Doctor-to-patient transmission of Hepatitis B virus: the potential of antiviral therapy for prevention

Healthcare workers as vectors of infectious diseases

Nosocomial infections cause considerable morbidity and mortality. Healthcare workers (HCWs) may serve as vectors of many infectious diseases, many of which are not often primarily considered as healthcare-associated. The probability of pathogen transmission to patients depends on several factors, such as the characteristics of a pathogen, HCW and patient. Pathogens with high transmission potential from HCWs to patients include norovirus, respiratory infections, measles and influenza. In contrast, human immunodeficiency virus (HIV) and viral hepatitis are unlikely to be transferred. The prevention of HCW-associated transmission of pathogens include systematic vaccinations towards preventable diseases, continuous education, hand hygiene surveillance, active feedback and adequate staff resources.

Needle stick injuries--risk and preventive factors: a study among health care workers in tertiary care hospitals in Pakistan

BACKGROUND

Health care workers (HCWs) are at substantial risk of acquiring blood borne infections such as HIV, Hepatitis-B and Hepatitis-C through needle stick injuries (NSIs). This study aimed to assess the proportion of NSIs and their associated factors among HCWs and also to identify the areas in which preventive efforts might be directed to protect against this occupational hazard.

METHODOLOGY

A cross-sectional study was conducted in two tertiary care hospitals of Pakistan representing both private and public health sector. A total of 497 HCWs (doctors and nurses) were interviewed using a structured questionnaire. Data was collected from January to May 2008.

RESULTS

Overall, 64% of the HCWs were exposed to at least one NSI during their career; among them 73% reported NSIs for two or more times. Factors found to be highly associated with NSIs were those practicing this occupation for more than five years (p < 0.001: OR = 5.92; 95% CI = 3.45-10.16) and working as nurse than doctor (p 0.001: OR = 2.12; 95% CI = 1.35-3.32). Having received booster dose of hepatitis B vaccine (p 0.02: OR = 1.85; 95% CI = 1.10-3.11), working in surgical specialty (p < 0.01: OR = 1.6; 95% CI = 1.09-2.51) and being a female (p 0.03: OR = 1.52; 95% CI = 1.04-2.22) were also found to be associated with NSIs. Most commonly reported reason for NSIs was injecting medicine and drawing blood (42%) followed by two-handed recapping of needle (37%). Only, 34% of study subjects were vaccinated against hepatitis B infection. Overall, HCWs had inadequate practices regarding standard precautions such as availability of gloves/protective cloths (40%) and infection control guidelines/protocols (10%) respectively in their working places.

CONCLUSION

In addition to very high rates of NSIs, low safety practices including inadequate vaccination coverage, unavailability of infection control guidelines and other preventive facilities were reported in this study. Prevention of occupational infections among HCWs should be a priority. Formal training, by health authorities in the local area, about safe practices and availability of preventive facilities should be ensured regarding NSIs among HCWs.

Prolonged antiviral therapy for hepatitis B virus-infected health care workers: a feasible option to prevent work restriction without jeopardizing patient safety

To prevent transmission of hepatitis B virus (HBV) from health care workers (HCWs) to patients, highly viraemic HCWs are often advised to restrict performing exposure prone procedures (EPPs). To prevent loss of highly qualified medical personnel and simultaneously minimize transmission risk to patients, we offered highly viraemic HCWs antiviral therapy and evaluated the effects of this strategy. Eighteen chronic HBV-infected HCWs have been monitored every 3-6 months for a median period of 5.6 years (range 1.1-12.5 years). Antiviral therapy was offered if HBV DNA was above 10(5) copies/mL and EPPs were performed or active liver disease was present. Median HBV DNA levels, the percentage of days with HBV DNA above 10(3), 10(4) and 10(5) copies/mL, and reduction of HBV DNA during antiviral treatment have been analysed for hepatitis B e antigen (HBeAg)-positive and HBeAg-negative HCWs separately. Prolonged viral suppression was achieved in both HBeAg-positive, as well as HBeAg-negative HCWs. In HBeAg-negative HCWs treatment with interferon or lamivudine maintained HBV DNA levels below 10(5) copies/mL. For HBeAg-positive HCWs continuous treatment with tenofovir or entecavir was essential for reaching low viraemia persistently. In 2004, median HBV DNA levels in both HBeAg-negative and HBeAg-positive HCWs were below 10(3) copies/mL and all HCWs executed their professional work full-range. For both HBeAg-positive and HBeAg-negative HCWs, antiviral treatment is effective in persistent suppression of virus levels below 10(5) copies/mL. This observation supports antiviral therapy as a viable management option instead of work restriction, with the provision of regular expert monitoring including quantification of HBV DNA.

Mastoidectomy and trans-corneal viral transmission

The incidence of chronic middle ear disease is falling in Britain, and in adults, is currently approximately 2.6% (inactive) and 1.5% (active). The incidence of HIV and hepatitis C is, however, rising. With this in mind, the chances of operating on a patient with undiagnosed infection is increasing. Operations involving the drilling or cutting of bone in patients with bloodborne communicable diseases are inherently dangerous to surgeons. In the pre-antibiotic era, many orthopaedic surgeons succumbed to infection and septicemia after being pierced with a spicule of bone during the execution of their duty. With the advent of the antibiotic era, the phenomenon is no longer life threatening where a bacterium is the offending microorganism. The principle, however, may be just as valid today with regard to viral communicable diseases. The world medical literature is full of reports of transmission of HIV from doctor to patient or dentist to patient. Very little is written about the reverse. This study attempted to address the apparent imbalance in the debate over exactly who is most at risk of iatrogenic transmission of potentially lethal viruses. We took fish eyes and held them in place around a mastoid cavity during drilling of a temporal bone. The eyes were then stained with fluorescein and a blue light shone over them to identify any spicules and corneal tears. Also, during this study, the maximum distance of bone dust scatter from an in vivo mastoid operation was measured from the cavity in all directions and documented. The HIV and hepatitis C virus are discussed and the importance of protection to staff highlighted.