Outstanding insecurities concerning the use of an Ov16-based ELISA in the Amazonia onchocerciasis focus

In a recent issue of Memórias do Instituto Oswaldo Cruz, published in Rio de Janeiro in February 2014 (109: 87-92), Adami et al. have published a survey reporting Mansonella parasite prevalence in the Amazon Region. This report makes a useful contribution to the existing knowledge of filarial parasite distribution within the Amazon area, parasite prevalence rates in relation to age and occupation and provides observations on the possible clinical impact of Mansonella ozzardi. Their publication also provides an account of what appears to be a novel ELISA that has recently been used in the Simuliidae and Onchocerciasis Laboratory of the Oswaldo Cruz Institute, Rio de Janeiro, Brazil. We are concerned that the publication of this ELISA may have created an excessively positive impression of the effectiveness of the onchocerciasis recrudescence serological surveillance tools that are presently available for use in the Amazonia onchocerciasis focus. In this letter we have, thus, sought to highlight some of the limitations of this ELISA and suggest how continuing insecurities concerning the detection of antibodies to Onchocerca volvulus within the Amazonia onchocerciasis focus might be minimised.

Anatomopatologia de bursite cervical (oncocercose) encontrada em bovinos abatidos sob inspeção estadual no estado do Rio de Janeiro / Anatomopathology of onchocerciases (cervical bursitis) in slaughtered bovine in the north of Rio de Janeiro state

A patologia descritiva das lesões em animais domésticos de açougue permite enriquecer a literatura médica veterinária especializada em inspeção sanitária de carnes, assim como subsidiar tecnicamente os profissionais inspetores. A oncocercose é uma parasitose causada pelo nematódeo Onchocerca sp,, sendo que a espécie O. gutturosa é a que mais acomete bovinos na América do Sul. Foram avaliados, pelo exame anatomopatológico, dois casos de lesões localizadas no ligamento nucal de bovinos abatidos para o consumo. A macroscopia de um caso revelou bursite crônica, representada por grande quantidade de líquido citrino e viscoso e, ainda, muitos corpúsculos livres, elípticos e achatados desprovidos de raiz (arrizo). A microscopia dessas estruturas evidenciou moldes de fibrinas amorfos e eosinofílicos. O segundo caso foi caracterizado por bursite aguda, e a microscopia das lesões ligamentar e periligamentar revelou granulomas epitelioides com reação gigantocitária, centralizados por formações semelhantes ao Onchocerca sp...

The descriptive pathology of lesions in butcher's domestic animals contribute to enrich literature specialized in veterinary sanitary inspection of meat as well as to guide professional meat inspectors. Oncorcecose is a parasitic disease caused by the nematode Onchocerca sp, and the O. gutturosa species affects cattle in South America. Two cases of lesions located in the nuchal ligament of cattle slaughtered for consumption were evaluated by pathological examination. Macroscopic analysis revealed a case of chronic bursitis represented by a large amount of clear and viscous liquid, and also many free, elliptical and flat corpuscles. Microscopy showed arrizoides molds fibrin, amorphous, and eosinophilic structures. The second case was characterized by acute bursitis and microscopic lesions and ligament periligamentous revealed multiple epithelioid granulomas and giant cells centered on formations similar to Onchocerca sp...

Onchocerciasis in the upper Imo river basin, Nigeria: prevalence and comparative study of waist and shoulder snips from mesoendemic communities

Onchocerciasis is endemic in the Imo River Basin, Nigeria. This study was aimed at assessing the prevalence and intensity of microfilaria of Onchocerca volvulus in the area. A cross-sectional study was carried out in the Okigwe Local Government Area, Imo State, Nigeria. Two skin snips [one from the waist and another from the shoulder] were taken from 1024 individuals examined. The survey coverage was high [91.8% of the study population]. An individual was considered mf positive if either of the waist or shoulder snips or both were mf positive. The SPSS for Windows package was used for entering and analysis of data. Thirty-seven percentage of those examined was positive for Onchocerca volvulus microfilariae [39.2% of males and 34.9% of females]. The mf prevalence increased steadily with increasing age to reach 70.4% in the oldest age group. The overall mf Geometric Mean Intensity among mf positive individuals was 16 mf/skin snip and was significantly higher among males [18 mf/skin snip] than females [14 mf/skin snip] [p<0.01]. A scatter plot of microfilariae numbers in snips from the waist against numbers in snips from the shoulder of the same individuals, showed close correlation [Pearson's correlation coefficient=+0.90; p<0.01], and those with mf intensities below 10 mf/snip had a more scattering tendency away from the regression line than those with higher mf intensities. Onchocerciasis is a public health concern in the area. Perhaps, 10 mf/snip is critical intensity threshold for reliable sampling using corneo-scleral punch

Evidence for the exacerbation of lymphedema of geochemical origin, podoconiosis, by onchocerciasis

The study was conducted to investigate a variation in the distribution of endemic elephantiasis previously determined to be of geochemical origin in three neighbouring and essentially homogenous villages, Bambili, Bambui and Finge of the Bambui Health District of NW Cameroon. A total of 301 subjects were examined for onchocerciasis and lymphatic filariasis in the area using standard procedures. The onchocercal microfilarial prevalence varied from 6.5% in Bambili through 20.4% in Bambui to 60.4% in Finge. The onchocercal serological prevalence based on IgG4 detection followed a similar trend. By contrast, blood microfilariae were absent in the area as verified by use of sensitive techniques. The community prevalence of elephantiasis varied from 1.1% in Bambili to 4.4% in Bambui and 10.4% in Finge. The correlation between the parasitological prevalence of onchocerciasis and the prevalence of lymphedema in the three villages was strong [r = 0.99, p < 0.05]. We confirm that the elephantiasis in the area is of geochemical origin and the results suggest that it is being exacerbated by onchocercal lymphadenitis

Approaches to the control and elimination of the clinically important filarial diseases

Mass drug administration programs are the mainstay of current attempts to control and rid the globe of the two major filarial diseases of humans, onchocerciasis and lymphatic filariasis. There are a number of important components to developing and maintaining a treatment program; these include advocacy, communication, financial support, and the presence of local "champions" to lead the program. Two active country programs -lymphatic filariasis elimination in Tanzania and onchocerciasis control in Sudan -provide practical examples of these program needs. There are a number of positive consequences of a successful program that extend outside the primary goal of disease control or elimination; these include national infrastructure and personnel development. The challenges and consequent actions that could be taken to ensure the success of control programs are discussed

Etude clinique et parasitologique de l'onchocercose dans huit villages de la vallee du Mbam (Province du Centre; Cameroun)

Une etude a ete entreprise dans la Vallee du Mbam afin de mieux repartir l'onchocercose dans cette region. Dans chacun de ces villages; environ 150 sujets ages de cinq ans et plus ont ete examines du point de vue clinique et parasitologique. Il ressort de cette etude que tous ces villages etudies sont hyperendemiques. Cependant; les charges microfilariennes moyennes varient largement. Ainsi; cette enquete confirme qu'au Cameroun; en zone de transition savane-foret; l'onchocercose a des repercussions oculaires graves. Un traitement de masse par ivermectine serait certainement souhaitable dans la region de Bafia

Correlación entre oncocercomas y positividad para microfilarias en oncocercosis / Correlation between onchocermata and positivity for microfilariae in onchocerciasis

El objetivo de este trabajo de investigación es evaluar la sensibilidad de la palpación de nódulos para el diagnóstico de la oncocercosis en los individuos de la localidad de Nueva Costa Rica, municipio de Mapastepec, en el foco endémico, sur del estado de Chiapas, México. A cada una de las 243 personas que voluntariamente participaron en esta investigación, se les interrogó y exploró con detenimiento para detectar los oncocercomas. La positividad e intensidad de la infección por Onchocerca volvulus se estimó por la presencia de una o más microfilarias en cualquiera de las cuatro biopsias tomadas, una en cada región supraescapular y glútea, así como por la media de las Dmf/mg de cada biopsia. Del total de sujetos estudiados, 131 (53.9%) fueron positivos a microfilarias y 37 (15.3%) a oncocercomas. La distribución de los positivos a nódulos, de acuerdo con la edad, fue similar en todos los grupos etáreos. En relación con la intensidad de la infección, se encontró que la media de las Dmf/mg de todos los individuos estudiados de esta localidad fue de 6.67; no se hallaron diferencias significativas (p>0.001), entre los del sexo masculino (6.35) y los del femenino(6.99). El grupo de personas entre 21 y 30 años de edad mostró de manera significativa tener una mayor media de las Dmf/mg que el resto de los grupos, (p<0.001). Sin embargo, se observó que en grupos de mayor edad existe una frecuencia más alta de positividad a microfilarias. La prevalencia para oncocercosis en esta localidad, estimada por la positividad a microfilarias y oncocercomas, fue de 59.6 por ciento. Se concluye que la sensibilidad de la detección de los oncercomas para el diagnóstico de la oncocercosis fue baja, posiblemente debido a que el programa de control de la oncocercosis, desde hace 60 años, ha instituido como medida de tratamiento la nodulectomía y, por lo tanto, existe una gran proporción de individuos positivos a microfilarias sin nódulos detectables.

The objetive of this work is to evaluate the palpation sensitivity of onchocercomata for the diagnosis of on­chocerciasis in individuals residents of the locality of Nueva Costa Rica, Mapastepec, in the south endemic area of the state of Chiapas, Mexico. Every one of the 243 individuals who voluntarily participate in this study was interrogated and physical examed for the detection of nodules. The positivity and the worm burden to the Onchocerca volvulus infections was estimated by the presence of one or more microfilariae in any of the for skin snips taken from both supraescapular and gluteal regions, and by the mean of the Dmf/mg of each skin snip. From the total number of individual studied, 131 (53.9%) were positives to microfilariae and 37 (15.2%) to on­chocercomata. Only 23 (17.6%) of the microfilariae positive individuals carried nodules. The distribution of positive individuals to nodules in relation to age, was similar in all the age groups. In relation to the intensity of the infection was found that, the mean of the Dmf/mg of all individuals was 6.67, there was not significant diffe­rences (p>0.001) between males and females; being the Dmf/mg of 6.35 and 6.99, respectively. The age group between 21 and 30 years old showed the higher mean of Dmf/mg than the rest of the groups (p>0.001). However, there was a high microfilariae positivity in the oldest groups than in the youngers. The prevalence for on­chocerciasis in this locality, estimated by the positivity to either microfilariae or nodules, was 59.9 per cent. It is concluded that, the onchocercomata detection sensitivity for the diagnosis of onchocerciasis was very low, proba­bly due to the nodulectomy activity of the onchocerciasis control program, which has been operating since 1930 and therefore, there are an important number of indivi­duals positive to mcirofilariae whithout detectable no­dules.

La lutte contre l'onchocercose en Afrique de l'Ouest: : un bilan

Nous présentons le vaste programme de lutte contre I'onchocercose en Afrique de l'Ouest qui intéresse onze Etats et couvre plus d'un million de kilomètres carrés' Nous réalisons une importante mise au point sur les aspects épidémiologiques' cliniques et thérapeutiques de I 'onchocercose mais aussi sur I 'impact socioéconomique de cette filariose dans les grandes zones bioclimatiques de savane et de forêt de I 'Afrique tropicale' Nous analysons les problèmes très particuliers que pose la lutte antivectorielle contre la simulie. Nous évoquons les nouvelles perspectives de lutte apportées par I'apparition de l' ivermectine. Ce travail est également l'occasion d'une vaste revue bibliographique actualisée'

Afecciones cutáneas granulomatosas tropicales / Tropical granulomatous cutaneous affections

Exponemos aquí las características más resaltantes de diversas enfermedades granulomatosas de la piel propias del medio tropical. Mostramos las Técnicas esenciales del diagnóstico y tratamiento. En varias de estas enfermedades los carácteres clínicos, histológicos y el pronóstico dependen de la defensa inmunológica especifica del huésped frente al agente causal. También es de importancia la procedencia geográfica del paciente y su habitat para el diagnóstico y prevención de la enfermedad. Señalamos la dirección de las futuras investigaciones necesarias

La aplicación de una prueva dermoreactiva, simple y segura para la oncocercosis / Use of a skin test, simple and safe for onchocercosis

Se describe la utilización de la dietilcarbamicina (DEC) en loción al 2% aplicada en una pequeña área de piel, como prueba para el diagnóstico de oncocercosis. Consideramos que esta técnica puede ser útil en investigaciones epidemiológicas a gran escala, pues tiene menos posibilidades de inducir daño ocular en pacientes portadores de la enfermedad y permite identificar a la gran mayoría de estos