What is TB(Tuberculosis)? Bacterial infection that can spread through the lymph nodes and bloodstream to any organ in your body. TB is caused by bacteria Mycobacterium tuberculosis. Tuberculosis is curable and preventable. Tuberculosis is spread from person to person through the air.
Working and traveling abroad often? Especially to regions struck by the Tuberculosis epidemic where the disease has high incidence and prevalence? Several things are important for you to know and act upon to ensure your health and ensuring the possibility that you do not develop the disease.
The Tuberculosis causing bacteria currently resides in a latent form in one third of the world’s occupants as estimated by the leading scientific experts. The only reason a person does not develop the disease is that he or she has enough immunity to break the life cycle of the bacterium.
Traveling to high incidence areas, usually the developing and third world countries can not only lower your immunity but also increase your chances of developing the disease by frequent encounter with diseased individuals.
Another grave complication is the increasing rates of antibiotic resistance of the Mycobacterium Tuberculosis which can limit treatment options as the only current therapy used to treat the disease heavily relies on antibiotics.
Special attention, however, should be given to healthcare workers traveling to such countries, where they work in hospitals and conditions packed with undiagnosed and diagnosed cases of the disease. Key moments of special interventions involve the time when you are preparing to leave for a country with high number of cases, the time when you are working in the field, and the time of your return.
A study has previously reported that there is a 10-15 percent increased risk of developing active tuberculosis infection in people working in health setup than in general population.
Before you move to a different place for work, either if you are in the health sector or otherwise, the first thing to do is; check the country’s TB profile. The highest number of cases and their prevalence has currently been reported in Southern Asia, South Africa and China. Countries like Angola, Gabon, Botswana, Central African Republic, Congo, Indonesia, Bangladesh, Lesotho, Djibouti and Namibia have high incidence of TB cases. Lists and profiles of such countries can be accessed at gov.uk and who.int at any time.
Give special attention to the country’s antibiotic resistant disease profile. As such infections are harder to treat and are associated with higher disease and death rates it will able you to access risk more accurately.
On medical front it is a good idea to get tested for both TB and HIV, as the two frequently occur together. This helps you to set a reference point or baseline if you need to get tested on return. Tests like tuberculin skin test, interferon gamma release assays, and chest radiographs are often performed to determine your health profile. Laboratory blood tests can be performed to check if you have any latent infection of the Tb bacterium.
If a person is not HIV positive, has a normal and active immune system, has not received BCG immunization, and has no other life threatening and possibly interfering health conditions, it is recommended by the United Kingdom guidelines to give such a health worker the vaccine.
The policy does not take into account the age of the individual receiving the vaccine even though little benefit has been shown if given to people above 35. People under the age of 16 are preferred to be given the vaccine if they are traveling overseas for more than three months and to an area with high TB risk.
United States on the other hand does not routinely advice the administration of the vaccine. Repeated vaccination is also not advised.
BCG vaccine is not given to any individual who:
- Has already been given the vaccine
- Has a past history of TB
- Has a positive Tuberculin skin test
- Has had a previous anaphylactic or allergic reaction to any of the substances in the vaccine
- Newborn babies even in a high risk environment
- Has septic skin condition at the area of administration
- Has received another live vaccination three weeks earlier
- Has weakened immune system due to chemotherapy, steroid tablets or HIV
- Has cancer of the white blood cells, bone marrow, or lymph nodes like lymphoma or leukemia
- Has a severe illness
- Is pregnant
The results of the tests and the proof of any vaccination should be kept which you may need before you return to work in your native low TB prevalent country.
Another helpful measure is to purchase or request the supply of N95 and FFP2 masks which especially fit to you according to size. The assurance that they have those in the country of your visit is never one hundred percent and as the saying goes it is far better to be safe than sorry.
Health workers are advised to take special precautions to lower the risk of disease once they reach the intended country. The first step is to take and enact prevention measures like maximizing ventilation. As the countries with high prevalence rates are often low on resources to ensure world class devices to do such a job, the little steps like opening windows and doors can improve ventilation and decrease the risk of transmission.
People working with sputum collection, bronchoscopy, autopsy, and intubation should keep their guard. In cases of laryngeal and unsuspected pulmonary tuberculosis cases in high risk people preventive measure like use of gloves, masks and respirators should be ensured.
Patients should be taught to dispose of their sputum correctly and also cough hygienically. Where needed and possible they should be given masks which are to be worn at all times.
People should be counseled if they perceive the masks as a stigmatizing factor for the patients. Due to limited supply a health care personnel can buy their own masks or ask the hospital to arrange it for them if possible.
Filter masks and powered air purifying respirators usually reduce the risk by 17.5 and 238 fold respectively. A cartridge respirator can reduce the risk by 45.5 fold. The mask needs to be fitted for each person and can is usually only used for a few hours or till it gets wet.
Current guidelines in UK recommend the use of face masks if there is a suspicion of drug resistant strain however Centers for Disease Control and Prevention (CDC) in US recommends the using the N95masks anytime you come in contact with a tuberculosis patient.
Other efforts to ensure safety can include decreasing the admission of patients with tuberculosis in the hospitals if it can be avoided, reducing the time they spend in the hospital, and increasing the speed and process of testing and diagnosing cases where tuberculosis is suspected.
DO I Have TB?
The first thing to understand about Tuberculosis is that if the bacterium causing the disease does enter your blood, the best response your body can have is to kill it by innate immune response and help avoid a latent infection.
The second condition if the bacterium is not killed can be that your body arrests its life cycle but you carry a latent infection with risk of it becoming an active disease at any time. Third condition can be that the latent cycle is short lived and you develop the disease as quickly as you catch the microorganism.
If you work in a high risk setting and have any symptoms associated with the TB disease like chest pain, night sweats, fever, persistent coughing, sputum, unexplained weight loss, diarrhea, or enlarged lymph nodes you should get tested immediately.
Risk factors can include HIV infection, repeated exposure to the TB germs, cigarette smoking, close quarters, diabetes, and age less than sixteen years, malnourishment, or any condition which has compromised your immune system.
Infection without the symptoms (latent infection) is usually diagnosed with a skin test known as TuberculinSkintest after six to ten weeks of suspected exposure.
If the test comes back positive an interferon gamma release assays (the QuantiFERON-TB Gold and T-SPOT-TB) can be used to confirm the findings, which if positive signal a need for tests like chest radiograph, computed tomography, and sputum culture. If the infection is confirmed the diagnosis is made for tuberculosis. If the latter tests come back negative diagnosis of a latent infection is made.
If the skin test comes back negative a TST test is performed which if negative is usually followed by a BCG vaccine. Repeat screening is ensured for every 3 to 12 months depending on exposure. History of BCG vaccine and exposure to bacterium before the tests are performed can lead to false positives. False positives can also result in patients with weakened immune system and in people with advance HIV infection.
People with HIV are not given BCG vaccine even if they work in high risk conditions. In people without HIV when diagnosed they are treated with isoniazid and rifampin. Management of drug resistant strains is unclear but managed through a TB specialist, though use of second line TB drugs is discouraged.
Currently, when a health worker is diagnosed with the multidrug resistant TB after an exposure they are briefed regarding signs and symptoms of active disease with serial chest radiographs following the act for continuous two years.
Get Set Again!
When returning to work in the country with low disease incidence and prevalence the first step is to again, yes you guessed it right; get tested. United Kingdom advises those returning to work after visiting high incidence areas (>40 cases/100000 population) for more than 3 months, to not start working till they are cleared and reviewed by occupational health.
You should produce the results of the test you had before you went overseas and proof of vaccination if you received any. BCG status can be verified with both the unique scar and the written paperwork. If diseased you should receive treatment and get disease free before returning to a health care setting.
In United States it is mandatory to perform yearly TB tests for health workers irrespective of their traveling work plans. The 1994 CDC guidelines recommend the TB testing to be performed once annually for all healthcare settings. However, the testing can be not performed so regularly if you work in a low risk setting once you return.
In a reply to a letter to an infection control coordinator,the Directorate of Enforcement Programs (DEP) for the Occupational Safety and Health Administration’s (OSHA), on TB testing guidelines for health workers explained that “employers are recommended to make determinations of risk categories only after performing a thorough workplace hazard assessment for TB”.
The Parting Note!
The risk is real when you travel to perform your duties or volunteer in such high risk setting. You should dot all your I’s and cross your t’s. Read up on the disease and especially the place you will be working in. Consider the risks when taking a position and do all the tests before your departure; the screening and diagnostic tests if needed.
The best way to ensure safety is to take your own gear of protective N95 masks or enquire if you will be issued one once you reach your destination. Remember to get it fitted.
Encourage and counsel patients to use masks and adopt safe practices. When working for more than a year in such a country, you should get regular six months testing done. If positive consider treatment and follow through your regimen religiously.
Get tested before you return to work at your usual place to ensure your own safety and other person’s who you would be helping along the line.