Adenovirus Starts as a Cold then Turns Killer

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Virus Starts Like a Cold But Can Turn Into a Killer

By Rob Stein, Washington Post Staff Writer

Tuesday, December 11, 2007; Page A01

Infectious-disease expert N. Gilbert was making rounds at the

Providence Portland Medical Center in Oregon in April when he realized

that an unusual number of patients, including young, vigorous adults,

were being hit by a frightening pneumonia.

" What was so striking was to see patients who were otherwise healthy

be just devastated, " Gilbert said. Within a day or two of developing a

cough and high fever, some were so sick they would arrive at the

emergency room gasping for air.

" They couldn't breathe, " Gilbert said. " They were going to die if we

didn't get more oxygen into them. "

Gilbert alerted state health officials, a decision that led

investigators to realize that a new, apparently more virulent form of

a virus that usually causes nothing worse than a nasty cold was

circulating around the United States. At least 1,035 Americans in four

states have been infected so far this year by the virus, known as an

adenovirus. Dozens have been hospitalized, many requiring intensive

care, and at least 10 have died.

Health officials say the virus does not seem to be causing

life-threatening illness on a wide scale, and most people who develop

colds or flulike symptoms are at little or no risk. Likewise, most

people infected by the suspect adenovirus do not appear to become

seriously ill. But the germ appears to be spreading, and investigators

are unsure how much of a threat it poses.

" This virus has the capability of causing severe respiratory illness

in people of all ages, regardless of their medical condition, " said

Su, a disease investigator for the Centers for Disease Control

and Prevention based in Texas, where the largest outbreak is tapering

off at an Air Force base after 10 months. Other outbreaks have been

reported in Washington state and South Carolina, along with a single

case in an infant in New York City.

" What people need to understand is that there is a virus out there

that can make you very, very sick, " Su said. " If you have a bad cold

and your symptoms keep getting worse, go see your doctor. This is

nothing to be necessarily alarmed about. But it is important to be

aware that this bug is out there. "

The emergence of the virus is the latest example of how new,

potentially dangerous pathogens can suddenly appear.

" Infectious agents have the capacity to mutate and change form, and

from time to time, either genuinely new agents appear or old agents

appear in new guises, " said Schaffner, an infectious-disease

expert at Vanderbilt University. " This appears to be another one of

those emerging infections that has taken on genetic material or

mutated so that it is now more virulent than it used to be. "

The virus, which spreads like those that cause flu or colds, raises

many questions: Why has it suddenly become more common? Why is it

apparently more dangerous? How often does it make people seriously

ill? Who is most vulnerable? Is the threat growing or fading?

" We don't know why it's associated with these severe cases, " said Dean

D. Erdman, who is studying the virus at CDC headquarters in Atlanta.

" We don't know whether it's going to become a bigger problem in the

future or whether we'll see more outbreaks of severe disease. These

are all questions we're trying to answer. "

There are 51 known strains of adenovirus, ubiquitous germs that cause

many illnesses, including colds, pinkeye, bronchitis, stomach flu and

a respiratory infection called boot camp flu that has long plagued

soldiers. But adenovirus infections rarely have been life-threatening,

especially for healthy young adults.

The new adenovirus is a variant of a strain known as adenovirus 14.

First identified in Holland in 1955, it has caused sporadic outbreaks

in Europe and Asia. No outbreaks, however, had ever been documented in

the Western Hemisphere.

But then Gilbert started seeing patients like ph Spencer, 18, a

high school varsity swimmer who was suddenly racked by fever, chills

and vomiting.

" At first I thought it was just the flu, " Spencer said. " But then it

was the worst feeling I ever had. I felt so miserable. I really felt

like I was dying. "

Spencer's mother took him to the emergency room, where he was placed

in intensive care, sedated and put on a respirator. " Even then, we

told the family we didn't think he was going to survive, " Gilbert said.

The teen spent 18 days in the hospital and was able to return home.

But after weeks of bed rest and physical therapy, he remains short of

breath and weak, and he is having memory problems.

" I don't know if I'll ever be fully recovered, " Spencer said. " I never

imagined anything like this would ever happen to me. "

Spencer was not even the sickest. Of the 30 patients Oregon officials

identified as having the virus, seven died. " That's an incredibly high

mortality rate, " Gilbert said.

At about the same time, health officials learned of another outbreak

affecting four residents of a nursing home in Washington state,

including one person who died, as well as a far larger outbreak at

Lackland Air Force Base in Texas. At least 579 recruits have been

infected since February at the base, including at least 24 who had to

be hospitalized. One recruit, Paige Villers, 19, of Norton, Ohio, died

after getting mononucleosis and the virus.

" All of a sudden out of nowhere she just got sick, " said Villers's

mother, . " She thought it was just something she needed to

fight off. But instead of getting better, she just got worse and worse. "

Another 220 cases later turned up at other Texas military bases, along

with about 200 more cases at the Marine Corps' Parris Island

installation in South Carolina.

Investigators also determined that an otherwise healthy 12-day-old

girl who died in Manhattan in May 2006 had been infected with the same

strain.

A genetic analysis of the microbe at the CDC revealed that the

currently circulating version of the virus is slightly different from

the original 1955 strain, suggesting the microbe had mutated in some

way to make it more virulent.

" There are some suspicious changes in certain genes, " Erdman said.

" What we're trying to do now is link those changes to behavioral

changes in the virus. "

Because doctors do not routinely test for adenovirus, investigators

are uncertain how common it is. But recent surveys, including testing

at military bases around the country, indicate that the virus suddenly

appeared widely across the United States in 2006, showing up in

significant numbers at military bases in San Diego, near Chicago and

in Georgia.

" It had been looked for but never identified prior to that, " said

Metzgar of the Naval Health Research Center in San Diego, who

has been tracking the virus among military recruits. " It was a very

widespread emergence. "

The CDC reported the emergence of the virus and 362 cases on Nov. 16,

but additional infections have since occurred in Texas and the report

did not include the South Carolina patients.

In Oregon, further testing has shown that the virus now accounts for

more than half of all adenovirus infections. " That's shocking, " said

, a state health investigator. " It went from being

imperceptible to being the majority. "

Officials emphasize that the virus, even if it is widespread, may be

only rarely causing serious illness.

" It's like the blind person touching different parts of the elephant.

We're touching the part of the elephant that is the sickest, " said Ann

of the Oregon Department of Human Services.

The outbreak in Texas, which appears to be tapering off, supports that

theory.

" Even though it was more common to get more serious illness than is

usual for adenovirus, most of the people who got infected had just a

cold, and a small percentage had the more serious complications, " said

Larry J. , director of the CDC's division of viral diseases.

" Why some who were infected got more serious illness we do not know. "

Some people may be genetically prone to the infection or have weaker

immune systems, he said. Or it could just take time for people to

build up immunity. But other experts say they believe the virus is

inherently more dangerous.

" My gestalt is that it's more virulent than average, " said C.

Gray, director of the Center for Emerging Infectious Diseases at the

University of Iowa. " The consensus among people who look at adenovirus

is this is a particularly virulent strain. "

In the meantime, researchers are trying to determine whether any

antiviral drugs are effective against the bug and whether vaccines

that protect against other strains offer any defense. They are on the

lookout for the virus.

" Are we going to have another huge outbreak, or will it disappear? "

Gilbert said. " We just don't know. "

Villers said she hoped her daughter's death might at least

alert others.

" After my daughter's funeral in August, my son got sick in September

with very similar symptoms, " she said. " It turned out he just had

strep throat. But parents need to press their doctor for tests, ask

for tests, and keep pressing until you get results. My daughter, she

had symptoms that just looked like the cold or like the flu. You hear

of people dying of pneumonia, but it's usually older people. Not a

19-year-old in the prime of her life. "

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