HBV, HCV and HIV transmission to healthcare workers

my$0.02 · 06-06-2009, 04:13 PM

This topic seems worth discussing.

Quote:

As of December 2001, occupational exposure to HIV has resulted in 57 documented cases of HIV seroconversion among healthcare personnel (HCP) in the United States. To prevent transmission of HIV to healthcare personnel in the workplace, the Centers for Disease Control and Prevention (CDC) offers the following recommendations.

Preventing Occupational HIV Transmission to Health Care Workers | Factsheets | CDC HIV/AIDS

See the chart showing occupation of infected healthcare workers.

Quote:

The most recent possible new case of occupationally acquired HIV/AIDS was reported to CDC in 2000; no new documented cases have been reported since that time, although several cases are in various stages of investigation. As yet, none can be classified as documented cases. The figure shows the number of exposures/injuries leading to documented transmission by year, from 1984-1999. There are usually delays between the exposure and the reporting of the case to CDC. The number of possible cases may decrease if individuals are reclassified when a nonoccupational risk is identified or may increase if new cases are reported.

More than 90% of healthcare personnel infected with HIV have nonoccupational risk factors for acquiring their infection.

Surveillance of Occupationally Acquired HIV/AIDS in Healthcare Personnel, as of December 2006 | CDC Infection Control in Healthcare

Quote:

In many countries for many years health care workers have become infected with HIV as a result of their work. The main cause of infection in occupational settings is exposure to HIV-infected blood via a percutaneous injury (i.e. from needles, instruments, bites which break the skin, etc.). The average risk for HIV transmission after such exposure to infected blood is low - about 3 per 1,000 injuries. Nevertheless, this is still understandably an area of considerable concern for many health care workers.

Health care workers & HIV prevention

Transmission rates cited in the excellent NIOSH document.

Quote:

HIV

To estimate the rate of HIV transmission, data were combined from more than 20 worldwide prospective studies of health care workers exposed to HIV-infected blood through a percutanous injury. In all, 21 infections followed 6,498 exposures for an average transmission rate of 0.3% per injury [Gerberding 1994; Ippolito et al. 1999]. A retrospective case-control study of health care workers who had percutaneous exposures to HIV found that the risk of HIV transmission was increased when the worker was exposed to a larger quantity of blood from the patient, as indicated by (1) a visibly bloody device, (2) a procedure that involved placing a needle in a patient's vein or artery, or (3) a deep injury [Cardo et al. 1997]. Preliminary data suggest that such high-risk needlestick injuries may have a substantially greater risk of disease transmission per injury [Bell 1997].

Post-exposure prophylaxis for HIV is recommended for health care workers occupationally exposed to HIV under certain circumstances [CDC 1998c]. Limited data suggest that such prophylaxis may considerably reduce the chance of becoming infected with HIV [Cardo et al. 1997]. However, the drugs used for HIV post-exposure prophylaxis have many adverse side effects [CDC 1998c]. Currently no vaccine exists to prevent HIV infection, and no treatment exists to cure it [CDC 1998d].

HBV

The rate of HBV transmission to susceptible health care workers ranges from 6% to 30% after a single needlestick exposure to an HBV-infected patient [CDC 1997b]. However, such exposures are a risk only for health care workers who are not immune to HBV. Health care workers who have antibodies to HBV either from pre-exposure vaccination or prior infection are not at risk. In addition, if a susceptible worker is exposed to HBV, post-exposure prophylaxis with hepatitis B immune globulin and initiation of hepatitis B vaccine is more than 90% effective in preventing HBV infection.

HCV

Prospective studies of health care workers exposed to HCV through a needlestick or other percutaneous injury have found that the incidence of anti-HCV seroconversion (indicating infection) averages 1.8% (range, 0% to 7%) per injury [Alter 1997; CDC 1998b]. Currently no vaccine exists to prevent HCV infection, and neither immunoglobulin nor antiviral therapy is recommended as post-exposure prophylaxis [CDC 1998b]. However, recommendations for treatment of early infections are rapidly evolving. Health care workers with known exposure should be monitored for seroconversion and referred for medical follow-up if seroconversion occurs.

NIOSH - NIOSH Alert: Preventing Needlestick Injuries in Health Care Settings

bluedevilmike · 06-09-2009, 03:38 PM

Hm.

Quote:

More than 90% of healthcare personnel infected with HIV have nonoccupational risk factors for acquiring their infection.

I'm trying to figure out what this means. Does this mean that the CDC suspects most of them actually got it from nonoccupational sources--that it was a coincidence that they got needlestuck (or whatever) at work?

Or does this mean that they were, say, immunocompromised or something, making them more susceptible to acquiring infections after a needlestick?

thirstylemonade · 06-16-2009, 09:57 AM

I think it means that as well as being needle stuck they were engaging in other risky behaviour which may have been the source of the aquisition of HIV rather than the occupational injury.

my$0.02 · 06-16-2009, 11:33 PM

Here is one of Julie Gerberding's early papers from UCSF.
Transmission of HIV to health care workers: risk and risk reduction.

The earliest papers out of UCSF's medicine department pooh-poohed the possibility of occupational transmission of HIV and instead sought "non-occupational risk factors" to explain seroconversion.
Recommended infection-control policies for patient...[N Engl J Med. 1986]