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 investigated 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

Geographic distribution and morphometric differentiation of Triatoma nitida usinger 1939 (Hemiptera: Reduviidae: Triatominae) in Guatemala

“…nitida was previously reported in Guatemala in the departments of Baja Verapaz, Alta Verapaz, Chiquimula, Jalapa and Guatemala (Peñalver 1953, Tabaru et al 1999. This is the first report of the presence of this species in the departments of Huehuetenango, Jutiapa, Quiche and Santa Rosa.…”

“…Peñalver (1953) included T. nitida together with T. dimidiata and Rhodnius prolixus, as the main vectors of Chagas disease in the country. A recent study reported the presence of T. nitida from inside houses (Tabaru et al 1999). However, the real vectorial importance of this species in Guatemala has not been established.…”

“…Geographic distribution -From 1994 to 1997, we searched for triatomine bugs in 2,809 houses over all of the 22 departments of Guatemala (Tabaru et al 1999), and T. nitida was never found in altitudes below 950 m above sea level (m.a.s.l.). Therefore during 1997 and 1998, 917 new houses were examined, all above this altitude.…”

The number of families of Triatoma dimidiata in a Guatemalan house

“…This would contribute to genetic variation within the populations of this vector. These results also suggest the existence of migration, which would explain the high rates of reinfestation found after fumigation of houses (Tabaru et al 1999). Migration makes difficult the development of effective vector control strategies.…”

Identification and characterization of microsatellite markers in the Chagas disease vector Triatoma dimidiata

“…While the domestic species R. prolixus has been reported to support higher transmission rates to humans and is therefore considered to be a more important disease vector (Ponce, 1999;Tabaru et al, 1999), T. dimidiata is a much greater challenge to control because of its adaptation to both domestic and peri-domestic habitats. Vector control programs in South America have proven highly successful at reducing both home infestation rates and the incidence of new infections in affected areas (Schmunis et al, 1996).…”