[In the latest incident, a woman with TB flew from India to
O’Hare International Airport in Chicago, landing on April 4. She traveled by
car to visit relatives in Illinois, Tennessee and Missouri before seeking
medical care sometime after May 18 at a hospital in Illinois. Tests there
detected extensively drug-resistant tuberculosis, or XDR-TB. Doctors notified
the state health department and the Centers for Disease Control and Prevention.
The arduous task of contact tracing began in the three states.]
By Denise Grady
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Susan Karras, the
communicable disease coordinator for McHenry County, outside Chicago,
where a
TB patient visited.
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Infectious diseases carried around the
world by air travelers have become a fact of modern life, with imported cases
in just the last year of Ebola,
Lassa fever and, now, a highly drug-resistant
form of tuberculosis.
In the latest incident, a woman with TB flew from India to
O’Hare International Airport in Chicago, landing on April 4. She traveled by
car to visit relatives in Illinois, Tennessee and Missouri before seeking
medical care sometime after May 18 at a hospital in Illinois. Tests there
detected extensively drug-resistant tuberculosis, or XDR-TB. Doctors notified
the state health department and the Centers for Disease Control and Prevention.
The arduous task of contact tracing began in the three states.
Health officials say the risk to the public is low. TB is nowhere
near as contagious as the flu or measles. But people who had long periods of
close contact with the patient, like the relatives with whom she stayed, are at
risk.
For people who were on the flight with the woman from India, the
odds of catching TB are low but not zero. Cases have occurred in passengers on
a long flight who sat near someone in advanced stages of the disease. In this
case, the C.D.C. said, it will obtain the flight manifest for the woman’s trip
from India and notify passengers who may have been exposed. An agency spokesman
declined to reveal the airline or flight number.
Visitors from other countries are not screened for TB when they
arrive, but those applying for legal residency are required to have TB tests,
according to the C.D.C. Even if the government wanted to screen arriving
passengers, it would be difficult, because there is no rapid test for
tuberculosis.
On Friday, the patient from India was transferred to the
National Institutes of Health in Bethesda, Md. In the past two decades, the
N.I.H. has treated about 20 patients with drug-resistant TB, the most recent a
year or so ago, according to Dr. Anthony S. Fauci, the head of the National
Institute of Allergy and Infectious Diseases. Most came from other countries.
“Our track record has been good,” Dr. Fauci said, adding that
about 80 percent were cured. That success rate is higher than the figures
usually cited — 30 percent to 50 percent cured — because the lower estimates
include results from poorer countries that have less access to drugs and other
resources.
“This person is looking at a very long course of careful
treatment and observation,” Dr. Fauci said.
Globally, nine million people contracted TB in 2013, and one and
a half million died from it, according to the World
Health Organization. Nearly a quarter of all the cases occurred in
India, which has the world’s largest epidemic.
Over all, drug-resistant bacteria cause only about 5 percent of
all cases, and XDR bacteria are a small subset of that group, causing about 48,000
cases in 2013. But XDR-TB has shown up in 100 countries, and it can be deadly,
particularly in countries with weak health care systems.
So far, 12 people who had contact with the woman in Illinois
have been identified, according to Susan Karras, the communicable disease
coordinator for McHenry County, northwest of Chicago, the part of Illinois the
patient visited. They were traced in 15 to 20 hours of interviews with the
patient and her family at the hospital and by phone.
Some have had TB tests, but Ms. Karras declined to reveal
whether any were positive. People whose initial results were negative will be
tested again in about eight to 10 weeks, because the infection does not always
show up on early tests.
Spokesmen for the Tennessee and Missouri health departments said
contacts were being traced in those states, but did not provide any details.
Anyone who is infected will be treated, Ms. Karras said. In many
people, TB can be latent, meaning that their immune systems keep the infection
in check so they are not sick or contagious. But latent disease can become
active. So even people with the latent form of the disease will be treated with
whatever mix of potent drugs it takes to kill this particular strain of XDR-TB,
she said.
“We want to treat it before it becomes infectious,” Ms. Karras
said. “That’s why we want to find them.”
The woman from India is in isolation in a hospital at the
N.I.H., Dr. Fauci said. She has no contact with other patients, and doctors and
nurses who treat her must wear gloves, gowns, eye protection and specially
fitted masks called N-95 respirators. Even though they take every precaution,
health workers who treat TB patients are usually tested for the disease once a
year, Dr. Fauci said.
At the N.I.H., patients with this kind of TB are usually kept in
the hospital for weeks or even months, until sputum tests no longer find the
bacteria, indicating that the disease is not contagious anymore, Dr. Fauci
said.
Standard TB usually requires treatment with four drugs, which
can take six to nine months. Treating XDR-TB takes longer, sometimes a year or
more, and requires more drugs.
The drugs have unpleasant side effects that are hard to
tolerate, Dr. Fauci said. They cause nausea, weakness and other problems that
make patients want to quit taking them before the full course is finished. But
missing doses and quitting too soon are precisely what cause drug-resistant
bacteria to develop — requiring even longer treatment with more drugs and
nastier side effects.
Sometimes in severe cases, surgery is needed to remove diseased
and scarred parts of the lung harboring bacteria that the drugs cannot reach.
The patient will not be charged for her treatment. Even if
patients are citizens of other countries, Dr. Fauci said, their governments are
not billed.
“Everything is free at the N.I.H.,” he said. “No one pays.”
Dr. Fauci said that the woman’s treatment would be expensive,
given the long stay and costly drugs needed, but that he could not even begin
to estimate the ultimate cost.
