The geographical distribution of vectors of Chagas' disease and populations at risk of infection in Guatemala

Abstract

: The fauna and the geographical distribution of vectors of Chagas' disease were investigated based on the man-hour collection, from mud walls or palm-thatched houses in 236 villages, from the year 1995 through 1997, throughout Guaternala. A total of 1,131 vectors cornprising 731 (64,6%) of Triatoma dimidiata, 53 (4,7%) of Tl nitida and 347 (30,7%) ofRhodniusProlixus were found. 71 dimidiata was collected in 16 eut of 22 departments, whereas R. Prolixus was collected in five departments, and T nitida was collected only in three departments. The total number of R, prolixus was not small, 85% of the bugs was collected frorn 800 m to 1,400 m above sea level in the present study areas. We collected more bugs in the east and the southeast departrnents of the country, such as in the borders with Honduras and El Salvador. The rate of positive houses with bugs is the highest in Jutiapa, followed by Alta Verapaz, Chiquimula, Santa Rosa, and Quiche. The bug density in the in- vestigated houses is the highest in Chiquimula, while the geographical dispersion of bugs is the widest in Jutiapa. The natural infection of bugs with Trypanosoma cntzi is the highest in Zacapa. Based on the above-rnentioned positive rate of bugs and from the data of the 1994 National Census in Guatemala, we concluded that the depart- ment$ with high risk to Chagas' disease are Jutiapa, Alta Verapaz, Chiquimula, Quiche and Santa Rosa, followed by Zacapa, Jalapa, Baja Verapaz, El Progreso and Escuintla. We have estimated that approximately 330,OOO people live in the areas at high risk to the infection of Chagas' disease in Guatemala.