Protocolo del Sistema Nacional de Vigilancia Epidemiológica: enfermedades vectoriales de origen parasitario. No. 04 / Protocol of the National Epidemiological Surveillance System: vector diseases of parasitic origin. No. 04

Estos protocolos están dirigido a personal médico, paramédico y otros profesionales que realizan acciones gerenciales y operativas de vigilancia epidemiológica en los servicios de salud del país, y están divididos en varios tomos para dar a conocer y actualizar la identificación y medidas de control para diversos padecimientos a fin de continuar con el mejoramiento de las capacidades técnicas de los trabajadores de salud, que permita planificar la prestación de servicios con decisiones partiendo de un enfoque epidemiológico comprobado, para responder a los cambios de tendencias epidemiológicas y con ello contribuir al fortalecimiento de prácticas asertivas de la salud pública de nuestro país.

Knowledge, attitudes, and practices toward onchocerciasis among local population in Bioko Island, Equatorial Guinea

Introduction: Since 1998, the African program for onchocerciasis control has been working with ultimate goal of reducing the public health impact associated with onchocerciasis in Equatorial Guinea. Although dedicated community engagement is crucial for the success of this program, there is no information on the levels of community's knowledge, attitude, and practice (KAP) toward onchocerciasis in this country. Methods: A cross-sectional study was carried out in Bioko Island from mid-January to mid-February 2014. Sampling was carried out by multistage cluster survey. Sociodemographic characteristics, KAP, and stigma-related questions were collected through a pretested questionnaire. A bivariate analysis was performed and results were adjusted by sex and age using logistic regression. Results: A total of 140 housekeepers or head of households agreed to participate. Around 54% of the interviewees had heard about the disease, of which more than one-third identified the disease as filariasis (28/68, 41.2%). Overall, 19.3% respondents highlighted the bite of a blackfly as the main mode of transmission. From those who had a familiar affected by onchocerciasis in the past, 21 out of 32 (65.6%) pointed ivermectin as the preferred treatment and 43.8% pointed out the health center as the first choice place to seek for treatment. About 67.1% of individuals believed that having onchocerciasis would not cause any contact avoidance with other members in the community. Conclusions: People's practices toward onchocerciasis tend to be better than disease knowledge in Bioko Island. Increasing awareness through community-based campaigns and educational activities is encouraged in the current onchocerciasis preelimination stage at Bioko Island

Presencia y distribución espacial de Simulium sp. (Díptera: Simuliidae) en dos provincias de Angola / Presence and spatial distribution of Simuliumsp.(Diptera: Simuliidae) in two provinces of Angola

En el oeste de África los miembros del complejo Simulium damnosum son los vectores de la oncocercosis. El objetivo es obtener datos sobre la presencia y distribución de simúlidos en dos provincias de Angola. El trabajo se realizó en las provincias de Huambo y Bié donde se muestrearon 24 cuerpos de agua entre julio y agosto, 2015. Todos los sitios se localizaron por encima de una altitud de 1 000 m y solo tres resultaron negativos a la presencia de simúlidos. Estos resultados constituyen los primeros que se obtienen sobre la presencia y distribución espacial de Simulium sp. en Angola de gran importancia, pues la superposición de los mapas de distribución de la infección humana y los vectores permiten localizar áreas con peligro de transmisión(AU)

In West Africa Simuliumdamnosum complex members are the main vectors of onchocerciasis. The objective of this paper was to collect data on the presence and spatial distribution of black flies in two provinces of Angola. The research work was conducted in Huambo and Bié provinces where 24 water bodies were sampled between July and August 2015. All the studied sites were located above 1 000 m of altitude and only three of them were found to be negative for the presence of black flies. These were the first results obtained on the presence and spatial distribution of Simulium sp. in Angola and are of great importance because overlapping the distribution maps of human infection and of vectors allows finding the areas at risk of transmission(AU)

Impacto de la ivermectina sobre las geohelmintiasis en el foco de oncocercosis en Colombia / The effect of ivermectin on geohelminth frequency (i.e. as used in the onchocerciasis control program in Colombia)

Objetivo: Evaluar el efecto de la ivermectina sobre la frecuencia de infección por geohelmintos en una población colombiana incluida en el Programa para la Eliminación de la Oncocercosis en las Américas. Métodos: Estudio de evaluación de impacto con enfoque longitudinal como punto referente inicial, la población de Naicioná (1996) y como control, sujetos de la misma población (2008). Para el enfoque transversal se usó como referente la población de Naicioná en 2008 y como control, sujetos de Dos Quebradas en 2008. El procesamiento de las muestras de materia fecal se hizo por Ritchie-Frick modificado. Resultados: Ascaris lumbricoides fue el parásito más frecuente 49,6 % (60/121; IC 95 %:37,8-63,8) en Naicioná y 47,4 % (36/76; IC 95 %: 33,2-65,6) en Dos Quebradas. El mayor efecto de la ivermectina en mayores de 5 años fue la disminución del riesgo de infección, para Trichiuris trichiura, de 86 % (IC95 %:74-93) en la evaluación longitudinal y 63 % (IC 95 %:24-82) en la evaluación transversal. La disminución en la frecuencia de Strongyloides stercoralis fue 93 % (IC 95 %: 45-99), en la evaluación longitudinal y 85 % (IC95 %:-031 - 99) en la evaluación transversal. Conclusiones: El uso de la ivermectina en el contexto del Programa para la Eliminación de la Oncocercosis en las Américas no es suficiente para el control de la morbilidad de todas las geohelmintiasis, se requiere de programas integrales que incluyan los componentes de educación y saneamiento básico.

Objective: Evaluating the effect of ivermectin on soil-transmitted helminthes (STH) infection frequency in a Colombian population included in the Onchocerciasis Elimination Program for the Americas (OEPA). Methods: This was an impact evaluation study which adopted a longitudinal approach using the population of Naicioná (1996) as baseline for comparison to people from the same population as controls (2008). The cross-sectional approach involved comparing the reference population of Naicioná (2008) to the population of Dos Quebradas (2008) used as controls. Fecal samples were processed by a modified Ritchie-Frick method. Results: Ascaris lumbricoides was the most frequently found parasite in Naicioná (60/121; 49.6 %: 37.8-63.895%CI) and in Dos Quebradas (36/76; 47.4 %: 33.2-65.6 95 % CI). Ivermectin’s main effect on the population aged over 5 years was a decreased risk of Trichiuris trichiura infection in both longitudinal assessment (86 % reduction: 74-93 95 % CI) and cross-sectional assessment (63 %:24-82 95 % CI). A 93 % reduction (45-99 95 % CI) in Strongyloides stercoralis frequency was found in longitudinal assessment, compared to 85 % in cross-sectional assessment (-031-99 95 % CI). Conclusions: Ivermectin use in the OEPA is not sufficient for STH morbidity control. Integrated programs including education and basic sanitation are required.

Onchocerciasis Control in South Sudan

This paper gives an overview of the Community Directed Treatment with Ivermectin (CTDI) projects in 2009. Data from the 2010 report will be published when it is available. Box 1 at the end of this article gives treatment guidelines

Adverse reactions from community directed treatment with ivermectin (CDTI ) for onchocerciasis and loiasis in Ondo State, Nigeria

Onchocerciasis is an endemic disease in Ondo state, Nigeria. Community directed distribution of ivermectin is currently on-going in some local government areas of the state. Randomly selected persons (2 331 males and 2 469 females) were interviewed using a modified rapid assessment procedure for Loa loa (RAPLOA) to assess community directed treatment with ivermectin. The retrospective study evaluated the coverage, impacts and adverse reactions to the drug treatment. A questionnaire was administered by house-to-house visit in six local government areas, implementing community directed treatment with ivermectin (CDTI) in this bioclimatic zone. A total of 2,398 respondents were reported to have participated in the treatment. The overall ivermectin coverage of 49.96% was recorded (range 0 - 52% in different communities). Adverse reactions from ivermectin administration were experienced in 38% of individuals. Diverse adverse reactions experienced included predominantly itching (18.50%); oedema, especially of the face and the limbs (8.2%); rashes (3.4%) and body weakness (2.4%). Expulsion of intestinal worms occurred in 0.96% of the respondents. The occurrence of adverse reactions in relation to age categories was statistically significant. Neither fatal nor severe adverse reactions were reported by respondents. Significantly, despite experienced adverse reactions, continued participation, acceptability and compliance to ivermectin treatment was expressed by the various communities. This attitude is in consonance with the African Programme for Onchocerciasis Control (APOC) objectives. Rev. Biol. Trop. 56 (4): 1635-1643. Epub 2008 December 12.

La oncocercosis es endémica en el estado Ondo, Nigeria. Se seleccionaron 4 800 personas al azar para evaluar con encuesta retrospectiva la cobertura, efectos y reacciones al tratamiento farmacológico con ivermectina administrado por la misma comunidad. La cobertura global de ivermectina fue 50 % con reacciones adversas en 38 % de los individuos. Estas fueron comezón picazón (18%), edema, especialmente de la cara y las extremidades (8%), erupciones cutáneas (3%) y debilidad (2%); dependieron de la edad y no hubo reacciones más graves. La expulsión de las lombrices intestinales se produjo en 96% de los encuestados. A pesar de las reacciones adversas, hubo continuidad, aceptación y cumplimiento del tratamiento con ivermectina, en consonancia con los objetivos del Programa Africano para el Control de Oncocercosis (APOC).

Susceptibility of Simulium damnosum complex larvae to temephos in the Tukuyu onchocerciasis focus; southwest Tanzania

Tukuyu onchocerciasis focus was earmarked for vector control using insecticide against larval stages.Susceptibility tests of mature larvae of Simulium damnosum s.l. vectors to temephos insecticide were carried out before and after two years of insecticide treatment of rivers within Tukuyu onchocerciasis focus, south-western Tanzania. The tests were done in 1999/2000 and 2004 using WHO standard methods. Mature larvae were exposed to 9 concentrations of temephos active ingredient, from the weakest 0.00975mg/litre to the strongest of 2.5mg/l. Each test concentration and control was run in duplicates of 25 larvae each, set for three hours in a cool temperature. After incubation, test solution was discarded and larval condition checked. Numbers of larvae in each category were recorded and used to determine mortality rate for each concentration as well as for the LC50 and LC95. A total of 1,666 larvae were tested, 942 during the pre- and 724 post-treatment. Results showed that both pre and post-treatment samples were susceptible, attaining 100% mortality at the diagnostic dose of 1.25mg/l, and LC50 between 0.129-0.34mg/l pre - and 0.144-0.211 mg/l (95% CI, P<0.05) post- treatment. These values fall within the standard diagnostic dose of ≤0.4mg/l for susceptible S. damnosum s.l populations. It was concluded that the endemic S. damnosum population was susceptible to temephos before and after two years of intermittent field application. Temephos was thus recommended for continued use in onchocerciasis vector control in the Tukuyu focus, to complement Community Directed Treatment with Ivermectin, but close monitoring of vector susceptibility should be done

Lutte antivectorielle dans le programme de lutte contre l'onchocercose au Nord du Togo à la suite du stage effectué à l'OMS/Oncho Kara du 1er janvier 1999 au 31 Mai 1999

L'onchocercose est une maladie parasitaire débilitante transmise par la piqûre de simulies infectées qui vivent et se reproduisent à proximité des rivières dans les régions tropicales. Une exposition prolongée aux piqûres de ces simulies peut entrainer des déficiences visuelles graves pouvant aller jusqu'à la cécité d'où le nom familier de la maladie, cécité des rivières. Dans la région de savane de I'Afrique de l'Ouest, l'onchocercose pose depuis de nombreuses années un grave problème de santé publique et constitue un obstacle au développement économique, forçant les communautés entières à abandonner leurs villages situés dans des zones fertiles au voisinage des cours d'eau pour échapper aux effets dévastateurs de l'infection. Le Programme de Lutte contre l'Onchocercose a été créé en 1974 pour combattre la maladie, d'abord par l'application généralisée de larvicides par épandage sur les gîtes larvaires de la simulie et, plus récemment, par le traitement de la communauté à l'ivermectine. Le programme couvre onze pays et, après vingt-cinq ans d'existence, a fait la preuve de son efficacité, étant parvenu non seulement à ramener le fardeau de la morbidité à un niveau insignifiant mais aussi à amener diverses organisations et des particuliers à travailler ensemble dans le cadre d'un effort concerté et soutenu afin d'atteindre l'objectif qu'il s'était fixé

Atividades preliminares do programa de controle e tratamento da oncocercose no território Yanomâmi, Roraima, Brasil / Preliminary activities of control and treatment programme of onchocerciasis in Yanomami territory, Roraima, Brazil

After to characterize the clinic and epidemiological picture of the onchocerciasis in Yanomâmi region, RR, Brazil, begun in 1993, the National Health Foundation (FNS) implemented a Control and Treatment Pilot Project in Tootobi and Balawaú. Here, it was studied skin biopsies from 426 inhabitants. In the nodules of 86.7 per cent from patients was encountered Onchocerca volvulus. The over-all prevalence in the examined population was 66.2 per cent . The treatment with ivermectin covered 80.1 per cent of total population. Adverse reactions, light and moderate, of the medicament were reported in 12.3 per cent of the patients. These results agreeing with the medical literature and suggesting the viability of to increase of the programme for all Yanomâmi area in the next phase.

Social anthropological aspects of onchocercal skin disease in Nebbi District; Uganda

"In providing health care; the busy medical practitioner often lacks the ""I-You"" quality of the personal experience of illness. This paper reports the perceptions; beliefs and practices of persons living in a hyperendemic focus of onchocerciasis in nebbi District; north-western Uganda. The study involved the use of focus group discussion and semi-structured interviewes designed to explore the experiences; meanings; and illness-related coping strategies employed by the community. The results indicated that oncherciasis believed that the cause of the disease is the small black fly (Kamacur); dirty water or rivers. However; non-affected individuals believed that the condition is caused by poor personal and environmental hydiene; and personal contact with persons affected by onchocerciasis. Affected people recommended public health education to control the diases while non-affected people; recommended the avoidance of personal contact with affected people; ensuring personal hygiene; and the improvement of environmental sanitation and the nutritional status of community. The belief systems of the community are probably responsible for the discriminatory practices of the people against those affected by the condition. The results indicate that onchocerciasis is a serious public health problem which needs to be controlled."

Onchocerciasis in Ecuador: the situation in 1989

Details are given of the prevalence rates of onchocerciasis from the most recent surveys (1989) conducted in northern Ecuador. The disease has intensified and dispersed considerably due to migration of infected individuals and the presence of a highly efficient vector. Comparison of these data with those from two previous surveys carried out in 1982/83 and 1986 and correlated with entomological findings highly the danger of the formation of new foci of onchocerciasis in areas currently free of the disease. Recommendations are made for further entomological studies in areas either recently or likely to be affected by the disease where potential vectors are unknown or different to those registred in the Santiago focus. Invermectin treatment with local vector control in specific areas is advocated to reduce the disease to a low level of public health importance