of understanding among the DOH, Department of Education, Department of Interior, and local governments was developed for the implementation of policies. InterpretationAside from generating evidence to inform programmes and policies, research serves as a good platform to initiate intersectoral collaboration. Support of local governments was crucial in the implementation of the campaign. Initiating intersectoral collaboration and soliciting the support of local officials are key steps in bridging research to policy, particularly in decentralised health systems like the Philippines. FundingAsian Community Trust.