Raymond, Russell Wayne (2008-08). Exploration of Potential Reservoir Hosts and Vectors of Leishmania in Nicaragua. Doctoral Dissertation. Thesis uri icon

abstract

  • Leishmaniasis is caused by infection with protozoan parasites within the genus Leishmania and, in the New World, is transmitted by the bites of female sand flies within the genus Lutzomyia. The occurrence of leishmaniasis in rodent species, the geographic distribution of sand fly species in Nicaragua, and environmental factors associated with the distribution of human cases of typical cutaneous leishmaniasis were investigated. Three hundred ninety five rodents representing 17 species were collected from 13 localities from August 2001-March 2006 and screened for Leishmania infections. One Heteromys desmarestianus and one Peromyscus mexicanus were found to be positive for leishmanial infections by PCR. This is the first report of Leishmania infections in rodents in Nicaragua. Five hundred fifty six sand flies representing 12 species were collected from 8 localities, including Lutzomyia hartmanni, a new record for this species in Nicaragua. The predominant sand fly species captured in western Nicaragua were Lutzomyia longipalpis and Lutzomyia evansi. The predominant species captured in central and eastern Nicaragua was Lutzomyia cruciata. The geographic distribution of sand flies in this study provides additional support to previouslypublished reports of suspected vectors of Leishmania species that cause typical and atypical forms of cutaneous leishmaniasis in Nicaragua. Distribution data of human cases of typical cutaneous leishmaniasis obtained from the Nicaraguan Ministry of Health, along with GIS and remotely sensed data of elevation, precipitation, temperature, soil types and land use/cover classes, were used to develop predictive logistic regression models for the presence or absence of human cases within 151 municipalities. Mean annual precipitation and land use/cover were determined to be the best environmental variable predictors for the occurrence of typical cutaneous leishmaniasis.
  • Leishmaniasis is caused by infection with protozoan parasites within the genus
    Leishmania and, in the New World, is transmitted by the bites of female sand flies
    within the genus Lutzomyia. The occurrence of leishmaniasis in rodent species, the
    geographic distribution of sand fly species in Nicaragua, and environmental factors
    associated with the distribution of human cases of typical cutaneous leishmaniasis were
    investigated. Three hundred ninety five rodents representing 17 species were collected
    from 13 localities from August 2001-March 2006 and screened for Leishmania
    infections. One Heteromys desmarestianus and one Peromyscus mexicanus were found
    to be positive for leishmanial infections by PCR. This is the first report of Leishmania
    infections in rodents in Nicaragua. Five hundred fifty six sand flies representing 12
    species were collected from 8 localities, including Lutzomyia hartmanni, a new record
    for this species in Nicaragua. The predominant sand fly species captured in western
    Nicaragua were Lutzomyia longipalpis and Lutzomyia evansi. The predominant species
    captured in central and eastern Nicaragua was Lutzomyia cruciata. The geographic distribution of sand flies in this study provides additional support to previouslypublished
    reports of suspected vectors of Leishmania species that cause typical and
    atypical forms of cutaneous leishmaniasis in Nicaragua.
    Distribution data of human cases of typical cutaneous leishmaniasis obtained
    from the Nicaraguan Ministry of Health, along with GIS and remotely sensed data of
    elevation, precipitation, temperature, soil types and land use/cover classes, were used to
    develop predictive logistic regression models for the presence or absence of human cases
    within 151 municipalities. Mean annual precipitation and land use/cover were
    determined to be the best environmental variable predictors for the occurrence of typical
    cutaneous leishmaniasis.

publication date

  • August 2008