Development of Leishmania (Mundinia) in guinea pigs

Background: Leishmaniasis is a human and animal disease caused by parasites of the genus Leishmania , which is now divided into 4 subgenera – L. (Leishmania) , L. (Viannia) , L. (Sauroleishmania) and L. (Mundinia) . Subgenus Mundinia, established in 2016, is geographically widely dispersed, its distribution covers all continents, except Antarctica. It consists of 5 species - L. enriettii and L. macropodum are parasites of wild mammals while L. martiniquensis , L. orientalis and unnamed L . sp. from Ghana are infectious to humans. There is very little information on natural reservoir hosts and vectors for any Mundinia species. Methods: Experimental infections of guinea-pigs with all five Mundinia species were performed. Animals were injected intradermally with 10 7 culture-derived promastigotes into both ear pinnae. The courses of infections were monitored weekly; xenodiagnoses were performed at weeks 4 and 8 post infection using Lutzomyia migonei . The distribution of parasites in different tissues was determined post mortem by conventional PCR. Results: No significant differences in weight were observed between infected animals and the control group. Animals infected with L. enriettii developed temporary lesions at the site of inoculation and were infectious to Lu. migonei in xenodiagnoses. Animals infected with L. martiniquensis and L. orientalis developed temporary erythema and dry lesions at the site of inoculation, respectively, but were not infectious to sand flies. Guinea pigs infected by L. macropodum and L . sp . from Ghana showed no signs of infection during experiments, were not infectious to sand flies and leishmanial DNA was not detected in their tissue samples at the end of experiments at week 12 post-inoculation. Conclusions: According to our results, guinea pigs are not an appropriate model organism for studying Mundinia species other than L. enriettii. We suggest that for better understanding of L. (Mundinia) biology it is necessary to focus on other model organisms.

Development of Leishmania (Mundinia) in guinea pigs

Background: Leishmaniasis is a human and animal disease caused by parasites of the genus Leishmania, which is now divided into 4 subgenera – L. (Leishmania), L. (Viannia), L. (Sauroleishmania) and L. (Mundinia). Subgenus Mundinia, established in 2016, is geographically widely dispersed, its distribution covers all continents, except Antarctica. It consists of 5 species - L. enriettii and L. macropodum are parasites of wild mammals while L. martiniquensis, L. orientalis and unnamed L. sp. from Ghana are infectious to humans. There is very little information on natural reservoir hosts and vectors for any Mundinia species. Methods: Experimental infections of guinea-pigs with all five Mundinia species were performed. Animals were injected intradermally with 107 culture-derived promastigotes into both ear pinnae. The courses of infections were monitored weekly; xenodiagnoses were performed at weeks 4 and 8 post infection using Lutzomyia migonei. The distribution of parasites in different tissues was determined post mortem by conventional PCR.Results: No significant differences in weight were observed between infected animals and the control group. Animals infected with L. enriettii developed temporary lesions at the site of inoculation and were infectious to Lu. migonei in xenodiagnoses. Animals infected with L. martiniquensis and L. orientalis developed temporary erythema and dry lesions at the site of inoculation, respectively, but were not infectious to sand flies. Guinea pigs infected by L. macropodum and L. sp. from Ghana showed no signs of infection during experiments, were not infectious to sand flies and leishmanial DNA was not detected in their tissue samples at the end of experiments at week 12 post-inoculation.Conclusions: According to our results, guinea pigs are not an appropriate model organism for studying Mundinia species other than L. enriettii. We suggest that for better understanding of L. (Mundinia) biology it is necessary to focus on other model organisms.

Development of Leishmania (Mundinia) in guinea pigs

BackgroundLeishmaniasis is a human and animal disease caused by parasites of the genus Leishmania, which is now divided into 4 subgenera – L. (Leishmania), L. (Viannia), L. (Sauroleishmania) and L. (Mundinia). Subgenus Mundinia, established in 2016, is geographically widely dispersed, its distribution covers all continents, except Antarctica. It consists of 5 species - L. enriettii and L. macropodum are parasites of wild mammals while L. martiniquensis, L. orientalis and unnamed L. sp. from Ghana are infectious to humans. There is very little information on natural reservoir hosts and vectors for any Mundinia species. MethodsExperimental infections of guinea-pigs with all five Mundinia species were performed. Animals were injected intradermally with 107 culture-derived promastigotes into both ear pinnae. The courses of infections were monitored weakly; xenodiagnoses were performed at weeks 4 and 8 post infection using Lutzomyia migonei. The distribution of parasites in different tissues was determined post mortem by conventional PCR.ResultsNo significant differences in weight were observed between infected animals and the control group. Animals infected with L. enriettii developed temporary lesions at the site of inoculation and were infectious to Lu. migonei in xenodiagnoses. Animals infected with L. martiniquensis and L. orientalis developed temporary erythema and dry lesions at the site of inoculation, respectively, but were not infectious to sand flies. Guinea pigs infected by L. macropodum and L. sp. from Ghana showed no signs of infection during experiments, were not infectious to sand flies and leishmanial DNA was not detected in their tissue samples at the end of experiments at week 12 post-inoculation.ConclusionsAccording to our results, guinea pigs are not an appropriate model organism for studying Mundinia species other than L. enriettii. We suggest that for better understanding of L. (Mundinia) biology it is necessary to focus on other model organisms.

Invasión urbana de flebotomineo transmisores de Leishmania en Mérida, Venezuela

El desarrollo urbano ha causado una serie de transformaciones ambientales, que ha promovido la propagación de la leishmaniasis con la adaptación de los flebotomíneos transmisores. Este estudio tiene como objetivo determinar la presencia de flebotomíneos y evaluar factores epidemiológicos asociados a la transmisión de leishmaniasis en una zona urbana de Zea, Venezuela. Se emplearon cinco métodos de captura de flebotomíneo en el interior de las viviendas en dos urbanizaciones en Zea, Venezuela. A través de un instrumento tipo encuestas, se determinaron las variables epidemiológicas asociadas a la transmisión de la leishmaniasis. Se demostró la presencia en el interior de la viviendas urbanas de Lutzomyia youngi, Lutzomyia spinicrassa, Lutzomyia migonei, Lutzomyia ovallesi, Lutzomyia walkeri, Lutzomyia venezuelensis, Lutzomyia atroclavata y Lutzomyia lichyi. El 62,5% de las especies capturadas en las áreas urbanizadas poseen hábitos de antropohematofagia. Se determinó un 67 % y 80% de infestación en las viviendas de las urbanizaciones estudiadas. Se evidenció un bajo nivel de conocimiento en los pobladores principalmente sobre los flebotomíneos, lo cual incrementa el riesgo de domiciliación y transmisión de la leishmaniasis. Se alerta a los entes encargados del control de dicha enfermedad a implementar las medidas preventivas y de educación necesaria.

Epidemiologia da leishmaniose visceral no município de Fortaleza, Ceará

RESUMO: O objetivo do trabalho foi analisar os dados relacionados à transmissão da leishmaniose visceral (LV), no município de Fortaleza, e discutir a respeito da distribuição do vetor, reservatório doméstico e casos humanos ocorridos no período de 2009 a 2013. O presente estudo é do tipo descritivo realizado por meio de levantamento de dados secundários. A correlação entre casos humanos, caninos e número de flebotomíneos foi feita pelo teste de correlação de Spearman, com nível de significância de 5%. No período de 2009 a 2013 foram confirmados 941 casos e 55 óbitos. A letalidade média no período foi de 5,84%. Na distribuição por sexo, houve uma maior proporção de casos no sexo masculino em todos os anos analisados. A faixa etária de 1 a 4 anos apresentou a maior porcentagem de casos, destacando-se o ano de 2010 com 31,5% dos casos. A distribuição média de casos por regional demonstrou um predomínio nas regionais I, V e VI. Em relação aos flebotomíneos, a espécie encontrada em maior abundância foi Lutzomyia (Lutzomyia) longipalpis, seguido de Lutzomyia (Lutzomyia) migonei e Lutzomyia (Lutzomyia) lenti. Segundo os registros da Secretaria Municipal de Saúde de Fortaleza, 39.626 cães foram soro reagentes para LV nos anos de 2009 a 2013, destes 14.313 foram eutanasiados. O ano de 2013 destacou-se com 17.808 cães soro reagentes, sendo 1.273 da SER (Secretaria Executiva Regional) III, 2.572 da SER V e 1.909 da SER VI. Não foi observada correlação significativa entre o número de flebotomíneos capturados e o número de casos caninos de LV(p>0,05). Houve correlação negativa entre casos humanos e caninos (r=-0,0388) e correlação positiva entre casos humanos e número de flebotomíneos (r=0,7469). Os achados criam perspectivas para a identificação de outros fatores que podem influenciar a incidência de casos humanos e caninos, como a participação de outros possíveis reservatórios e vetores na cadeia de transmissão da leishmaniose visceral no município de Fortaleza.

Identificación rápida de Lutzomyia longipalpis a partir de cinco descriptores del aparato genital masculino

El flebótomo Lutzomyia longipalpis es, hasta el momento, el vector comprobado de la leishmaniosis visceral canina. Capturas realizadas en Corrientes (Argentina) permitieron identificar a Lutzomyia neivai, vector de la leishmaniosis cutánea, así como a Lutzomyia migonei y Lutzomyia cortelezzii-sallesi, ambos considerados vectores secundarios de la leishmaniosis cutánea. Para el control epidemiológico resulta primordial la identificación del vector. Luego de la captura de los insectos, el paso más complicado es el reconocimiento de las distintas especies de Lutzomyia, para lo cual es necesario lograr el aclaramiento de sus estructuras y observarlo al microscopio prestando atención a los descriptores característicos y particulares de la especie. Existen aproximadamente 30 descriptores para identificar Lutzomyia longipalpis por la observación microscópica de su aparato genital masculino. El objetivo de este trabajo fue seleccionar cinco descriptores de fácil identificación, que en orden de importancia resultaron ser: setae diferenciadas del parámero, relación entre longitud del parámero y lóbulo lateral, forma y apariencia del coxito o basistilo, características y ubicación del mechón de setae del coxito y morfología de la bomba eyaculadora. La sencilla visualización de estos descriptores permite una rápida identificación taxonómica de la especie.