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.

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).

Dermatitis caused by Simulium [Blackflies] bite

A 32-year-old man was attacked by flies while camping around Khorram Abad, Lorestan Province, western Iran. Pruritic dermatitis with marked edema and considerable discomfort appeared mainly on the lower legs. The flies were identified as Simulium. Simuliids are tiny bloodsucking flies, popularly known as blackflies or buffalo flies, belonging to the dipterous, family Simulidae. They are occurred worldwide, breed in fast-flowing streams, and are a major animal pest

Identificaçäo de áreas de estratificaçäo epidemiológica no foco de oncocercose na regiäo Yanomami, Roraima, Brasil / Identifying areas of epidemiological stratification in an onchocerciasis focus in Yanomani territory, Roraima, Brazil

Visando a um adequado planejamento, análise e acompanhamento do Programa de Tratamento, Controle e Eliminaçäo da Oncocercose Humana no Brasil, foram estudadas 27 áreas geográficas e examinados 3.974 indivíduos. Assim, foram identificadas e estratificadas quatro áreas epidemiológicas, tendo por base as prevalências diferenciadas em cada uma delas.

Estudios comparativos clínicos y epidemiológicos de la oncocercosis entre dos grupos raciales del área hiperendémica de Ecuador / Comparative clinical and epidemiological studies between 2 racial groups in the hyperendemic area of onchocercosis in Ecuador

Se evaluó la importancia de los factores raciales en la epidemiología y las manifestaciones clínicas de la oncocercosis en la raza negra y la raza indígena Chachi, dos grupos étnicos diferentes del área hiperendémica del foco oncocercótico ecuatoriano. Los Chachi presentaron una significativa mayor densidad de microfilarias en la piel. De los negros, 72,2 por ciento presentaron lesiones oncocercóticas en la piel comparado con 56,4 por ciento en los Chachi. Se encontró mayor prevalencia de nódulos palpables en los Chachi (51,4 por ciento vs. 43,0 por ciento). La presencia de microfilarias en la cámara anterior del ojo fue más frecuente en los Chachi (51,9 por ciento vs. 34,2 por ciento), pero se evidenció una mayor prevalencia de corioretinitis y atrofia del nervio óptico en los negros (17,6 por ciento vs 11,2 por ciento y 8,5 por ciento vs. 0,5 por ciento, respectivamente)

Screening for high prevalence areas of onchocerciasis - a feasibility study on the application of the indirect questionnaire approach in Kafa; South Western Ethiopia

"A cross-sectional study was undertaken to test the validity and operational feasibilty of the so-called ""indirect questionnaire approach"" for the screening of communities for Onchocerciasis in Kafa; south west Ethiopia. Pretested questionnaire was distributed via the Awraja (district) education office to six junior high schools. Students were interviewed and their perceived morbidity; as reflected by the occurrence of selected features of Onchocerciasis; was recorded by their teachers. Subsequently a medical team has visited the same schools and undertook clinical and parasitological test to validate the first estimates. Using the Spearman's rank correlation; the positive response rate of students was found to be negatively correlated to the parasitological estimates of Onchocercal infection; probably due to the immune tolerance and adaptation to the features among the high prevalence groups; and poor perception of the problem in general. The indirect questionnaire approach using the educational sector is considered to be operationally feasible and 7.5 times less costly than the biomedical approach; but not advantages speed wise. Further study is recommended to assess the applicability of the method in different demographic and socioeconomic situations."

The potential for dispersal of onchocerciasis in Ecuador in relation to the distribution of the vector Simulium exiguum (Diptera: Simuliidae)

The future dispersal of onchocerciasis in Ecuador is dependent on the distribution of cytotypes of the vector species complex Simulium exiguum. Over the last 14 years, collections of larvae have been made from over 25 rivers, between 80-1600 m altitude, from various sites on both sides of the Andes, Analysis of larval polytene chromosomes was used to determine the distributions of each cytotype. On the western side of the Andes, the Cayapa cytotype (the only cytotype directly incriminated as a vector) has a distribution from Santo Domingo de los Colorados northwards. The Quevedo and Bucay cytotypes occurs from Santo Domingo de los Colorados southwards. On the eastern side of the Andes, the Aguarico cytotype occurs in the Rio Aguarico and a new cytotype is present in the tributaries of the Rio Napo. Whether the disease will spread south of Santo Domingo and on the eastern side of the Andes depends on vector capacity and the dispersal patterns of individuals infected with onchocerciasis. At present the Aguarico, Bucay and Quevedo cytotypes are known to be efficient hosts, but their biting preferences and biting densities have not yet been evaluated.

Onchocerciasis in Ecuador: prevalence of infection on the Ecuador-Colombia border in the Province of Esmeraldas

The prevalence of onchocerciasis infection was determined in communities on 7 rivers located in the northern area of the canton San Lorenzo, province of Esmeraldas. Diagnosis of the infection was obtained by skin biopsies and recombinant-antigen based-serology. No evidence of infection was detected in 9 communities studied along the Rio Mataje, which forms the frontier between Ecuador and Colombia, nor in 10 adjacent communities located on 5 interior rivers. Evidence for Onchocerca volvulus infection was found in 4 communities on the Rio Tululvi with the following prevalence: La Boca (3,5 per cent by biopsy and 3,9 per cent by serology), Guayabal (9,1 per cent by both biopsy and serology), La Ceiva (51,5 per cent by biopsy and 53 per cent by serology), and Salidero (4 per cent by biopsy and 7,7 per cent by serology). A few individuals in these communities were seropositive for O. volvulus in the absence of detectable dermal microfilariae: these might harbor very light or prepatent infections. No clinical disease attributable to onchocerciasis was found. The infected communities will be included in the ivermectin-based National Control Program for the disease, with no evidence of the infection having extended north of the Ecuadorian-Colombian border.

L'Onchocercose en milieu urbain : Cas du foyer de Brazzaville

Les auteurs rapportent les resultats cliniques; parasitologiques d'une enquete sur l'onchocercose realisee a Brazzaville au (Congo) en Mai 1992 par sondage en grappe selon la methode Henderson sur 1189 personnes ages de 5 ans et plus. Les indices recherches montrent que le taux de prevalence est de 40 pour cent; l'indice kystique a 2;4 pour cent. Un seul cas de cecite et tous facteurs etiologiques confondus a ete observe

Onchocerciasis in Ecuador: changes in prevalence of ocular lesions in Onchocerca volvulus infected individuals over the period 1980-1990

Trends in prevalence rates of onchocercal ocular lesions were examined over the period 1980 to 1990 using data from two cross-sectional surveys. There was evidence for increasing prevalence of anterior chamber microfilariae, iridocyclitis, optic atrophy, and chorioretinopathy. Large increases in prevalence, in particular, were seen for posterior segment lesions: optic atrophy increased from 2,7 per cent to 6.4 per cent and chorioretinopathy from 8.8 per cent to 35.6 per cent. Greatest increases in these lesions were seen in the Chachi which was attributed to the large increases in prevalence of microfilariae in the anterior chamber particularly in those aged 30 years or greater. The study findings suggest that ocular onchocerciasis is evolving in parallel with the well documented parasitological changes.

Prevalence of Onchocerca Volvulus in Southern Sudan

Onchocerciasis is endemic in southern Sudan. The prevalence in human population may range from 10to 40. In the Eastern Equatorial Region of Southern Sudan; more cases are found in Nimule on the Sudan-Uganda border than in rural highlands of Labone and Chukudum basins. Onchocerciasis was highest in males (with a prevalence of 70.2based on data from hospital records)) than in females; with prevalence of 19. Overall; prevalence of onchocerciasis in children was 10.8.Considering cost-effectiveness; public health priorities and the security situation in this area; we recommend active search on onchocerciasis cases in the community and treatment

Oncocercosis en Colombia? una revaluación del foco de López de Micay / Onchocerciasis in Colombia? Follow-up of the in López of Micay focus

En 1965 se describió el primer foco de oncocercosis humana en Colombia en López de Micay, en la costa pacífica. Doce años después, una visita de seguimiento mostró que la prevalencia de infección había disminuído del 15 al 7,5 por ciento. Ya que no se volviron a reportar pacientes, se consideró extinguido el foco hasta 1989, cuando un niño con queratitis ocular fue remitido al Hospital Universitario de Cali. Se confirmó el diagnóstico de oncocercosis con una biopsia de piel. En julio de 1989 se hizo una visita al área y se tomaron muestras a 170 personas. La prevalencia de infección detectada por biopsia de piel fue de 4,1 por ciento (7/170). Se detectaron microfilarias (mf) en piel en 10 por ciento de los hombres muestreados y 0,9 por ciento de las mujeres. La microfilarodermia varió entre 0,5 mf por miligramo de piel y 47mf/mg y estaba directamente relacionada con la edad. No se encontraron nódulos subcutáneos palpables ni alteraciones dérmicas atribuibles al parásito en ningún paciente. Dos pacientes presentaron cambios oculares: queratitis bilateral y degeneración de la retina, respectivamente. Durante la visita, la actividad de los simúlidos fue muy baja y no se intentaron capturas. Es probable que la transmisión ocurra en sitios río arriba, donde la actividad de los vectores es mayor. Con la construcción de vías de acceso y una planta hidroeléctrica se espera un aumento de la población no inmmune en área. Cabe preguntar, cúal será el impacto de esta población susceptible sobre este foco hopoendémico

Manuel Martínez Báez: una visión muy personal de las enfermedades tropicales / Manuel Martínez Báez: a very personal view of tropical diseases

La obra del doctor Manuel Martínez Báez (1894-1987) es muy vasta y se agrupa claramente en torno a tres áreas de la medicina: Parasitología, salud pública y sociología médica e historia de la medicina. Este trabajo estudia un aspecto de su ideología en salud pública y sociología médica, el relativo a las enfermedades tropicales. La aportación de Martínez Báez en está área fue relevante porque adecuó a la realidad de los países subdesarrollados los conceptos que sobre enfermedades tropicales surgieron en países ajenos a esta problemática

Etude epidemiologique de l'onchocercose dans la vallee de la Bini (Adamaoua) Cameroun : prevalence de l'infestation et charge parasitaire

L'Enquete epidemiologique effectuee dans la vallee de la Bini montre que l'onchocercose touche l'ensemble de la population urbaine. Les resultats obtenus dans les villages sont sensiblement identiques. On note en effet que la prevalence parasitaire est de 57;3pour les hommes et de 50;3pour les femmes. Cette difference entre les sexes est encore accentuee par le calcul du nombre moyen de microfilaires par biopsie entamee. Celui-ci est de 55 pour les hommes et de 22 pour les femmes

Etude epidemiologique de l'onchocercose dans la Vallee de la Bini (Adamaoua); Cameroun: pouvoir pathogene de la souche locale d'o. volvulus: atteintes oculaires et cutanees

A N'dena; dans la Vallee de la Bini (Ademaoua) ou la prevalence de l'onchocercose est de 51;4 pour cent d'apres la microfilarodermie; l'importance des atteintes cutanees et oculaires est mesuree. La depigmentation et l'atrophie cutanees s'observent chez 33;1 pour cent des habitants. Et 20;3 pour cent d'entre eux sont porteurs de kystes onchocerquiens. Des microfilaires sont vues dans le segment anterieur de l'oeil chez 23;3 pour cent des sujets et dans la chambre posterieure chez 9;8 pour cent. L'etude du pouvoir pathogene de la souche forestiere locale d'o. volvulus isolee met en evidence un contraste entre; d'une part; une infestation onchocerquienne massive et; d'autre part; la faible repercussion de cette pathologie sur la sante des populations