The Truth About TB

Q. What is tuberculosis (TB) and why is it a concern in the dental office?

A. TB is a bacterial infection caused by mycobacterium tuberculosis; it is endemic in certain areas of the world. Because dental professionals never fully know the complete health history of their patients, they need to be aware of any transmissible diseases that they are likely to encounter in their practice.

In dentistry, practitioners are exposed to a variety of diseases through a myriad of mechanisms. Dental offices have the appropriate infection controls for most but not all diseases. With TB, the level of protection in the dental office is not enough to prevent transmission. Thus, dental professionals must be able to assess patients’ potential for TB infection, especially if the community served is at risk for TB exposure.

Q. How is TB spread?

A. TB is transmitted through coughing, singing, sneezing, and speaking. Any activity that causes bacteria to be dispelled into the air where it lingers for a certain amount of time can spread TB.

Q. What are the specific concerns in dentistry regarding the way TB is transmitted?

A The standard surgical masks that dental professionals use do not filter out TB particles so they’re not protective enough during aerosol-producing procedures to prevent the spread of TB. Dental offices are not usually equipped with the necessary airborne and environmental infection control procedures that prevent transmission. These are more likely found in hospitals or public health care settings.

Q. If a patient visits a dental office and TB infection is suspected, should the patient be advised against treatment or should other infection control protocols be used?

A. If a patient is suspected of having TB, the patient should be isolated from other individuals. The patient should wear a mask, which will help to some degree. The cough etiquette that is employed each year during flu season should be used (Table 1). Then confirmation of a TB infection should be ascertained as well as whether the person is infectious.

If the dental professional cannot get confirmation that the infection is indeed TB, then the patient should be referred to his/her primary health care provider. Dental professionals are allowed to defer elective treatment of an individual with suspected or confirmed TB until the suspicion is removed and the patient does not have TB, or, if he/she does have TB, until the patient is cleared for treatment by a physician, which is generally after three negative sputum tests.

This is not the case if emergency dental treatment is needed. Dental professionals are obligated to provide, to the best of their ability, relief of pain or infection without exposing staff or other patients to an organism. One way to address this obligation is to find another facility that has the appropriate ventilation and respirators necessary for airborne infection control and the other procedures needed to safely treat a person with active TB.

The decision on how to treat an emergency in a patient with TB rests on clinical judgment. If another facility is not available, the dental professional should provide the best treatment possible without performing procedures that will create aerosols or small airborne particles that could be dispersed in the room. Dental professionals should make these decisions in consultation with either the primary health care provider, infectious disease specialist, or state health department/infectious disease epidemiologist.

Q. What if the patient doesn’t have a primary care provider?

A. With consent of the patient, the local health department should be asked for a referral for the patient. Certain hospitals in an area may have a special TB clinic.

IN THE NEWS

Q. The recent case of Andrew Speaker who flew to Greece for his wedding with a case of drug-resistant TB created concern among many. How infectious is TB and why does the incidence of TB appear to be on the rise?

A. TB is actually not on the rise. In 2006, 13,760 cases where reported, which is about 4.6 per 100,000.¹ According to the Centers for Disease Control and Prevention (CDC), this is the lowest reporting since 1953. Between 1993 and 2000, the number of TB cases decreased by 7.3%.¹ In 2000, it dropped to 3.8% per year. And in 2006, it was 3.2% per year.¹ The highest rate of TB is in foreign-born individuals.

The media reports of drug-resistant TB cases, like Andrew Speaker, create a public fear surrounding TB. When examining the multidrug-resistant TB cases, the last date of reporting was 2005, when the CDC noted 124 cases, which was only 1.2% of the total number of TB cases reported.¹

Q. The fact that the general public has to depend on the goodwill of someone to follow the advice of physicians and take the necessary precautions to prevent transmission may heighten people’s fears.

A. According to media reports, Andrew Speaker was advised against traveling by airplane but he was not mandated or regulated not to travel. For those who are not learned in infectious disease, a recommendation not to travel without a strict mandate against traveling because it may put others at risk creates a blurry line.

Q. Plus, no one on the flights he took has come down with a case of TB.

A. Correct. So should Speaker have traveled? Probably not. Should it have been much more clear to him that he shouldn’t travel due to the risk to others? Yes, I believe there was a failure to communicate.

LEVEL OF RISK

Q. How infectious is TB?

A. Infection doesn’t always result in disease. You can be exposed, infected, and not demonstrate disease. According to the CDC, 90% of those who become infected with TB remain infected without any clinical signs or symptoms of disease.^2,3 Then 5% of those infected actually experience the disease, 85% of which turns out to be the pulmonary disease.⁴ So a number of factors exist that determine how infectious someone is, including proximity to the individual, the health of the person’s immune system, and the ability of the body to fight off infection. People living in close-proximity to a TB-infected person are at the highest risk of infection.

Dental professionals may be at a higher risk due to the fact that aerosols are generated from many dental procedures. However, if they’ve done the appropriate screening of an individual, followed both 1994 and 2005 CDC guidelines for preventing transmission of TB in health care settings, and they have the identification and administrative controls in place, the infected individual should not get to the point where he or she is in the chair.

Q. How does a dental professional recognize a person who might be infected with TB?

A. Through understanding how TB is transmitted and recognizing the symptoms. The main symptoms are coughing, chest pain, night sweats, feeling sick, general weakness, weight loss, and fever. These symptoms can be confused with other illnesses, however with TB, the cough doesn’t go away, the cough may contain blood, and the risk is increased if the person reports having been exposed to TB or comes from or visited an area where TB is endemic.

Q. What are the areas that are endemic?

A. Africa and Asia have the highest rates of infection with parts of South and Central America also having elevated rates.¹ Patients should not be stigmatized because of their country of origin. However, this information should be part of a community profile so that the risk for TB exposure can be assessed. TB risk assessment sheets are available in the 2005 CDC guidelines, which briefly state that the generation of droplet nuclei resulting from dental procedures has not been demonstrated to transmit TB. However, the CDC also notes that dental procedures can stimulate coughing and disperse infectious particles. Because dental professionals are sharing the same airspace with patients, this puts them at risk. Thus, the CDC recommends that dental practices be aware of risk assessment, have an appropriate medical history and update, and be aware of the signs and symptoms of disease.

If an office decides to treat an individual with TB, the CDC recommends that the office maintain the appropriate respiratory protection, which is not the standard mask, and then to observe strict respiratory hygiene, cough etiquette, and have the patient wear a mask, defer elective treatment, and make an appropriate referral. The guidelines also include a TB risk assessment worksheet in the appendix for facilities to review.

Every dental practice should assess its risk of TB exposure. The first protocol is to have established procedures. All employees should be tested for TB exposure upon hiring and at subsequent dates if indicated. Training on TB infection control procedures is also an important step. Engineering controls should be determined. Most dental offices do not have the proper ventilation, negative air pressure, HEPA filtration, and ultraviolet light. The final tool is personal protective equipment, which includes personal respiratory protective devices, the National Institute for Occupational Safety and Health (NIOSH) N95 respirator. These require a personal fit and they’re expensive items, so they are not a standard protocol in the dental office. Without all of these tools, identifying, referring, and deferring treatment are the most appropriate steps for most practices.

Q. What tests are available to screen for TB?

A. The Mantoux skin test and the TST two-step test are most widely used, with the CDC recommending the Mantoux test. It involves the injection of a a small amount of PPD (purified protein derivative) tuberculin within the skin of the inside forearm. The site is then checked within 48 to 72 hours for a local reaction to the injected material.

Dental offices are considered very low-risk facilities so they don’t have to meet the same standards as other settings in terms of their TB infection control program. But dental offices do have to train staff to understand the signs and symptoms of TB, understand how to refer a patient, and have had at least a baseline screening for TB and follow-up if necessary.

All dental/health care workers need to make sure they’re getting their appropriate Occupational Safety and Health Administration (OSHA) and infection control training and update.

REFERENCES

1. Tuberculosis. Yellow Book/CDC Traveler’s Health. Available at: www.cdc.gov/travel/yellowBookCh4-TB.aspx. Accessed August 9, 2007.
2. Questions and Answers About TB 2007. Available at: www.cdc.gov/tb/faqs/default.htm. Accessed August 15, 2007.
3. TB Guidelines. Available at: www.cdc.gov/tb/pubs/mmwr/Maj_guide/infectioncontrol.htm. Accessed August 15, 2007
4. Controlling Tuberculosis in the United States. Available at: www.cdc.gov/mmwr/preview/mmwrhtml/rr5412a1.htm. Accessed August 15, 2007.

From Dimensions of Dental Hygiene. September 2007;5(9): 12-14.