Ecoepidemiologia de Fasciola hepatica (Trematoda, Digenea) en el norte de la provincia de Corrientes destacando aspectos ecologicos de Lymnaea columella (Pulmonata, Lymnaeidae) y su rol como hospedador intermediario [recurso electronico] = Ecoepidemiology of Fasciola hepatica (Trematoda, Digenea) in the north of the province of Corrientes emphasizing ecological aspects of Lymnaea columella (Pulmonata, Lymnaeidae) and its role as intermediate host / Lucila Prepelitchi ; director, Maria Cristina Wisnivesky.

Format:

Book

Thesis/Dissertation

Author/Creator:

Prepelitchi, Lucila.

Contributor:

Wisnivesky, Maria Cristina.

Language:

Spanish

Subjects (All):

Biologia.

Ecologia.

Biology.

Ecology.

Local Subjects:

Biologia.

Ecologia.

Biology.

Ecology.

Physical Description:

138 p.

Other Title:

Ecoepidemiology of Fasciola hepatica (Trematoda, Digenea) in the north of the province of Corrientes emphasizing ecological aspects of Lymnaea columella (Pulmonata, Lymnaeidae) and its role as intermediate host

Place of Publication:

Buenos Aires, Argentina : Universidad de Buenos Aires, 2009.

Summary:

La fasciolosis, causada por Fasciola hepatica, es una parasitosis de gran importancia para el ganado domestico porque ocasiona importantes perdidas economicas a nivel mundial. En Argentina es endemica y la cuarta enfermedad mas importante para el ganado vacuno, su hospedador definitivo. Con el objetivo de describir la dinamica de transmision de F. hepatica en una region de Argentina con clima subtropical, se realizaron muestreos estacionales entre la primavera de 2002 y de 2005 en un establecimiento en el norte de la Provincia de Corrientes. Se identifico al caracol hospedador intermediario, se caracterizo su habitat y se estudio su abundancia, estructura y dinamica poblacional en funcion de las condiciones climaticas y ambientales. Se estimo la prevalencia por F. hepatica en el hospedador intermediario y definitivo. Una sequia de 6 meses en el medio del estudio permitio estudiar su impacto en la poblacion de caracoles y en la dinamica de transmision de la fasciolosis. En el la zona de estudio se detecto un foco de transmision de F. hepatica bien establecido con altas prevalencias en ambos hospedadores. Lymnaea columella fue el unico hospedador intermediario hallado, siendo este su primer registro de infeccion natural por F. hepatica en Argentina. Antes de la sequia la prevalencia de L. columella oscilo entre 0 y 9 por ciento y la del ganado bovino entre 7,9 y 95 por ciento. La mayor prevalencia se observo en otono e invierno, cuando las variables climaticas no limitaron el desarrollo de los caracoles ni del parasito. Durante la sequia no se encontraron caracoles vivos y la prevalencia en el ganado disminuyo de 3,8 por ciento a cero. Cuando mejoraron las condiciones ambientales los caracoles se recuperaron rapidamente. La infeccion aparecio simultaneamente en caracoles y en ganado un ano despues de la sequia, con prevalencias de 0,1 por ciento y 1,6 por ciento, respectivamente. Se recolectaron en total 7.851 L. columella en Banados y Malezales, dos ambientes tipicos del Macrosistema del Ibera. Durante los periodos humedos se hallaron caracoles todo el ano, con altas abundancias en invierno, intermedias en otono y primavera y bajas en verano, siendo esta ultima la estacion mas critica por las altas temperaturas y la falta de agua. Durante los periodos desfavorables los individuos medianos fueron los mas resistentes y los que permitieron una rapida recuperacion de la poblacion. La dinamica de transmision de F. hepatica en la zona de estudio estuvo influenciada principalmente por la disponibilidad de agua. Con suficiente humedad en el ambiente la transmision se produce durante todo el ano pero ante una sequia de 6 meses de duracion se interrumpio naturalmente. El calor y la falta de agua producirian la muerte de los estadios de vida libre del parasito y de los caracoles infectados, disminuyendo la contaminacion de las pasturas. En base a esta informacion se propone un programa de control de la fasciolosis que podria hacerse extensivo a otras regiones con climas y ambientes semejantes al de la zona de estudio.

The fasciolosis, caused by Fasciola hepatica, is a parasitic disease of great veterinary importance due to major economic losses in livestock, the definitive host. In Argentina, fasciolosis is endemic and the fourth most important livestock disease. To investigate the transmission dynamics of F. hepatica in a subtropical Argentine region, seasonal samplings were performed over a three-year study period between spring 2002 and 2005 in a cattle farm in the north of Corrientes Province. The intermediate snail host was identified and its habitat was characterized. The abundance and population structure and dynamics were analyzed in relation to climate and environmental conditions. The prevalence of F. hepatica infection was determined in both hosts. A 6-month drought occurring in the middle of the study was an opportunity to investigate its impact on the snail population and on the transmission dynamics. A well-established transmission focus of F. hepatica was detected in the study area, with high prevalence values in both hosts. Lymnaea columella was the only intermediate host found, this being the first record of natural infection of this snail with F. hepatica in Argentina. Before the drought, the prevalences of L. columella and cattle ranged between 0-9 por ciento and 7.9-95 por ciento, respectively. The highest prevalence values were obtained in autumn and winter, when climate conditions favored snail and parasite development. No snails were found during the drought and prevalence in cattle decreased from 3.8 por ciento to zero. The snail population achieved full recovery when environmental conditions became milder. Infection appeared simultaneously in snails and cattle one year after the drought, with prevalences of 0.1 and 1.6 por ciento, respectively. A total of 7,851 L. columella were collected in Banados and Malezales, two typical environments of the Ibera Macrosystem. Snails were found throughout the humid periods, with high abundances in winter, intermediate in autumn-spring and low in the hot, dry summer. The medium-sized snails were more tolerant to unfavorable environmental conditions, allowing a rapid population recovery. The transmission dynamics of F. hepatica in the study area was mainly influenced by water availability: transmission occurs all year round in humid periods and it is naturally interrupted by a 6- month drought. High temperature and lack of water may lead to the death of free-living parasite stages and infected snails, thus limiting pasture contamination. A fasciolosis control program is proposed based on the information provided herein, which may be extended to other regions with similar climates and environments.

Notes:

Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios de la Inmunidad Humoral (IDEHU), Facultad de Farmacia y Bioquimica, UBA.

OCLC:

811371877