CURBING LATENT TB CASES KEY TO SOLVING A RESILIENT DISEASE
WHEN someone with tuberculosis coughs, sneezes, talks, or even sings, they send TB bacteria into the air.
If you happen to be near that person and breathe in these bacteria, one of three things will happen: your body kills off the TB bacteria so they cannot harm you now or in the future; the TB bacteria make you ill—in which case, you now have what is called “active TB”; or the TB bacteria remain asleep in your body, you do not feel sick and do not have any symptoms, and you cannot pass TB on to others.
While most health authorities give priority to curbing cases of active TB, experts now believe there should be one for those who might be harboring these inactive form of TB, otherwise known as “latent TB”.
“As much as 30 percent of the population—that’s 30 million Filipinos—are thought to have latent TB infection. What is more worrisome is that about 5 percent from this group will develop active TB disease within the next two years if they do not receive treatment,” informs Dr. Camilo Roa, founding chair of Philippine Coalition Against Tuberculosis or PhilCAT.
This means 1.5 million Filipinos will be added to the current number of those suffering from active TB.
The disease remains a major cause of death and economic suffering among Filipinos—in 2015 alone, some 14,000 Filipinos died from TB, while 4.8 million, mostly poor, contracted the disease.
Major contributor
Dr. Aamir Khan, an epidemiologist and social entrepreneur based in Karachi, Pakistan, explains that latent TB infection is one of the major contributors to the pool of active TB cases around the world. “In 2016 alone, 10.4 million people around the world fell ill with TB, and 1.7 million died from the disease. Shrinking this reservoir of people who are infected with latent TB is the only way to stop the epidemic.”
During PhilCAT’s annual convention held at Crowne Plaza Hotel in Pasig, Dr. Khan tells his audience that latent TB should be regarded as a major public health problem as those infected have an increased chance of developing active TB disease later in life, especially if they become sick with other diseases that weaken their immune system, for example, contracting HIV or developing chronic kidney disease.
But how will we be able to tell those who may be harboring latent TB?
Higher risk
According to Dr. Regina Ber- ba, PhilCAT national chair and Infection Control Unit chair of the Philippine General Hospital, certain individuals should be tested for infection because they are at higher risk for being infected with TB bacteria.
Among these individuals include those who have spent time with someone who has active TB infection; those who live or work in high-risk settings (for example: correctional facilities, long-term care facilities or nursing homes, and homeless shelters); healthcare workers who look after patients with increased risk for TB infection; as well as infants, children and adolescents who are exposed to adults who may be harboring the active form of TB.
“The good news is that latent TB can be treated. Identifying this group of patients and providing them with preventive therapy may hold the key to curbing TB cases in the Philippines where prevalence rate remained high at 1,159 per 100,000 Filipinos, citing the 2016 National Tuberculosis Prevalence Survey,” shares Berba.
Roa says while screening tests such as interferon gamma release assays (IGRAs) or even the less accurate, yet more affordable tuberculin skin test (TST) may be done to these individuals, PhilCAT believes preventive therapy may already be given without these screening tests considering their exposure risk.
Treatment regimens
“There are four treatment regimens currently available for those with latent TB infection, using drugs that include isoniazid, rifapentine, or rifampin. While all the regimens are effective, we advise our col- leagues to prescribe the more convenient shorter regimens, when possible. This is because patients are more likely to complete the shorter treatment regimens,” says Roa.
Without treatment, developing the active form of TB can be fatal, according to Berba. “Having the active form of the disease could bring complications that include spinal pain (back pain and stiffness are common complications of tuberculosis); joint damage (tuberculous arthritis) that usually affects the hips and knees; swelling of the membranes that cover the brain (meningitis), and possible occurrence of mental changes; liver or kidney problems; and even heart disorders.”
Berba suggests observing household members for these typical symptoms that should alert them of possible active TB infection: coughing that lasts three or more weeks; coughing up blood; chest pain, or pain with breathing or coughing; unintentional weight loss; fatigue; fever; night sweats; chills; and loss of appetite.