The risk of accidental exposure to hepatitis B virus via blood contamination in medical students

Seroconversion by EMS Personnel Vaccinated with HBV Recombinant DNA

Objective:

To evaluate the seroconversion rate of EMS personnel given the hepatitis B virus (HBV) recombinant deoxyribonucleic acid (DNA) vaccine series.

Design:

Retrospective review of paramedics and firefighters consecutively completing the HBV recombinant DNA vaccine program.

Setting:

Urban, non-prof it, private, regional EMS Resource Hospital. The Chicago North EMS System is under contract with the Chicago Fire Department. This contract allows for the voluntary vaccination of EMS personnel with recombinant DNA-HBV vaccine and treatment and follow-up of paramedics and firefighters possibly exposed to HBV.

Population:

Initial 68 EMS personnel completing HBV recombinant DNA vaccine program (48 primary prophylaxis and 20 post-exposure prophylaxis).

Intervention:

HBV recombinant DNA vaccine series was administered voluntarily to Chicago EMS System paramedics and firefighters per manufacturers recommendations. Two weeks after completion of the vaccination series, blood samples for HBV antibody titres were drawn to determine reactivity and the need for further immunization.

Results:

Of the 68 vaccinated individuals, only two had negative titres (3%). These two individuals were given a fourth dose of vaccine with successful seroconversion.

Conclusions:

Prehospital care personnel are known highrisk, health-care workers for acquiring HBV and should be vaccinated prophylactically. There is a high seroconversion rate (97%) utilizing HBV recombinant DNA vaccine. However, post-vaccination antibody titres must be performed to identify those rare individuals that do not seroconvert.

The prevalence of hepatitis B serologic markers in suburban paramedics

Urban emergency medical services personnel have documented hepatitis B virus (HBV) seropositivity rates ranging from 0.6% to 25%. We studied 85 suburban paramedics for Hepatitis B serologic markers. All paramedics answered a questionnaire describing age, race, duration of employment, known hepatitis exposure, blood transfusions, gamma globulin injections, and Hepatitis B vaccination. HBV surface antibodies (Anti-HBs) were present in 6/85 (7.1%) paramedics of whom one (1.2%) had reactive HBV core antibodies (Anti-HBc). No paramedic had HBV surface antigen (HBsAg). Seropositivity was not associated with duration of employment, or exposure to a patient with either jaundice (28.2%) or confirmed hepatitis B (20.0%) within the six months prior to testing. The 7.1% prevalence of HBV markers found in this group of suburban paramedics is intermediate between previously reported rates for urban paramedics. We conclude that prehospital personnel do not constitute a homogenous occupational category at risk for hepatitis B infection.

Effect of changing needle disposal systems on needle puncture injuries

Accidental needle puncture injuries continue to pose a hazard to hospital workers. In order to reduce the number of such injuries in our hospital, needle disposal procedures were revised to discourage recapping and prevent bending or clipping of needles before discard. Collapsible cardboard boxes were replaced with impervious containers. An educational program accompanied these changes. We compared reports of needlestick injuries before and after the change of procedure, for three parallel 9-month periods. During the 27-month study, injuries occurred during administration of medication (22%), or recapping of used needles (16%), from needles protruding through (10%) or out of the "mouth" (9%) of the container, from needles left in the patient's environment (10%), or those left on procedure trays (7%). Seven percent were the result of being stuck by someone else, usually in the operating room. The mechanism of injury for 19% was not described. Altering the disposal procedures did not change the number or anatomic site of injuries, nor the risk of injury among the various job categories. A reduction in the rate of sticks from needles protruding through the container (1.3 vs 0.3/mo, p less than or equal to 0.005) was the only difference observed. Changing the needle receptacle changed the type but not the overall number of injuries. The education program had little effect on the number and types of injuries. These data point to the need for developing innovative approaches for eliciting changes in behavior of health care personnel.

Needlecaps to prevent needlestick injuries

Hospital employees are at risk for numerous possible complications of accidental needlesticks. The mechanisms of such accidents suggest that many are preventable. This article presents a simple but novel revision of the needlecap which facilitates resheathing of a used needle. With routine use the hospital environment could be made safer for virtually all employees at almost no additional cost. Ultimate hospital savings could be significant through prevention of injury.

Needle punctures--documentation and incidence rate calculation

Potential hazards of puncture wounds have been well-defined and include transmission of hepatitis B virus, acquired immunodeficiency syndrome, syphilis, malaria, and other infectious diseases. Yet, standard methodology has not been used for statistical comparison. Attack rates have been expressed as needlesticks per full-time equivalents, needlesticks per employee per year, punctures per number of personnel, or punctures per number of hospital beds. These calculations do not account for the amount of time during which an employee is at risk of receiving a needle puncture. Also, numbers alone cannot account for intensity of care, potential exposures, or hours at risk. Nor can numbers provide an estimate of potential risk. A rate is more valuable than numbers because it measures the probability of occurrence. A meaningful incidence rate would be based on uniform data collection and would provide the number of puncture wounds per year for a standardized work period. This is similar in concept to nosocomial infections per patient-days of exposure. We propose the application of standard labor statistics methodology which accounts for man-hours worked, can be readily obtained in health care facilities, and can be modified as described here.