Virus Starts Like a Cold
But Can Turn Into a Killer
By Rob Stein
Washington Post Staff Writer
Tuesday, December 11, 2007; A01
Infectious-disease expert David 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
"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 John 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 William 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
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
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
But then Gilbert started seeing patients
like Joseph 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
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,"
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,
Michelle. "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
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
"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 David
Metzgar of the Naval Health Research
Center in San Diego, who has been
tracking the virus among military
recruits. "It was a very widespread
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 Paul Lewis, a
state health investigator. "It went from
being imperceptible to being the
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 Thomas 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. Anderson,
director of the CDC's division of viral
"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 Gregory 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."
Michelle Villers said she hoped her
daughter's death might at least alert