Seroprevalence of Chagas disease in urban and rural indigenous populations of the south of Gran Chaco

Abstract

Background: In Latin America, Chagas disease is endemic, with a high prevalence in rural indigenous communities and an increasing prevalence in urban areas owing to migration from rural areas with active vector transmission. This study aimed to assess differences in the prevalence of Chagas disease in urban and rural moqoit communities, one of the main ethnic indigenous groups in the south of Gran Chaco.Methods: A seroprevalence study was conducted in six moqoit populations in the Santa Fe province, Argentina. The variables studied were serology results for Chagas disease, residents of urban or rural areas, age, and sex. Results:The results showed that 9.26% of the 702 volunteers evaluated and 18.32% of the 131women of childbearing potential were seropositive. According to the calculated prevalence ratio, the prevalence of Chagas disease in urban communities was6.41 (95% confidence inverval: 3.73-11.02) times higher than that in rural communities: 21.59% in urban communities vs. 3.37%in rural communities. Conclusions:The seroprevalence found in the moqoit community was higher than the estimated level for the general population of the same region, with a greater impact in urban areas than in rural areas. The urbanization of groups of people with poor socio-sanitary conditions in the second half of the 20th century could have caused this higher seroprevalence of Chagas disease.

Chagas Disease: Seroprevalence and Associated Factors in Indigenous Communities of the Southern Limit of Argentine Chaco

“…Although, in the present work, it was found that the risk of infestation is present, the residual effect of insecticides would keep homes free of infestation for the time being; hence, the prevalence found is due to the fact that the infection is chronic, and serology remains positive for life. In this sense, other authors [ 7 ] found greater seroprevalence in urban populations than in rural ones, due to the migration to the cities of families that had worse social and sanitary conditions in rural areas.…”

“…On the other hand, this activity was developed with these three communities due to the feasibility of access, and it should not be ruled out that, in the most remote communities and with greater difficulties to access, the risks and seroprevalence are different. In this sense, a seroprevalence study in the region [ 7 ] found that Chagas disease was more frequent in urban communities than in rural ones, because people with the worst socioenvironmental conditions migrated more frequently to urban settings and, therefore, these people were the most at risk of infection. This point may also explain the higher seroprevalence found in the present work compared to [ 7 ], in which urban and rural communities were studied.…”

“…In this sense, a seroprevalence study in the region [ 7 ] found that Chagas disease was more frequent in urban communities than in rural ones, because people with the worst socioenvironmental conditions migrated more frequently to urban settings and, therefore, these people were the most at risk of infection. This point may also explain the higher seroprevalence found in the present work compared to [ 7 ], in which urban and rural communities were studied. In the present work, only the communities with greater ease of access, which are urban or close to urban centers, were included, and these communities would have a higher seroprevalence.…”

“…When the risk factors that influenced this difference in prevalence were investigated, it was found that the distribution coincided with social and economic factors, with the Chaco region being the most disadvantaged [ 6 ]. A more recent seroprevalence study found 18.32% of Chagas disease in indigenous communities of the southern Gran Chaco, but risk factors were not evaluated [ 7 ].…”