Cases of tuberculosis that defy existing drugs are being recorded globally at the highest rates ever seen, with parts of the former Soviet Union especially vulnerable, the World Health Organization has said.
In a report based on data from 81 countries, the WHO estimated nearly half a million people a year worldwide become infected with a form of TB resistant to two or more of the primary drugs used to treat it. That number accounts for about 5 percent of the 9 million new TB cases annually.
Extensively drug-resistant TB, the form that is hardest to treat, was seen in 45 countries and may be present in others because only extremely limited data was available from Africa, the U.N. health agency said.
"This is my frustration here -- the world is not taking this epidemic seriously," Dr. Mario Raviglione, director of the WHO Stop TB Department, said in a telephone interview. "What the report shows is simply that we are in big trouble in many parts of the world."
Parts of the former Soviet Union -- Russia, Azerbaijan, Moldova and Ukraine -- were among the countries hit hardest by drug-resistant TB. Raviglione attributed this to years of socioeconomic deterioration, dismantling of public health systems, poor living conditions and other factors.
Tuberculosis is an infectious bacterial disease typically attacking the lungs. The emergence and spread of drug-resistant germs makes treating it much harder and could make the disease, which has killed people for untold centuries, even more deadly.
An estimated 1.6 million people a year die from TB worldwide.
The report tracked multidrug-resistant tuberculosis, called MDR-TB, and XDR-TB. MDR-TB does not respond to the treatment by two or more of the primary drugs used to combat TB. XDR-TB is the most dangerous form of TB. It is resistant to nearly all drugs used to treat TB.
The report said 489,139 MDR-TB cases emerged in 2006. Raviglione estimated that perhaps 40,000 of these are XDR-TB. The highest rate of MDR-TB was recorded in Baku, capital of Azerbaijan, where 22 percent of all new TB cases were reported as multidrug-resistant. That's the highest proportion ever recorded in any population, Raviglione said. MDR-TB also was unusually common in Moldova (19 percent of new TB cases) as well as parts of Ukraine, Russia and Uzbekistan, the WHO report showed. MDR-TB also may be widespread in China, according to the report.
The study, the first big WHO report on TB since 2004 and the first to track XDR-TB, said progress had been made in Estonia and Latvia, which were identified in the 1990s as hot spots for drug-resistant TB. The Americas, Central Europe and Africa reported the lowest proportions of MDR-TB, aside from Peru, Rwanda and Guatemala.
Only six countries in Africa, where TB has its highest rates, provided drug resistance data. "It is likely there are outbreaks of drug resistance going unnoticed and undetected," said WHO TB expert Abigail Wright said.
About a third of people worldwide are infected with the bacterium that causes TB. The WHO estimates 5 percent to 10
percent of the infected will become sick with TB or infectious at some time in their life. It can be spread by breathing in air droplets from a cough or sneeze of an infected person.
The WHO estimates that $4.8 billion is needed for TB control efforts in low- and middle-income countries in 2008, but countries, international organizations and others have fallen $2.5 billion short of that total.
Date created : 2008-02-27