Tuberculosis may reach the point where most new cases in some countries are resistant to many drugs unless far greater efforts are made now to stop the spread of the infection, World Health Organization officials said on 5 June.
That chilling forecast is based in part on the organization's analyses showing that on average, a patient infected with drug-resistant tuberculosis in 2004 is resistant to more drugs than a similar patient with that diagnosis in 1994, Dr Paul P Nunn, a TB expert for the organization, said at a news conference.
The case of Andrew Speaker, the Atlanta man with extremely drug-resistant tuberculosis who took commercial flights for his wedding in Greece and honeymoon in Europe and set off an international health scare, has focused attention on the disease, and prompted the news conference.
Health officials say that Speaker's was not an isolated case because the extremely resistant form has been reported in 37 countries. With the growth of international travel, health officials say that TB anywhere is TB everywhere. About 420,000, or 5%, of the estimated 8.8 million new cases of tuberculosis in the world are now resistant to many standard anti-tuberculosis drugs, Dr. Mario C. Raviglione, who directs the WHO's tuberculosis department, said in an interview. About 30,000 of the 420,000 cases are extremely drug-resistant, meaning they are resistant to first-line and a number of second-line drugs.
Raviglione said the organization had begun to undertake statistical modeling studies to estimate how prevalent drug-resistant tuberculosis might become. Outcomes from such studies depend on a number of variables and none have been published.
"It is possible that in some settings drug-resistant tuberculosis could completely replace standard tuberculosis," Raviglione said. That possibility is greatest in settings where poor public health services and laboratory facilities mean that no one knows the number and proportion of tuberculosis cases that are susceptible and resistant to drugs. In such areas, many people do not know they have tuberculosis.
An area of great concern is Africa, where AIDS patients often develop tuberculosis. Other areas are China, Eastern Europe and India. Coughing, sneezing, singing and other activity spread the tuberculosis bacteria in the air. Anyone can become infected, but prolonged exposure is usually required.