ON THE MEND: Misha K. has suffered from two bouts of tuberculosis, the second of which proved be the hard-to-treat, multidrug resistant variety of the disease. Image: Merrill Goozner/© Scientific American
TOMSK, RUSSIA—Misha K.—ex-con, ex-drug abuser, family man—arrived promptly at 4 P.M. for his daily dose of antibiotics. He is fighting his second bout with tuberculosis (TB), both times caught while serving a four-year prison term in this small city at the edge of Siberia. His crime: petty thievery to support his drug habit.
The first time, prison doctors put him on a nine-month regimen of antibiotics, a standard prescription for routine cases of so-called susceptible TB. The susceptibility label is something of a misnomer. When streptomycin was discovered in the 1940s, the miracle drug was hailed as the magic bullet that cured TB. But the wily Mycobacterium tuberculosis quickly developed resistance. Now it takes four drugs to cure "susceptible" TB.
The four-drug regimen worked for Misha. But shortly before his release, he caught TB a second time, probably from another prisoner. Again he was put on standard four-drug therapy. But when he got out, he stopped taking the pills. "The first time it took nearly a year," said Misha, who did not want his last name used. "So by the second time I was on the drugs, I became very tired of it all."
It was not an irrational response. The initial few months of standard therapy succeeds in knocking out most of the bacteria, and the symptoms disappear. But some M. tuberculosis develop a waxy coat and hide in the recesses of the lung. Among those survivors are mutant strains, unfazed by some of the drugs. When the four-drug cocktail is removed prematurely, these strains become dominant, and the bacteria cells multiply at M. tuberculosis's slow but inexorable once-a-day rate.
A year after leaving prison, Misha's disease came roaring back—this time multidrug resistant, or MDR-TB. Tired, coughing blood, the 30-year-old factory worker was told by civilian health authorities that he now had to take six drugs a day, including one by injection, or he would probably die. DOTS (short for "directly observed therapy, short course"—the World Health Organization's prescription for proper treatment of susceptible TB) gave way to DOTS-Plus, the psyche-bending two-year regimen of six drugs that it takes to defeat MDR-TB.
This past June, when I interviewed Misha at the dispensary that coordinates TB care in the region, he was well into his second year of treatment. "He's almost cured," said an upbeat Guzel Davidova, the nurse who prepares and observes his daily treatment. "I'm trying to make a new life now," whispered the rail-thin father of two. As he absently fingered his right forearm's deep purple scar, a souvenir from his prison days, he looked up and added, "I'm off drugs completely." He wasn't referring to the TB drugs, not yet anyway.
The Siberian provinces of the central Russian plateau—poor, even by Russian standards, with high rates of alcoholism, drug abuse and a large prison population—are among the epicenters of a worldwide epidemic of drug-resistant tuberculosis. Whereas the 490,000 reported cases of MDR-TB account for just a small fraction of the 9.2 million new cases and 1.7 million deaths from TB reported to the World Health Organization in 2006, MDR-TB represents a significant global public health hazard. In parts of Siberia, it accounts for more than 15 percent of all cases.
Left untreated, the resistant TB can spread to the general population through the usual route: airborne transmission of spewed sputum. Treated poorly, it can spawn extensively drug-resistant TB (XDR-TB), a more virulent and nearly impossible-to-treat version of the disease.