In 1962, Marvel Comics introduced a new super-hero in their comic book titled “Journey into Mystery!” That character would become famous both in the book and eventually on the big screen. He was the mighty Thor. Through the years this Norse god of thunder would have many adventures and travel into many strange and unusual places all to protect his home of Asgard and to save the people of his adopted home planet, Earth. While the character of Thor willingly chose to journey into those many unknown places, those who work in the laboratory with bloodborne pathogens should not.
Evan popped the tops off of the serum separator tubes and placed them into the analyzer rack. He used a counter-mounted shield to protect himself from a splash. He picked up the rack containing five specimens and walked over to the chemistry analyzer to run them, but as he neared the analyzer his grip loosened, and he dropped the rack. It fell about an inch onto the analyzer and serum splashed up into Evan’s eyes. He did not know from which tube or tubes was the source of his exposure.
Rose was running late when she started her shift in the histology grossing lab. She did not notice that the small sharps container for scalpel blades was over full at the bench. When it was time to change her blade, Rose reached up without looking to eject the blade into the sharps container. She felt a sharp pain and saw that she had cut herself on several used blades that were sticking up out of the container access hole. Her injury had to be treated as an unknown source exposure.
If a bloodborne pathogen exposure occurs in the lab, there are several regulations that should be in place to help protect the exposed employee. OSHA’s Exposure Control Plan includes hepatitis vaccinations for employees, and follow up source testing instructions to discover the HIV and hepatitis status of the known source patient. Prophylaxis for an HIV exposure in the lab must be administered quickly to be effective, usually within 2 hours of the exposure, so rapid testing is key.
There are, unfortunately, accidents that occur for which the bloodborne pathogen source cannot be determined. The incidents described above could have been prevented, and they should have been, because treatment for an unknown source exposure is a journey no ne should want to make. In some cases, like with the sharps exposure, it is impossible to determine the source. In other cases, as with a rack of tubes, it is too costly and there is no time to test all possible exposure sources.
In some facilities, after an unknown source exposure, the policies call for complete serological testing of the exposed victim for HIV and hepatitis. This does not provide useful information, however, it only provides the serological status before the exposure, it does not alter the necessary treatment.
Treatment for an unknown source exposure usually consists of the immediate administration of prophylactic drugs. While these drugs are designed to help prevent the post-exposure development of HIV or hepatitis, they are known to be toxic to the body and can have many ill effects. Personal consequences can occur as well after such an exposure. As a precaution, the exposed victim may be told to avoid intimate relationships for six months. Clearly, this is not a journey anyone would willingly want to take.
All exposure incidents in the laboratory setting should be prevented, and the majority of them can be prevented easily. Pay attention to the surroundings and look for potential sources of exposure. Consistently use proper PPE including face protection whenever handling open specimens or performing maintenance on an analyzer where tubing or reservoirs are involved. Empty sharps containers when ¾ full, and never allow anyone to open them or dig through them, even for a lost specimen. The risk is too high.
In many ways, the work of a laboratorian should be a journey into mystery. There are test results to produce, diagnoses to be made, and new techniques to discover. With the work in the lab environment, all exposure risks should be assessed, and they should be mitigated using engineering controls, safe work practices, and PPE so that this work can be performed safely. Let the scientific mysteries be those that prevail and not the scary alien consequences of an unknown source exposure.
–Dan Scungio, MT(ASCP), SLS, CQA (ASQ) has over 25 years experience as a certified medical technologist. Today he is the Laboratory Safety Officer for Sentara Healthcare, a system of seven hospitals and over 20 laboratories and draw sites in the Tidewater area of Virginia. He is also known as Dan the Lab Safety Man, a lab safety consultant, educator, and trainer.