What is the recommended screening and treatment approach for tuberculosis (TB) in individuals with Human Immunodeficiency Virus (HIV) infection?

From the Guidelines

Individuals with HIV should undergo regular TB screening using a combination of symptom assessment, tuberculin skin test (TST) or interferon-gamma release assay (IGRA), and chest radiography, as recommended by the HIV Medicine Association of the Infectious Diseases Society of America 1. The goal of this approach is to identify and treat latent TB infection (LTBI) or active TB disease early, reducing the risk of morbidity and mortality associated with TB in HIV-infected individuals. Key considerations in TB screening and treatment for HIV-positive individuals include:

• Using TST or IGRA to test for M. tuberculosis infection, with treatment for LTBI if test results are positive and active TB has been excluded 1
• Repeat testing in patients with advanced HIV disease who initially had negative TST or IGRA results but subsequently experienced an increase in CD4 cell count to >200 cells/µL on antiretroviral therapy (ART) 1
• Treating HIV-infected patients who are close contacts of persons with infectious TB for LTBI, regardless of TST or IGRA results, age, or prior courses of TB treatment, after active TB has been excluded 1 For latent TB infection in HIV-positive individuals, treatment options include:
• Isoniazid 300mg daily for 6-9 months
• A shorter regimen of isoniazid 900mg plus rifapentine 900mg weekly for 12 weeks For active TB disease, the standard treatment consists of a 2-month intensive phase with isoniazid, rifampin, pyrazinamide, and ethambutol, followed by a 4-month continuation phase with isoniazid and rifampin 1. It is essential to initiate ART within 2 weeks of TB treatment for patients with CD4 counts <50 cells/mm³, or within 8 weeks for those with higher CD4 counts, and to carefully manage drug interactions between rifamycins and certain antiretrovirals 1. Regular monitoring for drug toxicity, treatment response, and immune reconstitution inflammatory syndrome (IRIS) is crucial to ensure the best possible outcomes for HIV-infected individuals with TB.

From the FDA Drug Label

Isoniazid is recommended as preventive therapy for the following groups, regardless of age. (Note: the criterion for a positive reaction to a skin test (in millimeters of induration) for each group is given in parenthesis): 1 Persons with human immunodeficiency virus (HIV) infection (≥ 5 mm) and persons with risk factors for HIV infection whose HIV infection status is unknown but who are suspected of having HIV infection. Candidates for preventive therapy who have HIV infection should have a minimum of 12 months of therapy.

The recommended screening and treatment approach for tuberculosis (TB) in individuals with Human Immunodeficiency Virus (HIV) infection is:

• Screening: A tuberculin skin test (TST) with a positive reaction of ≥ 5 mm is recommended for individuals with HIV infection.
• Treatment: A minimum of 12 months of isoniazid preventive therapy is recommended for individuals with HIV infection who have a positive TST reaction.
• Key considerations:
  • The risk of hepatitis must be weighed against the risk of tuberculosis in positive tuberculin reactors over the age of 35.
  • Preventive therapy may be considered for HIV-infected persons who are tuberculin-negative but belong to groups in which the prevalence of tuberculosis infection is high.
  • Candidates for preventive therapy who have fibrotic pulmonary lesions consistent with healed tuberculosis or who have pulmonary silicosis should have 12 months of isoniazid or 4 months of isoniazid and rifampin, concomitantly 2.

From the Research

Screening for Tuberculosis in HIV-Infected Individuals

• The recommended approach for screening tuberculosis (TB) in individuals with Human Immunodeficiency Virus (HIV) infection involves the use of tuberculin skin test (TST) and interferon-gamma release assay (IGRA) 3, 4, 5, 6.
• Latent Tuberculosis Infection (LTBI) screening is crucial for individuals with a known risk factor for progression to active disease, especially in the setting of HIV infection, to ensure early diagnosis and prompt treatment 3.
• Studies have shown that the prevalence of LTBI among HIV-infected patients is quite high, highlighting the need for encouraging screening of at-risk individuals to prevent morbidity and mortality associated with TB in this population 3.

Comparison of TST and IGRA

• Research has compared the effectiveness of TST and IGRA in diagnosing LTBI among HIV-infected individuals, with some studies finding that IGRA may be more sensitive than TST, especially in individuals with low CD4 cell counts 4, 5, 6.
• However, other studies have found that the agreement between TST and IGRA is poor, and that combining both tests may improve the sensitivity of LTBI diagnosis in HIV-infected individuals 3, 4, 5.
• A systematic review and meta-analysis found that IGRAs perform similarly to the TST at identifying HIV-infected individuals with latent tuberculosis infection, but that both tests have modest predictive value and suboptimal sensitivity 6.

Treatment Approach

• A study compared a 2-month regimen of daily rifampin and pyrazinamide with a 12-month regimen of daily isoniazid in preventing TB in HIV-infected persons, and found that the shorter regimen was similar in safety and efficacy to the longer regimen 7.
• The study suggested that the 2-month regimen offers practical advantages to both patients and TB control programs, and that it may be a viable alternative to the traditional 12-month isoniazid regimen 7.