Serological survey for Chagas disease in the rural areas of Manaus, Coari, and Tefé in the Western Brazilian Amazon.
BACKGROUND
Deforestation, uncontrolled forest, human population migration from endemic areas, and the large number of reservoirs and wild vectors naturally infected by Trypanosoma cruzi promote the endemicity of Chagas disease in the Amazon region.


METHODS
We conducted an initial serological survey (ELISA) in a sample of 1,263 persons; 1,095 (86.7%) were natives of the State of Amazonas, 666 (52.7%) were male, and 948 (75.1%) were over 20 years old. Serum samples that were found to be reactive, indeterminate, or inconclusive by indirect immunofluorescence (IFI) or positive with low titer by IFA were tested by Western blot (WB). Serologically confirmed patients (WB) were evaluated in terms of epidemiological, clinical, ECG, and echocardiography characteristics.


RESULTS
Fifteen patients had serologically confirmed T. cruzi infection, and 12 of them were autochthonous to the state of Amazonas, for an overall seroprevalence of 1.2% and 0.9% for the state of Amazonas. Five of the 15 cases were males, and the average age was 47 years old; most were farmers with low education. One patient who was not autochthonous, having originated from Alagoas, showed right bundle branch block, bundle branch block, and anterosuperior left ventricular systolic dysfunction with an ejection fraction of 54%.


CONCLUSIONS
The results of this study ratify the importance of monitoring CD cases in Amazonia, particularly in the state of Amazonas.
Escola Superior de Ciências da Saude, Universidade do Estado do Amazonas, Manaus, AM, Brasil.
Belisa Maria Lopes
BM
Magalhães
Leíla Ines Aguiar Raposo Câmara
LI
Coelho
Marcel Gonçalves
MG
Maciel
João Marcos Benfica Barbosa
JM
Ferreira
Eufrozina Setsu
ES
Umezawa
José Rodrigues
JR
Coura
Jorge Augusto de Oliveira
JA
Guerra
Maria das Graças Vale
Md
Barbosa
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D015153:Blotting, Western; D001938:Brazil / Q000453:epidemiology; D014355:Chagas Disease / Q000175:diagnosis / Q000453:epidemiology*; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007303:Insect Vectors / Q000145:classification; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D015995:Prevalence; D012424:Rural Population; D016036:Seroepidemiologic Studies; D012959:Socioeconomic Factors; D014349:Trypanosoma cruzi / Q000276:immunology*; D055815:Young Adult
D000913:Antibodies, Protozoan