Air trip by drug-resistant TB patient prompts passenger testing

Jan 2, 2008 (CIDRAP News) – Federal health officials recently issued an alert about a woman with multidrug-resistant tuberculosis (MDR TB) who flew from India to the United States in mid December, and efforts are under way to locate and test several of her fellow passengers for the disease.

The US Centers for Disease Control and Prevention (CDC) in a statement sent to clinicians on Dec 29 said the patient, who was not named, was diagnosed in India with MDR TB and traveled from New Delhi to Chicago on Dec 13 on American Airlines Flight 293, and then took a shorter flight within the United States.

The patient is a 30-year-old woman whose final destination on Dec 13 was San Francisco and who is recovering in an isolation ward at a Bay Area hospital, according to a Dec 31 Los Angeles Times report.

About a week after the flight the woman went to the emergency department at Stanford Hospital with advanced symptoms of the disease, according to the Times report. The CDC said the woman sought treatment for hemoptysis, fever, and chest pain. "These and other findings indicated a potential for transmission of drug-resistant TB to others," the agency added.

Marty Fenstersheib, MD, MPH, health director for Santa Clara County, told the Times that the woman had symptoms during the flight, including coughing.

MDR TB is defined as TB that resists at least two key drugs that are considered first-line treatments for people who have TB infections—isoniazid and rifampicin, according to the CDC.

Because of the risk of infection and according to World Health Organization (WHO) guidelines, the CDC is recommending TB testing for passengers who sat within two rows of the infected woman as well as airline crew members who worked in the cabin during the flight. The group includes 44 passengers. The woman who has the MDR TB infection sat in row 35, and the patients flagged for testing sat in rows 33 through 37.

Based on location information provided by 42 of the passengers, the CDC has asked health officials in 17 states to contact the patients who have been flagged for testing. Location information was not available for two of the passengers. The CDC has asked states to notify the agency if they are unable to contact any of the passengers in their states.

The CDC said it recommended testing of only the passengers and crew on the New Delhi to Chicago flight because that leg was longer than the 8-hour duration specified by the WHO for testing for TB exposure. The WHO and CDC don't recommend notification and testing of passengers on shorter flights because they consider the transmission risk to be minimal.

All forms of TB are believed to spread when TB bacilli from a person with the disease become aerosolized as a result of coughing, sneezing, speaking, or singing, the CDC said in its statement. The bacilli can float in the air for several hours, and people who breathe them in can become infected. Those who become infected have usually been exposed for several hours or days in poorly ventilated or crowded environments.

In May 2007 the CDC in a rare action ordered Andrew Speaker, an Atlanta lawyer, to isolation after he flew internationally after he was diagnosed with what was believed to be extensively drug-resistant tuberculosis (XDR TB). Those events also provoked testing of passengers who flew with Speaker, but none tested positive, according to previous reports.

Speaker was later found to have MDR TB, and the developments in his case highlighted the lack of a foolproof test to distinguish between drug-resistant TB strains, prompting criticism of the CDC's testing and situation response procedures.

See also:

CDC fact sheet on TB
http://www.cdc.gov/tb/topic/drtb/default.htm

Sep 13 CIDRAP News story "House panel sees CDC errors in case of traveling TB patient"

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