Latent TB Infection

Abstract

1 1) What is latent TB? Latent tuberculosis infection (LTBI) is a state of persistent immune response to stimulation by Mycobacterium tuberculosis antigens without evidence of clinically manifested active TB. Someone has latent TB if they are infected with the TB bacteria but do not have signs of active TB disease and do not feel ill. However, they can develop active TB disease in the future. 2) Why should I take pills to treat latent TB when I do not feel ill? You have been asked to take treatment for latent TB because your health-care worker or clinician believes you have an increased chance of developing active TB disease from the infection. Effective drugs are available for the treatment of latent TB and taking a complete course of treatment can prevent the infection from becoming active disease. 3) Do I need to take TB preventive treatment if I am living with HIV and receiving ART, and have a high CD4 cell count? All adults and adolescents living with HIV should take TB preventive treatment as part of a comprehensive package of care for HIV, regardless of their CD4 cell count. Although regular ART reduces the overall risk of developing TB among PLHIV, the risk remains very high compared to HIV-negative people. Combined use of TB preventive treatment and ART significantly reduces the risk of TB. 4) Should I receive TB preventive treatment if a person in my family has multidrug-resistant TB? Please consult your health-care worker or clinician. The health-care worker or clinician will make the decision to provide preventive treatment in selected household contacts of patients with multidrug-resistant tuberculosis, if they are regarded as high-risk for developing drug-resistant TB. 5) What should I do if I develop drug-related adverse events? If you are receiving treatment for latent TB, and become aware of symptoms such as anorexia, nausea, vomiting, abdominal discomfort, persistent fatigue or weakness, dark-coloured urine, pale stools or jaundice you should immediately contact your health care provider. If a health care provider cannot be consulted at the onset of such symptoms, you should stop treatment immediately and continue to seek help from your health care provider. 6) Who should receive testing and treatment for latent TB? Adults, adolescents, children and infants living with HIV, infants and children < 5 years who are contacts of TB patients, and HIV-negative clinical risk groups, such as patients initiating anti-TNF treatment, receiving dialysis, preparing for organ or haematological transplantation have the highest likelihood of developing active TB disease and should be prioritized for systemati c testing and treatment of LTBI, regardless of setting or the background TB epidemiology. Additional groups for LTBI testing and treatment are: HIV-negative children >5 years, adolescents and adults who are contacts of patients with pulmonary TB and contacts of patients with multidrug-resistant TB. Systematic testing and treatment of LTBI may be considered for HIV-negative prisoners, health-workers, immigrants from high TB burden countries, homeless persons and people who use illicit drugs, if living in low TB burden settings. 7) Should pregnant women living with HIV take TB preventive treatment? Pregnant women living with HIV are at risk for TB, which can have severe consequences for both the mother and their unborn child. Pregnancy should not disqualify them from receiving preventive treatment. Sound clinical judgement is required to determine the best time to provide treatment. 8) How can we rule-out active TB in PLHIV prior to TB preventive therapy? Adults and adolescents living with HIV should be screened for TB according to a clinical algorithm and those who report any of the symptoms of current cough, fever, weight loss or night sweats may have active TB and