- Tuberculosis remains the most deadly
infectious disease in China accounting for more than 250,000 deaths each
- Tuberculosis, the Godzilla of bacterial
diseases, infects up to a third of the world's population and currently
kills more people per year than any other single infectious agent.
- Ninety-five percent of TB cases occur
in developing countries, so it's easy for Americans to ignore this affliction.
But we may no longer be able to afford to do so, health experts warned
at a press conference sponsored by the World Health Organization in connection
with its annual World TB Day on Wednesday.
- The reason? Deadly drug-resistant TB
strains are springing up around the world.
- "In today's global society, increasing
drug resistance [to tuberculosis] anywhere becomes a threat everywhere,"
Dr. Ken Castro, director of the Centers for Disease Control's TB Elimination
Division, said at the briefing. "Tuberculosis has the power to adapt,
to grow stronger, and to travel as easily as we do from one nation to another."
- Just last October, a Ukrainian emigre
traveling on a Paris-New York flight may have infected a number of passengers
with a strain of multi-drug resistant TB.
- Luckily, the man visited a Pennsylvania
health clinic two days later, and state health investigators immediately
called the airline and contacted the passengers who had sat near him.
- Thirteen of the passengers tested positive
for TB, and were treated immediately with preventative medication (although
it's not clear that the man actually infected the passengers: some may
have already had the bug).
- This case is the latest in a small but
growing number of incidents where travelers have spread active TB on airplanes.
- From 1992 to 1994, the CDC reported seven
such cases, including two that involved multi-drug-resistant tuberculosis.
These seven people, including six passengers and one flight attendant,
potentially exposed more than 2,600 passengers on a total of 191 flights
to TB, according to a recent WHO report, Tuberculosis and Air Travel: Guidelines
for Prevention and Control.
- Most of the exposed passengers were tracked
down by the airline, tested, and treated. In many cases, the people who
tested positive may have already been infected with TB, and no person has
actually developed active TB symptoms from an airline flight, the WHO report
- However, as air travel increases, and
the number of drug-resistant TB cases careens out of control in Russia
and other nations, the likelihood that planes will become incubators for
dangerous TB infections is increasing, the report warned.
- "While screening for TB is usually
mandatory for immigrants and refugees, the overwhelming majority of passengers
flying on commercial aircraft" are not screened for TB, according
to the Tuberculosis and Air Travel Report.
- In 1994 alone, "there were almost
97 million passengers on international flights between the U.S. and the
rest of the world, the report said. "Clearly, medical examination
of millions of people traveling by air worldwide would not be possible."
- Tuberculosis accounts for more than 250,000
deaths each year in China.
- If new strains of TB are spread to the
U.S., they could prove highly expensive to treat. Ordinary TB can be effectively
treated with a six to eight month course of four very cheap medications.
But the medications which work against drug-resistant TB can cost up to
$10,000 per patient. In the late 1980s and early 1990s, the U.S. spent
over $1 billion to treat a mini-epidemic which involved less than 2,000
cases of multi-drug resistant tuberculosis, Castro said.
- Do refugees and immigrants pose a health
- The U.S. requires both refugees and immigrants
to be medically screened for TB and a host of other infectious diseases
within a year before leaving their home country, and also provides free
medical screening and treatment to refugees within 90 days of their arrival
in the U.S., according to Dr. David Smith of the U.S. Government Office
of International and Refugee Health.
- Under these requirements, a person can
theoretically become infected with TB within a year before entering the
U.S., then become infectious once he or she has entered the country.
- One indication that current TB screening
procedures may not be working: 42 percent of documented TB cases in the
U.S. last year occurred in foreign-born residents, said Castro, up from
about 22 percent in the mid-1980s.
- The CDC is "concerned" about
the possibility that current regulations are inadequate to stem the flow
of infectious, multi-drug resistant TB into the U.S., said Dr. Robert Wainwright,
director of the agency's Division of Quarantine. "We are now working
with the INS to look at the possibility of decreasing [the] times"
in which a person has to have a medical exam before entering the country.
- But requiring medical exams closer to
the time of emigration is not necessarily the solution, Wainwright said.
"Somebody could be infected with TB and not about to transmit the
disease at the time of the medical exam, and theoretically, within a few
days or weeks, could convert to being infectious."
- Another strategy for addressing the problem
is to spend more U.S. government money to combat the global TB epidemic,
health advocates at the WHO briefing recommended.
- "What we choose to do globally will
benefit us," Dr. Castro said. "If we sit back and allow drug-resistant
tuberculosis to grow unchecked, we may one day be faced with the threat
of incurable TB in our own midst."