Date Published: December 26, 2007
Publisher: Public Library of Science
Author(s): Ricardo E. Gürtler, Albert Ko
Partial Text: With 10–15 million of people infected with Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae) and many more exposed to risk of infection, the burden of Chagas disease in Latin America amounts to as much as 2.7 times the combined burden of malaria, schistosomiasis, leishmaniasis, and leprosy in 2002 . Following a short, mostly subclinical acute phase and a very long asymptomatic phase with very low parasitemia, 25%–40% of infected humans develop chronic disease with cardiac, digestive, or neurologic manifestations that leads to a reduced life span . Human transmission of T. cruzi is mediated by nearly a dozen blood-sucking species of triatomine bugs that infest resource-limited, rural houses and their outbuildings, but it may also occur by blood transfusions and from infected mothers to their children.
Michael Levy et al. , describe for the first time the emergence of T. cruzi transmission in an urban or periurban environment, and its possible epidemic spread from one or several points of parasite introduction in a geographically defined area in the city of Arequipa, Peru. The primary aim of the study was to develop targeted screening strategies to detect T. cruzi infection in children from data collected during a vector control campaign directed against the major vector Triatoma infestans. Although household clustering of T. cruzi infection and vector infestation has long been known –, the researchers are also the first to describe the spatial aggregation of seropositive children within looser clusters of infected vectors.
Major strengths of the Levy and colleagues study may be found at levels that encompass study design and careful data collection in a well-defined area, to data analysis with sophisticated statistical methods and cautious interpretation of findings.
Levy et al.  raise two subjects that are rarely debated in the field of Chagas disease control: the optimal use of limited resources, and the integration of case detection and treatment of children into disease control programs that traditionally have focused on vector control. Mathematical modelling also supports the hypothesis that vector control combined with specific treatment is highly cost-effective compared with vector control alone . Lack of integration between both components entails lost opportunities for improved disease control.