Person-to-person spreading of disease worries experts
| • | State investigating two Kaua'i patients |
By Rob Stein
Washington Post
New diseases have emerged periodically throughout human history, but the one the world is struggling to contain and explain today has aroused intense concern largely because it is the first often life-threatening illness to surface in nearly two decades that spreads directly from one person to another.
Associated Press
The ailment, dubbed severe acute respiratory syndrome, or SARS, has stricken at least 264 people outside China, killing at least 14. Other new, sometimes deadly respiratory diseases have erupted around the world the past decade, but they were transmitted from animals to people and subdued by killing or segregating the animal carriers. The most recent new disease in the United States, the West Nile virus, is spread by mosquitoes.
A pedestrian wears a mask as he walks in a crowd in Guangzhou in southern China's Guangdong province, yesterday. The World Health Organization is trying to determine whether an outbreak of a mystery illness in Guangzhou in November is connected to a similar global outbreak that has been linked to 14 deaths.
"Anytime something is transmissible person to person, it bears very careful watching," said Stephen Morse of Columbia University in New York.
Raising fears that the disease may spread more easily than has been thought, health officials in Hong Kong reported yesterday that the outbreak there may have begun when one guest in a hotel infected six other people on his floor.
The doctor had been treating patients in mainland China's Guangdong province, where hundreds of people have been stricken by a similar disease since November. Between Feb. 12 and March 2, six people contracted the disease after staying on or visiting the doctor's floor, including three from Singapore, two Canadians and a Hong Kong resident. The local resident apparently spread the disease to the Hong Kong hospital hit hardest by the epidemic. The doctor died.
Also yesterday, U.S. officials said they were investigating 11 people in the United States who have symptoms consistent with the disease who recently returned from Asia.
In most cases, the disease does not appear to spread casually — from simply sitting next to a sick person on an airplane, for example. The majority of cases over the last few weeks have been among family members and hospital workers. Officials were increasingly optimistic that worldwide containment efforts were working, and some victims were starting to recover.
But in addition to jumping from one person to another, the SARS pathogen has resisted antibiotics and, so far, eluded identification.
"All of these things are coming together to make this a potentially very bad agent," said Robert Webster of the St. Jude Children's Research Hospital in Memphis. "It has the pattern of an emerging viral disease of significant importance."
That pattern includes the ability to show up quickly in far-flung parts of the world.
"We're seeing waves of disease and we're seeing the spread from the geographic area where it originated to other areas of the globe," said Margaret Hamburg, a disease expert at the Nuclear Threat Institute in Washington.
The AIDS virus is perhaps the last new, often deadly infectious agent to be discovered that can be transmitted from one person to another, but it requires intimate contact.
"HIV is very, very serious, but one of the saving graces is it requires intimate contact. This apparently does not," Webster said. "This is the kind of emerging infectious disease that is the greatest worry."
The greatest fear is a repeat of the 1918 Spanish flu, the world's most deadly flu pandemic. It killed more than 20 million people worldwide, including 500,000 in the United States.
Experts have been warning for years that the world was due for another global flu pandemic because of natural shifts in the genetics of viruses. Hamburg noted that, as in 1918, the world today is poised for war, during which people tend both to disperse, carrying diseases with them, and to congregate in places such as military camps, which provides "a lot more opportunity of spread," she said.
And as with the Spanish flu, "previously healthy people in the prime of their lives are becoming seriously ill," Hamburg said.
Fears of another global flu pandemic have long shadowed public health workers. The 1976 swine flu outbreak, which began with soldiers at Fort Dix in New Jersey, prompted an attempt to vaccinate all Americans. But the epidemic never materialized, and the vaccine ended up killing some recipients and seriously injuring hundreds. The vaccination program was seen as one of the great blunders in public heath.
Also that year, a mysterious pneumonia-like disease struck conferees at an American Legion convention in Philadelphia. Ultimately, 221 patients were stricken and 34 eventually died from what became known as Legionnaire's disease. The cause was discovered six months later: a bacterium, dubbed Legionella.
Throughout the 1990s, a series of new, sometimes fatal respiratory diseases emerged, all of which were spread to humans from animals.
But some seemingly frightening new diseases quietly subside before doing much damage.
"Many of them fizzle out. We often don't understand why something that seems aggressive at first doesn't get passed around. We're just lucky," said Joshua Lederberg of the Rockefeller University in New York.
One reason is that when viruses jump from animals to people, their ability to spread tends to diminish as they get passed along, according to David Heymann of the World Health Organization.
"When an agent gets into humans that doesn't normally reside there sometimes ... the second generation of infections is less severe," Heymann said. "That's the hope with this one."
