Neglected tropical diseases: prevalence and risk factors for schistosomiasis and soil-transmitted helminthiasis in a region of Minas Gerais State, Brazil

• Published in: Transactions of the Royal Society of Tropical Medicine and Hygiene Vol. 108; no. 6; pp. 363 - 371
• Main Authors: Couto, Luzivalda D., Tibiriça, Sandra H.C., Pinheiro, Izabella O., Mitterofhe, Adalberto, Lima, Adilson C., Castro, Milton F., Gonçalves, Murilo, Silva, Marcio R., Guimarães, Ricardo J.P.S., Rosa, Florence M., Coimbra, Elaine S.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.06.2014
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Biological and medical sciences; Brazil - epidemiology; Child; Child, Preschool; Cross-Sectional Studies; Diseases caused by trematodes; Feces - parasitology; Female; General aspects; Helminthiasis - epidemiology; Helminthiasis - transmission; Helminthic diseases; Humans; Infant; Infant, Newborn; Infectious diseases; Male; Medical sciences; Middle Aged; Neglected Diseases - epidemiology; Parasitic diseases; Prevalence; Risk Factors; Schistosomiases; Schistosomiasis - epidemiology; Schistosomiasis - transmission; Soil - parasitology; Water - parasitology; Young Adult; South America; Brazil; America; Brazil; Kato-Katz; Schistosomiasis; STH infections; Diagnosis; Low-transmission area; Prevalence; Trematode disease; Transmission; Parasitosis; Epidemiology; Helminthiasis; Infection; Somatotropin; Neglected disease; Tropical disease; Risk factor; Tropical medicine
• ISSN: 0035-9203; 1878-3503
• DOI: 10.1093/trstmh/tru054

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.