DENVER — Officials at National Jewish Medical and Research Center in Denver on Tuesday said yet another lab test on XDR TB patient Andrew Speaker's respiratory secretions did not find any tuberculosis germs.

The new test results continue to reduce the likelihood that an Atlanta man infected any airline passengers with an extensively drug-resistant tuberculosis.

Jason Getz/AJC (ENLARGE)

Dr. Jenny Graham, supervisor of the clinical reference laboratory at the National Jewish Medical and Research Center in Denver, inspects incubators where cultures of tuberculosis are stored. Andrew Speaker's samples are being tested there.

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While Speaker has extensively drug resistant TB, tests of his sputum over the past few months have consistently been negative for the germs. Only when Speaker's samples are put in an incubator for weeks does TB grow. Experts say this indicates he is at low risk of infecting others with the disease.

While Speaker has XDR TB, doctors in Denver on Monday declared him "relatively non-contagious," based on daily sputum tests taken Friday, Saturday and Sunday.

"So far there's nothing different about my condition than there was before I left [the United States] when they told me I was not contagious and told me I was not a threat to anyone," Speaker said Monday in a brief phone interview with The Atlanta Journal-Constitution.

"This is more like the ninth or tenth negative smear test," Speaker said.

Speaker has never had any symptoms or cough. His TB was only identified by chance: Doctors in January saw a spot on his lung after he had an X-ray for an injury.

World Health Organization guidelines say that people with multidrug resistant TB -- Speaker's diagnosis -- are considered potentially contagious to airline passengers.

But the international attention directed at Speaker's case goes beyond any risk he posed to travelers. Several government agencies that failed to stop his travels despite numerous opportunities are sharing the spotlight.

These government failures raise troubling questions about how local health departments, the Centers for Disease Control and Prevention and the U.S. Department of Homeland Security would respond if presented with a highly contagious patient or a bioterrorism threat, experts have said.

A hearing is scheduled Wednesday before the U.S. House Homeland Security Committee. The Republican staff of the House Energy and Commerce Committee, which has oversight authority over the CDC, has asked for a briefing from the agency and committee officials expect that to happen this week.

Their questions may include why the CDC delayed in alerting the WHO, Italian and Greek health authorities that U.S. officials were looking for an XDR TB patient.

Speaker has consistently maintained that Fulton County health officials only said they "preferred" he not travel and that they never said he posed a threat to anyone. Speaker says he never would have done anything to endanger the public, let alone his new wife and her 8-year-old daughter.

County health officials, however, contend that they clearly "advised" Speaker not to travel. But they have refused to let the county official in the May 10 meeting, Dr. Eric Benning, talk to the media. And when directly asked whether Benning advised Speaker he was not dangerous to others, they have declined to answer.

April Jones, spokeswoman for the Fulton County Department of Health and Wellness, said Monday that the agency is not going to discuss further details of the meeting in deference to patient confidentiality.

Speaker on Monday said Fulton County should answer the question. "It's a simple yes or no question: Did they or did they not tell me I was not contagious?" Speaker has said his father recorded the May 10 meeting, but the tape has not been made public.

Fulton County officials, in response to a Georgia Open Records Act request, released to the AJC a copy of a two-paragraph letter they unsuccessfully tried to hand deliver to Speaker on May 11 and 12.

The letter was redacted for privacy reasons, but it reads:

"The Fulton County Department of Health and Wellness ... has been notified that you are planning to travel to Greece on May 14, 2007. As a precaution it is strongly recommended that you postpone your travel and see a ... specialist in Denver, Colorado. In the event you do not comply with this recommendation the Fulton County Department of Health and Wellness ... cannot be responsible for the exposure of this [redacted] to the public. It is imperative that you are aware that you are traveling against medical advice [AMA]."

Speaker never received the letter.

He decided to leave earlier for Greece because he'd just found out he'd have to get part of his lung cut out, but that the Denver hospital couldn't take him for several weeks, he said.

Also, most of the people invited to his wedding had already left for Greece and his then-fiancee urged him to go ahead so he could relax, he said.

Here is the text of National Jewish Medical and Research Center's latest news release:

Third Sputum Smear Test Negative for XDR TB Patient Andrew Speaker

Andrew Speaker learned Monday evening that his third consecutive sputum smear test had come back negative. This confirmed results from several smear tests previously performed at other institutions.

The sputum smear test helps evaluate if there are large numbers of tuberculosis organisms in a patient's sputum, and is a helpful tool in determining how sick and how contagious a patient is. A sample of the patient's sputum is smeared on a slide, stained, then examined under a microscope. If a laboratory technician sees the organism, then the patient is considered "smear positive." A smear positive patient is considered infectious.

If the technician sees no TB bacilli, the test is deemed negative. Current Centers for Disease Control/American Thoracic Society Guidelines indicate that patients on therapy with three consecutive negative sputum smears may be regarded as non-infectious in most settings. However, in cases with multidrug or extensively drug-resistant (MDR/XDR) strains, additional caution should be exercised due to unpredictable responses to therapy and the unavailability of medications for preventive therapy in newly infected contacts.

A patient with a negative smear test may well have viable bacteria in his/her sputum, which were not detected through visual examination in the smear test. A recent study from San Francisco indicated that up to 20% of new TB cases could be traced back to contact with smear-negative patients.

Tuberculosis is transmitted in almost all cases by the air-borne route.

Patients with active TB of the lungs cough, generating fine particles which float in the air for minutes to hours. Some of these particles contain the bacteria which cause TB, Mycobacterium tuberculosis. The more bacteria in the sputum, the greater the risk of transmitting infection. Mr. Speaker does not have a cough.