Nadey S Hakim
MD PhD FRCS
International College of Surgeons
Healthcare workers are at risk of exposure to potentially infected human blood and blood fluids via many routes, including needlestick injuries and splashes. A North American surveillance scheme, which included 24,425 healthcare workers, found that 2,730 exposures to blood and body fluids occurred over a four-year period, resulting in an overall annual rate of 5.5 events/100 employee full-time equivalents and a rate of 3.9 for percutaneous exposures.(1) Much higher rates were observed for nurse anaesthetists, inpatient nurses, phlebotomists and surgical theatre room technicians.
Although risk reduction strategies are having an impact in many countries, the risk to healthcare workers remains substantial. A French study assessed the impact of multimodal reduction strategies introduced in 61 hospitals affiliated with the Northern France Network.(2) Data from four years of blood and body fluids exposure reports were examined. Of 7,649 exposures, nurses and nursing students accounted for 4,587 (60%), followed by nurses’ aides and clinicians. Most reports (77.6%) concerned needlestick injuries. Although exposure was reduced with the introduction of universal precautions and engineering controls, risk was far from eradicated. In the same way as in other countries, healthcare workers remain at risk from bloodborne infections, including human immunodeficiency virus (HIV) and hepatitis B.
Recently, World Health Organization researchers developed a model to estimate the global burden of hepatitis B (HBV), hepatitis C (HCV) and HIV infection due to percutaneous injuries among healthcare workers in 14 geographical regions on the basis of the probability of injury, the prevalence of infection, the susceptibility of the worker and the percutaneous transmission potential.(3) Their results indicated that in the year 2000 a global total of 16,000 HCV, 66,000 HBV and 1,000 HIV infections may have occurred among healthcare workers due to occupational percutaneous injuries.
Risk factors for HIV and HBV
Despite the similarities in the modes of transmission, the risk of HBV infection in healthcare settings far exceeds that for HIV. It has been estimated that the risk of acquiring HBV infection following puncture with a needle contaminated by an HBV carrier ranges from 6% to 30%, far in excess of HIV, which is estimated to be less than 1%.
HIV infection is known to have been transmitted by organ transplants and blood transfusions received from persons who were HIV-seronegative at the time of donation. Falsely negative serology can be due to improperly performed tests or testing in the time window during which a recently infected person is infective but has not yet converted from seronegative to seropositive.
Workers occupationally exposed to blood, blood fluids or tissue can be protected from the recognised risks of HBV and HIV infection by imposing barriers in the form of work practices and protective equipment that are readily available and minimally intrusive.
This is defined in terms of actual skin mucous membrane or parenteral contact with blood body fluids and tissues. Tissues and fluids should be understood to designate not only human tissues but also potentially infectious fluids associated with laboratory investigations of HBV or HIV organs and excretions from experimental animals, embryonated eggs’ tissue, or cell cultures and culture media.
From a routine physical examination at the GP’s office to a prolonged transplant procedure, every interaction between doctor and patient begins with putting gloves on. The use of gloves in surgery can be traced as far back as the mid-1700s when they were occasionally used in obstetric and gynaecological examinations. The first rubber gloves did not have any clinical use until around 1890 to protect the surgeon’s or the nurse’s hands from harsh chemicals.
Disposable natural rubber latex gloves arrived on the scene in the 1960s. It was during the AIDS epidemic of the early 1980s that glove use saw its greatest upsurge. During the year 1987 glove usage increased tenfold, putting pressure on glove manufacturers to meet the increased need for gloves and address the rapidly growing concerns over comfort safety and ease of use.
The residual risk when using a barrier protection such as gloves is the unobserved perforation of the barrier. A survey of glove perforation in 100 consecutive hand surgery operations during which 397 pairs of gloves were used found evidence of perforation in 19% of the gloves used. In only 12 of these cases did the surgeon realise that a perforation had occurred. With a perforation rate of 43%, the surgeons were significantly more at risk of glove perforation than the other members of the operating team.
Studies such as this have led to the practice of wearing two pairs of gloves, triple gloving, glove liners or cloth outer gloves as opposed to one pair, in order to provide an additional barrier and further reduce the risk of contamination.
A prospective study which compared the presence of visible blood on the hands of surgeons wearing single or double gloves during 45 consecutive major obstetric and gynaecological operations found that single-gloved hands revealed the presence of visible blood in 38% of cases, whereas visible blood was noted in only 2% of double-gloved hands.(4)
In an Australian study which employed a more realistic setting, patients were randomised to undergo surgery with a single- or double-gloved operating team.(5) Perforation rates were compared for two operating teams. All gloves were tested postoperatively by water-filling and individual digital distension; 115 single-gloved operations and 103 double-gloved operations were performed. There were 841 individual operating team members at risk. In the single-glove group, 20.8% of individuals had perforations, but only 2.5% had perforations in both inner and outer gloves (dual perforation) in the double-gloves group. The surgeon was most at risk of glove perforation, and longer operations were associated with increased risk of glove perforation.
A recent Cochrane review of 14 randomised controlled trials measuring glove perforations showed that there were significantly more perforations to single glove than to the innermost of the double-gloves.(6) Eight trials of indicator gloves (coloured latex gloves worn underneath regular latex gloves to alert the team to perforations more rapidly) showed that significantly fewer perforations were detected with single-gloves compared with indicator gloves or with standard double-glove compared with indicator gloves. Three trials of knitted gloves (knitted glove worn on top of latex surgical gloves) and one trial of triple gloving all compared with standard double gloves showed there were significantly more perforations to the innermost glove of a standard double gloves in all comparisons. Although there was no direct evidence that additional protection worn by the surgical team reduces site infection, the addition of a second pair of surgical gloves significantly reduces perforations to the innermost glove.
A US-based study evaluated the accuracy of the nonlatex and latex double-gloves hole puncture indication systems using five commonly used sterile surgical needles.(7) After subjecting both the nonlatex and the latex double-gloves hole puncture indication systems to surgical needle puncture in each glove fingertip, the gloves were immersed in a sterile basin of saline, after which the double-gloved hands manipulated surgical instruments. Within two minutes, both the nonlatex and latex hole puncture indication systems accurately detected needle punctures in all of the surgical gloves, regardless of the dimension of the surgical needles.
As surgical gloves become more and more important – given the increase in knowledge concerning infection and cross-contamination in hospital settings – it is good to see so many advances in glovemaking technology. It is safe to assume that technology and safety will only continue to improve.
Perforations are difficult to detect conventionally (up to 88% remain undetected). Evidence clearly demonstrates that to reduce risk to the patient and surgical team using a double-gloving indicator system can mean that up to 97% of punctures are detected. The world-renowned Cochrane Collaboration review on double-gloving stated that wearing two pairs of gloves during low-risk surgery offered significantly more protection against perforations than single-gloving.
It is also important to change gloves between each patient contact and to use hand-hygiene procedures after glove removal. Barrier protection has an important role to play in reducing healthcare-associated infections; however, clinicians must also take responsibility for ensuring that hand hygiene remains part of every patient’s care.
- Dement JM, et al. Blood and body fluid exposure risks among healthcare workers: results from the Duke Health and Safety Surveillance System. Am J Ind Med 2004;46(6):637-48.
- Tarantola A, et al. Occupational blood and body fluids exposures in healthcare workers: four-year surveillance from the Northern France network. Am J Infect Control 2003;31(6):357-63.
- Pruss-Ustun A. et al. Estimation of the global burden of disease attributable to contaminated sharps injuries among healthcare workers. Am J Ind Med 2005;48(6):482-90.
- Cohn GM, Seifer DB. Blood exposure in single versus double gloving during pelvic surgery. Am J Obstet Gynecol 1990;162(3):715-7.
- Gani JS, et al. Efficacy of double versus single gloving in protecting the operating team. Aust NZ Surg 1990;60(3):171-5.
- Tanner J, Parkinson H. Cochrane Database Syst Rev 2006;19:3. CD003087.
- Edlich RF, et al. Reliability and performance of innovative surgical double-glove hole puncture indication systems. J Long Term Eff Med Implants 2003;13(2):69-83.