A highly drug-resistant form of tuberculosis (TB) has been linked to HIV/AIDS in a study conducted in rural South Africa by researchers at Yale School of Medicine.
Published in the October 26 issue of The Lancet, the study is the result of a five-year collaboration between a Yale and South African team of researchers who aim to integrate HIV and TB care and treatment.
TB is the most common cause of death and illness in those with HIV infection in sub-Saharan Africa. HIV greatly increases the risk of active TB disease and about 80 percent of patients with active TB in the province of KwaZulu Natal, South Africa, are co-infected with HIV. Death rates of up to 40 percent per year have been reported in patients with both HIV and TB.
Led by senior author Gerald Friedland, M.D., director of the AIDS Program at Yale and Professor in the Departments of Medicine and Epidemiology and Public Health, the study measured the prevalence of multi-drug resistant (MDR) tuberculosis and extensively drug-resistant (XDR) tuberculosis in a hospital in KwaZulu Natal. Between January 2005 and March 2006, sputum samples from 1,539 patients were screened. MDR TB was found in 221 patients and of those, 53 had XDR TB. Those patients with XDR who were tested for HIV were found to be co-infected. All but one of the 53 patients with both XDR TB and HIV died, with an average survival of 16 days.
"This is an issue of grave worldwide importance," said Friedland. "MDR and XDR carry the danger of blunting or reversing the success of TB programs and the roll-out of anti-retroviral therapies for HIV where they are desperately needed in resource limited settings. Urgent intervention is necessary, especially now that we know that MDR tuberculosis is far more prevalent than previously thought and that XDR tuberculosis has been transmitted to HIV co-infected patients and associated with high mortality."
Future studies will involve defining the extent and consequences of the problem in greater detail, Friedland said, with operational research focused on quickly determining what kind of infection control practices can practically and feasibly be instituted to reduce the transmission of this lethal form of tuberculosis to others.
Friedland said there is a desperate need for new diagnostic tests and treatment for TB. "It is still being diagnosed the same way it was in 1882," he said. "Modern technology for diagnosis and new treatment needs to be developed urgently. The last approved TB drug was 40 years ago."
In addition to Friedland, the study also included first author Neel R. Gandhi, M.D., a former Yale Robert Wood Johnson Clinical Scholar, now at the Albert Einstein College of Medicine; Kimberly Zeller, M.D., a former Yale Robert Wood Johnson Clinical Scholar, now at Brown Medical School; and Yale School of Medicine student Jason Andrews. South African co-investigators included Anthony Moll of the Church of Scotland Hospital and Philanjalo; A. Willem Sturm, M.D., Robert Pawinski and Umesh Lalloo, M.D., of the Nelson R. Mandela School of Medicine; and Thiloshini Govender of the KaZulu Natal Department of Health.
The study was funded by the Irene Diamond Fund, the Doris Duke Charitable Foundation and Yale University.
Citation: The Lancet, Early online edition (October 26, 2006)
Journal
The Lancet