ABSTRACT
OBJETIVO: Presentar la perspectiva general del control de Rhodnius prolixus, el principal vector en la transmisión de la enfermedad de Chagas en Centroamérica, durante el período 1998-2009 en Nicaragua. Describir el control vectorial realizado y presentar la distribución geogrßfica de las localidades infestadas. MÉTODOS: Se estudió y analizó la información disponible en el Ministerio de Salud de Nica ragua. Se visualizó la distribución geogrßfica de R. prolixus mediante el programa visualiza dor de mapas Quantum GIS 1.5.0. RESULTADOS: Se determinó que 59 localidades en 14 municipios de 8 departamentos presen taron antecedentes de infestación con R. prolixus entre 1998 y 2009. La altitud de las locali dades infestadas oscila entre 160 y 1 414 metros sobre el nivel del mar. Se han tratado con mßs de dos ciclos de control químico 56 localidades. En el segundo ciclo de rociamiento se detectó la presencia del vector, pero durante el tercer ciclo no se lo encontró en ninguna localidad. CONCLUSIONES: La mayor concentración geogrßfica de R. prolixus se observó en dos depar tamentos de la región norte: Madriz y Nueva Segovia. La cantidad de localidades infestadas es menor en Nicaragua que en otros países centroamericanos. El control químico ha sido exitoso en las localidades intervenidas, pero es necesario fortalecer el sistema de vigilancia institucio nal y comunitaria tanto para vigilar la reinfestación con R. prolixus como para ampliar la cobertura del control vectorial.
OBJECTIVE: Present an overview of the control of Rhodnius prolixus, the principal vector in the transmission of Chagas' disease in Central America, during the period 1998-2009 in Nicaragua. Describe the vector control carried out and the geographical distribution of the infested localities. METHODS: The available information in Nicaragua's Ministry of Health was studied and analyzed. The geographical distribution of R. prolixus was visualized using the Quantum GIS 1.5.0 map visualization program. RESULTS: It was determined that 59 localities in 14 municipalities of 8 departments had a history of R. prolixus infestation between 1998 and 2009. The altitude of the infested localities ranges between 160 and 1 414 meters above sea level. A total of 56 localities have been treated with more than two cycles of chemical control. The presence of the vector was detected in the second spraying cycle, but it was not found in any locality during the third cycle. CONCLUSIONS: The greatest geographical concentration of R. prolixus was found in two departments in the northern region: Madriz and Nueva Segovia. There were fewer infested localities in Nicaragua than in other Central American countries. Chemical control has been successful in the localities treated, but the institutional and community surveillance system needs to be strengthened to monitor R. prolixusreinfestation and expand vector control coverage.
Subject(s)
Animals , Humans , Chagas Disease/prevention & control , Insect Control/organization & administration , Insect Vectors , Rhodnius , Altitude , Chagas Disease/transmission , Government Programs/organization & administration , Insect Vectors/parasitology , Insecticides , Nicaragua , Population Surveillance , Program Evaluation , Retrospective Studies , Rhodnius/parasitology , Trypanosoma cruziABSTRACT
BACKGROUND: Assam, in north-east India, is extremely rich in hydrocarbon deposits and the oil industry is the major contributor to its economy. A large number of oil fields and related installations in Assam are located in forest areas or on their fringes where malaria is a serious problem among field staff and security personnel, adversely affecting oil production. We carried out an operational research study for one year in a forest-based industrial security camp of Dibrugarh district and developed an effective malaria control strategy for such areas. METHODS: The specific strategy was formulated and implemented after taking into account the local epidemiology of malaria, vector's ecology and malaria risk behaviour of the camp inmates. The strategy was based on reducing the man-vector contact, using deltamethrin-treated mosquito nets in conjunction with mosquito repellent cream and weekly chemoprophylaxis with 300 mg chloroquine. The impact of the strategy was monitored entomologically and epidemiologically for one year after implementation. RESULTS: The mean landing rate of Anopheles dirus, the vector mosquito in the camp area, was 5.03 per person per night during the monitoring. In spite of such a high density of the vector, the man-vector contact was effectively checked by the intervention measures adopted. As a result, the incidence of malaria in the camp was reduced by > 90% as compared to previous years and the number of malaria cases came down from 6.7 per 1000 man-nights in 1998-99 to 0.06 in 2000-01. Mortality due to malaria was completely eliminated. CONCLUSION: Control of malaria should be based on the local determinants of transmission. The use of insecticide-treated mosquito nets in conjunction with a mosquito repellent cream is a good intervention for controlling Anopheles dirus-transmitted malaria in the forests of north-east India. The control module developed on the principle of reducing man-mosquito contact is easy to implement, cost-effective and replicable in similar forest-based locations.