Neglected tropical diseases: prevalence and risk factors for schistosomiasis and soil-transmitted helminthiasis in a region of Minas Gerais State, Brazil.
BACKGROUND
Among the neglected tropical diseases (NTDs), schistosomiasis and the three main soil-transmitted helminthiases (STHs), i.e., ascariasis, trichuriasis and hookworm infection, represent the most common infections in developing countries. In Brazil, there is a lack of epidemiological data in many parts of the country, which favors the unawareness of the real situation concerning these diseases. Due to this, we investigated the occurrence of schistosomiasis and STHs in a region of Minas Gerais State, Brazil.


METHODS
One stool sample was collected from 503 individuals, whose ages ranged from 0.1 to 91.2 years, and screened using both the Kato-Katz and the Formol-Ether methods. In parallel, a malacological survey was carried out in the main water bodies of the district, and Biomphalaria susceptibility assays and kernel-based techniques were also performed.


RESULTS
No individual was found infected with Ascaris lumbricoides or hookworm. Schistosoma mansoni was the most common parasite found (1.6%). The prevalence was higher in males and the chance of acquiring the disease increased by 43.35 times with contact with a body of water. None of the Biomphalaria tenagophila and B. glabrata specimens were found naturally infected, but B. glabrata was highly susceptible to infection with Schistosoma mansoni. Using kernel-based techniques, clusters of Biomphalaria were found near the households where the infected individuals lived.


CONCLUSIONS
Schistosomiasis was the most prevalent parasitic infection found. Our findings show that the occurrence of this disease has been underestimated by the local health care service, and highlight the importance of epidemiological surveillance in areas of low prevalence for schistosomiasis.
Programa de Pós-graduação em Saúde Brasileira, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brasil.
Luzivalda D
LD
Couto
Departamento de Clínica médica, Faculdade de Medicina, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brasil.
Sandra H C
SH
Tibiriça
Superintendência Regional de Saúde de Juiz de Fora, Secretaria de Estado da Saúde de Minas Gerais, Juiz de Fora, MG, Brasil.
Izabella O
IO
Pinheiro
Superintendência Regional de Saúde de Juiz de Fora, Secretaria de Estado da Saúde de Minas Gerais, Juiz de Fora, MG, Brasil.
Adalberto
A
Mitterofhe
Superintendência Regional de Saúde de Juiz de Fora, Secretaria de Estado da Saúde de Minas Gerais, Juiz de Fora, MG, Brasil.
Adilson C
AC
Lima
Superintendência Regional de Saúde de Juiz de Fora, Secretaria de Estado da Saúde de Minas Gerais, Juiz de Fora, MG, Brasil.
Milton F
MF
Castro
Superintendência Regional de Saúde de Juiz de Fora, Secretaria de Estado da Saúde de Minas Gerais, Juiz de Fora, MG, Brasil.
Murilo
M
Gonçalves
Embrapa Gado de Leite (CNPGL), Juiz de Fora, MG, Brasil.
Marcio R
MR
Silva
Laboratório de Geoprocessamento, Instituto Evandro Chagas, Ananindeua, PA, Brasil.
Ricardo J P S
RJ
Guimarães
Departamento de Parasitologia, Microbiologia e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brasil.
Florence M
FM
Rosa
Departamento de Parasitologia, Microbiologia e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brasil elaine.coimbra@ufjf.edu.br.
Elaine S
ES
Coimbra
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005243:Feces / Q000469:parasitology; D005260:Female; D006373:Helminthiasis / Q000453:epidemiology* / Q000635:transmission; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D058069:Neglected Diseases / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors; D012552:Schistosomiasis / Q000453:epidemiology* / Q000635:transmission; D012987:Soil / Q000469:parasitology*; D014867:Water / Q000469:parasitology*; D055815:Young Adult
D012987:Soil; D014867:Water
Brazil; Diagnosis; Kato-Katz; Low-transmission area; STH infections; Schistosomiasis