Efficacy and safety of dimeticones in the treatment of epidermal parasitic skin diseases with special emphasis on tungiasis: an evidence-based critical review

ABSTRACT Epidermal parasitic skin diseases encompass scabies, pediculosis, cutaneous larva migrans, myiasis, and tungiasis. Tungiasis is probably the most neglected of all Neglected Tropical Diseases (NTD). It occurs in South America, the Caribbean and Sub-Saharan Africa and affects marginalized populations where people live in extreme poverty. In endemic communities the prevalence can be up to 30% in general population and 85% in children. Over time, chronic pathology develops characterized by hyperkeratosis, edema around the nail rim, fissures, ulcers, deformation and loss of nails. This leads to a pattern of disabilities, eventually resulting in impairment of mobility.Dimeticones are a family of silicon oils with a potential to kill parasites located on top or inside the epidermis by a physical mode of action. They are considered the treatment of choice for pediculosis capitis and pediculosis pubis. With regard to tungiasis, the so called rear abdominal cone of the parasites has been identified as a target for treatment with dimeticones. NYDA®, a mixture of two dimeticones with different viscosity, is the only dimeticone product for which data on the mode of action, efficacy and safety with regard to tungiasis exists. The product has been shown highly effective against embedded sand fleas, even in very intense infection with more than 500 parasites situated on top of each other. A randomized controlled trial showed that seven days after a targeted application of NYDA® 97% (95% CI 94-99%) of the embedded sand fleas had lost all signs of viability.Comprehensive toxicological investigations on the dimeticones contained in NYDA® showed that there is practically no risk of embryotoxicity, fetotoxicity, teratogenicity, and other toxicity. The safety of dimeticones was also demonstrated in clinical trials with a total of 106 participants with tungiasis, in which not a single adverse event was observed.

Evidencia clínica de tracoma en indígenas colombianosdel departamento de Vaupés / Clinical evidence of trachoma in Colombian Amerindians of the Vaupés Province

Introducción. El tracoma es la primera causa infecciosa de ceguera. En 2008 había 1’300.000 ciegos por su causa y 8 millones de personas tenían lesiones oculares que podrían conducirlos a la ceguera. En América Latina se ha documentado su presencia en Brasil, Guatemala y México. Objetivo. Informar por primera vez la presencia de tracoma en Colombia, en indígenas del departamento del Vaupés. Materiales y métodos. En 2003 y 2006 se visitaron las comunidades makú de San Joaquín y Santa Catalina, a 5 km de Brasil, y entre 2007 y 2009, las de San Gerardo, San Gabriel y Nuevo Pueblo, a 35 km de las anteriores. Resultados. En 2006, se examinaron 114 personas en San Joaquín y Santa Catalina. Se diagnosticó clínicamente tracoma en 21 (18,4%), 15 de ellas (13,2%) menores de 15 años. Se detectaron todas las fases de la enfermedad. Tres mujeres tenían opacidad corneal con notoria disminución de la agudeza visual. En las tres últimas comunidades se detectaron tres mujeres con tracoma avanzado, con opacidad corneal y ceguera. La vivienda precaria, la carencia de agua potable y de sistemas adecuados de disposición de los excrementos, y la abundancia de moscas domésticas del género Hippelates, constituyen factores de riesgo para la transmisión del tracoma.Discusión. El tracoma existe en Colombia, con incidencia frecuente en las comunidades estudiadas. Su localización definida hace posible su eliminación en programas de salud pública. Es necesario realizar una búsqueda del tracoma en otras comunidades indígenas del Vaupés con condiciones de vida similares.

Introduction: Trachoma is the leading cause of infectious blindness in the world. In 2008 there were 1,300,000 persons with blindness caused by trachoma and 8 million with trichiasis, which might eventually lead to blindness. In Latin America it has been documented in Brazil, Guatemala and México. Objective: To inform the presence of trachoma for the first time in Colombia, amongst Amerindians of the Department of Vaupés.Materials and methods: In 2003 and 2006 the Amerindian Makú communities of San Joaquín and Santa Catalina, located 5 km from the border with Brazil, were visited. From 2007 to 2009, San Gerardo, San Gabriel and Nuevo Pueblo, at a 35 km distance from San Joaquín were visited. Results: In 2006 114 people were examined in Santa Catalina and San Joaquin; 21 patients were clinically diagnosed with trachoma (18.4%), 15 (13.2%) of them children under 15 years old. All trachoma phases were observed. Three women had corneal opacity with poor vision. In the remaining three communities, three women with advanced trachoma with corneal opacity and blindness were detected. The poor quality of living conditions without fresh water and adequate sanitary disposal systems, and the abundance of flies identified as Hippelates sp., are risk factors for the transmission of the disease. Discussion: Trachoma exists in Colombia, and it is frequent among the studied communities. Its focalized distribution makes it amenable to elimination. It is advisable to search for trachoma in other indigenous communities in Vaupés with similar living conditions.

Tungiasis en población indígena del departamento de Vaupés: epidemiología, clínica, tratamiento y prevención / Tungiasis in native amerindians in Vaupés province: epidemiology, clinical aspects, treatment, and prevention

Introducción. La tungiasis, o infestación cutánea por la pulga Tunga penetrans, ocurre en comunidades muy pobres.Objetivo. Presentar la entidad en indígenas del Vaupés. Métodos. En primer lugar, se revisó el tema. Luego, se describió el área y la vivienda de los pacientes afectados; se detectaron los animales infestados con la zoonosis. Se iIustró el aspecto clínico y sus complicaciones y, posteriormente, se trataron los pacientes con creolina. Se logró hacer modificaciones en el piso de las malocas de dos comunidades, con humedad y arcilla, y se impartió educación a la comunidad sobre esta parasitosis. Resultados. El 95% de los 33.000 habitantes del Vaupés son indígenas. Algunos moran en viviendas de piso arenoso, seco, con detritos alimenticios y perros con tungiasis. Entre 1996 y 2007 confirmamos 942 casos del parasitismo. De los indígenas estudiados, 3 a 8 de cada 1.000 y 62% de los perros, presentaban tungiasis. Los pies se vieron afectados en 98% de los pacientes. Se presentaron casos graves con más de 20 lesiones, en niños y ancianos. Como complicaciones, se presentaron: infección secundaria, dolor, anoniquia, deformación y amputación de los dedos de los pies e imposibilidad para la marcha. Hubo sepsis mortal en tres pacientes. No se presentaron casos de tétanos. Los baños con creolina y la extracción del parásito fueron curativos, en hombres y animales. La modificación de los pisos redujo a cero la enfermedad en una comunidad. Conclusiones. La enfermedad es intradomiciliaria. El piso de la vivienda y la convivencia con perros infestados son ideales para adquirirla. La creolina, la humectación del piso y el cubrirlo con arcilla controlaron un foco de la enfermedad, actividad que podría generalizarse. Ésta es la primera investigación colombiana sobre la tungiasis, entidad conocida en Colombia desde que afectó a los soldados de Gonzalo Jiménez de Quesada, fundador de Santafé de Bogotá en 1538.

Introduction. Tungiasis, the skin infestation with the flea Tunga penetrans, occurs in poor communities.Objective. To present a study of this condition among native Amerindians from Vaupés (Colombia). Methods. After reviewing this topic, we present a description of the geographic area and the housing of the affected subjects; animal carriers infected with this zoonosis were also detected. We illustrate the clinical aspects and complications. Patients were treated with creolin (liquid cresol). We modified the floor of malocas in two communities using wet clay, and we educated the community on this parasite. Results. About 95% of the 33,000 inhabitants of Vaupés are native Amerindians. Some households have dry sandy floors, where food leftovers attract dogs infested with tungiasis. From 1996 to 2007 we confirmed 942 human cases of this parasitic disease. Among the native communities, 3 to 8 per 1,000 persons and 62% of the dogs have tungiasis. Feet were affected in 98% of the patients. Severe cases, with more than 20 lesions, occurred among children and the elderly. Complications included secondary infections, pain, anonychia (loss of toenails), toe deformities, amputation of toes and walking problems. Three patients died as a result of sepsis originating from toe infections. Topic use of liquid creolin and extraction of the parasite cured the problem in humans and dogs. Floor modifications eradicated the problem in one community. Conclusions. Tungiasis is an intradomiciliary disease. Favorable conditions for infestations include dry sandy floors and infected dogs. Treatment of the floors with creolin and wet clay resulted in control of one focus of the disease; this method could be applied more widely. This is the first known research study on tungiasis in Colombia, a disease that affected the soldiers of the Spanish Conquistador Gonzalo Jiménez de Quesada in the 1500s.