Epidemiological and ecological aspects related to malaria in the area of influence of the lake at Porto Primavera dam, in western São Paulo State, Brazil

Authors

  • Almério de C. Gomes Universidade de São Paulo; Faculdade de Saúde Pública; Departamento de Epidemiologia
  • Marcia B. de Paula Universidade de São Paulo; Faculdade de Saúde Pública; Departamento de Epidemiologia
  • Ana Maria R. de C. Duarte Secretaria de Estado da Saúde; Superintendência de Controle de Endemias; Laboratório de Bioquímica e Biologia Molecular
  • Maura A. Lima Universidade de São Paulo; Faculdade de Saúde Pública; Departamento de Epidemiologia
  • Rosely dos S. Malafronte Universidade de São Paulo; Instituto de Medicina Tropical de São Paulo; Laboratório de Protozoologia
  • Luis F. Mucci Secretaria de Estado da Saúde; Superintendência de Controle de Endemias; Laboratório de Entomologia Médica
  • Sabina Lea D. Gotlieb Universidade de São Paulo; Faculdade de Saúde Pública; Departamento de Epidemiologia
  • Delsio Natal Universidade de São Paulo; Faculdade de Saúde Pública; Departamento de Epidemiologia

Keywords:

Malaria, Porto Primavera Hydroelectric Power Station, Entomology, Antibodies to Circumsporozoite Protein, Antibodies to Plasmodium blood-stage antigens

Abstract

A study was carried out in the area of influence of the Porto Primavera Hydroelectric Power Station, in western São Paulo State, to investigate ecological and epidemiological aspects of malaria in the area and monitor the profile of the anopheline populations following the environmental changes brought about by the construction of the lake. Mosquitoes captured were analyzed by standardized indicator species analysis (ISA) before and during different flooding phases (253 m and 257 m elevations). The local human population was studied by means of parasitological (thin/thick blood smears), molecular (PCR) and serological tests. Serological tests consisted of Enzyme Linked Immunosorbent Assay (ELISA) with synthetic peptides of the circumsporozoite protein (CSP) from classic Plasmodium vivax, P. vivax variants (VK247 and "vivax-like"), P. malariae and P. falciparum and Indirect Immunofluorescence Assay (IFA) with asexual forms of P. vivax, P. malariae and P. falciparum. The results of the entomological survey indicated that, although the Anopheles darlingi population increased after the flooding, the population density remained very low. No malaria, parasite infection or DNA was detected in the inhabitants of the study area. However, there was a low frequency of antibodies against asexual forms and a significant prevalence of antibodies against P. vivax, P. vivax variants, P. falciparum and P. malariae; the presence of these antibodies may result from recent or less recent contact with human or simian Plasmodium (a parallel study in the same area revealed the existence of a sylvatic cycle). Nevertheless, these results suggest that, as in other places where malaria is present and potential vectors circulate, the local epidemiological conditions observed could potentially support the transmission of malaria in Porto Primavera Lake if infected individuals are introduced in sufficient numbers. Further studies are required to elucidate the phenomena described in this paper.

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Published

2008-10-01

Issue

Section

Malaria

How to Cite

Gomes, A. de C., Paula, M. B. de, Duarte, A. M. R. de C., Lima, M. A., Malafronte, R. dos S., Mucci, L. F., Gotlieb, S. L. D., & Natal, D. (2008). Epidemiological and ecological aspects related to malaria in the area of influence of the lake at Porto Primavera dam, in western São Paulo State, Brazil . Revista Do Instituto De Medicina Tropical De São Paulo, 50(5), 287-295. https://revistas.usp.br/rimtsp/article/view/31204