From drug-resistant tuberculosis in California to high disease rates in South African gold mines, stubborn challenges threaten health officials’ goals for drastically reducing TB globally within 10 years, several studies show.
Many public health officials worldwide are using a World Health Organization-recommended approach to halve TB prevalence and death rates between 1990 and 2015, according to a report in Wednesday’s Journal of the American Medical Association.
The strategy includes standard drug treatment, a system to ensure regular drug supplies, a standard reporting system, and political commitment to tackling the tuberculosis threat.
But despite falling rates in some developed nations including the United States, TB still affects more than 8 million people worldwide annually — slightly more than in 1991, and kills about 2 million people — most in Asia and Africa, several JAMA reports said.
“Tuberculosis continues its 3,000-year history of decimation,” according to an editorial by JAMA Editor-in-Chief Dr. Catherine DeAngelis and Annette Flanagin, managing deputy editor, who devoted this week’s edition to tuberculosis reports.
As of 2003, the global incidence rate continued to rise by about 1 percent yearly and U.S. cases will never be eradicated unless the disease is eliminated elsewhere, the reports said. Most U.S. cases occur in foreign-born people.
A WHO report in JAMA said reduction of TB incidence could be achieved in most of the world by 2015, but that the challenge will be greatest in Africa and Eastern Europe because of HIV/AIDS and drug resistance.
Other reports include a study showing that despite an overall decline in California TB cases during the past decade, about 1 percent to 2 percent of cases in the state involved TB strains resistant to several mainstay drugs from 1994 to 2003.
Drug-resistance a concern
Multidrug-resistant disease was strongly linked with previous drug treatment for tuberculosis, which could mean previous treatment was inadequate, according to a report by Dr. Reuben Granich of the federal Centers for Disease Control and Prevention and California health officials. That might include taking antibiotics for a shorter period of time than recommended.
Granich now works for the office of the U.S. Global AIDS Coordinator.
Drug-resistant TB is a concern because infected people are difficult to treat, face an increased risk of death, and risk transmitting drug-resistant strains to others.
“Multidrug resistance is a manmade phenomenon” that is largely preventable if cases are treated correctly, according to a JAMA commentary.
A separate report found that a family of TB strains involved in some drug-resistant disease outbreaks in the United States also is prevalent in the Samara region of Russia, including among incarcerated residents. The study said the results are relevant elsewhere, given increasing rates of migration from Russia to the United States and Western Europe.
Overcrowded living conditions with poor ventilation contribute to disease risk, and high HIV rates make South African gold miners particularly vulnerable.
Researchers examined TB rates among HIV-infected miners who visited a South African health clinic, where WHO-recommended preventive treatment with the mainstay drug isoniazid was implemented.
TB incidence among clinic patients, including those who didn’t receive the drug, declined 38 percent during an average of almost two years of follow-up, but overall prevalence “remained unacceptably high” at 9 percent per year, said lead author Dr. Alison Grant of the London School of Hygiene and Tropical Medicine.
