| Abstract|| |
Healthcare personnel, especially medical students, represent a high risk population for Hepatitis B Virus (HBV) infection. Hepatitis B is the most important infectious occupational hazard which Indian medical students and healthcare workers (HCWs) encounter. The medical students and HCWs all over the world do not practice universal precautions on a routine basis and there exists the widely prevalent problem of under reporting of percutaneous and mucocutaneous exposures and a lack of awareness about the disease transmission, its consequences and the importance of adhering to universal precautions at all times. This further compounds the issue of safety of student HCWs. This article highlights the dismal scenario vis-ΰ-vis awareness about these risks and HBV prophylaxis amongst medical students from a student's perspective and suggests how to tackle the situation to protect the unfortunate medical students from an unwarranted predicament.
Keywords: Anti-HBs, Hepatitis B, HCW, health care worker, medical student, immunization, prophyaxis.
|How to cite this article:|
Chouhan S. Hepatitis B prophylaxis practice among medical students : An overview. Hep B Annual 2008;5:102-16
| Introduction|| |
Hepatitis B is a dreaded infectious disease and global public health problem. The etiological cause of this disease is the hepatitis B virus (HBV) which specifically targets the liver and is capable of causing extensive, sometimes irreparable, liver injury. It has a wide spectrum of outcomes which ranges from acute to chronic and mild or asymptomatic to potentially fatal. The global disease burden is staggering with about two billion people acutely infected and nearly 350 million chronically infected with HBV. ,, At least 15-20% of chronically HBV infected people die due to liver disease which amounts to nearly one million people each year. It is the most common cause of chronic liver disease worldwide, including cirrhosis and hepatocellular carcinoma (HCC). In India, nearly three to four per cent of the population is infected by the virus, with chronic hepatitis B constituting more than 50% of the chronic hepatitis cases. This, in the context of a large population and absence of a national hepatitis B immunization program could spell a projected increasing burden of the disease in this country in the years to come. In this perspective, the HBV epidemiology in India becomes relevant not only nationally but also internationally because of the possibility that India may soon become the largest infection pool in the world.  The total number of HBV carriers in India is estimated to be about 40 million, which constitutes nearly 12-15% of the entire HBV carrier pool in the world. HBV is also the second most common cause for acute hepatitis in India (after hepatitis E), being responsible for nearly one-third of acute viral hepatitis patients. It is also the causative factor in about 30-40% of patients with cirrhosis and a large proportion of patients with HCC. 
Healthcare personnel represent a high risk population for HBV infection. Hepatitis B is the most important infectious occupational hazard which Indian medical students and healthcare workers (HCWs) encounter. The factors responsible for the high risk of being infected by HBV are the high prevalence of HBV carriers in the population and the high contagiousness of HBV. In fact, HBV infection is more dangerous compared to HIV infection vis-a-vis occupational exposure is due to the fact that its transmission rate after percutaneous exposure to blood is much higher (about 30%) than that of HIV (0.3%).  If infection with HBV becomes chronic, a lengthy course of anti-viral treatment may be necessary, which is not only highly expensive but also works in only 40-60% of the cases. If this fails, the medical student or HCWs who perform exposure prone procedures may need to be restricted from doing so. The infected student/HCW not only suffers morbidity himself but also poses the serious threat of unwittingly transmitting it to unsuspecting patients. Also, it would act as a significant economic liability, especially in a resource limited country like India, due to loss of highly skilled manpower if such infected HCWs were to be barred from carrying out their professional duties. Once a medical/nursing student is infected by HBV, he is left to fend for himself. The hapless student could then face the following daunting prospects, such as difficulties securing health insurance, loss of income due to unemployment, long term disability and premature death.
It is a fact well documented that universal precautions are universally ignored. Medical students and HCWs all over the world do not practice universal precautions on a routine basis as is evidenced by numerous studies. This only adds to the increased risk of getting infected by dangerous blood borne pathogens. To add to this, there exists the widely prevalent problem of under-reporting of percutaneous and mucocutaneous exposures by doctors, HCWs and students alike.  Lack of awareness about the disease transmission, its consequences and the importance of adhering to universal precautions at all times further compounds the issue of safety of student HCWs. Student HCWs are more likely to be exposed to patients' blood and body fluids because of their inexperience in doing invasive procedures and handling patients . Also, students may not perceive themselves to be at a high risk of contracting deadly blood borne infections as they are not full fledged doctors/nurses yet and since they have only a limited clinical exposure. This might result in a callous attitude towards self protection and usage of sub-optimal protective measures. All these factors combined can lead to the risk of the medical students being exposed to blood borne pathogens like HBV to a level perhaps somewhat higher than that of an average HCW. In view of all these problems, the best preventive option which can be widely adopted would be vaccination. A safe and effective vaccine against hepatitis B has been available for over 2 decades now and has brought about remarkable changes in the global epidemiology of HBV infection.  Primary HCC due to HBV, one of the causes of most cancer deaths in the world, is an undisputed vaccine preventable cancer. Countries which have exploited the benefits of this vaccine like US, UK and Taiwan have shown highly successful results. Unfortunately in our country, unlike US, there are no provisions or regulations regarding hepatitis B vaccination yet, leading to poor vaccination status of the healthcare community and the population at large. , As the age old wisdom goes, "prevention is better than cure". If preventive strategies are to be implemented for hepatitis B at all, then why not begin with a high risk group like the HCWs? The best way to put that one stitch in time which would later save nine is to catch them young during their training period.
HCWs all over the world and students constantly face the danger of getting exposed to HBV in the clinical setting. Yet the problem of exposure to contaminated blood among the medical students has received inadequate attention, more so in India. The magnitude of the problem can be gauged from the fact that 4.4 million HCWs in the US receive approximately 800,000 needle sticks and other injuries from sharp objects annually.  An estimated 16,000 of these objects are contaminated with HIV, and even more are contaminated with HBV or HCV.  Medical students receive percutaneous injuries as often or more often than HCWs. ,,,,,,,,,,, 48 % of all graduating medical students recalled being exposed at least once to potentially infectious body fluids during their last two years of medical school.  A recent American study revealed that 32.8 % dental students reported experiencing occupational exposures (OEs) to blood or other potentially infectious materials. Of these, 39% reported two or more exposures each. 
Infection control practices is still a burning issue as is evidenced by the fact that several studies have been conducted and numerous research articles have been published over the years on this issue. All these bear testimony to the great importance of these practices in the world of healthcare. In fact, they are vital, indispensable and constitute one of the foundation pillars of good healthcare. Having said all this, the question arises that since so many studies already exist on the above said subject matter, what is the need for one more study? In other words, how is this study different from others and what extra goals does it aim to achieve? The answer to all these questions is multidimensional and an effort shall be made to highlight each of these dimensions.
Each study is conducted in a certain setting amongst a certain sample population. Difference in setting, for example, the western and the Indian setup, will have a bearing on the results as attitudes might vary due to sociocultural and demographic factors. Rules and regulations regarding vaccination for students are not the same everywhere. These factors can play a major role deciding certain crucial aspects such as the overall risk of acquiring infection. For example, Indian medical and nursing students are at a greater risk of being infected by the HBV as compared to their western counterparts due to the following reasons:
Different institutions follow variable curricula of imparting instructions to preclinical students. The amount of stress laid on clinical conduct and importance of infection control practices may not be the same in all medical colleges, hospitals and other places of healthcare delivery. This can be assessed by finding out what proportion of medical students were counselled about the preventive measures at the time of admission to college or later, before they started their clinical term, how many of them are vaccinated and what kind of vaccination norms the institution has adopted.
- Higher prevalence of HBV carriers in the population compared to the developed countries.
- Absence of a national hepatitis B immunization program. 
- Absence of a policy requiring mandatory hepatitis B vaccination at school/ college level at the time of admission as is followed in several states of the US. 
Medical/nursing students and HCWs may acquire the infection through percutaneous and muco cutaneous exposure to blood and body fluids. This can occur in a variety of ways such as during phlebotomy, other invasive procedures and due to improper disposal of contaminated sharps. The mucocutaneous exposure could also occur through splashes of blood and body fluids, the risk of transmission increasing several folds if the skin or mucous membrane is not intact or broken. Low compliance among medical and nursing students, especially in using masks and protective eyewear, may be partly explained by the perception that they are exposed to blood splashes or aerosols less frequently. However, the incidence of blood or body fluid splashes is often underestimated and student HCWs who do not routinely wear protective barriers for all patients, when the potential for blood or body fluid contact exists, are at risk of exposure. 
A number of studies have clearly established that re capping the needle is responsible for causing injury to a large proportion of students, which is significantly higher than injuries occurring during entry into the vein or during withdrawing the needle.  A national survey of HCWs in the United States found that re capping is the most common cause of percutaneous injury.  A Canadian study revealed that students who reported two-handed re capping of needles had twice the number of percutaneous injuries (mean, 1.9/year) than those who avoided recapping or recapped with one hand using a device or scoop technique (mean, 1.1/year) (p less than 0.05).  That is why re capping of needles by healthcare workers is not recommended.
Vaccination is the best way by which one can arm oneself against hepatitis B. Transmission rate is as high as 30% in those who are not immune but rare in those who have been immunized.  Several studies have been carried out in India and in other countries to find out the frequency and type of occupational exposure along with the vaccination status of students. Review of all exposures reported by third and fourth year medical students from the classes of 1990 through 1996 at the University of California, San Francisco, School of Medicine found that 119 of 1022 medical students sustained 129 exposures. Of these, 82% occurred during the following four postings: obstetrics-gynecology, surgery, medicine, and emergency medicine. Survey of two graduating classes at the beginning and end of the study showed that the percentage of exposures reported increased from 45% to 65% over the seven-year study period. Thus, the reported injury rates represent minimum estimates of actual occurrences. Human immunodeficiency virus infection and hepatitis were not reported, although follow-up was limited. 
A Canadian study investigated nonsterile occupational injuries and infection control practices reported by final year dental, medical and nursing undergraduates. Non-sterile occupational injuries in the previous year were reported by 82% of dental, 57% of medical and 27% of nursing respondents, including one hepatitis B virus (HBV) and one human immunodeficiency virus (HIV) exposure. Although students received appropriate management for known HIV and HBV exposure, 48% of dental, 77% of medical and 59% of nursing students reporting injuries also reported no postexposure follow-up. All dental and 99% and 95% of medical and nursing students, respectively, reported HBV immunization; however, six per cent of dental students showed inadequate response (i.e., titre of antibodies to HBV surface antigen [anti-HBs] less than 10 mIU/mL) and 13% of dental, 24% of medical and 41% of nursing students did not know whether their postimmunization antiHBs titre was adequate. 
In another American questionnaire-based study, out of 224 students surveyed, only 146 (64%) responded with completed questionnaires. In this study, 43 students (30%) reported needle stick injuries which occurred most commonly in the operating room; 86% of students reported always using double gloves in the operating room; 90% reported always wearing eye protection, and all but one student had been vaccinated against hepatitis B. A concern about contracting a blood borne pathogen through work was noted in 125 students. 
The Indian scenario
In New Delhi, a study on safety precautions observed while performing various invasive procedures during clinical posting was conducted involving 200 medical students. Only 106 students responded with the completed questionnaires. The most common procedure performed by the students was drawing of blood, with an average frequency of 60.8 per month. About 61% of the students reported being injured during the various procedures and only 35.5% of them used gloves. Re capping the needle was responsible for causing injury to 69% of the students, which was significantly higher than injuries occurring during entry into the vein or withdrawal of the needle (p less than 0.05).  A study from New Delhi in 1997 revealed that while only 2.3% preclinical students were positive for HBsAg, and 18% and 10.4% for anti HBs and anti HBc respectively, amongst the clinical group who had been exposed to the clinical departments, the corresponding figures were 1.4%, 69% and 55% respectively; these figures clearly show how great is the risk of exposure to HBV infection during exposure to clinical departments.  Another study from Mumbai in 2002 highlighted the lack of awareness among medical and nursing students. Besides, the study also revealed that only 26.3% of the medical students had taken three doses of hepatitis B vaccination. 
However, a study from Orissa in 2000 found that although the vaccination rate was 86.7% among dental students and 79.5% among medical students, it was an abysmal 1.9% among nursing students.  High cost of vaccination and lack of free vaccination programs were the reasons cited for nonvaccination in all but one nursing student. None of the students received counseling about hepatitis B vaccination at the time of admission to medical college. The investigators concluded that the vaccination rates among medical and dental students were suboptimal. However, the vaccination rate for nursing students was disproportionately low. They suggested that all students should be counseled about hepatitis B vaccination at the time of entry to medical schools and the vaccination should be offered free to all students who are not only at risk of acquiring HBV infection but may also be potential transmitters of this infection to their patients. 
Scenario in other South Asian countries
A report from a study in Lahore, Pakistan, to assess the vaccination status among HCWs and medical students found that only 49% HCWs and 42.20% medical students were vaccinated. The main reasons for nonvaccination (47.7%) among HCWs was the high cost of vaccination, while the most often cited reason (33.7%) among medical student was the belief that they were not at risk. This belief was also prevalent among nurses (36.4%), laboratory workers (38.6%) and paramedics (33.2%). The authors concluded that in a low-income country like Pakistan, the health institutions should bear the cost for vaccinating their staff. Efforts should also be made to impart appropriate health education regarding hepatitis B infection. 
A study from Sri Lanka investigated the presence of HBV and HCV markers in new entrant medical students and found that none of them had been vaccinated against hepatitis B. At least one risk factor for hepatitis B or C was present in 32 (7%) of them. None of the samples were positive for HBsAg or anti-HCV, and only two (0.44%) were positive for anti-HBs. Investigators concluded that since most new entrant medical students were not immune to hepatitis B and C viral infections; there is a strong case to vaccinate medical students against hepatitis B before they were exposed to clinical work. 
Another study was conducted at Lahore Medical and Dental College, Pakistan to assess the knowledge and practice of first year MBBS students, for the prevention of Hepatitis B by administering a pre-tested structured questionnaire. Out of 50 students, 78% said it was communicable, 19% assumed that it was water borne. Other responses included spread via blood transfusion (28%), through use of injection (21%), close physical contact (8%) and un-hygienic conditions (18%). For prevention of Hepatitis B, the more common responses were, provision of clean water (24%), improvement in hygiene (27%), restriction to single sex partner (6%), avoidance of sharing syringes and needles (19%), screening blood before transfusion (9%) and vaccination (15%). The high risk group was identified as the poor people living in unhygienic conditions (34%), surgeons (32%), barbers (12%), Intravenous drug users (eight per cent), recipient of blood transfusion (six per cent) and uneducated people (six per cent). Only one respondent (two per cent) said sex workers could be at risk of getting this disease. When inquired about their vaccination status, 66% of students admitted to have been vaccinated against Hepatitis B, while 34% had not been vaccinated. The study concluded that there is lack of awareness among the medical students entering into the profession about the hazards of Hepatitis B, its routes of spread and its modes of prevention. Similarly, all the students were not vaccinated against Hepatitis B, which made them very vulnerable to this. 
| Summary|| |
Apart from the aspects already discussed before, some other facts which stand out from the above studies and deserve some thought are: Most of the studies on HBV prophylaxis in medical students have been conducted among third and fourth (final) year students who have been well involved in clinical care of patients and doing exposure prone procedures for a considerable period of time, perhaps even on a routine basis. This experience might have benefitted them over time regarding usage of preventive measures against blood borne infections like hepatitis B, resulting in them being more cautious. But junior students, who have just stepped into the clinical setting and are often left to deal with patients by themselves, without prior appropriate guidance and counseling, may not grasp the importance of practising infection control practices at all times. Hence, they may not undertake the necessary precautionary measures.
Young and inexperienced medical and nursing students might underestimate their risk of exposure. Even if they do not perform invasive procedures, chances of mucocutaneous exposure while examining the patients physically still exist, as do those of accidental exposures due to improper disposal of sharps. This reduced perception of risk may translate into recklessness which can prove hazardous. Compliance with universal precautions has been found to be lower among health care workers with a lower perception of risk. 
Vaccination is not the same as immunization. Just because a person has been vaccinated, it is not necessary that he has been rendered sufficiently immune to the disease. Ideally, one should receive a complete course of hepatitis B vaccine, that is, at least three doses. The job does not end there. After that, it is advisable to perform an anti-HBs assay to make sure that the response to vaccination was adequate or in other words to confirm whether the antibody titre was greater than or equal to 10mIU/mL. Unfortunately, students are unaware of this and do not bother to do it. Students who are unaware that they have had an inadequate response to HBV immunization may have a false sense of security and may not use appropriate prophylaxis after exposure to HBV. Hence, further probing is required to find out if all students who claim that they are vaccinated have taken all the three required doses of vaccine, and whether they have documented adequate anti-HBs titre.
Attention should be paid to find out if young medical and nursing students possess correct knowledge about the disease, its risk factors, modes of transmission and consequences and do not harbour any misconceptions about it. A strong hold of such basic knowledge would go a long way in helping them to protect them.
All students should be counseled, at the time of admission to college or at least before they start their clinical rotations, about the appropriate way to deal with patients and practise infection control measures. Although the US Center for disease control (CDC) in 1987 recommended that universal blood and body fluid precautions (UBBFP) be consistently used for all patients regardless of their blood-borne infection status, it has been observed on several occasions that they are followed only in specific patients after they have been branded HIV/ HBsAg positive. This gross misconception only adds to the increased risk of getting infected by dangerous blood borne pathogens. All patients should be treated as infective, because infected patients cannot always be identified. Any lowering of standard can increase the risk of cross-infection, and exceeding these standards in patients with Hepatitis B infection can result in charges of discrimination. Hence, it is necessary to investigate if students really comprehend the meaning and significance of universal precautions and to what extent they use them.
Since nursing and medical students may be required to complete their clinical experience at more than one institution with a variable arrangement for postexposure management, there is potential for some confusion related to postexposure protocol. Since exposure cannot practically be avoided, it should be surveyed if students know the standard postexposure prophylaxis protocol in case any accidental exposure occurred. They should be made to realise the extreme importance of immediately reporting the incident to the concerned authorities, undergoing prompt investigations and seeking appropriate treatment and suitable follow-up. This is especially important because there are time constraints for the administration of hepatitis B immune globulin to persons who have inadequate HBV antibody protection. 
Lastly, an attempt should be made to identify factors which influence the awareness level and vaccination status of students so that we may be able to exploit them later to our benefit. Interventions to improve and maintain optimal compliance with infection control guidelines are required and must take into consideration personal factors as well as organizational and administrative factors. 
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