US health authorities have urged to shorten the treatment of latent tuberculosis from nine months to three.
People age 12 and over who test positive for TB or have been exposed but show no symptoms are among those who could benefit from the shorter treatment, the US Centers for Disease Control and Prevention said.
A total of 8.8 million people around the world fell ill with the contagious lung disease last year and 1.4 million died, according to the World Health Organization.
Three randomized controlled trials have shown that a new combination regimen that includes isoniazid (INH) and rifapentine (RPT), given weekly under a doctor's supervision, "is as effective for preventing TB as other regimens," the CDC said.
The shorter treatment "is more likely to be completed than the US standard regimen of nine months of INH daily without" a doctor's supervision, it added in its Morbidity and Mortality Weekly Report.
Tuberculosis develops in five to 10 percent of people who get infected by Mycobacterium tuberculosis, usually after a period of six to 18 months when the infection lies dormant, but it can endure decades in some people.
Isoniazid (INH) is the only medication approved by the US Food and Drug Administration for preventive therapy against latent TB.
"However, self-supervised daily INH regimens have completion rates of 60% or less in typical settings, attributable largely to the duration of six or more months," the CDC said.
In cases in which the TB is believed to be a drug-resistant strain, patients are often given daily rifampin (RIF) for four months.
The new, shorter treatment combines a similar antibiotic to RIF, known as rifapentine (RPT), which works as a microbicide against TB and is approved by the FDA for off-label use against TB.
The CDC recommended the shorter combination treatment for people over 12 who have been recently exposed to TB, have tested positive for infection or show evidence of healed pulmonary TB after a radiological scan.
"HIV-infected patients who are otherwise healthy and are not taking antiretroviral medications also are included in this category," it added.
In order to choose which approach is best, patients and doctors should consider whether there is adequate access to a physician for weekly treatments, how easy or hard it is to get the drugs, and personal preference, the CDC said.