Seroepidemiology of HBV infection among health-care workers in South Sulawesi, Indonesia

Hepatitis B virus (HBV) infection is one of the world infectious problems with an estimated 257 million chronically infected people. This infection accounts for 887,000 deaths annually due to its complications, including cirrhosis and hepatocellular carcinoma [1]. Indonesia with a total population of more than 250 million people has 7.1% prevalence of hepatitis surface antigen (HBsAg), and therefore is classified as a moderately hepatitis B endemic country [2].

Several groups have been assigned as special populations who have particular risks for acquiring HBV infection. Among these are the health-care workers (HCWs) who have occupational hazard of getting infected by this virus from their work place; and correspondingly, HBV-infected HCWs may potentially transmit HBV to patients and their families [3]. It has been shown that HCWs have an up to four-fold incidence of this infection in the general population. The main risk factor to acquire HBV infection for HCWs is direct contact with infectious material, especially HBV-infected blood or body fluid. Some studies also have reported that awareness of HBV and proper precautions against blood-borne infections are lacking in these workers [4].

Preventive vaccination as part of occupational safety measures has been standard in many countries. Nevertheless, it is still not formulated in many resource-poor settings [4, 5]. The World Health Organization (WHO) has reported that HBV vaccination coverage among HCWs is only 18–39% in low- and middle-income countries (LMIC) in comparison to 67–79% in high-income countries. This could be a consequence of lack of formulated policy and guidelines for the prevention and control of HBV infection among HCWs in most LMICs [6‐8].

Recognizing this particular problem, the Global Health Sector Strategy (GHSS) on Viral Hepatitis 2016–2020 that was adopted by the World Health Assembly in May 2016 has stated occupational health measures as the core intervention and priority actions for countries to combat viral hepatitis [9]. More recently, the WHO Regional Office for South-East Asia in July 2017 has included routine hepatitis B vaccination among HCWs as a strategic direction in the Regional Action Plan for Viral Hepatitis 2016–2021 [10]. In Indonesia, efforts to control viral hepatitis have been made and supported with increasing commitment by the government [11]. However, the extent of hepatitis B among HCWs is unknown and specific strategy to control this problem has not been in place.

Over the course of more than 40 years since the first published cases of HCW-to-patient HBV transmission, there have been numerous publications on HBV infection among HCWs covering areas of epidemiology and intervention strategies [5, 12]. Most of the publications came from countries with low endemicity. Notably, there is still paucity of information on this particular problem in Indonesia [13, 14]; although such information is urgently needed to know the magnitude of the problem and to have accurate information on epidemiological estimates of the disease burden. This preliminary study strived to present information of HBV infection among HCWs by evaluating the seroprevalence of HBV infection and associated risk factors in health workers four areas in South Sulawesi Province, an area of transitional zone between the western part of Indonesia that have better social-economics and lower HBV infection, and the eastern part with less development and higher HBV infection rates.

This study revealed a high burden of HBV infection among HCWs from four areas in South Sulawesi Province of Indonesia. The overall prevalence of current HBV infection (HBsAg positivity) was 6.2%, and that for exposure to HBV infection (anti-HBc positivity) was 19.2%. These figures were lower than the average national prevalence of HBsAg and anti-HBc (7.1 and 31.9%, respectively) and that in the same province (7.6 and 39.4%, respectively) as released by the National Health Survey in 2013 [2, 20, 21]. Immunity to HBV infection was present in 26.1% of HCWs, which was attained through resolved infection in 14.6% subjects. The proportion of subjects who had immunity due to natural infection provides further evidence that HCWs have a high risk of becoming infected with HBV through their occupation [4, 16, 22]. Of all HCWs, 66.7% were still susceptible to HBV infection.

A significantly higher rate of HBV exposure was observed in older HCWs than the younger ones. One explanation could be that there is a relatively constant risk of exposure during their service period time which results in the increase of hepatitis B prevalence with age [15]. This could be an additional risk to the existing phenomenon of horizontal HBV transmission as shown by the age-related increase of anti-HBc in the general population in the 2013 National Health Survey [2, 21].

As an important occupational hazard, the work category of HCW may reflect the varying levels of risk of exposure to a HBV infection. To the best of our knowledge, this is the first published study based on job category of HCWs in Indonesia which includes serological analysis and risk calculation with confidence intervals. Our findings demonstrated the increasing exposure and immunity rates to HBV across the three types of work: administration, non-intervention, and intervention. This result is consistent with the pattern observed in other countries, regardless of economic status and hepatitis B endemicity, that HCWs who perform invasive procedures have been consistently shown to have higher rates of HBV infection than their counterparts [4, 5, 16].

In this study, longer duration in service did not give significant contribution to the risk of current infection. This result is in line with other reports from hepatitis B endemic areas, with an assumption that the prevalence of hepatitis B in HCWs could be as high as in the general population [4]. On the other hand, this study showed that long occupational period was associated with higher exposure rates and natural immunity to HBV infection. This finding is consistent with other studies [4, 23, 24]; however, it could be associated with the higher acquisition of HBV markers which also increase by age [16].

In line with other studies, the most common mode of exposure to HBV infection was through needlestick which occurred mostly in the intervention group [4, 7, 13‐16]. Even though HCWs have repeated a given procedure so many times, one slip can cause injury with potentially serious consequences. An unexpected or sudden movement by the patient or a transient lack of concentration can result injury [22, 25, 26]. Other possible reasons for high prevalence of needlestick injuries include lack of specific measures to address occupational challenges, lack of information, and non-adherence to standard precautions [26]. Adverse schedule characteristics such as long work hours can result in stress, emotional and physical exhaustion may also increase the chance of human error and poor compliance with the general precautions [5, 26].

In response to the risk of exposure, safeguards have been put in place to lessen the risk of injury. These include the adoption of universal precautions, needleless systems to connect with intravenous tubing, double gloving, and having a neutral zone in which to pass sharp instruments, use of puncture resistant, leak proof, and labelled or color-coded containers [25, 27]. In addition, devices have been developed to reduce injuries including retractable needles and syringes with a sliding sheath [28]. Guidelines have been developed for the management of exposure to HBV that involves proper risk assessment, determination of HBV status of the source and the exposed, and the administration of post-exposure prophylaxis as appropriate [29]. Hepatitis B immunoglobulin can be offered for immediate protection upon significant exposure to HBV, while HBV vaccination can be given to individuals who lack HBsAg and have not been vaccinated or developed satisfactory immune response after previous completed immunization series [17, 30].

Among 367 questionnaire respondents, only 45 (12.3%) HCWs had been vaccinated against HBV. This vaccination coverage is very low compared to developing countries like India, Pakistan, and several countries in Africa [8, 16, 31, 32]. Within this vaccinated group, immunity to HBV could be demonstrated in 62.2%, while 37.2% were in doubtful protection despite feeling well protected. Indeed, of the vaccinated subjects, HBsAg was positive in 6.7% and anti-HBc was positive in 11.1%.

Indonesia has implemented universal hepatitis B vaccination to all infants since 1997 and administered birth dose immunization since 2000. However, nationwide hepatitis B vaccination program for high risk groups including HCWs has not been in place. In hepatitis B endemic countries where people have high rates of natural immunity, providing universal HBV vaccination for HCWs is often discussed because of questionable cost effectiveness of this preventive measure [33]. Nevertheless, this present study showed that 66.17% of HCWs did not have any of HBV serological markers, and therefore susceptible and at risk of acquiring HBV infection.

Considering the high exposure rates to HBV revealed in this study, these subjects highly need vaccination to be protected. This is in line with the recent WHO updated position paper on hepatitis B vaccine – July 2017, which recommends that HCWs and other groups with occupational exposure should be the targets for vaccination [34]. It is emphasized that hepatitis B vaccination safeguards health workers when administered early, ideally before occupational exposure. Drawing upon the GHSS on Viral Hepatitis 2016–2020 and the WHO Regional Action Plan for Viral Hepatitis in South-East Asia 2016–2021, it is targeted that all Member States have started implementation of routine hepatitis B vaccination among high-risk groups including health-care workers by 2020 [9, 10].

In some resource-limited countries, approaches have been made to avoid unnecessary vaccinations. Introduction of point-of-care tests for HBsAg and anti-HBs in a pre-vaccination screening of HCWs could be cost-effective by not giving unnecessary vaccinations for individuals already infected, save vaccine for those having immunity to HBV, and provide an opportunity to refer people with HBV infection for care and treatment [4]. Although routine post-vaccination testing is not recommended, persons at risk of occupational exposure to HBV infection including HCWs should be considered for post-vaccination testing where laboratory facilities are available to ensure that they have achieved a protective anti-HBs level (≥10 mIU/mL) [17, 34].

We acknowledge several limitations of this study. Firstly, the cross-sectional design that did not make it possible to accurately detect serological HBV markers that might wean or fluctuate over times at low titers, which could be different than the rates revealed in this study. Secondly, this study could not accurately define the job changes of some HCWs that might happen in certain individuals due to age or physical reasons. However, it should not be a major problem as job changes were not frequent occurrences; job assignments were based on the skills of HCWs that would need certain qualification to perform a given duty. Thirdly, the coverage of the study that investigated health workers from four areas of South Sulawesi Province could not represent the large HCW population of the Indonesian archipelago. Similar studies in areas with different socio-economic development, lifestyle, and prevalence of HBV infection would be needed. However, by performing serological analysis in each work type and employment periods, combined with risk calculation of the HCWs, this study provides the evidence of increasing exposure to HBV infection associated with job categories and length of employment among the HCWs.

This study reported the occupational risk of acquiring HBV infection among the studied HCW population. The risk is associated with the age, type of work, and length of service of HCWs, particularly in the profession that routinely perform exposure-prone procedures. Needle-stick injury contributed the highest risk among the variables investigated. A particular attention has to be given to two-thirds of HCWs who were still susceptible to HBV infection. These facts confirm the necessity to safeguard the HCWs with hepatitis B vaccination, which further provides greater protection to patients from infection through exposure to infected health workers. Infection control needs to be strengthened and continuing education has to be imparted to all HCWs at various health-care setups. A policy and roadmap for intervention at the national level is required to mount effective and efficient measures for the prevention, diagnosis, post-exposure management, and treatment of HBV infection in this special population.