R&D MODEL & PORTFOLIO
DNDi works on diseases that are transmitted in a variety of ways, from parasites living in two different hosts to viruses, worms, and a fungus. Curing these diseases requires not only an understanding of the infectious agents, but also an understanding of the interplay between infection, vector, and host.
Chagas Disease HAT
Chagas disease is caused by the kinetoplastid protozoan parasite Trypanosoma cruzi. It is primarily transmitted by large, blood-sucking reduviid insects widely known as ‘kissing bugs’.
HAT is caused by two sub-species of kinetoplastid protozoan parasites: Trypanosoma brucei (T.b.) gambiense (West and Central Africa) and T. b. rhodesiense (East Africa). Parasites are transmitted to humans by tsetse flies.
Leishmaniasis is a diverse and complex disease caused by more than 20 species of the kinetoplastid protozoan parasite. Leishmania parasites can be transmitted to humans by some 30 species of phlebotomine sandflies. Malaria is caused by the Plasmodium parasite. Five species are involved: P. falciparum, P. malariae, P. vivax, P. ovale & P. knowlesi. They are transmitted from person to person by the bite of infected anopheline mosquitoes. Onchocerciasis (River blindness), Lymphatic filariasis (Elephantiasis), and Loiasis (Loa loa infection) are all caused by parasitic filarial nematode worms. They are transmitted between humans by blood-sucking insects.
The human immunodeficiency virus is a lentivirus that causes HIV infection and acquired immunodeficiency syndrome. About 90% of the infected infants acquire the HIV virus from their HIV-positive mothers during pregnancy, delivery, or through breast-feeding (known as mother-to-child transmission).
The hepatitis C virus exists in six genotypes that cause liver disease. It is a blood-borne virus that is commonly transmitted through unsafe injection practices, contaminated medical equipment, and transfusion of unscreened blood.
Mycetoma is a slow-growing bacterial (Actinomycetoma) or fungal (Eumycetoma) infection. The exact route of Eumycetoma infection is unknown but it is thought to enter the body after the skin has been pricked (e.g. by a thorn).
18 › DNDi Annual Report 2015