Length of Time Needed To Cure TB Might Be Related to Amount of Bacteria in Body, Study Finds
The reason it takes several months to cure tuberculosis might be because people with high concentrations of active TB have large amounts of bacteria that remain dormant in their bodies, the co-author of a study published on Tuesday in PLoS Medicine said recently, United Press International reports (Susman, United Press International, 3/20). Scientists have long believed that the ability of Mycobacterium tuberculosis to remain dormant was unique to the TB bacteria and was the reason that the disease requires several months to treat. However, the study indicates that the dormant state occurs with other bacterial infections and that it is the number of dormant bacteria, not TB-specific pathology, that is linked to total bacterial burden (ANI/DailyIndia.com, 3/20). "There are many bacteria that take a longer time to kill off in a human than in culture," Lalita Ramakrishnan -- associate professor of microbiology and infections diseases at the University of Washington-Seattle and co-author of the study -- said. In addition, almost all types of antibiotics work against only replicating bacteria, so the dormant state of TB makes it resistant to some current antibiotics, according the study. Ramakrishnan said there is a need for drugs that attack bacteria such as TB in their dormant stage to improve treatment. She also said that researchers need to "look upon TB as similar to other infections that are similarly difficult to eradicate." According to Len Horovitz, a pulmonary specialist at Lenox Hill Hospital in New York City, the ability of the TB bacteria to remain viable in the body is "why reactivation of tuberculosis is still possible after a long course of therapy." He added, "While the likelihood of this reactivation is less than 1%, that possibility still exists" (United Press International, 3/20).
The study is available online.