Patient-To-Patient HEP B Transmission
By Kay Carl, RN, BS, Infection Preventionist
After reading this article, the reader should be able to:
- Identify the type of blood-borne Hepatitis that is easiest to transmit by poor infection control practices.
- Examine the epidemiological investigation of the patient-to-patient transmission that transpired.
- Identify the 3 tools necessary to prevent the transmission of Hepatitis.
State & Federal Investigation
Officials from The New Mexico Department of Health (DOH) and the Centers for Disease Control and Prevention (CDC) took part in the epidemiological investigation. The research report on the investigation was published in the Journal of Infectious Disease in 2007 [Redd JT, Baumbach J, Kohn W, Nainan O, Khristova M, Williams I. Patient-to-patient transmission of hepatitis B virus associated with oral surgery. J Infect Dis 2007;195(9):1311–1314]. The oral surgeons at the center cooperated with the health officials in the investigation. So let us look at the findings.Index Patient
In April 2002, the DOH was notified of an acute case of HBV. The patient was a 60- year old woman who became symptomatic that February. She had not received the HBV vaccination. She had no known traditional risk factors. In the six months before the manifestation of her disease, she had not been sexually active nor had occupational blood exposure. She did not receive any blood products or blood transfusions. She had no history of IV drug use or hemodialysis. She had no household contact with a person with hepatitis B. She did recover from her HBV infection.Red Flags
What was interesting about this case were two pieces of information that alerted officials. First, as stated above, the index case had no known risk factors, but she did have oral surgery on October 10, 2001. This started the epidemiological investigation. Secondly, officials had access to a confidential HBV registry kept by the DOH. Cross-referencing the registry with a list of patients treated at the oral surgery center, they found a known HBV chronic carrier who had oral surgery at the center the same morning as the index patient. The chronic carrier was operated on first, and 161 minutes later, the index patient had her procedure performed.Similarities
The same oral surgeon and assistants treated both the source and index patients in the same operative suite. Both patients had uncomplicated extractions of teeth. Three patients had oral surgery between the source patient and the index patient. Of the three assistants, one scrubbed in, one circulated and one held the patient’s head and monitored the anesthesia. All maintained the same duties for all five surgeries. Both the source patient and the index patient received identical intravenous anesthetic (the source patient received two additional medications) from multiple-dose vials. The source patient received oxygen from a reusable rubber nasal mask. The same type of local anesthetic was used. The index patient also received nasal oxygen.Testing
Molecular epidemiologic techniques were used in this investigation. Research of the medical records on the source patient indicated she was an HBV chronic carrier with a high viral load at the time of surgery. DNA sequencing indicated an identical match between the source patient and the index patient. Patients, who were seen that week for oral surgery after the source patient’s procedures, were notified by the oral surgeons to expect contact from the DOH. Patients were tested for HBV, Hepatitis C (HCV), and Human Immunodeficiency Virus (HIV). 25 of 27 patients were tested. 64% of the patients had been vaccinated against HBV. Of the patients who tested positive for Hepatitis B surface antigen, a sign of infection, their blood samples were further tested to determine if there were DNA matches to the source patient. No additional cases were found. All employees involved in direct patient care were tested serologically. Of the 15 employees tested, 14 had received three doses of the Hepatitis B vaccine. None of the employees tested positive for HBV infection. No patients or employees tested positive for HCV or HIV.No “Smoking Gun”
A thorough on-site investigation revealed no apparent breaches in technique. They found a clean and modern facility. Personal protective equipment was changed between patients. Appropriate disposable coverings were used to cover equipment and changed between cases. Surface disinfectants were used appropriately between patient procedures. Rubber nasal masks were cleaned and then disinfected according to manufacturers’ instructions. Particular attention was paid to the way the intravenous medications were handled. Medications were found to be drawn up in a separate medication room using appropriate techniques with a strict one-way flow of needles. No needles were reused. No improper technique was observed. Handpieces were sterilized between use and handpiece motors were covered with disposable plastic barriers. Surgical instruments were manually washed with a soap and bleach solution and then autoclaved. Instruments were removed from surgical packs and placed on trays, covered and placed in clean storage before use.Conclusions
As there was no direct observation of the procedures at the time of transmission, the investigators could only speculate as to what was the cause. During the onsite investigation, observed procedures were not found to be deficient in infection control practices. Hepatitis B is a hardy organism that can survive over a week on surfaces even in the absence of visible blood. As the source patient was found to have a high viral load at the time of her surgery, it is theorized that perhaps an environmental surface was contaminated with her blood and passed onto the index patient due to inadequate cleaning and disinfection. The fact that a majority of the patients and the staff received Hepatitis B vaccinations helped to prevent higher morbidity.Hepatitis
Hepatitis is an Inflammation of the liver caused by bacterial or viral infections, parasitic infestation, alcohol, drugs, chemical exposure, or incompatible blood transfusion. In dentistry, our concern is with viral, bloodborne hepatitis as it can be spread from patient to dental health care worker (DHCW), DHCW to patient, and patient to patient. The greatest risk is from the patient to DHCW. There are several types of viral infectious hepatitis:- Bloodborne
- Hepatitis B (HBV)
- Hepatitis C (HCV)
- Hepatitis D (HDV) delta virus
- Hepatitis F (hepatitis B mutant)
- Hepatitis G
- Enteric (fecal/oral)
- Hepatitis A (HAV)
- Hepatitis E (HEV)
Testing
Defining testing For HBV can be extremely complicated. I would like to simplify it and just address two portions of the HBV panel that I feel are the most important to know:Hepatitis B Surface Antibodies (Anti-HBs)
- A positive result represents Immunity to HBV by either vaccination or recovery from the disease.
- A negative result implies no immunity
- A positive result represents acute or chronic illness with HBV. The person is infectious and can transmit the disease to susceptible persons.
Prevention
Vaccinations: Presently, we only have vaccines available for Hepatitis A and B. Hepatitis B and C are the two most common bloodborne diseases in the dental environment. These diseases can be transmitted by poor infection control practices. Of the two, HBV is much easier to transmit. It produces a high viral load and can cause infection at least 30% of the time when transmitted from a source patient to a susceptible person through bloodborne exposure. There is a 3% chance of Hepatitis C under similar circumstances. The greater risk is then HBV. Vaccination for HBV has reduced healthcare workers’ risk of the disease by over 90%, bringing it below the general population's risk.Standard Precautions According to the CDC: “Standard Precautions combine the major features of Universal Precautions (UP) and Body Substance Isolation (BSI) and are based on the principle that all blood, body fluids, secretions, excretions except sweat, nonintact skin, and mucous membranes may contain transmissible infectious agents. Standard Precautions include a group of infection prevention practices that apply to all patients, regardless of suspected or confirmed infection status, in any healthcare setting. These include hand hygiene; the use of gloves, gowns, masks, eye protection, or face shield, depending on the anticipated exposure; and safe injection practices. Also, equipment or items in the patient environment likely to have been contaminated with infectious body fluids must be handled in a manner to prevent transmission of infectious agents (e.g., wear gloves for direct contact, contain heavily soiled equipment, properly clean and disinfect or sterilize reusable equipment before use on another patient).”
Aseptic Technique is the process of inhibiting the growth and multiplication of microorganisms. To further define aseptic technique, we usually refer to two separate categories, surgical and medical. The surgical aseptic technique refers to the process of rendering and keeping objects and areas free of all microorganisms. The goal is to achieve the elimination of all microorganisms. Medical aseptic technique refers to the practice of reducing the transfer of pathogens from one person to another either directly or indirectly. Medical asepsis, through a clean environment, is the state of being free of pathogenic organisms. Reducing the bioburden to safe levels is also a goal of medical asepsis; in other words, if there are not as many bugs, you lower the chance of infection.
In dentistry, we use a combination of both surgical and medical aseptic is not sterile.” Then the lines fade to gray as to what is necessary to keep the environment safe for our patients. What we need to address is how we decide when to sterilize, when to disinfect, and when to just clean when we are reusing patient care items. The easiest way to do this is to put the patient care items in four categories: critical, semi-critical, non-critical, and environmental. Always, always clean the item first before disinfection or sterilization. c technique. Sometimes, to my dismay, little attention is spent on surgical asepsis as ”the mouth
Critical items are those items that will come in contact with sterile body areas. In dentistry, this means if the procedure is invasive, beyond intact mucous membranes, you must use instruments that are heat sterilized. They must be wrapped and sterilized and the packages not opened until the time of use. An example of this would be an explorer or surgical instrument. In dentistry, all dental instruments capable of heat sterilization come under this category. Semi-critical items are those items that come in contact with intact mucous membranes. An example would be an impression tray. However, in dentistry, many times we are using an impression tray with non-intact mucous membranes so it would be best to sterilize the reusable tray or use a clean single-use disposable tray. Noncritical items contact only unbroken skin or make no contact with the patient. Noncritical items must be kept clean and sanitary. An example would be the dental chair. Environmental surfaces that have no direct contact with the patient must be cleaned and then disinfected if contaminated with bioburden. Examples are countertops.
And Finally... Kay’s Two Cents
I would not venture a guess as to what caused the transmission at the oral surgery center. However, I would like to share some of my thoughts on oral surgery practice. And yes, according to Karen Lewis, M.D., Epidemiologist for the Arizona Department of Health Services, Arizona has a chronic HBV registry. It can be used to identify possible sources of infection in an outbreak of public health importance.Instrument Washing: Surgical instruments should be cleaned either in ultrasonic machines using enzymatic cleaners or in FDA approved dental washers. After the mechanical cleaning, instruments should be examined for any remaining biological debris. It is usually the bone files that may still have material in them along with hinged instruments that have been kept closed. A long-handled brush should be used to remove the remaining debris. No handwashing of instruments should occur before mechanical cleaning. United States Department of Labor Occupational Safety & Health Administration (OSHA) law considers this putting the employee at risk for bloodborne pathogen infection.
Oral Surgery Set-ups: The instruments should remain intact in sterile surgical wrap until the time of use. The pack should be opened at chair side immediately before surgery. Taking instruments out of sterile packs, placing them on trays, and then in storage negates their sterility.
Disposable/Single-Use Items: When possible, single-use disposable items such as nasal hoods should be used for patient care items to avoid disease transmission.
Irrigating Solutions: Irrigating solutions should be drawn up at chair side at the time of surgery. A sterile syringe and a sterile solution unit intended only for the individual patient should be used. Bulk filling of syringes, kept only in clean storage cannot be considered sterile at the time of use.
