Leishmania are a group of vector-borne protozoan parasites causing leishmaniasis disease in humans and animals with an estimated 0.2-0.4 million, and 0.7-1.2 million, annual new cases of visceral and cutaneous leishmaniasis, respectively. The transmission cycles involve a diversity of zoonotic reservoirs and different sand fly vector species. The disease spectrum in humans includes cutaneous to disseminated and metastasised mucocutaneous lesions to life threatening visceral involvement. Against transmission, there are no human vaccines, animal culling is controversial and vector control is complex and usually unsustainable. Novel methods to combat transmission are under field evaluation.
Chagas Disease due to infection with trypanosoma cruzi is responsible for an estimated 1.2 million human cases of potentially lethal cardiomyopathy in Latin America. One important route of transmission is from blood-feeding triatomine bugs. Long-term vector exposure and repeated T. cruzi superinfections are considered major determinants of cardiomyopathy risk; treatments are ineffective to reverse established heart disease progression. Prevention of infection through effective vector control is therefore the best available tool to decrease the burden of Chagas disease.
Human onchocerciasis, also known as “river blindness”, is caused by chronic infection with Onchocerca volvulus, a filarial nematode worm transmitted by blackflies. 99% of cases worldwide occur in Africa where Simulium damnosum sensu lato (s.l.) is the most important vector. Mathematical transmission models to optimize control options in support of the WHO 2021-2030 NTD roadmap currently suffer from uncertainties due to the absence of data on age- and sex-related individual exposure to vector bites. Current methods of measuring biting rates largely rely on human landing catches (HLC), but which are labour intensive, prone to error, and often considered unethical.