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People with HIV who have latent TB infection or TB disease can be treated effectively. The difficulty is that HIV — above all untreated HIV — makes TB both more likely to progress and harder to detect, and that many HIV drugs interact with TB drugs. This guide follows CDC's advice for U.S. health care providers, step by step.
Why HIV changes the risk
A weakened immune system may not be able to stop TB bacteria from multiplying and spreading. HIV, especially with a low CD4 count, is therefore an important risk factor for TB infection turning into TB disease.
| Person with TB infection | Risk of developing TB disease |
|---|---|
| Without HIV or other TB risk factors | 10% over a lifetime |
| With HIV, not on antiretroviral therapy | 7% to 10% each year |
TB outside the lungs (extrapulmonary TB) is also more common in people with HIV, and some patients with it have TB in the lungs at the same time.
Step 1: test for TB infection
Evaluate people with HIV for TB infection, particularly after they have been exposed to someone with TB disease. Two kinds of test are used:
- a TB blood test — interferon gamma release assay (IGRA); how its result is read depends on which test is used;
- the TB skin test (Mantoux tuberculin skin test), read by the size of the induration together with the person's risk factors. For people with HIV, an induration of 5 mm or more counts as positive.
Read either result with the patient's TB risk factors and your clinical judgment in mind.
| Result | What it means | Next |
|---|---|---|
| Positive | usually TB infection | rule out TB disease: physical examination, chest radiograph, and sometimes sputum or other tests |
| Negative | TB infection is unlikely — but not excluded, especially if the patient is immunocompromised or has signs or symptoms of TB disease | see anergy, below |
Anergy: when a negative test can't be trusted
Anergy is the failure to react to a TB blood or skin test because the immune system is weakened, and untreated HIV is an important cause of it. The result can be a false negative. A provider may then order a second blood or skin test, or diagnose latent TB infection or TB disease from other evaluations or from the epidemiology.
For example, if a person with HIV has had prolonged, frequent exposure to someone with TB disease, the provider may consider treating for latent TB infection whatever the test results.
What the chest radiograph may show
| CD4 count | Typical picture of pulmonary TB |
|---|---|
| Above 200 cells/mm³ | generally like TB in people without HIV: upper-lobe infiltrates, with or without cavitation |
| Below 200 cells/mm³ (advanced HIV) | may be atypical: lower-lobe infiltrates, hilar adenopathy — or a radiograph with no lesions at all |
More: Clinical Testing and Diagnosis for Tuberculosis.
Step 2: choose a regimen
Base the choice on drug susceptibility results, the patient's other medical conditions, and the potential for drug–drug interactions. Those interactions matter a great deal here: many antiretroviral drugs interact in clinically significant ways with the drugs recommended for latent TB infection, rifampin and rifapentine in particular.
Latent TB infection
| Regimen | For |
|---|---|
| Isoniazid (H) daily, 6 to 9 months | adults and children of all ages with HIV |
| 3HP — isoniazid plus rifapentine, once a week for 3 months | adults and children aged 2 and older with HIV, as drug interactions allow |
| 3HR — isoniazid plus rifampin, daily for 3 months | adults and children of all ages with HIV, as drug interactions allow |
Guideline: Guidelines for the Treatment of Latent Tuberculosis Infection: Recommendations from the National Tuberculosis Controllers Association and CDC, 2020, MMWR Recommendations and Reports volume 69, number 1, pages 1–11.
Drug-susceptible TB disease (adults with HIV)
The 6- to 9-month regimen (details):
- intensive phase, the first 2 months: isoniazid, a rifamycin, pyrazinamide and ethambutol;
- continuation phase, the last 4 to 7 months: isoniazid and a rifamycin.
Six months is the minimum for adults with HIV, even when the TB disease is culture-negative. Extend to 9 months (a 7-month continuation phase):
- in the uncommon case that the patient does not take antiretroviral therapy during TB treatment — although HIV treatment is itself a critical predictor of TB treatment success;
- to be considered when the response is slow — for example, cultures still positive after 2 months of treatment.
The 4-month rifapentine–moxifloxacin regimen (details): an 8-week intensive phase and a 9-week continuation phase, 17 weeks in all. It is an option for people with HIV whose CD4 count is at least 100 cells/µL, provided there is no other known interaction between their TB and antiretroviral drugs.
Guidelines: Updates on the Treatment of Drug-Susceptible and Drug-Resistant Tuberculosis (ATS/CDC/ERS/IDSA); Treatment of Drug-Susceptible Tuberculosis (ATS/CDC/IDSA).
Drug-resistant TB disease
Treatment decisions for drug-resistant TB in a patient with HIV may be much the same as for a patient without HIV, but it can help to consult experts in managing both diseases for the HIV-related complications. Guidelines: Updates on the Treatment of Drug-Susceptible and Drug-Resistant Tuberculosis; Treatment of Drug-Resistant Tuberculosis (ATS/CDC/ERS/IDSA).
Step 3: time antiretroviral therapy
For a patient with HIV who is not yet on ART, HIV treatment is critical to TB treatment succeeding.
| CD4 count | Start ART |
|---|---|
| Below 50/mm³ | ideally within the first 2 weeks of TB treatment |
| 50/mm³ or above | by 8–12 weeks after TB treatment starts |
| TB meningitis, any count | not in the first 8 weeks of TB treatment — consult a TB and HIV expert |
See "Special Considerations Regarding ART Initiation" in the Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents With HIV.
Step 4: support adherence
Use directly observed therapy (DOT) or other adherence strategies for every patient with HIV-related TB disease. CDC recommends video DOT as an equivalent alternative to DOT in person.
Where to get help
- State TB programs and the TB Centers of Excellence for Training, Education, and Medical Consultation advise providers caring for people with HIV and TB — including on interactions between specific anti-mycobacterial and antiretroviral drugs.
- HIV.gov guidelines:
- CDC: TB clinical guidelines; for patients, TB Risk and People with HIV.
Sources
Based on "Clinical Care for People with TB and HIV," Centers for Disease Control and Prevention; a work of the United States government in the public domain. A stock photograph is left out.
Licenza: CC0 1.0 (pubblico dominio) · Tratto da www.cdc.gov
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