Prevention and control of congenital transmission of Chagas disease is one of the major goals of the World Health Organization Chagas disease Control Program; screening of infected pregnant women is important for diagnosing infection and testing their babies.22
In this study, the prevalence and risk factors associated with T. cruzi
infection in pregnant women in Casanare, Colombia, were studied as a first step to emphasize before health authorities the need to implement a surveillance system for congenital Chagas disease in Colombia.
The observed prevalence of 4.0% is the highest reported until now in pregnant women in Colombia. This prevalence is lower than that reported in disease-endemic regions of Argentina and Bolivia, but higher than those reported in Peru and Brazil.7–9
The most relevant T. cruzi
infection risk-associated factors were age, knowledge of vector, rural residency and level of education. Similarly, Hidron and others using a multivariate model reported that longer residence in a disease-endemic province, residence in a rural area, and poor housing conditions were associated with T. cruzi
In this respect, it is important to highlight that housing characteristics of the pregnant women included in our study were better in 2010, when the study was conducted, than during their childhood. A lower frequency of this risk factor was observed in 2010. This finding could explain the higher prevalence of infection found in older women. Housing conditions have been investigated in Colombia as risk factors associated with the presence of triatomines inside households.24
Although our study explored the association with a different but related outcome (T. cruzi
infection), some variables, such as having animals inside the houses, could be related to infections in households.
Education level has an interesting dose-response effect that shows a correlation between the lower level of education and the higher risk for disease. It has been established that education level is an important risk factor related to the prevalence of neglected tropical diseases and, in particular, for Chagas disease. Having subsidized health insurance was found to be an important risk factor by bivariate analysis. This finding is of special importance because in Colombia testing for Chagas disease is not included in this type of health insurance.25
Consequently, this finding indicates that health policy planners should include this testing in insurance coverage. Moreover, Viotti and others found that a low rate of cardiomyopathy progression is associated with more years of education and higher medical insurance coverage.26
These findings are similar to those in our study, which showed that social inequities and socioeconomic problems can increase the likelihood of acquiring diseases.
Few studies have been conducted to determine risk factors for T. cruzi
infection in pregnant women; most studies focused on congenital cases. Risk factors found in this study constitute an important base for conducting a more specific and direct search for Chagas disease. For regions where Chagas disease is not endemic, it is especially important to investigate possible congenital transmission of Chagas disease among neonates on the basis of age and housing conditions of the mother during her childhood.6
Trypanocide drugs are not indicated during pregnancy. For that reason, this study, the etiologic treatment of women after delivery and breastfeeding was implemented as a way to prevent congenital transmission during future pregnancies or complications during chronic disease.27
Likewise, the prevalence of infection in relatives was higher (9.3%) than in pregnant women (4.0%). This finding is consistent with those of several reports suggesting that screening of Chagas disease in siblings and relatives of infected mothers is an imperative necessity. Home visits represented an important way to find more infected persons.28
This kind of door-to-door investigation has been implemented with great success in identifying congenital cases in Paraguay and Bolivia.29,30
The associated risk factors found are important for conducting a more specific and direct search for Chagas disease. For regions where Chagas disease is not endemic, it is especially important because physicians seldom consider a diagnosis of Chagas disease among their pregnant patients.6
In summary, the prevalence results of T. cruzi infection in pregnant women point out the importance of implementing a Chagas disease surveillance program in this population as a way to control congenital Chagas disease. Also, the results obtained reflect the prevalence of Chagas disease in young women in a disease-endemic region in Colombia, who could benefit from specific anti-parasitic treatment. Finally, the risk factors associated with T. cruzi infection in pregnant women found in this study constitute an important base to design a more specific and directed program for screening for Chagas disease pregnancy.