Uptake of hepatitis B vaccination and its determinants among health care workers in a tertiary health facility in Enugu, South-East, Nigeria

Hepatitis B is spread through contact with blood and body fluids of an infected person. It is a major public health problem in Nigeria and health care workers (HCWs) including general physicians, surgeons, dental surgeons, nurses and other medical staff. These HCWs are at increased risk of acquiring the disease due to occupational exposure to blood and body fluids [1, 2]. Hepatitis B is a life-threatening liver infection caused by Hepatitis B Virus (HBV). It can cause chronic and often fatal liver diseases, such as liver cirrhosis and cancer. Globally, about a billion individuals have been infected with HBV at some point in their lifetime and almost 350 million people are chronically infected with HBV, out of which more than a million die annually from its related causes [3]. Majority of the infected cases are living in sub-Saharan Africa [4].

World Health Organization (WHO) reported that about two million health care workers risk occupational exposure to HBV each year and vaccination coverage is low among them [5]. The Department of Health and Human Services, Centers for Disease Control and Prevention (CDC) reported in United States that “the risk of being infected is dependent on the prevalence of the HBV carriers and frequency of exposure of HCWs to blood and body fluids and the infectivity of the virus” [6]. Health care workers in Nigeria are particularly at a greater risk because Nigeria is a holoendemic area, with HBV carrier rate of 15–37% [7]. The risk of acquiring HBV in some cadres of HCWs is four times greater than that of the general population [8].

Hepatitis B vaccination is the mainstay of HBV prevention and has been reported to reduce the risk of acquiring the infection virtually to zero [9, 10]. It is recommended for exposed HCWs as part of the universal precautions policy for protection of HCWs [6]. HCWs who are HBV negative after screening should take hepatitis B vaccination, while those who are HBV positive should be treated. However, vaccination among HCWs remains a challenge for many countries [11]. Some studies reported that all HCWs including administrative staff in a hospital can receive the hepatitis B vaccine [11]. The mode of transmission of HBV in health care settings is most often by needle prick injuries and poor adherence to universal precautions [12]. The prevention of occupational hazards requires a thorough knowledge of the risks and practical measures to be taken, and the need for HCWs workers to familiarize themselves with universal work precautions [13]. It is estimated that about a million HCWs had cut and puncture injuries per year [14].

There is wide implementation of policy and uptake of the hepatitis B vaccine in some countries such as UK, USA, and Israel [10]. In 2016, Nigeria developed a national guideline for prevention, care and treatment of HBV and hepatitis C virus (HCV) infections, and vaccination of HCWs was included as one of the preventive methods in health care settings. However, to the best of the authors’ knowledge, there is no policy or implementation of any policies that makes uptake of Hepatitis B vaccination compulsory to all HCWs in Nigeria. This study was conducted to evaluate the uptake of hepatitis B vaccination and its determinants among HCWs in a tertiary health facility in South-East, Nigeria.

This study showed that the uptake of hepatitis B vaccination among HCWs in Enugu, Nigeria was poor. This is similar to the study conducted in Pakistan [15], but differs from other studies from India and Ethiopia [16, 17]. The authors found that 28.5% of the participants knew their hepatitis B status, and that 2.4% were hepatitis B positive, while 97.6% were hepatitis B negative. The observed low knowledge of hepatitis B status (28.5%) in this study could be due to absence of pre-employment screening for hepatitis B as well as lack of policy concerning hepatitis B screening in the facility. It also suggests that the facility has not been regularly conducting free or subsidized screening for its HCWs. While it is expected that all individuals who are hepatitis B negative should take the vaccination, while those who are hepatitis B positive receive treatment, the study found that only 51% of participants who are hepatitis B negative have received hepatitis B vaccination.

The overall uptake of hepatitis B vaccination among HCWs in this study was 14.2%. This is similar to what was observed in previous studies [18, 19]. However, it is lower than 22.4% reported in the similar study in 2006 [20], and also among HCWs in a teaching hospital in Ile-Ife, South-West Nigeria which revealed that 65% of the health workers have been vaccinated against hepatitis B virus [4]. The observed uptake in this study is also lower than 54.8% reported among theatre and laboratory workers at a teaching hospital in Imo state, Nigeria [21]. These differences could be due to the fact that the current study involved a larger population, and also administrative staff which were not involved in previous studies. This study also revealed that only 28.5% of the participants had prior knowledge of their hepatitis B status. This poor result could be due to the cost of screening for hepatitis B surface antigen and its poor accessibility in Nigeria. Regular free or subsidized screening programmes might bring improvement in this regard.

It was observed that a higher proportion of administrative staff have not received hepatitis B vaccination compared to nurses, doctors, pharmacists and laboratory technologists. This higher uptake of hepatitis B vaccination among the clinical than administrative staff could be as a result of their pre-employment training and education which might have included the importance and safety of vaccination to health. The management of health facilities should pay attention to administrative cadre of staff for improved uptake of hepatitis B vaccination among its HCWs. Similarly, the duration of HCWs that had worked in the facility also influenced the uptake of hepatitis B vaccination. Higher proportion of those who had worked for more than 5 years in the facility received hepatitis B vaccination than those who had worked for less. This result could be due to lack of policy concerning hepatitis B vaccination of workers in the hospital. Also higher proportion of participants older than 30 years of age received hepatitis B vaccination than those below 30 years old. This higher uptake of hepatitis B vaccination among older HCWs who are also more likely to have worked for longer duration might be due to their previous observations. It is possible they might have observed their colleagues suffer fulminant hepatitis and/or liver cancer as a result of possible non-uptake of hepatitis B vaccination. The reason for this higher uptake among this category of HCWs may also be due to previous hepatitis B vaccination related encouragements from colleagues. Such encouragement could lead to increase in awareness and knowledge of importance of screening and uptake of hepatitis B vaccination for those who are hepatitis B negative, and treatment for those who are hepatitis B positive. Formulation of policies to make screening for hepatitis B surface antigen and uptake of hepatitis B vaccination compulsory and at free or subsidized cost for all HCWs may bring improvement in uptake of hepatitis B vaccine.

This study found that 48.9% of those who were vaccinated had full coverage of the three doses of the vaccine, while 16 and 35.1% took two or one dose respectively. This is similar to the study conducted in Tanzania, and India among HCWs where 48.8 and 50% received three doses of the vaccine respectively [22, 23]. It is also similar to the study conducted among doctors and nurses in Lagos, Nigeria where 48.5% completed three doses of hepatitis B vaccination [24]. It is however lower than results documented in the study conducted among doctors and nurses in Iran which reported that 86.2% completed the recommended three doses of vaccine [25]. This difference might be due to the fact that the present study involved all health workers including administrative staff compared to study from Iran where only doctors and nurses were included. Thus, the differences in this study compared with other studies could be due to the inclusion of administrative staff, and the larger sample size. Interestingly, those who received three doses of vaccine in the current study is higher than the findings in other studies conducted in Nigeria, Sweden, Pakistan, and South Africa which reported 16.3, 29.7, 39.8, 37.2, and 19.9% respectively [20, 21, 26–28]. However, it is lower than the findings in a study done in Ethiopia where 61.2% of those vaccinated had received all 3 doses of the vaccine [17].

Our study revealed that age, staff category and duration of work in the facility significantly influenced uptake of hepatitis B vaccination, but no factor significantly influenced full vaccination status. However, after adjusting for confounders, the odds for full hepatitis B vaccination were higher among female participants than males (AOR = 1.17, 95%CI = 0.76–1.78, P = 0.265), tertiary education compared to primary education (AOR = 2.94, 95% CI = 0.64–12.43, P = 0.328), and among participants with longer duration of work (AOR = 1.23, 95%CI = 0.96–1.59, P = 0.106). These observations are similar to findings from some other studies which reported that sex, years of occupational practice, and educational status significantly influenced vaccination pattern [4, 20, 21].

The findings in the current study showed that 10.8% of the participants did not receive hepatitis B vaccination because of cost of vaccination, 47.5% did not know where to take the vaccination, 6.6% believed they could not be infected, while 51.1% gave other reasons such as long vaccination schedule, and lack of time. These findings are similar to a study conducted to find reasons for non-uptake of vaccine which reported inadequate vaccine information as a factor [11] and unavailability of vaccine and high cost of vaccine as major determinants [29]. The prevalence of HBV markers which includes individuals with HBsAg, anti-HBc, and anti-HBs who do not need hepatitis B vaccination is 72.5% in Nigeria [30]. Recommendations from American College of Physicians and the Centers for Disease Control and Prevention is that screening for HBV should include testing to three HBV screening sero-markers so that persons can be classified into the appropriate hepatitis B category and properly recommended to receive vaccination, counselling, and linkage to care and treatment [31]. However in Nigeria, accessibility and cost of hepatitis B serological tests for HBV markers is a great challenge. The authors’ opinion is that all HCWs should be screened for only HBsAg, and those that are negative should receive hepatitis B vaccination to reduce the cost and other challenges.

This study revealed that uptake of hepatitis B vaccination as well as number of doses received was low among HCWs in Enugu, Nigeria. Age, staff category, and duration of work in the hospital, were independently associated with hepatitis B vaccination. It is therefore recommended that Management of health facilities in Nigeria should provide hepatitis B surface antigen screening facilities and hepatitis B vaccination sites for easy accessibility, and also subsidize the cost of screening for hepatitis B surface antigen and hepatitis B vaccination for all HCWs. They should also formulate policies that make screening for hepatitis B surface antigen and uptake of hepatitis B vaccination for hepatitis B negative HCWs compulsory and at free or subsidized cost. If possible, the Management should also frequently organize free screening for HBV for all its HCWs. This would increase the proportion of HCWs that know their hepatitis B status, as well as stimulate those that are hepatitis B negative and positive to receive the required vaccination and treatment respectively.