Tuberculosis (TB) is a infectuous disease that spreads the air and air. Symptoms can be minor in the early course of the disease. The symptoms include cough (lasting for more than two weeks), fever, loss of appetite, body-weight loss, fatigue, night sweats, chest pain, etc. People who live together or have close contact with confirmed TB cases are the most vulnerable to TB infection.

What is latent TB infection (LTBI)?

• If an immunocompetent person is infected with TB, they may be asymptomatic. This status is called LTBI. Those who have close contact with TB infected cases are at high risk of TB infection. There is an approximately 5~10% chance of LTBI developing to an active disease, and the highest incidence of onset is within a year of infection.
• Patients with LTBI are usually asymptomatic with negative chest X-ray findings, and are  unable to transmit TB pathogens to others. However, asymptomatic patients with TB infection could become an active disease at any time, and the period from infection to onset is known as LTBI .
• The number of TB bacteria is low in a  LTBI patient. If the LTBI is treated, the chance of developing to active TB in the future would be effectively minimized.

Population susceptible to TB when body resistance is poor

• Family of TB infected case, persons with poor immune status, older people, diabetics, silicosis patient, long-term steroid users, alcoholics, immunocompromised and AIDS patients.

Who needs to be tested for LTBI?

• People in contact with cases of highly infectious TB need to be tested for LTBI. The health department will determine whether they are highly infectious based on their clinical and testing status, and check the LTBI exam items on the "TB contact referral form" to refer the contacts to a designated hospital for examination.

What are the exam methods?

• Chest X-ray examination.
• Diagnostic tools for latent TB:

1. Tuberculin skin test (for people children younger than 2 years old or for people children between 2 to 5 years old but can’t do blood test)
2. Interferon-gamma release assay (for people older than 2 years old )

The doctor will choose one of the following treatments according to your condition

* In cases undergoing treatment with the 9H prescription, if taking the medication proves stable without any adverse effects, the general principle is to continue the medication until the completion of the treatment. However, if there is a desire to shorten the course to the 6H prescription, please respect the assessment of the treating physician and proceed with the transition after thorough communication with the patient.

The caregiver should personally deliver the medicine and confirm the patient is taking the medicine correctly in order to achieve the greatest reduction in the incidence of active disease.

How to live with LTBI patients

• Help monitor the LTBI for common symptoms: loss of appetite, skin rash, jaundice …etc.
• Relatives and friends should support and care about them, accept them, help them recover soon, and remind them to take medicine on time and return to the hospital for follow up.
• Daily life as usual, no need for special diet nor getting more rest.
• Develop healthy lifestyle habits, maintain better immunity, and reduce the possibility of TB bacteria re-activation leading to active disease.