title: Epidemiological aspects of Toxoplasma gondii infection in riverside communities in the Southern Brazilian Amazon.
abstract: BACKGROUND
  Toxoplasma gondii infection is widely prevalent in humans and other animals worldwide. Information on the prevalence of T. gondii infection is scarce in some regions of Brazil, including riverside communities along the Amazon River basin.
  The prevalence of T. gondii in 231 people, aged 1-85 years, who were living in four riverside communities along the Purus River, Lábrea, State of Amazonas, Brazil, was determined. Antibodies against T. gondii were assayed using a commercial enzyme-linked immunosorbent assay (ELISA) kit. The hearts and brains of 50 chickens, which were raised free-range in the communities, were pooled according to the community of origin and bioassayed in mice. The isolates were genotyped using polymorphisms at 12 nuclear markers (SAG1, 5' and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3).
  
  
  RESULTS
  The overall seroprevalence of T. gondii was 56.7% (131/231). IgG antibodies were presented by 117 (89.3%) and IgM by 14 (10.7%) of the 131 positive individuals. No association between age group and gender with prevalence was observed (chi-square test, p > 0.05); however, the comparison between localities showed that the seroprevalence of T. gondii was significantly lower among the individuals living in the Boca do Ituxi (p < 0.05) community. Five isolates of T. gondii were obtained in the mouse bioassay, and genotyping revealed two complete genotypes that had not been described previously and three mixed isolates.
  
  
  CONCLUSIONS
  These results support previous findings that T. gondii population genetics are highly diverse in Brazil and that T. gondii infection is active in these riverside communities.
authors.affiliation: Curso de Medicina Veterinária, Faculdades Metropolitanas Unidas, São Paulo, São Paulo, Brazil.
authors.forename: Sérgio Neto
authors.initials: SN
authors.lastname: Vitaliano
authors.affiliation: Faculdade São Lucas, Porto Velho, Rondônia, Brazil.
authors.forename: Gabriel Maciel
authors.initials: GM
authors.lastname: de Mendonça
authors.affiliation: Faculdade São Lucas, Porto Velho, Rondônia, Brazil.
authors.forename: Felipe Amsterdam Maia
authors.initials: FA
authors.lastname: de Sandres
authors.affiliation: Faculdade São Lucas, Porto Velho, Rondônia, Brazil.
authors.forename: Juliana de Souza Almeida Aranha
authors.initials: Jde S
authors.lastname: Camargo
authors.affiliation: Faculdade São Lucas, Porto Velho, Rondônia, Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: de Tarso
authors.affiliation: Faculdade São Lucas, Porto Velho, Rondônia, Brazil.
authors.forename: Sérgio de Almeida
authors.initials: Sde A
authors.lastname: Basano
authors.affiliation: Faculdade São Lucas, Porto Velho, Rondônia, Brazil.
authors.forename: Jéssica Carolinne Damasceno E
authors.initials: JC
authors.lastname: Silva
authors.affiliation: Faculdade São Lucas, Porto Velho, Rondônia, Brazil.
authors.forename: Viviane Krominski Graça
authors.initials: VK
authors.lastname: de Souza
authors.affiliation: Laboratório Central de Saúde Pública, Secretaria Municipal de Saúde de Porto Velho, Porto Velho, Rondônia, Brazil.
authors.forename: Glenci
authors.initials: G
authors.lastname: Cartonilho
authors.affiliation: Faculdade São Lucas, Porto Velho, Rondônia, Brazil.
authors.forename: Alexandre Thomé da Silva
authors.initials: AT
authors.lastname: de Almeida
authors.affiliation: Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Solange Maria
authors.initials: SM
authors.lastname: Gennari
authors.affiliation: Faculdade São Lucas, Porto Velho, Rondônia, Brazil.
authors.forename: Luís Marcelo Aranha
authors.initials: LM
authors.lastname: Camargo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001681:Biological Assay; D001921:Brain / Q000469:parasitology; D001938:Brazil / Q000453:epidemiology; D002415:Cats; D002645:Chickens; D002648:Child; D002675:Child, Preschool; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D051379:Mice; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D015995:Prevalence; D045483:Rivers; D012424:Rural Population; D016036:Seroepidemiologic Studies; D014122:Toxoplasma / Q000235:genetics / Q000276:immunology; D014123:Toxoplasmosis / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan