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Assessment of knowledge, awareness and acceptance of hepatitis B infection and its vaccination among dental students in metro city of western Maharashtra

Introduction: Hepatitis B infection is a potentially life-threatening liver infection caused by hepatitis B virus. It is considered as an important occupational hazard for dentists as they are at a greater risk of exposure to the virus from an infected patient. The present aim of the study is to evaluate knowledge, awareness and vaccination status on hepatitis B among dental students. Materials and Methods: A questionnaire study was conducted among dental students. The data was collected by a structured, self-administered and pre-tested questionnaire and analyzed. The statistical analysis was done using descriptive statistics. Results: In this study, there were a total of 150 participants between 18-35 years of age. 64% of the students were aware about different modes of transmission of hepatitis B. 96.6% of the students were aware of hepatitis B vaccine but only 53.3% had the knowledge about vaccination dosing schedule for adults. 70.7% dental students were vaccinated whereas 18% students were non-vaccinated. Among those, 38.6% of the students were partially vaccinated. Conclusion: Knowledge and awareness regarding Hepatitis B infection and its vaccination was satisfactory. Majority of the dental students were either fully or partially vaccinated. Therefore, the dental students must be encouraged to not only take the vaccination but also to complete their doses during their clinical practices.


Introduction
Hepatitis B infection is a serious life threatening liver infection caused by hepatitis B virus (HBV), which is a DNA virus belonging to Hepadna virus family [1,2] . In 2020, World Health Organization (WHO) estimated that around 3.25 million people worldwide were living with chronic hepatitis B infection and approximately 900,000 people died due to Hepatitis B virus [3] . Therefore, it is known as one of the major public health problem worldwide [1] . Hepatitis B virus causes acute as well as chronic liver diseases. The acute infection begins with symptoms such as general malaise, loss of appetite, nausea/vomiting, body ache, low grade fever and darkened urine which progress to development of jaundice. The incubation period is 30-180 days. The chronic infection may either be asymptomatic or associate with chronic inflammation of liver leading to cirrhosis, liver cancer and liver failure over a period of several years, if left untreated [4] . Hepatitis B is 50-100 times more contagious than HIV and is predominantly transmitted through transfusion of blood and other body fluids, sharing contaminated needles or syringes, needle stick injury, sexual contact or from mother to baby at birth [5] . Since healthcare workers are more exposed to blood and body fluids, they are at a greater risk of developing the infection. It has also been documented that HBV infection is the most important infectious occupational hazard among dental professionals because of percutaneous injury that happen in dental practice. So, training for precautions and awareness for hepatitis B virus and vaccine should be mandatory [6,7] . WHO recommends the use of oral treatment with antiviral drugs such as tenofovir or entecavir as the most potent drug for hepatitis B virus.
However, the treatment does not cure the infection but only suppresses the replication of the virus [8] . Therefore, prevention by vaccination is the only safe strategy against high prevalence of hepatitis B infection. Hepatitis B virus vaccine is available since 1981 which contains HBs Ag protein and aluminium phosphate and aluminium adjuvant. In 1992, the Global Advisory Group to WHO recommended that all countries integrate hepatitis B vaccine into national immunization programs by 1997 [1] . Hepatitis B vaccine was introduced in India in the year of 2008 [2] . One of the local vaccine is Gene Vac-B, manufactured by Serum Institute of India Ltd, Pune, Maharashtra. Engerix-B, manufactured by Glaxo Smith Kline, Rixeinsert, Belgium has also been marketed in India for several years [9] . The recommended dozing schedule for adults is 0, 1, 6 months, given intramuscularly and for infants, it is as soon after birth, 6 weeks, 14 weeks or 6, 10, 14 weeks. The volume of monovalent hepatitis B vaccine depends on the age of an individual which is 0.5 ml per dose for 19 years and younger and 1ml per dose for 20 years and older [10,11,12] . The complete vaccine series induces protective antibody levels in more than 95% of individuals which lasts at least 20 years and is probably lifelong [8] . Hence, the purpose of the study was to assess the knowledge, attitude and practice of hepatitis B infection and it's vaccination, among dental students in metro city of Western Maharashtra.

Materials and Method
A questionnaire based study was conducted among students of dental colleges in metro city of Western Maharashtra. The study aimed to assess the knowledge, awareness and acceptance of hepatitis B infection and its vaccine. The main objective was to determine how many students were vaccinated and to know the reasons for those who have not taken the vaccine. The study was carried out for duration of three months. The participants were selected based on the following inclusion criteria: i) undergraduate students including interns and ii) postgraduate students. Healthcare professionals (teaching staff) and grade IV workers (nonteaching staff) were excluded from this study. The input parameter for sample size calculation using G*power software version 3.1.9.2 as follows: 80% power of the study, alpha error 0.05, effective size 0.5 and degree of freedom 5. Calculated sample size was 140. The final considered sample size was 150. Convenient sampling technique was used in the study. The data was collected through structured, selfadministered, pre-tested and validated questionnaire, written in English language. It consisted of two parts and comprised of 33 questions. The first section included demographic data such as age, gender, designation, religion and marital status and the second part consisted of questions based on knowledge, attitude and practice towards hepatitis B virus and vaccine. Some of the responses were based on Likert scale and some were yes/no questions. The reliability statistics were calculated and the Cronbach alpha value was 0.618. The questionnaire was designed on Google forms (Google LLC, Mountain view, California, United States) and the link was distributed among dental students (UG and PG) via e-mail, WhatsApp number and other social media platforms. A brief introduction about the study was given and informed consent was also obtained from each student in which voluntary participation was assured. Data collected were entered into a spreadsheet (Microsoft excel 2016). Statistical analysis was done using descriptive statistics using statistical package for the social science (SPSS) 23.0 version (IBM, Chicago, Illinois, United States). The p-value was set at 5%.

Results
In table 1, from a total of 150 students who completed the questionnaire, more than half of the participants (89.3%) belong to age group of 18-25 years, while individual of age group of 26 to 35 years constituted of only 10.7% of the study population. Majority of the study population were female (66.7%). In table 2, about 95.3% students were aware that Hepatitis B is caused by hepatitis B virus, but there is still lack of knowledge in 4.6% students about the causative organism. Regarding modes of transmission, an average of 64% of the students were aware about different types of transmission whereas 24.7% of the students were not aware of transmission of hepatitis B through sharing of items like toothbrush and razor. Regarding Hepatitis B vaccine, 96.6% students were aware of it and 80% believed that vaccination is the most effective way to prevent Hepatitis B infection. 53.3% of the students had the knowledge about vaccination dosing schedule for adults while 40% were aware about the dosing schedule for infants. In table 3, around 78.7% dental students were vaccinated and 18% were non-vaccinated. Among those who were vaccinated, 38.6% of the students were partially vaccinated. Reasons for not taking the vaccine include: not aware of the vaccine (6.7%), fear of needle (5.3%), don't feel the need (4.7%), and fear of side effects (4%). 88.7% of the students indicated routine use of PPE and 92% followed proper sterilization and disinfection.

Discussion
Dentists are among the population groups that are highly exposed to HBV infected patients. They are at a higher risk for accidentally acquiring the infection as their routine practice includes the use of sharp instruments in an environment contaminated with saliva and blood. Although virus transmission via saliva is possible, the major occupational risk is accidental needle stick injuries [5,6] . Several studies around the world have shown that vaccination prevents hepatitis B infection and dentist vaccination has proven beneficial in preventing the spread of the disease and improving the health status of dentists. Other studies have also shown that poor knowledge among dentists accounted for lower numbers of people vaccinated against hepatitis B. Therefore, it is necessary that dental students be aware of Hepatitis B infection and its vaccination. In this study, 98.6% were aware of Hepatitis B infection. Knowledge regarding modes of transmission was found to be moderate; around 64% of students were aware of all the modes of transmission while the rest mentioned only few modes. This result is better than the study done by Khan et al. [13] among medical students of Karachi, which found 57.1% had knowledge about all modes of transmission of hepatitis B. This is contradictory to the studies by Kasetty et al. [14] which revealed 82.1% of dental professionals had correct knowledge regarding the same. A similar result was found by Sadanandam P et al. [2] among first year medical students (63%). Prevention is more effective than any other therapy for hepatitis B infection. Therefore, immunization is the best way to eliminate HBV related diseases. Since 1982, when the hepatitis B vaccine became available and has been proven safe to both adults and children, attempts have been made in different parts of the world to encourage vaccination among dental professionals also. In this study, around 78.7% students were vaccinated and 18% students were never vaccinated.
Result of this study is good compared to the studies done in Iran and Nigeria, where vaccination rate among dental surgeons were 51.2% and 68.6% respectively [6,15] . Similar results were reported by Gomathi TP et al. [16] in their study among dental interns (76%) and Mustafa S et al. [7] (80.5%) among dental students in Multan. To take the vaccine and also encourage others to take the vaccine, proper and adequate amount of knowledge on the vaccine and its doses is required. This study reported that 60% of the students pointed out that hepatitis B vaccine have a total of 3 doses. But, among those who were vaccinated, only 40% had completed the doses and 38.6% were partially vaccinated.
The study in Islamabad, by Mohsin B et al. [1] among medical students had a similar result (33% and 27% respectively), which is better than the results found by Azodo CC et al. [15] where 48.6% of the Nigerian dentists were partially vaccinated and only 20% were fully vaccinated. This is contradictory to the results seen in the study by Jalaleddin H et al. [6] where majority (48.1%) of Iranian dentists were fully vaccinated and only 3.1% of the vaccinated dentists had incomplete vaccination. The study in Multan showed that out of 80.5% vaccinated students, 27.1% were partially vaccinated and 53.4% were fully vaccinated, but 38.6% of the fully vaccinated students, had also taken booster dose. 7 Poor knowledge about the doses of the vaccine resulted in more number of students being partially vaccinated. In the study conducted by Mohsin B et al. [1] the most common reasons for not taking the vaccine among medical students were laziness (53%) and lack of awareness (23%).
Another study in Multan reported that most of the dental students did not take vaccine due to busy schedule (39.7%) or lack of knowledge (21.4%) while fear of needle was seen in only 6.1% of the students [7] . Whereas in this study, the most common reasons were lack of knowledge (6.7%), fear of needle (5.3%) and doesn't feel the need (4.7%). Around 95% of the students believed that Hepatitis B vaccine should be mandatory for all dentists and that the institution should provide the vaccine to all their students. 84% would also recommend their family members to get vaccinated. The limitation of this study was the small sample size. The study can be done using a large population with different variables in different region of India.

Conclusion
Knowledge and awareness regarding Hepatitis B infection and its vaccination was satisfactory. Majority of the dental students were either fully or partially vaccinated, however there were few who were non-vaccinated. Therefore, the dental students must be encouraged to not only take the vaccination but also to complete their doses during their clinical practices.

Recommendations
1. It is recommended that a policy be implemented for complete vaccination and health education of all students in all dental colleges to ensure complete immunization. 2. The strongest recommendation for improving hepatitis B vaccination is that vaccine should be mandatory for all students before beginning of their clinical training and provision of vaccine free of cost by the institute.