Bridging the innovation gap for neglected tropical diseases in México: capacity building for the development of a new generation of antipoverty vaccines

The neglected tropical diseases (NTDs) represent a group of chronic parasitic and related infections that promote poverty because of their impact on child development, pregnancy, and worker productivity. The estimated 20 million Mexicans who live below the poverty line suffer disproportionately from a high prevalence of neglected tropical diseases such as amebiasis, Chagas disease, dengue, leishmaniasis, soil-transmitted helminth infections, trachoma, and vivax malaria. However, because the NTDs occur predominantly among the poor, new industrial and financial models are required to establish innovative technologies to address these conditions in Mexico and elsewhere in Latin America. In response, the Slim Initiative for Antipoverty Vaccine Development was established to foster a public/private partnership between key academic, government, and industrial institutions in the U.S. and Mexico. Initial emphasis will be placed on developing new vaccines for Chagas disease and leishmaniasis, two of the highest burden NTDs in Mexico and Mesoamerica.

Protective immunity elicited by ultraviolet-irradiated third-stage infective hookworm (Necator americanus and Ancylostoma caninum) larvae in mice and hamsters.

The protective immunity elicited by ultraviolet-irradiated third-stage infective larvae of Necator americanus (UV-NaL3) and Ancylostoma caninum (UV-AcL3) was evaluated in laboratory mice (a non-permissive model) and hamsters (a permissive model). After optimizing the time of exposure to UV-irradiation, both oral and subcutaneous vaccination routes with UV-AcL3 in mice were explored. Oral vaccination was more effective at reducing the number of challenge AcL3 entering the lungs, whereas subcutaneous vaccination was more effective at blocking muscle entry. When UV-irradiated NaL3 and non-irradiated AcL3 were used as vaccines in hamsters, both of them were effective at reducing adult hookworm burdens. However, the length of protection afforded by UV-irradiated L3 was substantially greater than that resulting from immunization with non-irradiated L3. A single dose was less effective than multiple doses. The protective immunity elicited by UV-irradiated NaL3 given once every other week for a total of three immunizations was similar to that elicited by non-irradiated AcL3 given during the same schedule. Protection was not significantly affected by administering the L3 on a weekly basis for a total of three immunizations, even though the antibody titers were reduced using this schedule. These studies will facilitate the elucidation of the mechanisms underlying larval protection.

Incorporating appropriate technology into North American schools of public health

El término tecnología adecuada se refiere a la tecnología sanitaria que se crea, produce, ofrece y monitorea en un contexto general donde se toman en cuenta los sistemas, las personas y la comunidad. Esta tecnología abarca el diseño, desarrollo y adopción de productos sanitarios, entre ellos nuevos medicamentos, vacunas y métodos diagnósticos, y de medios computadorizados aplicables a la genómica funcional, vigilancia epidemiológica, evaluación de la carga de morbilidad, adjudicación de recursos sanitarios, creación de modelos matemáticos y análisis de efectividad en función del costo. En conjunto, estos medios son especialmente promisorios para el control y la eliminación de diversas enfermedades tropicales que han recibido escasa atención. Actualmente, buena parte de la investigación y el desarrollo en torno a tecnologías adecuadas está a cargo de alianzas formadas recientemente entre los sectores público y privado. No obstante, es preciso incrementar la investigación y el entrenamiento en este campo en las escuelas de salud pública de América del Norte en vista de los efectos sanitarios y económicos que se calcula que tendrá la tecnología adecuada en países en desarrollo.

Epidemiology of hookworm infection in Itagua, Paraguay: a cross sectional study

A cross-sectional study in Itagua, Paraguay tested 192 people for the presence, intensity and species of hookworm infection. Fifty-nine percent of these individuals were found to be infected. Intensity of infection was determined on 92 per cent of infected individuals by quantitative egg counts. The high intensity hookworm infections, which cause the greatest morbidity, were clustered between the ages of five and 14 years. No differences were seen between genders. The species of hookworm was determined for parasites reared from 72 per cent of infected individuals. Both Necator americanus and Ancylostoma duodenale were identified, although the former species predominated. We conclude that hookworm infection continues to be a public health problem in Paraguay, particularly among children and adolescents who suffer from high intensity infections. A. duodenale continues to persist in the Western Hemisphere and has not been completely displaced by N. americanus.