Blood Borne Diseases and Risks for Health Care Workers
A number of different infectious diseases may be transmitted via contact with blood or other body fluids (Hofmann, Kralj & Beie 2002). The pathogens of blood borne diseases that are important in health care settings are the hepatitis B virus (HBV), the hepatitis C virus (HCV) and the human immunodeficiency virus (HIV) (Daghofer et al 2002; Hofmann, Kralj & Beie 2002; Robert-Koch-Institute 2004). Needlestick injuries play a major role in the transmission of those diseases (Hofmann, Kralj & Beie 2002). Other pathogens, like the other hepatitis forms, or Plasmodium malaria, may also be transmitted to health care workers, but they are very seldom compared to hepatitis and HIV (Hofmann, Kralj & Beie 2002).
This essay deals with blood borne diseases and their affect on health care workers. It will start with a look at the three important diseases, including their incidence in German public. After that, it will lead over to the risk for health care workers and discuss some ways to decrease that risk. The work will close with a description of post-exposure prophylaxes.
2. Overview over blood borne diseases
2.1 Hepatitis B
HBV is the principal agent of the hepadnaviruses (Kayser, Bienz, Eckert& Zinkernagel 2001). Humans are the only known reservoir (Kayser et al 2001). The virus is contracted by contact with blood or other body fluids (Kayser et al 2001). According to the Robert-Koch-Institute (RKI), sexual transmission seems to be the most important way of infection (RKI 2004). Hepatitis B is a notifiable disease (RKI 2004).
Hepatitis B has an incubation period of four to twelve weeks, followed by an acute infection period of two to twelve weeks (Kayser et al 2001). For 0,5 – 1% of the patients, the disease is fulminant and often lethal , for 80 – 90% the infection is benign with complete healing, and 5-10 % of the cases develop a chronic infection (Kayser et al 2001), which can lead to liver cirrhosis (Henein 1997).
Epidemiological studies showed that approximately one million people in Germany carry HBV (Hofmann, Kralj & Beie 2002). Not immunised health care workers have an 2,5 – 3 times higher risk for an HBV infection (Hofmann, Kralj & Beie 2002). However, hepatitis-B vaccination has fortunately decreased the HBV-incidence among health care workers (Hofmann, Kralj & Beie 2002).
2.2 Hepatitis C
HCV is an RNA virus that was first discovered in 1988 (Kayser et al 2001). The disease has many similarities with hepatitis B (Kayser et al 2001), however ‘nearly 100 per cent of people infected (…) will eventually develop symptoms’ (Henein 1997, p. 658).
The HCV incidence in Germany lies with 0,5% or 400 000 people (Hofmann & Krajl 2001). In contrast to HBV and HIV, sexual contact seems to be no risk factor (RKI 2004). HCV can be transmitted through blood and blood products (Kayser et al 2001). As blood products are screened for HCV-antibodies since 1990, the risk of a transfusion-associated transmission today is very low: approximately < 1 : 1,000,000 (RKI 2004). Intravenous drug-abuse with needle-sharing is an often reported source of infection (RKI 2004). About 20 to 30 % of the cases (www.kompetenznetz-hepatitis.de) are ‘sporadic’ infections where the transmission route remains unexplained (Kayser et al 2001). Hepatitis C is a notifiable disease; since 2003, all newly discovered cases of hepatitis C are reported (RKI 2004). No vaccine against HCV is available (www.kompetenznetz-hepatitis.de) or will probably be on hand in near future (Hofmann & Kralj 2001; Knüppel 2004).
HIV is a retrovirus that infects T4-lymphocytes (Kayser et al 2001). It is the pathogen of AIDS, which was first described as a separate disease in 1981 (Kayser et al 2001). During the incubation period, which can endure for years, the carrier may shows no clinical symptoms but may transmit HIV to others (Kayser et al 2001).
HIV is transmitted through blood and blood products, through sexual contact, and from mother to child intrauterine, perinatal or through breast-feeding (Kayser et al 2001). Approximately 50, 000 – 60, 000 people in Germany are HIV-positive (Hofmann, Kralj & Beie 2002). There is no vaccine obtainable at the moment (Knüppel 2004). HIV and aids are notifiable diseases (RKI 2004); however, HIV-tests may be performed anonymous to protect the right of the individual (www.hivlife.de). HIV-tests as a matter of routine, without informed consent of the patient, are illegal (www.hivlife.de).
3. Risk for health care workers
Health care workers are at risk of contracting HBV, HCV and HIV due to contact with infectious material (Bain 1998; Daghofer et al 2002; Henein 1997; Hofmann, Kralj & Beie 2002). Blood borne pathogens are frequently transmitted after needlestick injuries (Hofmann, Kralj & Beie 2002). In Germany, 500,000 occupational needlestick injuries are reported each year (Klinik Management Aktuell 2003). The estimated number of unknown cases is high and assumed to lie between 80 to 90 % (Daghofer et al 2002; Hofmann, Krajl & Beie 2002). According to Knüppel (2004), the majority of needlestick injuries happens in the hospital setting. This sounds logical because of a higher number of procedures with sharp objects. In the course of the ongoing reformation of the German health system, however, it is proposed to reduce the time a patient has to stay in hospital (STERN 48/2002). As a consequence, health care workers in the community setting will have to perform activities that were traditionally part of the hospital, and their risk of injury may therefore increase.
The risk of infection after a needle stick injury with a positive source patient differs among the different diseases. As a rule-of-thumb, literature talks about 30% risk in case of HBV, 3% in case of HCV and less than 0,3% in case of HIV ( Hofmann & Krajl 2001; Hofmann, Kralj & Beie 2002). Those numbers have been rounded for didactical reasons (Hofmann, Kralj & Beie 2002), and several studies show different rates of infection (CDC 1997). All literature sources, however, agree on the point that the risk of contracting HCV or HIV during occupational injuries is much lower than for HBV (CDC 1997; Daghofer et al 2002; Hofmann, Krajl & Beie 2002; RKI 2001).
Preventing the transmission of blood borne pathogens means to cut down the number of injuries (Hofmann, Kralj & Beie 2002). A number of recommendations for the prevention of needlestick injuries have been written during recent years (Hofmann, Kralj & Beie 2002). Using personal protection equipment – gloves in particular – are part of the standard precautions (Hofmann, Kralj & Beie 2002; Haamann 2004). However, those precautions, for example the wearing of gloves during venal punctures, or the use of sharps disposals, are not always followed (Hofmann, Kralj & Beie 2002). Besides, gloves can reduce the risk of blood contact down to one-fifth to one-tenth of the original risk (Hofmann, Krajl & Beie 2002), but they may be perforated while performing working activities (Hofmann, Krajl & Beie 2002).
Vaccination against hepatitis B provides an adequate protection against infection (Henein 1997; Hofmann, Krajl & Beie 2002, RKI 2004). Since 1995, the ‘Ständige Impfkommision’ (Permanent Commission for Vaccination) (STIKO) recommends a hepatitis-B-vaccination for babies or children (RKI 2004). Further recommendations include a vaccination for defined risk groups, for example health care worker and other persons with an occupational risk of contact, patients with chronicle diseases, in need of dialysis, or hemophilia patients (RKI 2004). Health care workers and other risk groups seem to profit from the campaign (Hofmann, Krajl & Beie 2002; RKI 2004). Unfortunately, not all health care workers take up the possibility of a hepatitis-B-vaccination, in particular in the community setting (Hofmann, Krajl & Beie 2002; RKI 2004).
A new chance to prevent needle stick injuries is the design of safety devices (Aids Alert 1997; Hofmann, Krajl & Beie 2002; Australian Nursing Journal 2003). Such devices are designed to reduce the risk of injury to a minimum, as the needle cannot be touched after use (Grüner & Koch-Wenger 2003; Haamann 2004; Hospital Employee Health 2003). Studies showed a decrease in needlestick injuries up to 90 % after the implementation of safety devices (Aids Alert 1997; Hofmann, Krajl & Beie 2002; Australian Nursing Journal 2003).
Unfortunately, the saving of costs hinder some employers from implementing technical interventions (Knüppel 2004; Aids Alert 1997). Few safety devices have been implemented in German hospitals and clinics so far (Knüppel 2004), as they are more expensive than traditional devices (American Nurses Association; Aids Alert 1997; Carsley, Robbillard & Roy 1997; Haamann 2004; Knüppel 2004). Budgeting and pay freezes have let to economy measures in all health care areas (Knüppel 2004). The anew use of empty glass bottles as sharps disposals has sporadically been reported (Knüppel 2004). Since November 1st, 2003, a new German ‘Technische Regel für Biologische Arbeitsstoffe’ (Technical Rules for Biological Substances) determines among other things that sharp, pointed, or breakable instruments shall be displaced by objects with a low risk of injury, particularly in areas with a high risk of infection (Knüppel 2004). There is hope that this rule will lead to a more sensible handling of needlestick injuries (Knüppel 2004).
5. Post-exposure prophylaxis
With organisational changes and safer equipment, the number of injuries may be decreased, but not eliminated, as sharp objects will always be necessary for some procedures (Daghofer et al 2002; Knüppel 2004). To prevent the outbreak of a blood borne disease, a proper post-exposition management is vital (Hofmann, Krajl & Beie 2002).
In case of an injury, a health care worker should get a post-exposition prophylaxis (PEP) immediately (Braveny & Maschmeyer 2002). The first activities should be the stimulation of bleeding and the disinfection of the wound (Hofmann, Krajl& Beie 2002). This should be followed by blood tests for HBs-antigen, Anti-HCV and HIV-antibodies for both the health care worker and the source patient (Braveny & Maschmeyer 2002). The accident should also be documented for actuarial reasons (Braveny & Maschmeyer 2002).
The recommendation of a medicamental PEP depends on the results of the donor’s blood tests (Braveny & Maschmeyer 2002). In respect of HBV, the treatment also depends on the vaccination status of the injured person (Braveny & Maschmeyer 2002). With an adequate protection or an HBs-antigen negative source patient, no further treatment would be necessary (Braveny & Maschmeyer 2002; RKI 2000). If the vaccination status is unknown, a quick blood test should be performed (RKI 2000). If the protection should be insufficient, the injured worker should receive both a HB-vaccination and a dose of HB-immunoglobulin (Braveny & Maschmeyer 2002; RKI 2000).
In respect of HCV, no medicamental PEP exists (Daghofer et al 2002; Hofmann, Krajl & Beie 2002). Acute hepatitis C may be treated with interferon (RKI 2004) or a combination of interferon and ribavirin (Hofmann, Krajl & Beie 2002). As the therapy has severe side effects (Henkel 1997), the Robert-Koch-Institute recommends extra Anti-HCV tests of the injured worker after two to four weeks (RKI 2004) for an early detection and following treatment of the infection.
In contrast to HCV, a therapy against HIV should be started as early as possible (Daghofer et al 2002; RKI 2001). The ideal time would be two hours after an injury (Daghofer et al 2002). 72 hours after the injury, a medicamental PEP would be ineffective (Daghofer et al 2002).
A triple combination therapy of two reverse transcriptase inhibitors with one protease inhibitor is recommended (Braveny & Maschmeyer 2002; RKI 2001). The PEP endures 28 days and may also have severe side effects (Daghofer et al 2002; RKI 2001).
The responsibility of documentation, tests and treatment lies with the accident medical consultant and the company medical officer. Hospitals usually employ their own consultants. Literature mentions that smaller institutes like community nursing services are less well-organized in respect to accident medical consultants (Hofmann, Krajl & Beie 2002).
In Germany, costs for blood testing, prophylaxis and treatment after an occupational accident are carried by the employers’ liability insurance association (Klinik Management Aktuell 2003). It quotes the costs for needlestick injuries in Germany as about 6000 Euro per case, and 12 millions Euro each year (Klinik Management Aktuell 2003). In 2002, 254 cases of Hepatitis C and 178 cases of Hepatitis were suspected occupational diseases (Knüppel 2004). The value of social and emotional consequences of the affected workers cannot be measured in numbers (Hofmann, Krajl & Beie 2002).
Health care workers are in danger of contracting HBV, HCV and HIV (among others) via direct blood contact. At the moment, workers in hospital settings seem to be more at risk, but this will probably change in future. Hepatitis-B vaccination protects from infection, but there is no vaccination against hepatitis C or AIDS. PEP may help after an injury but has severe side effects.
Despite the risk of infection, the importance of needlestick injuries is still underestimated, as only few of them are reported.
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