TB Carrier's Case Called Less Severe Than Believed

The strain of tuberculosis infecting Andrew Speaker, the Atlanta lawyer who was the object of an international hunt by public health authorities in May, turns out not to be as dangerous as doctors originally thought.

That was the conclusion announced yesterday by physicians and laboratory scientists at National Jewish Medical and Research Center in Denver, where Speaker is being treated. Repeated tests there have shown his infection to be "multidrug resistant" (MDR) and not "extensively drug resistant" (XDR).

The revised diagnosis opens new options for treating Speaker and raises his chances of being cured. But a federal official said yesterday that it would not have changed the government's urgent response to Speaker's transatlantic travel, which triggered headlines around the world when it was disclosed.

"The public health action taken in his case was sound and appropriate," said Mitchell L. Cohen of the Centers for Disease Control and Prevention.

Speaker, 31, flew to Europe in May for his wedding against the advice of Atlanta's Fulton County health department. At the time, he knew he had MDR tuberculosis but said he was told that his chances of infecting anyone else were small.

When CDC tests, completed during his honeymoon, concluded that his infection was the more dangerous XDR variety, federal health officials tracked him down in Italy and told him to seek treatment and not to travel. He ignored the advice and returned to the United States. Soon after reentering the country, he was ordered into medical isolation, the first time the federal government had taken such a step since the 1960s.

TB experts said yesterday that drug resistance is not an all-or-nothing characteristic; it can range from mild to severe. Furthermore, a single sample of material taken from a patient can contain multiple strains of TB, with not all showing the same resistance profile. For that reason, conflicting results between labs are not uncommon.

"This is not a black eye for the CDC," said Richard E. Chaisson, an expert in drug-resistant tuberculosis at the Johns Hopkins University Bloomberg School of Public Health. "It is embarrassing and difficult to explain, but that is because it is complicated. It is not a sign of incompetence or bad practice."

Speaker released a statement that expressed gratitude for the news but also referred twice to the "misdiagnosis" of his case.

"It had been an incredibly long and difficult month, but today is a day of relief for both myself and my family. For the international panic that was created after my misdiagnosis and the way my case was handled, I can only hope that this news helps calm the fears of those people that were on the flights with me," the statement said.

Speaker, a personal-injury lawyer, remains under an order of isolation from Denver's health department. However, he has been able to leave his room and walk around the hospital grounds, said Charles L. Daley, the medical center's head of infectious diseases.

Speaker's infection is resistant to three of the four first-line TB drugs -- isoniazid, rifampin and pyrazinamide. That qualifies it as MDR.

However, earlier tests done by the CDC found it also resistant to two important groups of backup drugs -- fluoroquinolones and at least one of three in a group of "injectibles." That put his case in the "extensively drug resistant" category, but the recent tests showed that the TB bacteria infecting him do respond to the backup drugs.

"This will allow us to change how we treat him," Daley said in a news briefing yesterday.

The backup drugs have been added to his antibiotic cocktail, and the treating physicians have for the moment shelved their plan to surgically remove the infected lobe of Speaker's right lung.

The recent tests involved three samples taken from his lungs: one on April 25 in Atlanta; the second in New York on May 27, after his return from Europe; and the third on June 1, after he arrived in Denver for treatment.

The sample that CDC scientists determined was XDR came from the Georgia health department. It was a "subculture" of a sample taken with a fiber-optic instrument at the Atlanta hospital where Speaker's condition was first diagnosed.

Such samples are tested by swirling a bacteria-laden swab across one "culture plate" containing an antibiotic and another plate with no antibiotic. If the number of bacterial colonies that grow on the antibiotic-containing plate is more than 1 percent of the number of colonies on the antibiotic-free plate, the bacteria are declared to be resistant to that drug.

In the case of Speaker's sample, the CDC test found that about 25 percent as many colonies grew on the fluoroquinolone- and injectables-treated plates as on the antibiotic-free plates -- a clear case of resistance, Cohen said.

The doctors said they do not know why the subsequent tests did not produce the same result, but they noted that the sample tested by the CDC may have been a variable mixture of many slightly different strains of TB bacteria that Speaker was harboring, one or two of them extensively resistant. They might have been caught by chance in the CDC's test but not in the later ones.

Daley said the treatment strategy does not have to cover every rare sub-strain of bacteria a patient is carrying in order to be successful.

"We target the one that grows in the laboratory in predominance," he said.

Speaker's father-in-law works as a laboratory scientist in the TB section of the CDC, but he was not involved in testing the sample, Cohen said.