SUMMARY OF THESIS AND DISSERTATION | RESUMO DE TESE E DISSERTAÇÃO | RESUMEN DE TESIS Y DISERTACIÓN

Natural infection of Lutzomyia (Nyssomyia) umbratilis Ward & Fraiha, 1977 (Diptera: Psychodidae: Phlebotominae) by Leishmania spp. (Kinetoplastida: Trypanosomatidae) in endemic areas of cutaneous leishmaniasis in Amazonas State, Brazil^*

Francimeire Gomes Pinheiro^I; Sérgio Luís Bessa Luz^II; Antonia Maria Ramos Franco^III

^IPrograma de Pós-Graduação de Entomologia, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brasil
^IILaboratório de Biodiversidade, Centro de Pesquisas Leônidas & Maria Deane, Manaus, Amazonas, Brasil
^IIILaboratório de Leishmaniose e Doença de Chagas, Coordenação de Pesquisas em Ciências da Saúde, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brasil

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Original Title: Infecção natural em Lutzomyia (Nyssomyia) umbratilis Ward & Fraiha, 1977 (Diptera: Psychodidae: Phlebotominae) por Leishmania spp. (Kinetoplastida: Trypanosomatidae) em áreas endêmicas de leishmaniose tegumentar americana no Estado do Amazonas, Brasil. Translated by: American Journal Experts

INTRODUCTION: Understanding the species involved in the transmission cycle of leishmaniasis in the Amazon is important. The maintenance of this endemic disease depends on the presence of its etiologic agent, mammalian reservoirs, vectors and the environmental conditions that favor its transmission.
OBJECTIVE: The objective of this study was to evaluate the rate of natural infection by Leishmania in Lutzomyia umbratilis by comparing traditional isolation methods (dissection and direct observation of the digestive tract) with molecular methods (Nested-PCR) to detect the infection of insects from areas with endemic leishmaniasis in the municipality of Manaus, Amazonas State, Brazil.
MATERIALS AND METHODS: Two study areas were selected due to presenting different characteristics: the settlement Tarumã-Mirim and the Base de instrução de Guerra na Selva-BI1 (CIGS). The former location is associated with a resident population (settled/representing major human disturbances), whereas the latter comprises individuals who migrate among several different localities throughout Brazil (representing minor disturbances). All samples were collected using "modified CDC" traps from November 2002 to October 2003.
RESULTS: We collected a total of 2,160 female L. umbratilis, of which 1,440 were dissected, and 720 were individually tested using PCR with mini-exon gene-specific primers (SLrev, SL2, SL1 and SLM2). Of the total number of females dissected, 1.6% (12/720) from Bl 1 and 0.4% (3/720) from Tarumã-Mirim were naturally infected. We tested 720 samples from Bl1 using PCR and found that 42.9% (308/720) were infected with the subgenus Viannia, whereas 3.2% (23/720) were infected with the subgenus Leishmania.
CONCLUSION: The natural infection rate was highest in the environments that were least disturbed by human activity. PCR was more effective than traditional methods for detecting Leishmania infection, and we recommend its use in epidemiological studies of cutaneous leishmaniasis in the Amazon region.

Keywords: Polymerase Chain Reaction; Psychodidae; Leishmania; Rural Settlements.

Financial support: Conselho Nacional de Desenvolvimento Cientifico e Tecnológico e CAPES/RENOR.

Correspondência / Correspondence / Correspondencia:
Antonia Maria Ramos Franco
Laboratório de Leishmaniose e Doença de Chagas,
Instituto Nacional de Pesquisas da Amazônia
Av. André Araújo, n° 2936
CEP: 79304-020
Manaus-Amazonas-Brasil
E-mail: afranco@inpa.gov.br

Recebido em / Received / Recibido en: 28/6/2010
Aceito em / Accepted / Aceito en: 26/8/2010

^*This dissertation was submitted to the Entomology Post-Graduation Program of the Instituto Nacional de Pesquisas na Amazônia on March 14, 2004, as a partial fulfilment of the requirements for the degree of Master of Sciences in Biology. The author was advised by Professors PhD. Antonia Maria Ramos Franco and PhD. Sérgio Luis Bessa Luz. Manaus, Amazonas State, Brazil.