Guías clínicas de la enfermedad de Chagas: Parte II. Enfermedad de Chagas en el adulto, la infancia y adolescencia

Chagas Disease Expands Its Epidemiological Frontiers From Rural to Urban Areas

The infection with the hemoflagellate parasite Trypanosoma cruzi originates from America where the wildlife cycle remains to alternate between mammals and hematophagous triatomines. Transmission through contamination of the bite site by vector feces containing highly infectious forms of parasite or direct ingestion of T. cruzi-infected triatomines appear to be the dominant transmission mechanisms. Man joins the transmission when he enters this wild environment or takes the leaves of palms carrying vectors to build houses. Rural Chagas disease develops associated with populations of low economic resources, with infection and reinfection of vector bites since childhood, and the consequent evolution toward chronic cases in adults, when there is little therapeutic benefit to infected people. The progressive migration of people from rural to urban areas and the adaptation of vectors to the peripheries of cities due to displacement caused by deforestation or urbanization that has favored the presence of enzootic cycles with Panstrongylus geniculatus as the most widely distributed species and mammals (synanthropic and domestic) allow vector transmission by ingestion of food contaminated with excrements containing infectious trypomastigotes as the dominant transmission mechanism in the urban environment. Human-to-human transmissions through vertical mother–child infection, transfusions, organ transplants, and the possibility of sexual transmission, transform the epidemiology and the clinical evolution of Chagas disease in the urban environment. Vectors of American trypanosomiasis are no longer restricted to the endemic area, but its presence has been demonstrated in nonendemic areas of the United States, Asia, and other latitudes. The worldwide plague of bedbugs (Cimex lectularius) threatens the possibility of expansion of transmission since they are vectors susceptible to infection, transmission to mammals, trans-stadial penetration, and not being affected by T. cruzi infection at least experimentally. These factors, added to the presence of an unknown number of migrating Latin American asymptomatic carriers together with the presence of triatomines in other continents, have initiated the globalization of a pathology originating in the American continent. Only with an integrative approach, based on new and better tolerated and efficient drugs, vaccines and residual action insecticides, all of them included in an epidemiological surveillance program.

Detection of Trypanosoma cruzi antibodies in multitransfused patients in Colombia

INTRODUCTION

Chagas disease is a public health problem in Latin America. Even though vector-borne infection is the most important transmission mode for this disease, other modes such as transfusions require evaluation.

OBJECTIVE

To describe the prevalence of T. cruzi infection in multitransfused patients.

MATERIALS AND METHODS

We detected IgG antibodies against T. cruzi by two immunoassays in samples from multitransfused patients in four hospitals located in Bogotá and Medellín, Colombia. We analyzed the association with known risk factors, and we calculated the odds ratios (OR) with 95% confidence intervals using Stata 11™ statistical software.

RESULTS

In total, 479 samples were tested. Overall, T. cruzi antibody prevalence was 1.88% (nine patients). Five were onco-hematological patients, two were hemodialyzed, one had thalassemia, and one had suffered acute blood loss. We found no hemophilia patients. There was no association between known risk factors for transfusion-transmitted infection (such as the number of transfusion events, number of blood units and type of blood component) and the presence of anti-T. cruzi antibodies in this study. Only the hepatitis C virus infection showed a positive association with the presence of anti-T. cruzi antibodies (OR=5.68, 95% CI: 1.36-23.63).

CONCLUSIONS

The results of this study showed a low frequency of T. cruzi infection in multitransfused patients, suggesting that the risk of transfusion infection in Colombia is low. Known risk factors for transfusion-related infection were not associated with the presence of anti-T. cruzi antibodies.

Chagas disease in pregnancy: a non-endemic problem in a globalized world

BACKGROUND

Chagas disease, caused by the Trypanosoma cruzi infection, is an endemic cause of morbidity and mortality in Latin America. Infection during pregnancy may increase the risk for adverse maternal-foetal outcome.

METHODS

Review of significant articles regarding maternal-foetal T. cruzi infection in free-vector non-endemic regions.

RESULTS

Vertical transmission, even in vector-free world regions, occurs in 1 out of 20 seropositive mothers. T. cruzi infection increases the risk of miscarriage, preterm birth and neonatal infection which may cause infant death or severe sequelae. Prevention of T. cruzi vertical transmission is not feasible, although early diagnosis allows appropriate treatment of newborns with a 100% efficacy. The present document will recall the importance of T. cruzi mother-to-child transmission and maternal-foetal consequences in non-endemic areas.

CONCLUSION

It is highly recommended that infected pregnant women in non-endemic regions be accurately assessed.