Leishmania mexicana (kinetoplastida: trypanosomatidae) in Neotoma micropus (rodentia: muridae) : a field study of prevalence and seasonal transmission and a simulation model of the infection cycle : a dissertation /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
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[College Station, Tex.] :
[Texas A&M University],
[1993]
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| Abstract: | ABSTRACT: The annual prevalence of Leishmania mexicana in Neotoma micropus from South Texas was studied by testing 192 N. micropus from 16 localities for L. mexicana. Forty-six Sigmodon hispidus from four of these localities also were tested. Seasonal transmission was investigated through trap-recapture studies at three localities and evaluation of infections in juveniles. Eighteen N. micropus from four localities tested positive for L. mexicana. Annual prevalence at these localities ranged from 5.6% to 54%. This range of prevalence supports the hypothesis that N. micropus is a reservoir of L. mexicana in Texas. Infections were most frequently transmitted in the fall; transmission also occurred in the spring. No S. hispidus tested positive. A simulation model of transmission of L. mexicana among N. micropus by Lutzomyia anthophora was developed to predict the threshold vector density below which L. mexicana would be eliminated from a population of N. micropus within two years. Model results also supported the hypothesis that N. micropus is a reservoir of L. mexicana. Leishmania mexicana could be maintained in a focus with an initial annual prevalence of 5.7%, which approximated the lowest non-zero prevalence found in this study, and a peak annual vector density of only 11 female sand flies/woodrat. At a peak density of 3 flies/woodrat, the prevalence approached zero at the end of two years. Simulations indicated that if the initial prevalence of infection were 54%, the highest annual prevalence found in field studies, prevalence would remain above zero (2.5%) after two years even if there were no sand fly activity whatsoever. |
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| Item Description: | Vita. "Major subject: Wildlife and Fisheries Sciences." "Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of Doctor of Philosophy August 1993". Approved as to style and content by: Norman O. Dronen, Jr., Thomas McKie Craig, William E. Grant, Rodney L. Honeycutt, Robert D. Brown. |
| Physical Description: | xiv, 121 leaves : illustrations ; 28 cm |
| Bibliography: | Includes bibliographical references. |