Interrupting Chagas disease transmission in Venezuela
Rev. Inst. Med. Trop. Säo Paulo
;
43(1): 37-43, Jan.-Feb. 2001. mapas, tab, graf
Article
in English
| LILACS
| ID: lil-285683
RESUMO
The interruption of vectorial transmission of Chagas disease in Venezuela is attributed to the combined effects of ongoing entomoepidemiological surveillance, ongoing house spraying with residual insecticides and the concurrent building and modification of rural houses in endemic areas during almost five decades. The original endemic areas which totaled 750,000 km², have been reduced to 365,000 km². During 1958-1968, initial entomological evaluations carried out showed that the house infestation index ranged between 60-80 percent, the house infection index at 8-11 percent and a house density index of 30-50 triatomine bugs per house. By 1990-98, these indexes were further reduced to 1.6-4.0 percent, 0.01-0.6 percent and 3-4 bugs per house respectively. The overall rural population seroprevalence has declined from 44.5 percent (95 percent C.I. 43.4-45.3 percent) to 9.2 percent (95 percent C.I. 9.0-9.4 percent) for successive grouped periods from 1958 to 1998. The annual blood donor prevalence is firmly established below 1 percent. The population at risk of infection has been estimated to be less than four million. Given that prevalence rates are stable and appropriate for public health programmes, consideration has been given to potential biases that may distort results such as a) geographical differences in illness or longevity of patients; b) variations in levels of ascertainment; c) variations in diagnostic criteria; and d) variations in population structure, mainly due to appreciable population migration. The endemic areas with continuous transmission are now mainly confined to piedmonts, as well as patchy foci in higher mountainous ranges, where the exclusive vector is Rhodnius prolixus. There is also an unstable area, of which landscapes are made up of grasslands with scattered broad-leaved evergreen trees and costal plains, where transmission is very low and occasional outbreaks are reported
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Insect Control
/
Triatominae
/
Chagas Disease
/
Insect Vectors
Type of study:
Evaluation studies
/
Prevalence study
/
Risk factors
Limits:
Animals
/
Humans
Country/Region as subject:
South America
/
Venezuela
Language:
English
Journal:
Rev. Inst. Med. Trop. Säo Paulo
Journal subject:
Tropical Medicine
Year:
2001
Type:
Article
Affiliation country:
Venezuela
Institution/Affiliation country:
Ministerio de Sanidad y Asistencia Social/VE
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