Impact of drainage and sewerage on intestinal nematode infections in poor urban areas in Salvador, Brazil

Abstract

This cross-sectional study was conducted in 1989 among children aged between 5 and 14 years old living in nine poor urban areas of the city of Salvador (pop. 2.44 million), capital of Bahia State, in Northeast Brazil. Three of these areas had benefited from both drainage and sewerage, 3 from improved drainage only, and 3 from neither. The children studied thus belonged to 3 exposure groups regarding their level of sanitation infrastructure. An extensive questionnaire was applied to collect information on each child and on the conditions of the household, and stool examinations of the children 5-14 years old were performed to measure nematode infection. Comparison of the sewerage group with the drainage-only group and the latter with the control (no sewerage or drainage) group showed that, when the level of community sanitation was better, the prevalence of infection among children was less, but risk factors identified for infection were more numerous and more significant. Intensity of infection with Trichuris, but not with Ascaris or hookworm, was also less. The results suggest that sewerage and drainage can have a significant effect on intestinal nematode infections, by reducing transmission occurring in the public domain.

Factors influencing growth and intestinal parasitic infections in preschoolers attending philanthropic daycare centers in Salvador, Northeast Region of Brazil

“…This is probably because T. trichiura was the predominant parasite in these children and not A. lumbricoides. Prevalence of parasitic infections and non-pathogenic cysts was greatest in the periurban favela daycare group, probably due to the close proximity to unpaved roads, use of contaminated water sources and poor drainage and sewage connections 33 .…”

Neglected diseases of neglected populations: Thinking to reshape the determinants of health in Latin America and the Caribbean

“…A recent systematic review and meta-analysis presents the positive impacts of water supply and hygiene interventions in reducing diarrhea in less-developed countries [59]. Examples of innovative interventions which address the disease determinants include home-based water treatment systems with filtration, flocculation and safe sealed storage containers [60]; simplified or condominial sewerage for shantytowns and other areas of urban poverty [61] and ecological disposal of excreta by the separation of urine and feces [62]; promotion of manual sanitary landfills; improved household and neighborhood drainage systems [63]; education to promote household hygiene, cleanliness and tidiness [64]; and animal corralling [65]. Improvements in rural housing (floors, ceilings, walls, and windows) have reduced the transmission of Chagas disease [66], while the use of mesh screens (for eaves, windows and doors) and sealing eaves have reduced human exposure to malaria vectors [67].…”

Promoting Health and Advancing Development through Improved Housing in Low-Income Settings

“…84 such as the frequency of water supply interruption, poor sullage disposal and absence of a washstand; these indicate the need for environmental interventions to address disease transmission in the home as well as the community. 42,43 For example, design features of a house, such as locating a washstand within easy reach of a latrine, may enable handwashing with soap 44 which can reduce diarrheal disease by up to 47 %. 45 Water supply and sanitation, like the best housing, comes at a cost: in the 1920s in the UK, relocation of inhabitants from an overcrowded slum to a purpose-built modern dwelling resulted in an increase in the death rate, predominantly from infectious diseases.…”