5. Scientists discussed below discount floripondio as an insecticide.
6. Leading this research are Dr. Gonzalo Tapia, director, and biologist Jose Luis Alcazar, both ofProyecto Chagas of the Universidad Mayor San Simon, Cochabamba; Dr. Gene Bourdy of Instituto Boliviano de Biologia de Altura (IBBA); and botanist Suzanna Arrazola of the Herbario, Cochabamba.
7. There is hope that a novel compound code-named D0870, which has been shown to cure both long-term and short-term Chagas’ disease in mice (Urbina et al. 1996), will do the same in humans; however, it is in the early phases of clinical development for other infections. (See Appendix 13.)
1. Meningoencephalitis due to T. cruzi has been reported in pharmacologically immunodepressed patients and in patients with AIDS (Jost et al. 1977; Corona et al. 1988; Del Castillo et al. 1990). (See Appendix II.)
2. In addition to these practical considerations, T. cruzi have unique properties that make them evasive targets for potential chemotherapeutic agents and therefore present formidable challenges to pharmacologists and medical chemists. T. cruzi are intracellular parasites, found in a variety of tissues. The effectiveness of a chemical compound depends on its capacity to cross the vascular endothelium and cell membranes into the cytoplasmic compartment of the parasite. T. cruzi is not a homogenous speciesthere are geographic strains which vary in tissue tropism and response to chemotherapy and biochemical parameters such as electrophoretic profiles of isoenzymes and peptides. The value of a particular drug depends on its effectiveness against both the amastigote and trypomastigote stages of all geographic strains (McGreevy and Marsden 1986:115-27). (See Appendix 13.)
3. In another study, Bryan and Tonn (1990:14) report higher rates of T. cruzi infection in captured (domestic) triatomines, with averages from 40 to 50 percent and infection rates of 70 to 90 percent in rural areas of the Cochabamba and Chuquisaca departments of Bolivia. (See Appendix 5.)
4. A recent study analyzed hemotherapy and the problem of transfusional Chagas’ disease in 850 Brazilian municipalities from 1988 to 1989. It found that some type of hemotherapy was practiced in 68.8 percent of these municipalities (Moraes-Souza et al. 1995). Prior screening of donors was carried out by 75.2 percent of the services for syphilis, 65.4 percent for hepatitis, 53.8 percent for AIDS, and 66.8 percent for Chagas’ disease. In the case of Chagas’ disease, only 10.3 percent of services used the chemoprophylaxis of gentian violet. Most services used only one serologic technique to screen donors, and the proportion of potential donors with positive serology for anti-T. cruzi was around 1 percent. (See Appendix 13.)
5. Although the potential problem of the blood supply in the United States has been recognized for some time (Schmunis 1985), the recent diagnosis of Chagas’ disease acquired through blood transfusion in the United States (Grant et al. 1989) and Canada (Nickerson et al. 1989) has significantly highlighted the seriousness of this problem (Skolnick 1989, Kirchhoff 1989).
6. In Brazil in 1911 Carlos Chagas considered the possibility of congenital transmission of T. cruzi when he found trypomastigotes in the blood-smear of a two-month-old child whose mother was also infected (quoted in Howard and Rubio 1968). In Venezuela in 1949 Dao reported other cases of congenital Chagas’ disease in Latin America (quoted in Bittencourt 1976). In Chile, Howard (1962) observed that 0.5 percent of premature babies weighing less than 2,000 grams (4.4 pounds) suffered from congenital Chagas’ disease. In Salvador, Bahia, and Brazil, Bittencourt and colleagues (Bittencourt and Barbosa 1972, Bittencourt, Barbosa, et al. 1972) found that 2 percent of stillborn babies were infected with T. cruzi; and, in Argentina, Salem and colleagues found slightly higher rates, 2.35 percent among stillborn infants (quoted in Bittencourt 1975). By 1979 the number of described cases had reached 100, giving the impression that congenital transmission of Chagas’ disease is infrequent. However, this impression is misleading, because the registered cases are only of fetuses and premature stillborns and do not include congenital Chagas’ disease in newborns delivered at term (Bittencourt et al. 1974). The varying degrees of fetal and neonatal pathology in such countries as Argentina, Brazil, and Chile may be related to inherent characteristics of the parasite (Moya 1994). The fact that the incidence of infection remains the same in each of these countries and geographic regions suggests that population-related factors are not involved. Various factors having to do with the mother, the fetus, and the parasite are more likely implicated in transplacental transmission.
7. The newborns were delivered at the Percy Boland Maternity Hospital in the city of Santa Cruz and observed from August 1979 until July 1980. Blood samples from newborns and mothers were used to investigate the presence of T. cruzi by means of the modified Strout concentration, which has the highest sensitivity (95.2 percent; but only for acute cases) when compared to other direct parasitological testing
