Latvia is one the six countries of the former Soviet Union where the problem is seen to be very serious.
Dr. Chow told RFE/RL that tuberculosis sufferers in parts of Eastern Europe and Central Asia are 10 times more likely to have multi-drug-resistant forms of TB than patients in the rest of the world.
"The rates in Central Asia and Russia are higher than average," Chow said. "[The] WHO is working with partners to increase the detection and cure of TB in these areas."
Every year 2 million people die globally from TB and 10 million people become seriously ill. Tuberculosis, known as the "disease of poverty," has been on the rise in countries of former Soviet Union in recent years.
Estonia, Kazakhstan, Latvia, Lithuania, the Russian Federation, and Uzbekistan are now among the top 10 global "hot spots."
With the collapse of public health infrastructures and the worsening of the economic conditions after the breakup of the Soviet Union, drugs against TB were in short supply. Now medicines are available again, but because of the interruption, a more drug-resistant form of TB is spreading throughout the region.
Yekaterina Goncharova, an expert at the Moscow Medical Academy, said that in Russia there are huge numbers of new TB cases and that as many as a quarter of all new cases might involve drug-resistant strains.
"Two years ago it was approximately 25 percent of the new cases," Goncharova said. "But it's not official. We don't know exactly because not each region has a bacterial lab and we haven't a data for this."
Chow explains how multi-drug-resistant TB develops.
"The crux of the problem is having continuous treatment over six to eight months. Each patient has to take the medicines every day for them to work," Chow said. "If patients lose access to medicines or they move away, or there is insufficient medicines, the drug-resistant form will emerge and could then infect other people. If a person contracts drug-resistant TB it can take up to two years to treat."
Aygul Omarova, a doctor at a TB clinic in the Kazakh city of Almaty, said that while TB can be cured with medicine worth $10, medicines for drug-resistant strains can cost hundreds or even thousands of dollars.
"Multi-resistant types of TB are increasing," Omarova said. "The medicine is expensive. It can cost as much as $9,000 to treat one person. Normal TB [can be] treated for six to eight months, this [more difficult] type can [require up to] 20 months."
Much of the former Soviet Union is also beset with high rates of HIV/AIDS. People with HIV/AIDS are particularly susceptible to TB.
"There is a very significant concern that TB and HIV -- the numbers of people who have both infections will go up very significantly in sub-Saharan Africa and in Russia [and] Eastern Europe unless [more complex treatments are] made [more] widely available," Chow said. "And multi-drug resistant TB is also of high concern if they infect people living with HIV."
Timely detection and diagnosis can be life-saving.
Precious time is often lost on an erroneous diagnosis. One patient at the Almaty TB clinic, Gulnar, told her story.
"When I first got sick it was because of bronchitis. But later on the diagnosis was tuberculosis," Gulnar said. "It took two months to find out. My life lost any meaning. I felt alone. There were no details [about the illness]. The doctors tried to soothe me and others [like me], assuring us that they will cure it."
Chow said that Latvia is successfully applying what's known as a "DOTS-Plus" strategy on a national level in the hope of saving lives and improving patient health. DOTS-Plus stands for "Directly Observed Treatment Short Course" and means providing a standardized, specialized medicine to patients.
"We have seen countries like Latvia, Estonia, and others who reinvigorated their campaign against tuberculosis and are able to stabilize it and bring it down. So the message is one of hope and of action," Chow said.
Health experts say the countries of the former Soviet Union need to expand their DOTS treatments without further delay.