A multifaceted intervention to prevent American cutaneous leishmaniasis in Colombia: results of a group-randomized trial / Prevención de leishmaniasis cutánea americana en Colombia mediante una intervención múltiple: resultados de un ensayo de grupos aleatorios

Introducción. La leishmaniasis cutánea americana es endémica en Colombia, donde cada año son notificados aproximadamente 6000 casos nuevos. En la actualidad las medidas de prevención y control están limitadas al diagnóstico y tratamiento de los casos. Objetivo. Evaluar la eficacia de una intervención múltiple para prevenir la transmisión de Leishmania en el foco endémico de Tumaco, costa Pacífica de Colombia. Materiales y métodos. Se realizó un ensayo de grupos aleatorizados. Veinte veredas fueron pareadas según prevalencia de Leishmania, habitantes y participación comunitaria y luego asignadas aleatoriamente a intervención o control. La intervención incluyó toldillos impregnados con deltametrina, repelente (N, N-dietil-m-toluamida 20 por ciento y Permetrina 0,5 por ciento), modificación de lugares de reposo para los vectores y educación. Al cabo de un año se comparó la incidencia de infección y enfermedad producida por Leishmania en los dos grupos, se monitorearon la adherencia a la intervención y la aparición de efectos adversos. Los resultados finales fueron ajustados por el efecto de correlación intra-grupo. Resultados. Se presentaron 10 casos de leishmaniasis cutánea americana en el grupo que recibió la intervención y 23 en el grupo control, OR=0,42, IC95 por ciento 0,14-1,26. La intervención tuvo un mayor efecto en los niños menores de 10 años, en aquellos que residían en la periferia de la vereda y en veredas con una prevalencia de infección en niños pequeños mayor del 1 por ciento. Se reportaron eventos adversos leves asociados con el uso de los toldillos impregnados y el repelente en 2 por ciento de los participantes. Conclusión. Los casos nuevos de Leishmaniasis cutánea americana se redujeron en un 58 por ciento en el grupo que recibió la intervención. Sin embargo, el número pequeño de casos hace que la estimación de la medida de efecto sea imprecisa y no nos permite afirmar que la intervención tiene un efecto protector. Poblaciones específicas podr...

Introduction. American cutaneous leishmaniasis is endemic in Colombia, where approximately 6.000 new cases are reported every year. Current prevention and control measures are restricted to the diagnosis and treatment of cases. Objective. To evaluate the efficacy of a multifaceted intervention to prevent the transmission of Leishmania in the endemic focus of Tumaco, on the Pacific Coast of Colombia. Materials and methods. A group-randomized trial was conducted. Twenty villages were matched according to prevalence of Leishmania infection, number of inhabitants and level of community participation, and then randomly assigned to intervention or control. The intervention included deltamethrin-impregnated bednets, repellent (20% diethyltoluamide and 0.5% permethrin), modification of sand fly resting sites, and health education. Villages were under surveillance for one year and the use of the intervention measures monitored. The incidence of American cutaneous leishmaniasis and Leishmania infection in the two groups were compared, adherence to the intervention and adverse events were monitored, and the results were adjusted for village intraclass correlation. Results. Ten cases of American cutaneous leishmaniasis were confirmed in the intervention and 23 in the control group, OR = 0.42, 95% CI 0.14-1.26. The intervention had a greater effect in children < 10 years old, in people living on the periphery of the village and in villages with a prevalence of infection in small children > 1%. Adverse events associated with the use of the bednets and the repellent were reported in 2% of the participants and were always mild. Conclusion. Incident cases of American cutaneous leishmaniasis were reduced by 58% in the intervention group. However, the small number of cases renders the effect estimate imprecise and precludes us to claim a protective effect for the intervention. Specific populations could be the targets of simpler and more cost-effective interventions in the future.

A multifaceted intervention to prevent American cutaneous leishmaniasis in Colombia: results of a group-randomized trial.

INTRODUCTION: American cutaneous leishmaniasis is endemic in Colombia, where approximately 6.000 new cases are reported every year. Current prevention and control measures are restricted to the diagnosis and treatment of cases. OBJECTIVE: To evaluate the efficacy of a multifaceted intervention to prevent the transmission of Leishmania in the endemic focus of Tumaco, on the Pacific Coast of Colombia. MATERIALS AND METHODS: A group-randomized trial was conducted. Twenty villages were matched according to prevalence of Leishmania infection, number of inhabitants and level of community participation, and then randomly assigned to intervention or control. The intervention included deltamethrin-impregnated bednets, repellent (20% diethyltoluamide and 0.5% permethrin), modification of sand fly resting sites, and health education. Villages were under surveillance for one year and the use of the intervention measures monitored. The incidence of American cutaneous leishmaniasis and Leishmania infection in the two groups were compared, adherence to the intervention and adverse events were monitored, and the results were adjusted for village intraclass correlation. RESULTS: Ten cases of American cutaneous leishmaniasis were confirmed in the intervention and 23 in the control group, OR = 0.42, 95% CI 0.14-1.26. The intervention had a greater effect in children < 10 years old, in people living on the periphery of the village and in villages with a prevalence of infection in small children > 1%. Adverse events associated with the use of the bednets and the repellent were reported in 2% of the participants and were always mild. CONCLUSION: Incident cases of American cutaneous leishmaniasis were reduced by 58% in the intervention group. However, the small number of cases renders the effect estimate imprecise and precludes us to claim a protective effect for the intervention. Specific populations could be the targets of simpler and more cost-effective interventions in the future.