|Year : 2019 | Volume
| Issue : 1 | Page : 6-11
Hepatitis B virus transmission and health-care workers: Prevention, management, and awareness toward the disease
Bineeta Kashyap1, Urvashi Tiwari2, Anupam Prakash3
1 Department of Microbiology, University College of Medical Sciences and Guru Teg Bahadur Hospital, New Delhi, India
2 Department of Microbiology, G.B. Pant Hospital, New Delhi, India
3 Department of Medicine, Lady Hardinge Medical College, New Delhi, India
|Date of Submission||23-Dec-2018|
|Date of Acceptance||24-Dec-2018|
|Date of Web Publication||18-Feb-2019|
Dr. Bineeta Kashyap
Department of Microbiology, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi - 110 095
Source of Support: None, Conflict of Interest: None
The risk of transmission of hepatitis B, a global communicable disease, has become a matter of concern in recent years. Health-care delivery has the potential to transmit hepatitis B virus (HBV) and hepatitis C virus to both health-care workers (HCWs) and patients. The risk of transmission is most clearly related to the frequency of exposure or the extent of direct contact with human blood and body fluids. Health care must be provided with the best practice of safety and standards of care. Adherence to recommended improved safety devices, standard precautions, and fundamental infection-control practices is a must to prevent transmission of blood-borne pathogens. Long-term treatment with the goal of clearance of HBV is often required. Safe and effective hepatitis B vaccines along with postexposure prophylaxis with hepatitis B vaccination alone or in combination with HBV immunoglobulin have been available, the impact of which has been reported in several countries in preventing HBV transmission among HCWs.
Keywords: Health-care worker, hepatitis B virus, needlestick injury, prevention, vaccination
|How to cite this article:|
Kashyap B, Tiwari U, Prakash A. Hepatitis B virus transmission and health-care workers: Prevention, management, and awareness toward the disease. Indian J Med Spec 2019;10:6-11
|How to cite this URL:|
Kashyap B, Tiwari U, Prakash A. Hepatitis B virus transmission and health-care workers: Prevention, management, and awareness toward the disease. Indian J Med Spec [serial online] 2019 [cited 2019 Dec 12];10:6-11. Available from: http://www.ijms.in/text.asp?2019/10/1/6/252476
| Introduction|| |
Health-care workers (HCWs) are a unique subset of workers since they are prone to contract infections from the patients whom they attend to while also having the potential to transmit infections harbored by them to the patients. Infections among HCWs, therefore, should be prevented, and most of the infections can be avoided by observing standard precautions., Occupational exposure is known to transmit at least 26 different infectious agents in addition to the possibility of transmission of hitherto unidentified infectious agents. Approximately 40%–60% of the occupational hepatitis B virus (HBV) infections are reported from developing countries and arise due to sharp injuries. HBV and hepatitis C virus infections have been reported in 14.4% and 1.4% of HCWs, respectively, the highest being observed in dentists, nursing personnel, dialysis, and laboratory staff or physicians., The World Health Organization (WHO) reports 0.2–4.7 occupational injuries annually region wise with the proportion of HCWs in the general population being 0.2%–2.5%.,
Although HBV infection is a preventable disease, it affects approximately two billion people worldwide, and a substantial proportion (~350 million) become carriers of HBV. HBV infection is the most important etiology of cancer mortality worldwide, being responsible for a million deaths worldwide annually., Despite the implementation of best infection control practices protocol HBV infection poses a significant occupational risk among HCWs.
| Prevention of Transmission of Hepatitis B Virus among Health-Care Workers|| |
Hospital Infection Control Practices Advisory Committee (HICPAC) Centers for Disease Control and Prevention (CDC) brought the concept of standard precautions in 1995 that contains the synthesis of universal precautions and body substance isolation that have to be observed in the care of all patients in a health-care setting, irrespective of the presumed infection status. Prevention of transmission of HBV, an important occupational hazard for workers exposed to infected blood and body fluids, is an important health issue and requires a robust and well-standardized infection control program within the health-care delivery system. The HCW must be adequately aware of the hazards associated with this infection and the various preventive strategies that are available. First and foremost is the adequate precaution that must be taken to prevent oneself from sharp injuries. Uninterrupted availability of hospital-wide hepatitis B vaccination program for all the HCWs and the postexposure prophylaxis (PEP) for any occupational exposure to a HCW must be ensured. Not only is efficient and adequate vaccination mandatory for all the HCWs but also a protocol for regular screening for evidence of sufficient protective immunity by means of cheaper and efficient alternative point-of-care tests must be in place. Appropriate vaccine is mandatory after evaluation of the immune status of the HCWs involved in any exposure-prone procedures. Prevention of transmission of HBV infection from HCWs to patients as well as from patients to providers requires a comprehensive approach incorporating the critical elements of adherence to universal precautions, compliance with appropriate sterilization and disinfection methods, and use of safe devices to minimize the risk of transmission. In fact, strong reinforcement of universal precautions along with a mandatory vaccination program for HCWs in some countries has drastically reduced the occupationally acquired HBV infection. Moreover, the primary HCWs who have limited expertise or experience must be trained in the basic standard safety principles such as hand hygiene, safe disposal of infected waste and sharps, personal protective equipment, or standard precautions while handling of potentially infectious blood and blood products or other body fluids. Despite all the recommendations and guidelines, compliance remains a major issue everywhere. Although PEP as a combination of passive immunization and hepatitis B vaccine is easily available, the most cost-effective method to control HBV infection is preventive vaccination along with strict compliance with infection control protocol. A study reports that a large number of HCWs remain unvaccinated and many of the needlestick injuries (NSIs) were never reported despite a low rate of occurrence. The authors suggested that lack of uniformity in payment protocol for vaccination and low compliance with standard precautions was largely responsible for the low vaccine coverage among HCWs. An Indian study reported 3.85 NSIs per HCW and further highlighted that 14.8% of the injured HCWs had not taken any precautions. Another study done to assess the availability of sufficient equipment for the prevention of HBV reported <18.8% HCWs double gloved during any procedure and 55.3% of them never used the blunt-tip suture needles in the operation theatres (OT) despite their adequate availability. It becomes the duty of every employer to adequately develop an occupational exposure control protocol, to ensure implementation of universal precautions and build up appropriate control measures to prevent any occupational exposure among HCWs. An exposure control plan prepared by a sufficiently qualified person with details of the associated hazards, the risks involved and the risk controls, or the safe work procedures should be laid down in the specific workplace. An occurrence management strategy with a look back policy would indeed be helpful in maintaining such a plan. The incidence of blood exposure to HCWs dropping down from 35.8% to 18.1% per year has been seen after standard precaution training on a self-reported questionnaire. There should be a well-defined risk management protocol wherein the documentation of the identified risks associated with the procedure, the detailed analysis of the risks in terms of how to reduce or eliminate the risk along with an ongoing evaluation process for the whole management should be done. Another very important aspect in the prevention is the adequacy of recommended sterilization and disinfection procedures for equipment or items contaminated with blood and body fluids involved with patient care. Education, training programs, or brief information sessions in a regular timed manner must be available to appraise all the HCWs about infection control, blood-borne pathogens, or development in safety devices. All HCWs who are involved with any exposure-prone procedure or who are liable to be in contact with patients' blood and body fluids should undergo a risk assessment in terms of nature of risk involved, duration and severity of the infection from whom risk exists, and probability of transmission in the existing context.
| Management of Transmission of Hepatitis B Virus Infection|| |
The management of HBV infection in health-care workers can be discussed under two headings, i.e., transmission of HBV infection from patients to HCW and transmission from infected HCW to uninfected patients.
Transmission of infection from patients to health-care workers
Among HCWs, care must be taken to prevent transmission of HBV from infected patient. If any transmission occurs, however, in spite of all preventive measures, then prompt and appropriate treatment should be instituted. The foremost measure is to educate all HCWs to recognize and timely report all blood or body fluid exposures and adhere to infection control guidelines and follow standard precautions to prevent transmission of HBV. We can classify the management measures into preexposure, postexposure, and treatment of infected individuals.
Prevaccination serologic testing is indicated in moderate-high endemic areas (with hepatitis B surface antigen [HBsAg] prevalence >2%) and in individuals with risk factors such as intravenous drug users, men who have sex with men, immunosuppressive therapy, and liver disease of unknown etiology. The individuals should be tested for HBsAg and either anti-hepatitis B core (HBc) or anti-HBs. All HCWs with or without prior serologic testing should receive at least three doses of hepatitis B vaccine. Additional vaccines should be given to HCWs who are incompletely vaccinated or who do not have proper documentation. A 4-week gap between the first two doses is recommended along with 8- and 16-week gap between second and third and first and third doses, respectively. HCWs should undergo anti-HBs testing 1–2 months after the administration of last dose. Anti-HBs titer >10 mIU/ml should be considered protective and the individual immune to hepatitis B. If the anti-HBs titer is <10 mIU/ml, further dose of HBV vaccine should be given and anti-HBs titers reassessed 1–2 months thereafter. Vaccinated HCWs whose anti-HBs titer is <10 mIU/ml after revaccination, i.e., after receiving 6 doses in total, should be tested for HBsAg and anti-HBc to determine the infection status. If not found to be infected, they should be considered susceptible to HBV infection. Records containing vaccination of HCWs and their serologic testing should be maintained by the institution and a copy should be given to the HCWs as a part of their personal health record which can further be available to their future employers.
After an exposure is reported, HCWs should be evaluated and counseled regarding the risk of transmission of blood-borne pathogens, PEP, and the importance of follow-up. The wound site should be washed with soap and water, and the mucous membranes and eyes should be irrigated with water. The injection of antiseptics or disinfectants into the wound is not recommended. The source patient should be tested after obtaining an informed consent. Patients found to be HBsAg positive should be appropriately managed as per the guidelines discussed later. When the status of source patient is unknown, it should be regarded as positive and PEP administered to the recipient. Hepatitis B immunoglobulin (HBIG) and hepatitis B vaccine should be administered as soon as possible to the susceptible HCW, i.e., unvaccinated or incompletely vaccinated or vaccinated HCW with anti-HBs titer <10 mIU/ml. The effectiveness of HBIG when administered after 7 days of exposure is not known. HBIG provides passive anti-HBs and temporary protection (lasting 3–6 months) when given at a dose of 0.06 ml/kg by intramuscular injection. HBIG given within 1 week of exposure gives 75% protection from HBV infection., According to the HICPAC guidelines, if the HCW is unvaccinated and the source is HBsAg positive, then one dose of HBIG should be given and hepatitis B vaccine should be initiated. If the HBsAg status of the source is negative, then vaccine should be given. In previously vaccinated HCW with anti-HBs titer >10 mIU/ml (responders), no treatment should be given. However, in a nonresponder, i.e., anti-HBs titer <10 mIU/ml, one dose of HBIG with hepatitis B vaccine should be given if the source is found to be positive for HBsAg or is a high-risk individual., After 6 months of PEP, the person should again be tested for protective antibodies, i.e., anti-HBs >10 mIU/ml., HCW exposed to HBsAg-positive patient should refrain from donating blood, plasma, organs, tissue, or semen during the follow-up period.
Health-care workers with hepatitis B virus infection
HCWs with documented HBV infection should be counseled about the prevention of transmission to the patients, and appropriate treatment should be instituted. The treatment of acute hepatitis B infection is mainly supportive and symptomatic care. Seven therapeutic drugs have been approved by the US Food and Drug Administration (FDA) for the treatment of chronic hepatitis B. Two formulations of interferon (interferon-alpha and pegylated interferon) and five nucleoside and nucleotide analogs including lamivudine, telbivudine, abacavir, entecavir, and tenofovir are used. Interferon therapy causes immune-mediated clearance, and no resistance to therapy has been found. Low drug resistance has been noted with entecavir and tenofovir. With treatment, HBV DNA levels start falling within few weeks due to suppression of viral multiplication. According to the US SHEA guidelines, HCWs should not perform exposure-prone procedure at HBV DNA levels >104 genome equivalents (GE)/ml (approximately 2000 IU/ml) and are HBsAg negative. The UK guidelines have set these criteria to 103 GE/ml (200 IU/ml). In patients who have low levels of HBV DNA, some transient elevation can occur due to emerging drug resistance necessitating change in therapy and frequent follow-up. CDC now recommends HBV level <1000 IU/ml (5000 GE/ml) for HCWs performing exposure-prone procedures. An expert panel oversees and evaluates the HCW's clinical status, viral burden, procedures performed, and adherence to treatment and provides counseling and recommends any changes in the management if required. The panel consists of infectious disease specialist, hospital epidemiologist, gastroenterologist, occupational health or primary care physicians, ethicists, human resource professional, hospital administrators, and legal counsel. Confidentiality of health care provider's reports and status should be maintained.
| Vaccination Against Hepatitis B Virus|| |
Vaccination is considered to be one of the most effective prevention strategies for the protection against hepatitis B infection, especially in high-risk groups including the HCWs who are at a constant risk of being occupationally exposed and hence acquire the infection. The protective ability of the hepatitis surface antibodies against the virus was established by a study during an outbreak of HBV hospital infection. This was eventually followed by the discovery of hepatitis B vaccine whose efficiency has been established by multiple studies beginning in 1982. This vaccine is also the first anticancer vaccine as it indirectly helps in the prevention of hepatocellular carcinoma besides protecting against HBV infection. Hence, considering the doubtless effectiveness and added benefits of this vaccine, it should be of utmost priority for every HCW to be well informed and effectively vaccinated against this virus.
Immunogenicity depends on many factors such as age, body mass index, sex, and smoking status but is reported to be generally 10–31 years after the primary vaccination series. The first HBV vaccine was a heat-treated form of HBV developed by Dr. Baruch Blumberg and Dr. Irwing around 4 years after the discovery of the HBV in 1965. However, it was only in 1981 that the first commercial hepatitis B vaccine containing the HBsAg was introduced. This FDA approved, plasma derived, inactivated type of vaccine was developed from the pooled blood of chronic hepatitis B carriers wherein it was inactivated by multiple processes including formaldehyde and heat treatment. This vaccine was soon discontinued in 1990. The safety concerns associated with its use resulted in the development of the second generation of recombinant DNA hepatitis B vaccine in 1986. Unlike the former, it was synthetically prepared with no use of blood products. Instead, immunogenic, spherical particles that were identical to the 22-nm particles found in the serum of hepatitis B carriers were formed. These particles resulted from the self-assembly of the HBsAg polypeptides on the small enveloped surface proteins produced in the yeast. This vaccine became one of the most widely used in the world. However, the unsatisfactory results of this conventional vaccine in the immunocompromised population and the nonresponders heralded the manufacture in the 1990s, of the superior, third-generation vaccines which involved the use of HBV-transfected mammalian cells. The standard vaccination schedule consists of three doses at 0-, 1-, and 6-month interval with the doses 1 and 2 at least 4 weeks apart while doses 2 and 3 at least 8 weeks apart that should be administered intramuscularly in the deltoid region with a 1–1.5-inch long needle.
In the US, the two approved recombinant hepatitis B vaccines for the use in adults which are equally effective and safe are Engerix B (marketed by GlaxoSmithKline) and Recombivax HB (marketed by Merck). These contain synthetically prepared HBsAg adsorbed onto aluminum or a similar adsorbent. Apart from these, the vaccines marketed by Europe and Israel also exist.
Recommended adult dosages (20 years and older) of Engerix B is 20 mcg while that of Recombivax HB is 10 mcg with a volume of 1 ml each. Both require three dose schedules at 0-, 1-, and 6-month interval. Not all hepatitis A and B combination vaccines can be given in 18 years and older, in 1 ml volume in three or four doses with a schedule of 0, 1, and 6 months or 0, 7, 21–30 days, 12 months interval, respectively.
Although hepatitis B vaccine is considered as one of safest and effective ever produced, few side effects are also reported. Pain, redness, and hardness at the injection site are the most common (<1 in 10 but more than 1 in 100 doses of vaccine) side effect. Other uncommon complaints include dizziness, headache, numbness, rash, abnormal liver function, fever, tiredness, and flu-like symptoms which occur in <1 in 1000 but more than 1 in 10,000 doses of vaccine. Serious side effects such as hypersensitivity, fainting, paralysis, degenerative changes in brain, bleeding disorders, difficulty in breathing, edema, and arthritis are very rare. Allergy to hepatitis B vaccine or any of its components such as thiomersal is an absolute contraindication to its use. The administration of the vaccine should be critically reviewed, and a delay or variation in vaccination schedule must be considered in certain situations such as in cases of candidates suffering from fever and infection, immunocompromised status, dialysis patients, pregnancy, history of health problem after previous administration of a vaccine, and possible recent exposure to hepatitis B infection.
The peak HBs antibodies have been found to be the best indicator of protection against HBV carriage postvaccination. The greater the peak antibodies after 1 month of complete primary vaccination series, the longer the persistence of anti-HBs and hence protection. Vaccine efficacy studies have revealed the protective cutoff to be taken as ≥10 mIU/ml anti-HBs. Following the first, second, and third doses of the recombinant vaccine administration, 20%–30%, 75%–80%, and 90%–95% of protections have been reported, respectively. Furthermore, in adults, a rapid decrease in anti-HBs within the 1st year after primary vaccination and slowly thereafter has been reported. A decrease to a level to 10 mIU/ml was seen in 7%–50% of vaccinated adults within 5 years and 30%–60% with 9–11 years after vaccination. Long-term protection can be measured by methods such as anamnestic response after booster dose administration, rate of infection in the vaccinated, in vitro B-cell and T-cell activity testing, and seroepidemiological studies.
In India, it is advisable to administer a booster dose when the anti-HBs antibody titer falls below 10 IU/L particularly for all people at risk. In fact, a booster dose is recommended after the first dose: The 0-, 1-, and 2-month primary vaccination schedule is followed with the next booster after 8 years while the booster may be required after 5 years after the 0-, 1-, and 6-month primary vaccination series. Unlike this, the European consensus group on hepatitis B immunity and the steering committee for the prevention of infectious disease in Asia do not recommend any booster vaccination for fully vaccinated healthy participants including the HCWs. However, specific-selected groups such as HIV or chronic renal failure patients are advised for serological monitoring and booster dose if levels fall to <10 mIU/ml. The postvaccination status of the vaccine is determined by the serological anti-HBs titers. The participant is considered to be either a responder (≥10 mIU/ml after 1–2 months after the last dose of vaccine) or a nonresponder (<10 mIU/ml after 1–2 months after last dose of vaccine and tested negative for HBsAg and anti-HBc). The responders are considered to be protected even if the anti-HBsAb level falls to <10 mIU/ml with no booster requirement or any periodic antibody concentration testing. However, around 5%–10% of immunocompetent individuals do not respond to HBV vaccination. Studies have reported 12%–20% of the HCWs as nonresponders. Many factors have been associated with the poor immune response such as male sex, older age, cigarette smoking, obesity, immunodeficiency, those on immunomodulation therapy, chronic diseases such as kidney disease, liver disease, diabetes mellitus, and certain HLA phenotypes such as DR4, DR7, FC31, B44, and DQ3). A persistent exposure to HBV with low-level viremia or infection with mutants from patients on antiviral therapy is also cited as a possible cause of poor immune response to HBV vaccination. HCWs who are HBsAg-positive nonresponders must be advised medical evaluation and treatment and they must be counseled to take appropriate prevention strategies from spreading the infection. However, nonresponders with HBsAg negative status are considered susceptible to HBV infections and therefore advised to take all precautions and HBIG in case of known or possible exposure to HBV-infected patient. Alternative therapies such as immunization with a high-dose standard vaccination schedule with hepatitis A and B combined vaccines or those with S subunit, pre-S1, and pre-S2 particles can be tried but are still under evaluation. The limitations associated with the current hepatitis B vaccines such as the noneffectiveness in nonresponders, injection delivery systems, multiple dosage schedule, and inability to induce a cellular and mucosal immunity and the need to circumvent them have consistently driven the researchers to explore and investigate several strategies such as use of adjuvants such as 3-deacylated monophosphoryl lipid A or delta inulin Advax™ (enhances immunogenicity), mucosal immunization, and development of surface functionalized novel antigen carriers. Newer vaccines include the third-generation pre-S/S vaccines and the next-generation DNA or plant-based vaccines. The pre-S/S vaccines are produced in CHO cells. They are highly immunogenic and also induce a rapid antibody response to the S component of the vaccine. Such high titers could provide for a longer duration of humoral and cellular immunity, thereby providing long-term protection. A good antibody response induced by this vaccine has been found to prevent infectivity of HBV escape mutants. The next-generation DNA vaccines have been extensively studied in several animal models such as mice, monkeys, and pigs with promising results. Apart from the conventional needle with syringe, other novel DNA delivery systems such as the Gene gun, Biolistic, PowderJect™ Accell, or particle-mediated DNA delivery (directly into epidermal cells) were used. PowderJect HBsAg DNA vaccine contains microscopic gold beads with a plasmid expression vector. Another combination of hepatitis A and B (TWINRIX) has been tried where the hepatitis A acts as an adjuvant, thereby enhancing the immune response. About 95% of the nonresponders developed the protective anti-HBs antibody titers. Unlike the above two, combination of hepatitis B vaccine with HPV16/18 failed to reveal any encouraging results. Besides the already existing intramuscular and intradermal routes, other routes of vaccine administration are also being explored. A nasal-based vaccine with a name of Nasvac and an oral-based vaccine named V-5 Immunitor™ have shown good efficacy both in healthy participants and in chronic hepatitis B carriers.
| Knowledge, Attitude, and Practices of Health-Care Workers Toward Hepatitis B|| |
Hepatitis B, a major global health burden, can be prevented to a great extent by the correct knowledge, attitude, and practice (KAP) of the HCWs involved with the management of this infection. It is a general presumption that HCWs are better informed and more knowledgeable about infections and control measures than the general population as they are in practice and are being regularly trained. Hence, testing the level of awareness among the HCWs would not only indirectly assess the general public but will also go a long way in the implementation of prevention programs in a better way. As per the WHO (KAP) study, the most frequently used survey tool to assess the knowledge, attitude, or practice of any specific target group represents what is known, believed, and done in the context of a particular procedure or protocol or program on any topic. A recent study on dental, medical, and nursing interns from North India on the awareness toward hepatitis B and C reported the majority of HCWs to be having an adequate level of knowledge about the infection. About 71% of the HCWs in the same study could not complete the vaccination for hepatitis B and the fact that they were quite attentive to prevent acquiring the infection, made them think that there was no need for vaccination, this was the most common explanation given for noncompliance. Few of them, however, thought that being in this profession did not pose any risk of transmission to them from the patients. This lack of knowledge is of serious concern as the same study showed a positive correlation of knowledge score with the attitude of the HCWs. Hussain et al. reported complete, partial, and nonimmunization rates for hepatitis B of 57.6%, 18.5%, and 24% in their study and further highlighted that 93.7% of the HCWs knew about their own hepatitis B status while 6.3% of them never got their anti-HBs titers done. A large-scale study done on undergraduate medical students in seven medical colleges reported 50%–70% of the respondents with average knowledge about HBV infection and further highlighted that the attitude regarding postexposure management was not satisfactory. In the same study, approximately half of the participants gave a history of at least one NSI during their clinical practice. Studies done on medical and dental students concluded lack of awareness among the lower level students and suggested promotion of health education at school level and policy for mandatory complete vaccination and continuing health education and awareness programs for students at entry level., In both these studies, the knowledge about HBV infection was basic but not adequate for a health-care provider who would be catering to a large community. Hence, HCWs need to be motivated and given ample opportunities through regular training and seminars to learn about the health effects of HBV infection so as to promote standard principles and practices among the patients, peer group and the general population. One study reported a positive correlation between knowledge and attitude, knowledge and practice, and attitude and practice; thereby concluding that as far as infection control practices are concerned a good level of knowledge will go a long way in instilling a positive attitude and thus leading to correct practices.
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