Professor Maria-Gloria Basáñez

EPIDEMIOLOGY AND MODELLING OF INDIRECTLY TRANSMITTED MACROPARASITES

Motivation: Macroparasites are important causes of morbidity worldwide.  Apart from the direct effects of infection, they may also have immunosuppressive effects that render hosts vulnerable to more lethal pathogens.  Indirectly-transmitted helminth infections are particularly complex.  The lifecycle of these parasites involves more than one host for their transmission; the lifespan of the worms may be long in comparison to that of the hosts, and morbidity is associated with the intensity of infection.  All this poses challenging problems for the development of mathematical frameworks for their population dynamics and the effect on these dynamics of control interventions.

Human onchocerciasis, better known as ‘River blindness’ has been endemic in 34 tropical countries.  Although the Onchocerciasis Control Programme (OCP) in West Africa (1975-2002) has greatly improved the situation in its 11 participating countries, infection by Onchocerca volvulus (the causal agent of River Blindness) still poses an important public health problem in many areas of Africa, Yemen, and Latin America.  In Latin America, the Amazonian focus (between Venezuela and Brazil) has levels of infection prevalence, intensity, and transmission similar to those present in West Africa before the inception of OCP.  Onchocerciasis is one of the Neglected Tropical Diseases (NTDs).  Collectively, the NTDs impose disease burdens similar to those of HIV and Malaria.  The NTDs include the filariases, the schistosomiases, the soil-transmitted helminthiases, the trypanosomiases and leishmaniases, and bacterial infections such as trachoma, among others.