Hepatitis B vaccine uptake among healthcare workers in a referral hospital, Accra

Introduction Hepatitis B vaccination among healthcare workers (HCWs) in Ghana has not been actively pursued despite the endemicity of the infection. This study measures the hepatitis B vaccine uptake among HCWs at the University of Ghana Hospital, Legon (UGHL) and identifies the factors associated with vaccination. Methods An analytical cross-sectional study involving all staff who have direct contact with patients was conducted. Self-administered questionnaires were used to collect data on vaccination status, age, sex, type of staff, duration of work in the facility, exposure to blood or blood products, blood stained linens/waste, sharp instruments and performance of invasive procedures. Data was analysed using STATA 14. Continuous variables were described using median values and interquartile ranges (IQR) and categorical variables as proportions. Bivariate and multivariate analysis were conducted to identify the factors associated with hepatitis B vaccination status. Results Of the 161 participants interviewed, 63.4% were females with median age 35 years (IQR: 27-45). Eighty-six (53.4%) of the respondents had taken the hepatitis B vaccine with 79.1% of them having completed the vaccination schedule. Factors associated with vaccination were working for more than 16 years (OR: 3.8, CI: 1.02-12.72), daily exposure to blood/blood products (OR: 4.1, CI: 1.43-11.81) and sharp instruments (OR: 4.45, CI: 1.39- 14.24), performing invasive procedures daily (OR: 3.0, CI: 1.07-8.45) and frequent exposure to blood stained linens/waste (OR: 6.1, CI: 1.41-26.51). Conclusion The lack of hepatitis B vaccination among some HCWs at UGHL puts them at risk of contracting hepatitis B infection.


Hepatitis B virus (HBV) infection affects the liver and can result in
acute or chronic liver disease [1]. The disease is a major public health concern currently affecting about 2 billion people globally and resulting in chronic infection in over 320 million people [2]. The infection and its complications continue to be a major cause of mortality [3,4]. Hepatitis B prevalence is highest in sub-Saharan Africa and East Asia, where between 5-10% of the adult population is chronically infected [1,5] and the lifetime risk of acquiring the infection is greater than 60% [2]. HBV infection has long been recognised as an occupational risk for health care personnel [6][7][8]. It is estimated that 5.9% of health care workers (HCWs) worldwide are exposed to hepatitis B infection annually [9] and the risk of infection after exposure to highly infectious fluids such as blood from a patient who is actively transmitting the disease is up to 30% [10][11][12].
Although the infection is vaccine preventable, studies in parts of Africa have shown low uptake of the hepatitis B vaccine among HCWs [13][14][15]. In sub-Saharan Africa, majority of studies report 35% to 65% of HCWs have ever received the vaccine and an even lower proportion have completed the vaccination schedule. The vaccination coverage was however approximately 92% in a hospital in Nigeria which had introduced a hepatitis B campaign for all its HCWs [16].
Hepatitis B infection is endemic in Ghana with sero-prevalence in different parts of the country ranging from 6.7% to 14.7% in blood donors [17][18][19][20], 10.6% to 14.3% in pregnant women [17,[21][22][23] and 15.6% in children [24]. Despite the paucity of data on prevalence of the infection among HCWs in the country, few studies in different parts of the country have looked at the knowledge and attitude of HCW towards hepatitis B and their uptake of vaccination against the infection [25,26] [27,28]. In Ghana the recommended adult vaccination protocol is 0.5ml of the vaccine given in 3 doses at months 0, 1 and 6. Hepatitis B vaccines are readily available in health facilities across Accra, the nation's capital, and the University of Ghana Hospital Legon (UGHL) has had this service available since the year 2016. However, prevention of HBV infection among HCWs has not been actively pursued in the country, just like in many other resource poor settings. This is evidenced by the lack of a structured vaccination plan for HCWs and the few studies on vaccine uptake among HCWs in Ghana. We therefore evaluated the hepatitis B vaccine coverage and the factors associated with vaccination status among HCWs at University of Ghana Hospital, Legon as a basis for advocacy and development of a more comprehensive vaccination plan for health workers in the facility.

Methods
Study design: an analytical cross-sectional study was conducted at the UGHL. Data was collected from HCWs at the facility using a structured questionnaire from July to December 2016. Study variables: the dependent variable was hepatitis B vaccination status and was measured as "yes" if the participant had taken at least one dose of the hepatitis B vaccine and "No" if they had not taken any dose. The independent variables measured were age, sex, staff type (whether clinical or non-clinical), duration of work in the hospital and in current capacity, frequency of exposure to blood or blood products, blood-stained linen, sharp instruments and frequency of performance of surgical or invasive procedure. Frequency of exposure to these risks was measured by asking participants to indicate whether they were never exposed or exposed on average about once a week, more than once a week or every day. These were further categorized as never exposed if they were never exposed to the risk, occasionally exposed if they were exposed on average once a week, frequently exposed if they were exposed more than once a week and exposed daily if they were exposed every day.  (Table 2).
Factors associated with vaccination status: the odds of having worked for 16 years or more among those who had been vaccinated against hepatitis B was 3.8 times higher compared to those who had not vaccinated (CI: 1.02-12.72). Those who were exposed to blood and blood products daily were 4.1 times as likely to have received the vaccine compared to those who were never exposed (CI:1.43-11.81).
The odds of being exposed to sharp instruments daily among those vaccinated was 4.45 times higher than in those who were not vaccinated. Staff who performed surgical/invasive procedures frequently were 9.7 times (CI: 2.69-35.09) more likely to have taken the hepatitis B vaccine compared to those who never performed these procedures. Those who performed the surgical/invasive procedures daily were also 3 times more likely (CI: 1.07-8.45) to have taken the hepatitis B vaccine. Compared to those who were never exposed to blood-stained linens and waste, those who were exposed frequently were 6.1 times more likely to have taken the vaccine. Frequently being exposed to blood and blood products was not significantly associated with vaccinating against hepatitis B after adjusting for duration of work, exposure to sharp instruments, performance of surgical or invasive procedures and exposure to blood stained linens and waste (Table 3).

Discussion
We found that the uptake of hepatitis B vaccination among healthcare workers at University of Ghana Hospital Legon was low (53%) compared to WHO recommendation of vaccination for all high risk groups including HCWs with direct contact with patients or their body fluids [29]. This means that about half of the HCWs who have direct contact with patients and/or their body fluids do not have immunity against hepatitis B and can potentially be infected if they are exposed The hepatitis B vaccination coverage seen at UGHL is comparable to that in some parts of Africa [30] but also higher than in other countries within the region [31,32]  Whereas sub-Saharan Africa generally struggles with low hepatitis B vaccination coverage, studies among HCWs in developed countries tend to report coverages higher than 65% [35][36][37][38]. In countries like Croatia where hepatitis B vaccination is mandatory for all HCWs, coverage is as high as 98% [39]. Western countries have higher coverages because there are policies that make it mandatory for HCWs to vaccinate and obtain post vaccination follow up care [40][41][42][43][44]. Some of these countries have developed information targeted at HCW education and setting guidelines to allow the HCWs to follow their own care [45]. Health workers who had worked for 16 years or more in the hospital were 3.6 times more likely to be vaccinated than workers with less than a year's experience. This may be because these HCWs may have learned to appreciate their risk of being infected with hepatitis B better with longer years of service as they experience occupational accidents such as needle stick injuries during their work. Our finding may also be attributed to the fact that in addition to the appreciation of their risk, a hospital-wide vaccination for Hepatitis B was last conducted in 2004 giving the HCWs present at the time the opportunity to receive the vaccinations. This may suggest that when HCWs are actively offered the vaccination they may utilize it. This reasoning is affirmed by findings from a survey done in a national hospital in Tanzania which found that one of the reasons HCWs gave for not vaccinating was that the vaccination had not been offered to them [14]. Our finding of an association between duration of service and vaccination status also corroborates the findings of Abebaw et al (2017) who found that HCWs who had been working for 10 years or more were 12 times more likely to be vaccinated in a health facility based survey conducted in Ethiopia [46]. Staff at UGHL who were exposed to blood or blood products daily were more likely to vaccinate compared to those who were never exposed. Those who worked with sharp instruments daily were also more likely to vaccinate compared to those who never did. Those who performed surgical procedures daily or frequently were also more likely to be vaccinated when compared with those who never performed these procedures. These results were likely obtained because these categories of staff perceived themselves to be at a higher risk of getting infected and so took steps to get vaccinated. Perception of risk was identified to influence vaccine uptake in a study in two health facilities in Georgia [47]. This is also in line with findings from Tanzania where hepatitis B vaccination coverage was 57% even though vaccination was free for all health workers [14]. Among HCWs in Kenya, a study assessing the prevalence of percutaneous injury, cited low risk perception as a reason for not taking the vaccination [34]. This suggests that HCW sensitization on risk of getting hepatitis B infection may be necessary to improve vaccine uptake even when the vaccine is offered to them at no cost.
Daily exposure to blood stained linens was not significantly associated with vaccination status after adjusting for exposure to blood and blood products, sharp instruments and performance of surgical procedures. A key limitation of the study was that the current hepatitis B status was not assessed for participants prior to enrolment in the study and so it is possible a HCW with hepatitis B infection may have been enrolled. This is however unlikely as a hepatitis B screening exercise had been carried out by the UGHL for its staff in 2016, the same year as the study was conducted. Participants hepatitis B status is therefore unlikely to have changed significantly prior to their participation in the study. The study also relied on self-report of the participants' vaccination status as some participants had lost their immunization records. This is not expected to affect the findings of the study as participants were aware hepatitis B vaccination was not mandatory for their employment and hence declaring their status would not influence their employment in any way. In addition, there were no identifiers linking the responses to the participants and hence they were likely to have given their true vaccination status.

Acknowledgements
The authors would like to acknowledge their research assistants for their role in data collection and entry. We also acknowledge the various heads of units at the UGHL for allowing their units to be used for the study and all categories of HCWs for participating in the survey. Table 1: demographic characteristics of participants