Waste Collection and Viral Hepatitis: Assessing the Occupational Risk of HBV and HCV

Abstract

Hepatitis B and C (HBV and HCV) infections persist as significant public health concerns. Specific occupational groups, such as waste collectors, continue to face elevated risk due to exposure to contaminated materials. Research studies have underscored heightened infection rates, notably from needle prick injuries. The present study aspires to re-evaluate the prevalence of HBV and HCV among waste collectors and to scrutinize associated risk factors, thereby contributing to the development of effective public health and occupational safety strategies. The study analyzed data from 116 Italian waste collectors who were undergoing regular occupational visits, examining demographics, health conditions, HBV immunization, and annual blood tests for the HBsAg, HBsAb, and HCVAb. The HBsAb was detected in 66 individuals (56.9%), while the HCVAb was found in 4 (3.4%). Logistic regression showed HBV immunization and longer job experience to be significant factors associated with HBsAb presence. Waste collection may increase HBV infection risk due to occupational exposure, unlike HCV, which requires blood-to-blood contact. Preventive strategies, including education, protective equipment, and HBV vaccination, are essential. Ensuring vaccination coverage among waste collectors could reduce infection risk. Further research should assess the occupational risks and the effectiveness of preventive measures.

1. Introduction

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections continue to pose significant public health challenges on a global scale. The World Health Organization (WHO) estimates that, as of 2019, approximately 296 million individuals were living with chronic HBV infection, and 58 million with chronic HCV infection [1]. As demonstrated in the relevant literature, these infections are associated with severe complications, including acute flares, cirrhosis, hepatocellular carcinoma, and extrahepatic manifestations. These factors contribute substantially to global morbidity and mortality [2,3,4,5]. The prevalence of HBV infections in Italy is approximately 0.51%, and the prevalence of HCV infections is approximately 0.68% [6]. It is evident that these figures have declined over recent decades, largely due to the implementation of mandatory HBV vaccinations in 1991 [7].

Nevertheless, certain populations continue to demonstrate elevated levels of risk. Occupational exposure to HBV and HCV represents a concern for a variety of professions, most notably those involving contact with blood or bodily fluids. Research has documented an increased prevalence of HBV among municipal waste collectors, with studies indicating that occupational exposure to waste constitutes a possible risk factor for HBV infection since 2012 [8]. Several studies have also highlighted the increased risk of both hepatitis B and C infections among waste collectors due to occupational exposure. A global meta-analysis published in 2021 found that the prevalence of HBV among waste pickers was 15% (95% CI: 10–20), while the prevalence of HCV was 8% (95% CI: 4–12), indicating a significant risk for bloodborne infections in this occupational group [9]. Additionally, a study conducted in Ethiopia reported an HBV prevalence of 5.07% (95% CI: 2.0–8.15) and an HCV prevalence of 1.46% (95% CI: 0.52–2.4) among waste handlers, further emphasizing the necessity for targeted preventive measures [10].

The occupation of waste scavenger is characterized by a high risk of infection with HCV and HBV, primarily due to the occurrence of needlestick injuries [11]. It is imperative that adequate training programmes are implemented and that personal protective equipment is utilized in order to mitigate the aforementioned risk [12]. It is particularly worrying that medical waste collectors appear to be at an even higher risk than other waste workers [13,14,15]. Furthermore, the handling and lifting of waste exposes workers to bioaerosols, which have been associated with respiratory issues, infections, gastrointestinal and skin diseases, and cancer [16]. In view of the growing emphasis on recycling and the repercussions of global warming, exposure to biological agents in the waste management sector is anticipated to increase. Consequently, it is essential to anticipate future challenges, fortify preventive strategies, and implement enhanced measures to mitigate both immediate and long-term health effects [17].

The most recent study addressing this issue in Italy was conducted in 2006 [18], underscoring the necessity for updated epidemiological data. Therefore, the aim of this study is to re-examine the risk of HBV and HCV infections in waste collectors and present novel findings to inform public health and occupational safety strategies.

The primary objective of the present study is to investigate the prevalence of HBV and HCV infections among a population of waste collectors engaged in manual waste collection. This assessment aims to provide a clearer understanding of the occupational risks associated with exposure to biological hazards in this specific workforce. By evaluating serological markers, the study seeks to determine the extent to which waste collection activities may contribute to HBV and HCV transmission, considering the potential routes of exposure inherent in this occupation. The study will also estimate the prevalence of infection and identify potential associations between seropositivity and various demographic, health, and occupational factors.

Secondary objectives include the examination of potential variables that may influence HBV and HCV status, such as sex, immune disorders, diabetes, and years of work experience. The inclusion of these factors will allow for a more comprehensive analysis of the interplay between occupational exposure, individual susceptibility, and vaccination history. Furthermore, by analyzing both HBV and HCV infections within the same study population, this research provides an opportunity to compare patterns of transmission and immune response in workers exposed to different viral agents. This approach may help to clarify whether waste collection poses a significant occupational risk for either of these infections and to what extent preventive measures, such as vaccination, contribute to reducing disease burden in this workforce.

2. Materials and Methods

The study was conducted at an Italian waste collection company (n = 116). Waste collection workers are regularly monitored through occupational health assessments due to the potential biological and physical hazards associated with their job. Using the information available in the workers’ health and risk records, we examined data from the population of workers who attend regular occupational visits. This approach ensured a systematic and comprehensive evaluation of health-related variables over time.

Specifically, we collected information on demographic and occupational factors, including sex, age, and years of work experience, as well as medical conditions that could influence immune response, such as diabetes and other immunocompromising conditions. Additionally, we recorded workers’ immunization statuses against HBV, which was determined based on documented vaccination history, and assessed whether the workers resided in rural or non-rural areas; this characterization was conducted according to the classification used in the literature [19].

As part of the company’s occupational health surveillance program, workers undergo annual medical check-ups, which include laboratory tests. In accordance with the established risk assessment protocol, a blood sample is collected annually to analyze serological markers for Hepatitis B and C, specifically the Hepatitis B surface antigen (HBsAg), the Hepatitis B surface antibody (HBsAb), and the HCV antibody (HCVAb). This standardized screening protocol facilitates data collection and ensures consistency in health monitoring without requiring additional examinations solely for research purposes.

Subject characteristics were summarized as numbers and percentages, depending on the variable type. The distribution of categorical variables was assessed using the Chi-square test, while logistic regression analysis was employed to identify potential associations between occupational and health-related factors. A significance level of p < 0.05 was considered statistically significant. All statistical analyses were performed using SPSS version 25.0 for Windows to ensure robust and reliable data processing.

3. Results

A total of 116 patient clinical records were analyzed, and the characteristics of the study population are summarized in

Table 1. Characteristics of study population.

		n	%	Mean (±SD)
Total		116
Gender	Male	103	88.8
	Female	13	11.2
Age				53.9 (±8.2)
Age > 54 years		66	56.9
Immunocompromising condition		1	0.9
Diabetes		9	7.8
Living place	Urban	99	85.3
	Rural	17	14.7
Job experience > 5 years		111	95.7
Immunization for HBV		14	12.1
HbsAg +		0
HbsAb +		66	56.9
HCVAb +		4	3.4

SD: Standard Deviation.

, providing an overview of key demographic and occupational variables. Among the serological markers assessed, 66 individuals (56.9%) tested positive for the HBsAb, indicating either a past infection or successful immunization against HBV. In contrast, the prevalence of the HCVAb was detected in only 4 individuals (3.4%), suggesting a relatively low burden of HCV infection within this occupational group. Notably, no cases of HBsAg positivity were observed, indicating the absence of active HBV infection in the studied population. Further examination of the immunization status revealed that only 9 individuals exhibited HBsAb positivity associated with childhood vaccination, suggesting that a small proportion of the workforce benefited from early-life immunization programs. Conversely, 57 individuals (49.1%) reported no prior history of HBV vaccination.

A chi-squared test was conducted to assess the association between HBsAb positivity and each examined variable. The following variables were included in the study: gender, categorized as male or female; age, stratified into appropriate age groups; and medical conditions, such as immunocompromising disorders and diabetes.

In addition, the impact of environmental and occupational factors was analyzed, including place of residence (rural vs. non-rural areas), years of job experience (grouped into relevant categories), and HBV immunization status, which was determined based on documented vaccination records. The same chi-squared test was used to evaluate the relationship between these variables and HCVAb positivity, following the same categorization criteria. This statistical approach enabled the identification of potential associations between serological markers and demographic, health, and occupational factors. The results obtained from these chi-squared analyses are presented in

Table 2. Cross tab HBsAb.

HBsAb
		−	%	+	%	p Value
Gender	Male	47	40.5	56	48.3	Ns
	Female	3	2.6	10	8.6
Age	>54 years	27	23.3	39	33.6	Ns
	<54 years	23	19.8	27	23.3
Immunocompromising condition	No	50	43.1	65	56.0	Ns
	Yes	0		1	0.9
Diabetes	No	46	39.7	61	52.6	Ns
	Yes	4	3.4	5	3.4
Living place	Rural	8	6.9	9	7.8	Ns
	Urban	42	36.2	57	49.1
Job experience > 5 years	No	4	3.4	1	0.9	Ns
	Yes	46	39.7	65	56.0
Immunization for HBV	No	45	38.8	57	49.1	Ns
	Yes	5	4.3	9	7.8

Ns: Non-significant.

and

Table 3. Cross tab HCVAb.

HCVAb
		−	%	+	%	p Value
Gender	Male	99	85.3	4	3.4	Ns
	Female	13	11.2	0
Age	>54 years	63	45.3	3	2.6	Ns
	<54 years	49	42.2	1	0.9
Immunocompromising condition	No	111	95.7	4	3.4	Ns
	Yes	1	0.9	0
Diabetes	No	103	88.8	4	3.4	Ns
	Yes	9	7.8	0
Living place	Rural	16	13.8	1	0.9	Ns
	Urban	96	82.8	3	2.6
Job experience > 5 years	No	5	4.3	0		Ns
	Yes	107	92.2	4	3.4
Immunization for HBV	No	98	84.5	4	3.4	Ns
	Yes	14	12.1	0

Ns: Non-significant.

, where significant and non-significant associations are reported. These tables provide a detailed overview of the distribution of positive and negative cases across the examined variables, allowing for a clear interpretation of potential trends within the study population.

In order to evaluate the associations between variables, a logistic regression analysis was performed to assess the presence of the HBsAb as the dependent variable. Independent variables included gender, age group, immunocompromising conditions, diabetes, place of residence, years of job experience, and HBV immunization status. The results of the logistic regression analysis are presented in

Table 4. Logistic Regression—HbsAb +.

	B	S.E.	p Value	Exp(B)
Gender (Male)	−0.9	0.7	Ns	0.4
Immunization for HBV	2.1	1.1	<0.05	8.5
Age (>54 years)	0.3	0.4	Ns	1.3
Immunocompromising condition	20.0	4.0 × 104	Ns	4.9 × 108
Diabetes	0.1	0.7	Ns	1.1
Living place (Rural)	−0.3	0.5	Ns	0.8
Job experience (>5 years)	3.5	1.5	<0.05	33.1

Ns: Non-significant.

, where both statistically significant and non-significant associations are detailed. This analysis identified both HBV immunization and longer job experience as significant predictors of HBsAb positivity, suggesting that these factors played a key role in determining the serological profile of the study population. Other variables included in the model did not reach statistical significance.

Due to the limited sample size and the low number of individuals testing positive for the HCVAb, it was not possible to conduct a reliable logistic regression analysis for the HCVAb. As a result, the statistical evaluation of potential associations with HCV infection was restricted to chi-squared analysis.

4. Discussion

This study provides valuable insights into the seroprevalence of HBV and HCV markers among waste collectors, highlighting occupational risks and the potential role of immunization. However, it is importnt to acknowledge that the study population was predominantly male, with a mean age of 54 years, indicating that the sample is not representative of the general population. This demographic limitation should be taken into account when interpreting the results and generalizing the findings.

In addition to the limitations inherent to the study’s demographic composition, the investigation did not encompass the collection of data pertaining to the participants’ adherence to standard safety protocols. Such protocols include, but are not limited to, the consistent utilization of personal protective equipment (PPE) and the frequency of needlestick injuries. A key limitation of this study is the lack of data on needlestick injuries, as such incidents are often not reported by the workers. The underreporting of occupational accidents, including needlestick injuries, is a common issue in this sector, which limits the ability to fully assess the associated risk. It is acknowledged that these factors exert a significant influence on the risk of HBV and HCV transmission among waste collectors. Subsequent studies should incorporate these variables to facilitate a more comprehensive understanding of the occupational risks inherent to this sector.

A notable aspect of our findings is that while the chi-squared test did not reveal statistically significant associations between HBsAb positivity and the examined variables, the logistic regression analysis identified HBV immunization and job experience as significant predictors. This discrepancy could be attributed to differences in the statistical power and the manner in which each method evaluates associations. The chi-squared test is a univariable analysis that examines associations without adjusting for potential confounders, meaning it is less sensitive when multiple interrelated factors influence the outcome. In contrast, logistic regression accounts for multiple variables simultaneously, allowing for the identification of independent predictors by controlling for confounding effects. This suggests that while simple comparisons did not indicate significant associations, the combined effect of covariates, particularly job tenure and vaccination status, played a crucial role in determining HBsAb positivity when analyzed through a multivariable model. Additionally, the relatively small sample size may have contributed to the lack of statistical significance in the chi-squared test, as it reduces the power to detect subtle associations that become more evident in a regression framework.

The observed prevalence of the HCVAb in our study is comparable to that reported in the general population, suggesting that waste collection as an occupational activity is not a significant risk factor for HCV infection. Conversely, the prevalence of the HBsAb appears to be higher in our sample than in the general population. This finding is particularly relevant as statistical analyses indicate a strong association between HBsAb positivity and two key factors: HBV vaccination and work experience. These results are consistent with existing literature, suggesting that long-term occupational exposure may influence the serological profile of workers in this sector.

Our findings suggest that waste collection activities may be a risk factor for HBV infection through occupational exposure. In contrast to HCV, which is primarily transmitted by blood-to-blood contact, HBV is known to have a higher transmission efficiency, including through percutaneous injury and mucosal exposure to contaminated materials. This difference in transmission mechanisms may explain why the occupational risk for HBV appears to be more pronounced among waste collectors, while no significant increase in the prevalence of HCV was observed. Needlestick injuries are a significant concern in waste management, as they can directly lead to HBV transmission. Studies have shown that waste collectors experience higher rates of needlestick injuries compared to other occupations, underscoring the need for targeted interventions to minimize such incidents.

Although our results highlight a potential occupational risk of HBV infection among refuse collectors, it is important to remember that other public worker populations are exposed to similar risks. Healthcare workers, emergency responders, and sanitation workers are at risk due to their routine exposure to biological fluids and contaminated materials [20,21]. However, unlike healthcare environments, where safety protocols are generally well defined and regulated, waste collectors often work in environments where exposure is less controlled. Lack of proper segregation of waste—particularly the presence of improperly discarded sharps—may expose waste collectors to a relatively higher risk of needlestick injuries and HBV transmission. Given these findings, continued attention to biological risks in manual waste collection workers is warranted. Preventive strategies should focus particularly on mitigating the risk of HBV infection and its associated complications. In this regard, comprehensive education and training programs should be implemented to ensure that workers are fully informed about the risks associated with hepatitis B, the importance of PPE, and best practices for minimizing exposure. It is imperative that educational programmes are subject to regular monitoring and evaluation in order to ascertain their effectiveness. The implementation of feedback mechanisms has been shown to facilitate the identification of knowledge and practice gaps, thereby enabling a continuous enhancement of safety protocols and a reduction in the transmission risk of HBV.

Furthermore, based on the observed association between HBsAb positivity and vaccination, we suggest that immunization against HBV should be strongly recommended, if not mandatory, for workers in this occupational category. Ensuring adequate vaccination coverage among waste collectors could significantly reduce the risk of HBV infection and its potential long-term consequences. In addition to vaccinations, the implementation of robust post-exposure protocols is imperative. The provision of immediate access to post-exposure prophylaxis and medical evaluation following potential HBV exposure can significantly mitigate the risk of infection among waste collectors.

Future research should aim to further investigate the occupational risks associated with waste collection and evaluate the effectiveness of preventive measures, including vaccination policies and adherence to biosafety protocols. Collaboration between waste management companies, public health authorities, and occupational health experts is imperative in order to develop and implement evidence-based policies. Such partnerships can result in the creation of standardized guidelines that protect waste collectors from HBV and other occupational hazards.

5. Conclusions

This study underscores the seroprevalence of hepatitis B and C virus markers among waste collectors, accentuating occupational risks and the pivotal role of immunization. The comparable prevalence of the HCVAb between waste collectors and the general population suggests that waste collection does not constitute a significant risk factor for HCV infection. Conversely, the higher prevalence of the HBsAb signifies that occupational exposure and vaccination influence the serological profile of these workers.

The strong association between HBsAb positivity and prior HBV vaccination underscores the effectiveness of immunization programmes in this sector. Given the high transmission efficiency of HBV, preventive measures should focus on ensuring full vaccination coverage and adherence to biosafety protocols, and educational initiatives should reinforce the importance of personal protective equipment and safe handling practices to minimize exposure risks. While this study provides valuable insights, further research is needed to explore specific occupational risk factors and evaluate the long-term effectiveness of preventive strategies. The reinforcement of immunization endeavors and occupational safety measures is of paramount importance in the reduction of the burden of HBV and the safeguarding of the health of waste collectors.