The Sanitary Parasitology Unit at Valencia University in Spain has supported WHO/Europe for more than a decade, helping to reduce the risk of microparasitic diseases in humans and livestock primarily caused by snail- and insect-borne infections. Recently redesignated as a WHO Collaborating Centre (CC) on Fascioliasis and its Snail Vectors, the centre focuses specifically on helminthiases, or intestinal worms found within livestock, with research targeting zoonotic helminthiases and snail- and insect- borne infectious diseases. In addition to its work as a CC, the unit serves as a Reference Centre on Parasitology for the Food and Agriculture Organization (FAO) of the United Nations.
“WHO’s relationship with the Sanitary Parasitology Unit of Valencia University gives us a critical foothold in reducing infectious disease in especially vulnerable communities and age groups,” explained Dr Denise Mupfasoni, WHO Technical Officer, Prevention, Treatment and Care. “This redesignation is a further commitment to the work they do and the global value they bring. Thanks to their work, the WHO Global Neglected tropical diseases programme is able to guide fascioliasis-endemic countries on control measures to reduce infections in humans, especially in children.”
Leading global efforts in the fight against neglected tropical diseases
The Sanitary Parasitology Unit of Valencia University has the multidisciplinary capacity and skills necessary to conduct field work in endemic areas, with access to complete infrastructures for experimental studies in the laboratory. These include using high molecular biology techniques on cultures of living freshwater snails.
The CC was originally designated as a WHO CC after it suggested the inclusion of a rare, parasitic infection known as fascioliasis in the group of foodborne trematode infections, in the WHO’s priority list of Neglected Tropical Diseases (NTDs). The CC was included by the WHO in the initial NTDs Roadmap 2010–2020. The unit leads the worldwide WHO initiative against human fascioliasis in direct collaboration with the WHO Global NTD programme, and focuses on the public health problems caused by this disease at global, regional and national levels.
Between 2019–2023, the unit also led on activities including:
- transmission and epidemiology assessments;
- implementing, and monitoring of, One Health control measures;
- developing tools to reduce human infection;
- mapping the global distribution of fascioliasis; and
- classifying the lymnaeid snail species involved in disease transmission in human hyperendemic areas.
Saving the lives of children globally
Fascioliasis is a waterborne zoonotic parasitic disease caused by Fasciola hepatica parasites, which are in the group of foodborne trematodes. People are infected when they ingest aquatic vegetables to which the parasite larvae are attached. Acute phase symptoms can include fever, nausea, swollen liver, skin rashes and severe abdominal pain, and chronic-phase symptoms include intermittent pain, jaundice, anaemia, pancreatitis and gallstones. Chronic infections result in liver cirrhosis due to long-term inflammation, and can even lead to death. Children are the most at risk for the disease.
Given its high capacity to cause disease and mortality, along with the strong impact of fascioliasis on children and communities in areas more likely to affect human populations, the CC undertakes research to understand the transmission and epidemiology of this disease. It leads control intervention activities in collaboration with national health ministries and agriculture ministries. These activities support the 2030 Agenda for Sustainable Development and the Global Action Plan for Healthy Lives and Well-Being for All, established by the WHO.
Fascioliasis is a global disease, affecting a significant number of countries throughout the world, with high burdens reported in Latin America and the Middle East. The CC began studying the human fascioliasis hyperendemic disease, mainly affecting children, in the Bolivian Altiplano, in 1992. Once it acquired sufficient knowledge on disease transmission, and after verifying the safety and efficacy of mass drug treatment, preventive chemotherapy was implemented from 2009 in Bolivia. The mass drug treatments, complemented by One Health measures, have been a great success, with monitored results from 2023 showing a strong reduction in the overall prevalence and individual burdens of the disease in Bolivia, and therefore an improvement in child development. Although cases of foodborne trematodes have been reported from more than 70 countries worldwide, data on actual prevalence and burden is scarce.
“To answer the requests of WHO, in our WHO CC we need multidisciplinary approaches to research and activity in both field work and laboratory experiments, given the high complexity, worldwide transmission and epidemiology heterogeneity of a freshwater snail-borne zoonotic disease, such as fascioliasis,” explained Professor M Dolores Bargues, Medical Doctor, and Deputy Director of the CC.