Risk of hepatitis A virus infection among sewage workers in Israel

Global systematic review of occupational health and safety outcomes among sanitation and hygiene workers

Introduction

Sanitary workers are exposed to a variety of occupational hazards in a variety of working environments, which can result in occupational-related outcomes. As a result, the goal of this review was to identify occupational health and safety outcomes among sanitary workers worldwide.

Methods

PRISMA was used as flow diagram and PICOS was used review questions. The studies published in English were searched from databases and others methods ranging from 2000 to 2022. Boolean logic (AND, OR), MeSH, and keywords used: (Occupation *OR Job *OR Work) AND (Occupational related respiratory Symptoms *OR Disease) AND [Solid waste collectors (SWCs) *OR Street sweepers (SS) *OR Sewage workers and waste treatment (STWs)] AND (Countries).

Results

A total of 228 studies were identified from 23 countries across the world. Studies were found via PubMed (n = 40), Medline (n = 25), Embase (n = 11) and Global Health (n = 66) and Google scholar (n = 63) and from previous (n = 23). From 8,962 of eligible sanitary workers, about 4,742 (54%), 1714 (19%) and 1,441 (16%) were sewage, sweepers and solid waste workers, respectively. A total study (n = 51) were eligible for occupational health and safety outcomes. Of these, respiratory problems accounted 27 (52%) and Gastroenteritis 14 (27%).

Conclusion

Despite a large number of studies to date provides sanitary employees all over the world face occupational-related risks, hence more research is needed to enhance and quantify illness burden among sanitary workers.

Sero-prevalence of hepatitis viral infections among sanitary workers across worldwide: a systematic review and meta-analysis

BACKGROUND

Sanitation or sanitary workers are exposed to hepatitis virus infections because of filthy and dangerous working conditions. The current global systematic review and meta-analysis aimed to estimate the pooled sero-prevalence of occupationally associated hepatitis virus infection among them.

METHODS

Preferred Reporting Items for Systematic Reviews (PRISMA), and Population, Intervention, Comparison, Outcome and study design (PICOS) were used for flow diagram, and review questions, respectively. Four databases other methods were used published articles from 2000 to 2022. Boolean logic (AND, OR), MeSH, and keywords were used: (Occupation *OR Job *OR Work) AND (Hepatitis A *OR Hepatitis B virus *OR Hepatitis C virus *OR Hepatitis E virus) AND (Solid waste collectors [SWCs] *OR Street sweepers [SS] *OR Sewage workers [STWs] *OR health care facilities cleaners [HCFCs)) AND (Countries). Stata MP/17 software was used for pooled prevalence analysis, meta-regression analysis (Hedges) at a 95% confidence interval (CI:95%).

RESULTS

A total of 182 studies were identified studies, a total of 28 studies were included from twelve countries. Of these, from developed (n = 7) and developing countries (n = 5). From total a of 9049 sanitary workers, 5951(66%), 2280 (25%) and 818 (9%) were STWs, SWCs and SS, respectively. Globally, the pooled sero-prevalence of occupational-related hepatitis viral infections among sanitary workers was 38.06% (95% CI: 30-0.46.12). Of this, it was 42.96% (95% CI: 32.63-53.29) and 29.81% (95% CI: 17.59-42.02) for high-income and low-income countries, respectively. Meanwhile, by sub-analysis, the highest pooled sero-prevalence of hepatitis viral infections by categories, type and year were 47.66% (95%CI: 37.42-57.90), 48.45% (95% CI: 37.95-58.96), and 48.30% (95% CI: 36.13-60.47) for SWTs, HAV, and 2000 to 2010 year, respectively.

CONCLUSION

The consistency of the evidence suggests that sanitation workers, particularly sewage workers, are susceptible to occupationally acquired hepatitis regardless of their working conditions, necessitating significant changes to occupational health and safety regulations from governmental policies and other initiatives to reduce risks among sanitary workers.

Occupational health outcomes among sanitation workers: A systematic review and meta-analysis

Background

Sanitation workers are essential to global public health and societal wellbeing. However, the health risks and outcomes associated with exposure to occupational risk factors among sanitation workers are neither well understood nor well quantified. We undertook a systematic review to (1) identify occupational risk factors among sanitation workers and (2) assess the effect of occupational exposure to human fecal sludge and wastewater on selected health outcomes among these workers.

Methods

We searched four databases (i.e., PubMED, MEDLINE, EMBASE, and LILACS) for eligible studies from inception through to January 01, 2020. The included population was workers ≥15 years engaged, formally or informally, in installing, operating, servicing, cleaning or emptying a sanitation technology at any step of the sanitation chain. The included comparator was workers in other occupations or the general population. Eligible outcomes were: mortality (any or all causes), gastroenteritis, occupational injuries, respiratory diseases, musculoskeletal disorders, and mental and social health conditions. Risk of bias was assessed separately on exposure assessment and health outcome using a modified Liverpool Quality Assessment Tool (LQAT). We pooled sufficiently homogenous studies using inverse variance meta-analysis with random effects.

Results

A total of 65 studies (9 cohort studies, 56 cross-sectional studies) met the inclusion criteria. One quarter of studies (n = 15) were from middle-income countries. Few studies assessed occupational risk factor exposures directly; most assigned exposure via proxy of occupation of sanitation worker. We judged nearly all studies to have “high risk of bias” in exposure and outcome assessment. Despite these limitations, the consistency of the overall evidence suggests that sanitation workers are at increased risk of gastroenteritis and respiratory conditions, and may be at increased risk of musculoskeletal disorders and mental/social health conditions. The pooled odds ratio for hepatitis A--the only outcome deemed suitable for meta-analysis--was 2.09 (95% Predicted Interval: 1.39–3.00, 12 studies). There was conflicting evidence from studies of increased risk of mortality; only one study reported on injuries.

Conclusion

Despite a large number of studies, there is limited evidence to date of the health risks faced by sanitation workers, particularly among groups that may be at particular risk-- women, informal workers and those living in low-income countries. Nevertheless, the research to date provides suggestive evidence of elevated occupational risk among sanitation workers across a range of health condition. More research is needed to improve the current bodies of evidence for all included health outcomes to be able to quantify disease burden among this occupational group.

Occupational health hazards in sewage and sanitary workers

An estimated 1.2 million scavengers in the country are involved in the sanitation of our surroundings. The working conditions of these sanitary workers have remained virtually unchanged for over a century. Apart from the social atrocities that these workers face, they are exposed to certain health problems by virtue of their occupation. These health hazards include exposure to harmful gases such as methane and hydrogen sulfide, cardiovascular degeneration, musculoskeletal disorders like osteoarthritic changes and intervertebral disc herniation, infections like hepatitis, leptospirosis and helicobacter, skin problems, respiratory system problems and altered pulmonary function parameters. This can be prevented through engineering, medical and legislative measures. While the engineering measures will help in protecting against exposures, the medical measures will help in early detection of the effects of these exposures. This can be partly achieved by developing an effective occupational health service for this group of workers. Also, regular awareness programs should be conducted to impart education regarding safer work procedures and use of personal protective devices.

Vaccinations for waste-handling workers. A review of the literature

A review of the literature relating to the need for vaccination against infectious disease in the solid waste industry was conducted, focusing on hepatitis A, hepatitis B and tetanus. Databases (Medline, PreMedline, EMBASE, CINAHL, Current Contents, Cochrane Database, HTA Database, DARE, OSHROM) were searched up to and including August 2003. Articles were included in the review if they reported the prevalence of immunity to hepatitis A, hepatitis B or tetanus in solid waste workers or the incidence of clinical infection with any of these diseases. Papers about hazardous or medical waste, incineration or other infectious diseases were excluded. Forty-four papers constituted the evidence database. Only one paper studied the prevalence of antibodies to hepatitis A and hepatitis B in solid waste workers compared with sewage plant workers and office workers, and no difference was found between these groups of workers. There was some evidence to support a theoretical risk of infection with hepatitis A, B and tetanus; however, no studies could be found of the risk of these diseases in solid waste workers. No single cases of these diseases being acquired occupationally in solid waste management were identified in the literature. Workers in the solid waste industry may theoretically be at increased risk of acquiring infectious diseases occupationally. However, at present no studies could be found which have documented this risk.

Work-related symptoms and inflammation among sewage plant operatives

Sewage operatives at five sewage treatment plants (n = 59) and controls not exposed to sewage (n = 55) were examined to determine work-related symptoms and inflammatory responses. Symptoms were elicited using a questionnaire, and spirometry was performed. Inflammatory markers were determined in blood and nasal lavage. Workplace endotoxin and hydrogen sulfide were measured and adeno- and enterovirus antibodies were evaluated in blood. Gastrointestinal and airway symptoms, joint pains, unusual tiredness, and toxic pneumonitis were more common among operatives, and the proportion of blood neutrophils was higher among operatives as compared with controls. A relationship was found between several reported symptoms and the inflammatory markers. Hydrogen sulfide levels were very low. Endotoxin levels were generally low, but high at some work sites.

Risk groups for hepatitis A virus infection

We report the conduct and results of a systematic search for evidence of risk of infection with hepatitis A virus (HAV) among blood transfusion recipients, travellers, the military, healthcare workers, sewage workers, foodhandlers, day care assistants, institutionalised subjects, blood transfusion recipients, drug addicts, homosexuals, prisoners and other risk groups such a liver transplantees. We report our recommendations for the use of the HAV vaccine in these groups.

Prevalence of hepatitis A virus infection among sewage workers in Georgia

BACKGROUND

Wastewater (WW) workers could have opportunity for direct contact with raw sewage, which might contain hepatitis A virus (HAV).

METHODS

A serologic survey of WW workers and a comparison population of roads and drainage workers (RD). Factors potentially associated with anti-HAV positivity were evaluated in univariate and multivariate analyses.

RESULTS

Among the 365 WW workers, overall anti-HAV prevalence was 38%, similar to that (35%) of the 166 RD workers (P = 0.5). Prevalence varied by wastewater job type from 45% among the 164 field crew workers to 32% among the 201 treatment plant workers. In multivariate modeling, factors associated with anti-HAV positivity included age > or = 40 years (odds ratio [OR] = 2.4; 95% CI = 1.6-3.7), black compared to other races (OR = 2.4; 95% CI = 1.5-3.8), birth outside the United States (OR = 7.5; 95% CI = 3.0-18.6), a high school education or less (OR 2.1; 95% CI = 1.4-3.2) and work on the field crew compared to RD work (OR 1.6; 95% CI = 1.1-2.4).

CONCLUSIONS

These results are consistent with no or a small increased risk of hepatitis A among WW workers, and do not provide a clear mandate for hepatitis A vaccination of these workers. Am. J. Ind. Med. 43: 172-178, 2003.

Hepatitis A in workers exposed to sewage: a systematic review

OBJECTIVES

To assess whether the scientific literature supports the hypothesis that workers exposed to sewage are at higher risk of hepatitis A (HA).

METHODS

All original papers reporting epidemiological studies published in English, French, or German which reported on the risk of HA infection in workers exposed to sewage were eligible. They were identified by several methods and each original paper was assessed independently with a checklist by two people. Studies were classified according to the strength of their design. Non-eligible studies were also examined to assess the impact of publication bias. If the risk estimates diverged widely, causes for heterogeneity were assessed. A distinction was made between seroprevalence studies based on subclinical HA (defined only by the presence of anti-HA antibodies) and clinical HA.

RESULTS

17 eligible studies were identified. No indication of an increased risk of clinical HA could be found. For seroprevalence the studies with the strongest design suggested a slightly increased risk of subclinical HA with an odds ratio (OR) <2.5. Heterogeneity was considerable and precluded a meta-analysis. Considering non-eligible studies would still decrease the OR.

CONCLUSIONS

The systematic review does not confirm an increased risk of clinical HA in workers exposed to sewage. An increased risk of subclinical HA cannot be excluded but the association between seropositivity and exposure to sewage was not strong and became still weaker if publication bias was taken into account.

Health effects among employees in sewage treatment plants: A literature survey

BACKGROUND

Over the years, there have been regular reports in the media of work-related symptoms among employees at sewage treatment plants. Concern has spread among employees over the lack of knowledge of risk agents' symptoms, and diseases in that environment. This paper reviews the investigations of health risks in employees working in the sewage treatment plants.

METHODS

A literature search was performed with the search terms; sewage, waste water, health effects, infection, and health hazards. Articles on health effects in relation to sewage were selected.

RESULTS

Work in sewage water plants can involve exposure to different types of microorganisms and chemicals. The bacterial exposure is dominated by bacteria that naturally occur in nature. However, different bacteria and viruses that give rise to infections can be present in this environment and thus there exists a risk of infection, especially of hepatitis A. Investigations suggest that gastrointestinal tract symptoms are more common among employees at sewage treatment plants than among controls. Respiratory symptoms, fatigue, and headache have also been reported in several investigations. The cause of the symptoms is unknown, although certain data suggest that they are caused by inflammation. The results suggest that endotoxin in Gram-negative bacteria may be one of the causative agents. As regards cancer, some studies report an increased risk of stomach cancer and a few studies report an increased risk of cancer in the larynx, liver or, prostate or of leukemia. The spread of the cancers over a multitude of organs does not support a hypothesis of causality with agents commonly found in sewage treatment plants.

CONCLUSIONS

Further investigations are needed to determine the work-related effects and ascertain the causal agents.