Intestinal parasite infections and associated risk factors in communities exposed to wastewater in urban and peri-urban transition zones in Hanoi, Vietnam

Abstract

BackgroundInfections with intestinal parasites (helminths and intestinal protozoa) are endemic in Southeast Asia and inappropriate management and reuse of wastewater might exacerbate the risk of human infections. In rapidly growing urban settings, little is known about the extent of intestinal parasite infections. We assessed the point-prevalence and risk factors of intestinal parasite infections in population groups differently exposed to wastewater in urban and peri-urban transition zones in Hanoi, the capital of Vietnam.MethodsA cross-sectional survey was carried out between April and June 2014 in people aged ≥ 18 years at risk of wastewater exposure from To Lich River: workers maintaining wastewater treatment facilities; urban farmers reusing wastewater; and urban dwellers at risk of flooding events. For comparison, two peri-urban population groups living in close proximity to the Red River were chosen: farmers using river water for irrigation purposes; and people living in the same communities. A single stool sample was subjected to Kato-Katz and formalin-ether concentration methods for the diagnosis of helminth and intestinal protozoa infections. A questionnaire was administered to determine risk factors and self-reported signs and symptoms.ResultsA total of 681 individuals had complete data records. Highest point-prevalence rates of intestinal parasite infections were observed for peri-urban farmers (30 %). Hookworm and Trichuris trichiura were the predominant helminth species (25 % and 5 %, respectively). Peri-urban farmers were at higher odds of infection with intestinal parasites than any other groups (adjusted odds ratio 5.8, 95 % confidence interval 2.5 to 13.7). Lack of access to improved sanitation and not receiving deworming within the past 12 months were associated with higher infection risk, while higher educational attainment and socioeconomic status were negatively associated with intestinal parasite infections.ConclusionsOur results suggest that exposure to wastewater was not directly associated with infection with helminths and intestinal protozoa in different population groups in Hanoi. These findings might be explained by a high level of awareness of health risks and access to safe sanitary infrastructure in urban areas. The high prevalence rates observed in peri-urban farmers call for specific interventions targeting this population group.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1809-6) contains supplementary material, which is available to authorized users.

Intestinal parasitic infections and associated risk factors in preschoolers from different urban settings in Central-Western Brazil

“…Public health interventions which focus on the provision of basic sanitation infrastructure, health education, and target drug administration are essential to prevent and control these parasitic diseases [5]. These measures should be based and adapted to a local context to assure their success and maintenance.…”

Infection hazard of exposure to intestinal parasites, H. pylori and hepatitis viruses among municipal sewage workers: a neglect high risk population

“…Results of a Kampala study revealed that sewer-men presented with lower detection rates than farmers who used untreated waste water to grow their crops (76%) [48] . Also, a study conducted by Fuhrimann et al [50] in different communities exposed to waste water in urban and peri-urban transition zones in Hanoi, Vietnam, showed that waste water exposure was not directly associated with IPIs. The investigators explained their conclusion by the high level of awareness of the population to the different health risks [50] .…”

Trichuris trichiura Infection in North Korean Defector Resulted in Chronic Abdominal Pain and Growth Retardation

“…1 The disease control was achieved by implementation of both the national control system and improvement of environment and sanitation. 6 Occasionally, sporadic cases occur in non-endemic, developed areas, because of immigration. 2 Therefore, to date, coming across a patient with parasite infection of T. trichiura in South Korea is highly rare in South Korea.…”

“…Such knowledge leads us to presume a high prevalence of intestinal parasitic infection in North Korea. 6 Recently, a single tertiary hospital in South Korea reported clinical characteristics of defectors from North Korea. In children, heavy colonic infection called TDS causes diarrhea with blood or mucus, rectal prolapse, and iron deficiency anemia.…”