TORONTO -- An extensively drug-resistant virulent strain of tuberculosis (XDR-TB) killed 52 of 53 patients who were co-infected with HIV during an outbreak in a rural South African hospital, researchers reported here.
TORONTO, Aug. 18 -- An extensively drug-resistant strain of virulent tuberculosis (XDR-TB) killed 52 of 53 patients who were co-infected with HIV during an outbreak in a rural South African hospital.
Most of the XDR-TB patients died within 16 days of first being seen, although at presentation their clinical symptoms did not seem all that dire, reported Neel Gandhi, M.D., of the Albert Einstein College of Medicine in New York.
"Some of these patients really weren't that sick," said Dr. Gandhi, who presented the study in a late-breaker session at the 16th International AIDS Conference here. "They weren't brought in near death."
The 53 XDR-TB patients were at the district hospital in KwaZulu province, about 120 miles north of Durban, the epicenter of the AIDS epidemic in South Africa. The patients infected with the strain died within one to 210 days after admittance to the hospital.
The rapidly fatal pathogen killed some of the patients so quickly that hospital staffers didn't have a chance to complete analysis of sputum samples taken at admittance.
From January 2005 through March 2006, sputum collected from 1,540 patients there revealed that 536 (35%) were culture positive for tuberculosis. Of these, 221 (41%) had multi-drug-resistant TB, and 53 (24% of multi-drug-resistant isolates, 10% of all positive cultures) had resistance to all first- and second line drugs tested (extensively-drug resistant, XDR TB), Dr. Gandhi said.
The strain is resistant to Isoniazid, rifampicin, ethambutol, streptomycin, kanamycin and Cipro (ciprofloxacin).
Spoligotyping revealed 90% of XDR TB patients were infected with a genetically similar strain.
"This is scary as hell," commented Dan Kuritzkes, M.D. director of AIDS research at Brigham and Women's Hospital in Boston. "It is very concerning. It shows us the importance of tuberculosis control methods."
Outside of the 53 cases in the hospital in South Africa, there have been just 347 cases of XDR-TB reported, Dr. Gandhi said. The investigation at the hospital also found that there were 224 cases of multidrug resistant tuberculosis in patients there. That compares with a total of 128 such cases reported in the United States in 2004, he said.
The outbreak that occurred from January 2005 through March 2006 killed six healthcare workers in the hospital, indicating that the strain was spread nosocomially. However, Dr. Gandhi noted that 18 of the cases were among patients who had not been previously hospitalized nor treated for tuberculosis previously. He said the strain appeared to be a form of recent infection in the rural community.
"When we were faced with these cases, there is nothing really left to treat them with, aside from surgery or other methods that were used in the pre-antibiotic era in the early part of the 20th century," Dr. Gandhi said.
Dr. Gandhi said that if an HIV-infected patient contracted the strain, the outcome proved similar whether the victim was male or female, young or old.