Urban transmission of schistosomiasis: new epidemiological situation in the forest area of Pernambuco

• Published in: Revista brasileira de epidemiologia Vol. 19; no. 4; p. 822
• Main Authors: Gomes, Elainne Christine de Souza, Mesquita, Millena Carla da Silva, Rehn, Vitorina Nerivânia Covello, Nascimento, Wheverton Ricardo Correia do, Loyo, Rodrigo, Barbosa, Constança Simões
• Format: Journal Article
• Language: English; Portuguese
• Published: Brazil 01-10-2016
• Subjects: Animals; Biomphalaria - parasitology; Brazil; Disease Vectors; Forests; Humans; Schistosomiasis - transmission; Schistosomiasis mansoni; Urban Health
• ISSN: 1980-5497
• DOI: 10.1590/1980-5497201600040012

Schistosomiasis is considered an endemic disease in Vitória de Santo Antão, Pernambuco, a district which has presented both high incidence and prevalence of it for decades. Poor environmental conditions lead to contamination of water sources in rural areas, which are used by the population during daily activities, resulting in typical transmission. Recently, there has been evidence of vector snails in urban areas, which could set a new model for schistosomiasis transmission in this district.
To identify the new epidemiological situation for the urban transmission of schistosomiasis in Vitória de Santo Antão, Pernambuco.
A malacological survey was conducted in all water sources in the city limits to investigate schistosomiasis vector snails (Biomphalaria spp.). The collected snails were examined for taxonomic identification and Schistosoma mansoni infection. All breeding sites were georeferenced to build risk maps through the TrackMaker PRO program and ArcGIS software.
We identified 22 Biomphalaria straminea breeding sites and collected 1,704 snails. One of these breeding sites was identified as a source of transmission and seven as potential sources of transmission. The designed maps identified two risk areas of urban transmission of schistosomiasis and expansion areas for breeding sites, establishing an increased risk of transmission to the population.
This study verified the existence of a new epidemiological situation in which the possibility of the urban transmission of the disease was confirmed.