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rh 1.html

Clarification of Rh Factor Risk in Health Care Workers

by Dr. Janine Jagger

The San Francisco Chronicle recently did a very extensive 3-day series on needlestick injuries. I provided a lot of information to one of the reporters. When the article was published on April 13-15 it was sensationalistic in tone and contained a great deal of misinformation. Unfortunately, this applied to an issue that was raised during my interview. Because this article is getting into more widespread distribution, I wanted to provide you with the facts in order to avoid confusion if questions about this are raised in your institution. The following paragraphs include my statement to the organization of Occupational and Environmental Medicine.

I was alarmed when I read the article about Rh factor risk in health care workers published in the San Francisco Chronicle on April 13, 1998. I am concerned that my statements have been incorrectly construed and presented by the reporter as exaggerated claims.

During an all-day interview, primarily dealing with other health care worker safety issues, I told the reporter that I was looking into the question of whether Rh immunization could occur after occupational blood exposures since there is no documentary evidence that this question has been considered in relation to occupational blood exposures. The reporter asked me some general questions about the Rh factor and the consequences of Rh immunization. When I saw the article I was shocked at how my comments had been transformed. The reporter treated this information as a "scoop" and turned it into a sensationalized piece. The article refers to a "discovery." There is no discovery, only questions. The article refers to my "research" on this subject. There is no research, only a literature review and conversations with colleagues. The article refers to thousands of health care workers who might be unknowingly affected and their fetuses threatened. I do not know of any case in which this has occurred. The article also outlines post-exposure treatment parameters which I would never presume to propose to my medical colleagues. If the facts had been accurately stated, there would not have been much of a story left to write.

I have raised the Rh issue as a theoretical question, and it remains an interesting question. Several cases of Rh immunization have been reported in needle-sharing, intravenous drug users. It should be noted that the circumstances are not necessarily similar to those of occupational needlestick injuries. Consequently, I have been looking into whether there are theoretical parameters under which Rh immunization could be an occupational risk. Based on experimental work done in the early 70's which quantifies volume of blood in an exposure and percentage of Rh negative cases developing antibodies, the risk of Rh immunization may be present in unusual cases when HCWs are accidentally injected with blood (a few such cases of injection have been described in HIV-infected HCWs) provided the HCW is Rh-negative and the source is Rh-positive. In reviewing the circumstances of those HIV+ cases, blood injection is most likely to occur when blood has been drawn into syringes, since blood can be injected out of a syringe, but not out of a vacuum tube. One cc of blood is well within the range that could cause Rh immunization. However, the amount of blood that could be contained within the bore of a blood drawing needle (in cases in which injection does not occur) is much less than the amounts that have been experimentally tested. The experiments did not define a threshold below which sensitization cannot occur. This is as much information as my inquiries have yielded to date.

I do think this question bears investigation. Testing a series of blood-exposed health care workers either prospectively or in a look-back study would determine whether a theoretical risk translates into a real risk. I am hoping that the SF Chronicle piece does not result in alarm among health care workers or frightened calls to occupational health personnel. And I hope this explanation puts the issue into a more realistic perspective.

There were other aspects of the 3-part series of articles that were sensationalized. I think the whole series should be taken with a grain of salt. However, after the dust settles, perhaps the attention drawn to the issue of health care workers’ risks will be a good thing overall.

Janine Jagger, M.P.H., Ph.D.
Director, International Health Care Worker Safety Center
University of Virginia Health System

Postscript: Please note that the above clarification does not include any suggestion regarding changes in post-exposure protocols. My investigation to date has involved information gathering only and should not be construed as any kind of recommendation. JJ