Second TB case on India flight

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Second TB case on India flight

U.S. HEALTH OFFICIALS SAY IT'S POSSIBLE PASSENGER CONTRACTED

TUBERCULOSIS FROM SILICON VALLEY WOMAN

By Mike Swift, Mercury News. Article Launched: 04/17/2008 01:30:45 AM PDT. Apr

17: Tuberculosis: a worldwide concern

The Sunnyvale woman who flew to the United States in December after

contracting a dangerous case of drug-resistant tuberculosis may have

infected another passenger on the flight from India, federal

officials said Wednesday, underscoring the slim but real threat of

contracting the potentially deadly disease on an airplane.

The U.S. Centers for Disease Control and Prevention released the

information after an aggressive effort to contact and test 44

passengers from 16 states who sat near the woman on the flight.

Although she had been diagnosed in India, she did not disclose that

she had the disease until she went to the emergency room at Stanford

Hospital upon her return to the Bay Area.

" It's impossible to definitively link the positive test to the

airline exposure at this point, " said , a CDC spokeswoman,

noting that the other passenger could have contracted the disease in

India as the Sunnyvale woman did. But " it is a possibility " the

disease was spread on American Airlines Flight 293 on Dec. 13, a 16-

hour Boeing 777 trip from New Delhi to Chicago's O'Hare International

Airport.

The threat of TB transmission on a commercial flight became a high-

profile public issue last year, when Speaker, an Atlanta

lawyer, flew to Paris with drug-resistant TB, potentially infecting

others on two trans-Atlantic flights. The CDC's follow-up

investigation has found that Speaker infected no one else in his

travels.

Sunnyvale woman suffers from a strain of disease that is resistant to

both primary TB drugs, isoniazid and rifampin, making her case much

more medically serious and expensive to treat. But the Sunnyvale

woman may have been even more contagious during her flight than

Speaker was, said the local public health officer in charge of

investigating her case.

" She had symptoms. She was coughing on the plane, " Dr. Marty

Fenstersheib, Santa Clara County's public health officer, said

Wednesday. " He wasn't really infectious, even though he carried that

same organism. "

The Sunnyvale woman was treated at Stanford Hospital for nearly three

months, but she has been released and is being treated at home, and

her prognosis is good. Nevertheless, because she has a multi-drug-

resistant case, she faces a difficult course of treatment that could

last as long as two years, Fenstersheib said. Her identity has not

been revealed by health authorities.

In the great majority of tuberculosis cases, infected people never

get sick or become contagious. The bacteria is kept harmlessly

dormant by the immune system. However, people who are HIV-positive,

who have other conditions or who take drugs that weaken the immune

system are at much higher risk.

Public health officials believe the risk of TB transmission on a

commercial airliner is probably minimal, and that there is risk only

on flights longer than eight hours and only to passengers sitting

within several rows of the infectious person.

Several medical studies have found evidence for probable or possible

transmission of TB to other passengers or flight crew members on long

international flights. But the quality of ventilation on modern

jetliners may make it even more difficult to transmit TB on an

aircraft than in a home or in other social settings, TB experts say.

" The evidence for transmission on airplanes is relatively incomplete

and not that strong, " said Dr. Jereb, of the CDC's Division of

Tuberculosis Elimination.

The CDC investigated 68 such cases in 2007, involving 2,062 passenger

contacts. Public health officials do not permit infectious TB

patients to fly, issuing " do not board " orders through airlines and

airports to prevent patients from flying if they are not willing to

comply with the advice not to travel.

Following the flight to Chicago, the Sunnyvale woman flew on to San

Francisco International Airport, but the domestic flight was too

short to be a risk for TB transmission.

Santa Clara County health officials have followed up with family

members and other local contacts at Stanford, and have definitely

confirmed that she did not transmit TB once on the ground in Silicon

Valley.

Ironically, the fact that she was so sick may have helped protect

people here.

" She was sick enough that she wasn't out Christmas shopping, "

Fenstersheib said. " Her symptoms led her to the hospital. That

limited her potential exposure to other people. "

http://www.mercurynews.com/healthandscience/ci_8955630