Estimating the current burden of Chagas disease in Mexico: a systematic review of epidemiological surveys from 2006 to 2017

Abstract

BackgroundIn Mexico, estimates of Chagas disease prevalence and burden vary widely. Updating surveillance data is therefore an important priority to ensure that Chagas disease does not remain a barrier to the development of Mexico’s most vulnerable populations.Methodology/Principal FindingsThe aim of this systematic review was to analyze the literature on epidemiological surveys to estimate Chagas disease prevalence and burden in Mexico, during the period 2006 to 2017. A total of 2,764 articles were screened and 38 were retained for the final analysis. Epidemiological surveys have been performed in most of Mexico, but with variable geographic coverage. Based on studies reporting confirmed cases, i.e. using at least 2 serological tests, the national seroprevalence of Trypanosoma cruzi infection was 2.26% [95% Confidence Interval (CI) 2.12-2.41], suggesting that there are 2.71 million cases in Mexico. Studies focused on pregnant women, which may transmit the parasite to their newborn during pregnancy, reported a seroprevalence of 1.00% [95% CI 0.87-1.14], suggesting that there are 22,930 births from T. cruzi infected pregnant women per year, and 1,445 cases of congenitally infected newborns per year. Children under 18 years had a seropositivity rate of 1.49% [95% CI 1.20-1.85], which indicate ongoing transmission. Finally, cases of T. cruzi infection in blood donors have also been reported in most states, with a national seroprevalence of 0.51% [95% CI 0.49-0.53].Conclusions/SignificanceOur analysis suggests a disease burden for T. cruzi infection higher than previously recognized, highlighting the urgency of establishing Chagas disease surveillance and control as a key national public health priority in Mexico, to ensure that it does not remain a major barrier to the economic and social development of the country’s most vulnerable populations.Author summaryIn Mexico, estimates of Chagas disease prevalence and burden vary widely due to the ecology and epidemiology of this disease resulting of many geographical, ecological, biological, and social interactions. Better data are thus urgently needed to help develop appropriate public health programs for disease control and patient care. In this study we analyzed published data on T. cruzi seroprevalence infection in Mexico between 2006 and 2017. This systematic review shows a national seroprevalence of T. cruzi infection of 2.26% [95%CI 2.12-2.41], with over 2.71 million cases in Mexico, which is higher than previously recognized. The presence of T. cruzi infection in specific subpopulations such as pregnant women, children and blood donors also informs on specific risks of infection and call for the implementation of well-established control interventions. This work confirms the place of Mexico as the country with the largest number of cases, highlighting the urgency of establishing Chagas disease control as a key national public health priority.

Historical Spatial Distribution of Zoonotic Diseases in Domestic, Synanthropic, and Wild Animals in the Mexican Territory of the Yucatan Peninsula

“…Although it was not the aim of the present study to establish a real estimation of the number of human cases in the region for each zoonotic disease, we must mention that the human cases officially informed on the Historical Epidemiological Bulletin are probably underestimated. For instance, concerning T. cruzi infection, a noticeable difference exists between the national official prevalence (0.65%) and the estimated prevalence obtained through a metaanalysis of recent research studies (3.38%) [59].…”