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

Background: Waste water may contain pathogenic human and animal excreta-derived micro-organisms that can cause infections. Municipal sewage workers are a relevant neglected high-risk population especially in the absence of effective protective equipment and lack of hygienic practices mainly washing hands. Objective: The present study aims to assess the hazards of infection with micro-organisms among municipal sewage workers as a neglected population, besides those infections that maybe acquired via sources other than their occupational hazard. Subjects and Methods: A cross-sectional study was conducted on sewage workers from different sectors in Alexandria Governorate, Egypt. Collected stool samples were subjected to the following techniques; Kato-Katz, ether concentration, Jones’ Media culture, modified Ziehl-Neelsen, and quick hot Gram-chromotrope staining. Stool samples were also tested for Helicobacter pylori antigen (H. pylori Ag). Serum was separated for detection of viral hepatitis C antibodies (HCV Ab), and HBV surface antigen (HBVs Ag). Results: Out of the 410 examined workers, 289 (70.5%) were infected; among them 111 (38.4%) had mixed infections. It was found that 56.8%, and 31.2% harbored intestinal parasitic infections (IPIs) and H. pylori, respectively; and 12.2% had hepatitis mainly HCV (9.8%). Protozoal infections amounted to 54.6%, and only 5.9% had helminthic infections. Blastocystis spp. was the most prevalent parasite (46.8%) followed by Cryptosporidium spp., Entamoeba histolytica/dispar and Microsporidium spp. (15.6%, 11.7%, and 7.8%, respectively). Almost equal percentages were recorded for single IPI and multiple infections (28.3%and 28,5% respectively). Significantly higher rates of IPIs and H. pylori were observed among workers who were in frequent contact with sewage. Also, IPIs were statistically higher among young workers (<40 years), while hepatitis was significantly more prevalent among those from rural areas. Conclusion: Although almost all the detected microbiological infectious hazards can affect sewage workers via sources other than their occupational hazard, our findings call for the importance of self-protection measures that should be in association with regular medical investigation and treatment.