By Rossely Paulo
Jürg Utzinger (Swiss Tropical and Public Health Institute) was one of the key note speakers at the recent meeting of the British Society for Parasitology. He gave a great overview of some of the history of Neglected Tropical Diseases (NTDs) and areas where innovation is needed.
NTDs: Where did the term come from?
Three of the eight Millennium Development Goals are health-related. Although NTDs were not specifically mentioned, Goal 6 is focussed on combating HIV, malaria, TB and other diseases. Jürg explained that the conceptual framework of the Neglected Tropical Diseases was formulated in the years following the 2000 launch of the Millenium Declaration. NTDs, as a concept, went on to be popularised in seminal papers written by David Molyneux, Peter Hotez, Alan Fenwick and David Rollinson. Many at this time were arguing that it is important to look across the spectrum of the diseases that particularly affect poorer people in low-income settings rather than singling out a few priority illnesses. An initial list of NTDs was drawn up that clustered together 15 complaints.
Innovation in work on NTDs
Jürg explained that large–scale, longitudinal, community-based surveys have provided a great opportunity to drive innovation in NTDs by allowing us to assess population risk and guiding interventions for control and elimination.
But challenges remain
For example the current anthelminthic drug – albendazol and mebendazole – have a low kill rate against Trichuris which lead us to the conclusion that there is an urgent need to develop new drugs. One alternative could be multiple dosing of existing drugs which decreases the Trichuris parasitemia rate, the hardest parasite to cure. Diagnosis of various NTDs such as S. mansoni are still largely dependent on stool examination based on the Kato-Katz thick smears technique. But this has become a big concern due to its low sensitivity particularly in low-endemicity areas. Therefore, more sophisticated diagnostic techniques are required such as the Point-of-Care urine assay for the detection of Circulating Cathodic Antigen (POC-CCA) and the multivalent faecal egg count (FLOTAC) methods which are three times more sensitive than Kato-Katz. There is a need for more integrated control programming which brings together different sectors. Jürg pointed to efforts in China and Zanzibar where work on schistosomasis control and elimination is based on working with stool samples, agricultural factors, Mass Drug Administration, snail control and vector behaviour as examples of interesting practice.
NTDs are finally on the radar screen of policy makers but how do we sustain these positive developments. We have some tools for control and elimination but they are insufficient! We need constant innovation and validation of the tools and strategies. Jürg ended by stressing that innovation is crucial to prepare and be ready for the future and that collaboration, communication and partnership are the absolute keys to success.