State and federal disease investigators are tracking a
disturbing increase
in deaths among children stricken simultaneously with the flu and a
hard-to-treat, fast-moving bacterial germ.
Massachusetts health authorities have linked two recent
childhood flu
deaths to a germ called methicillin-resistant staphylococcus
aureus, known
as MRSA, which evades the most common antibiotics. Nationally, of
the 74
children known to have died from the flu in the United States in
2006-2007,
22 also had staph infections, most of which were MRSA.
Authorities at the US Centers for Disease Control and Prevention
are so
concerned by the phenomenon that next flu season they will activate
a
monitoring network at five sites - including one in Rochester, N.Y.
- to
hunt for patients co-infected with flu and MRSA. Specialists said
that
information and other findings could guide doctors to determine how
to
quickly intervene, preventing flu-MRSA cases from turning fatal.
Originally confined to hospital wards where it could find easy
targets
among the seriously ill, MRSA began migrating more broadly a decade
ago,
establishing a foothold across the United States and endangering
otherwise
healthy children and adults.
Scientists suspect that influenza is playing a deadly role in
MRSA cases:
The flu virus acts almost like a doorman for the bacterium, causing
changes
in the respiratory tract that allow the lethal germ to sneak in and
start a
devastating cascade of complications.
"I've been surprised by this phenomenon of MRSA with flu, which
has been
really quite shocking this winter," said Dr. Kenneth McIntosh, an
infectious disease specialist at Children's Hospital Boston, who
said he
believes there were other children with both flu and MRSA who
survived. "I
think everybody's concerned about it. What to do about it is not
clear."
So far, cases have been identified principally in children,
which probably
says more about the rarity of severe illness in youngsters than
about the
habits of the germs, specialists said.
Adults who die from the flu tend to be afflicted with an array
of
underlying medical problems, making it more difficult to identify
all the
factors contributing to their death.
Still, the tracking network being established next year will
endeavor to
more broadly gauge the impact of flu and MRSA on both children and
adults.
"For whatever reason, it does seem that people who are
co-infected are
more likely to die than people who are just infected with staph
aureus,"
said Dr. Alex Kallen, an Epidemic Intelligence Service officer at
the CDC
in Atlanta.
Researchers have known for the better part of a century that flu
patients
are prone to developing staph infections that can bring on
pneumonia, a
finding that became evident during the monumental flu epidemic that
swept
the world in 1918.
MRSA is a particularly virulent strain of staph that is a legacy
of
overusing antibiotics. When patients don't take their full course
of
antibiotics or they are given antibacterial medicine when they
don't really
need it, that allows hardier germs to survive, thrive, and acquire
the
genetic ability to outwit first-line antibiotics.
The germs find ready reservoirs in the noses and throats of
healthy people.
Most of the time, the bacteria just sit there, causing no obvious
harm.
"Being a carrier of MRSA has increased a lot, especially among
school-aged
kids," said Lyn Finelli, chief of influenza surveillance at the
CDC. "And
being colonized may put them at risk for a severe staph aureus
infection
when they get the flu."
That's because the flu virus destroys protective cells lining
the
respiratory tract, making it easier for staph germs to attach
themselves.
Plus, patients with flu have more difficulty clearing mucus lodged
in their
lungs, making pneumonia more likely.
MRSA germs "can get a foothold and cause pneumonia that they
wouldn't have
caused if the influenza virus hadn't been infecting," said Dr.
Alfred
DeMaria, director of communicable disease control for the
Massachusetts
Department of Public Health.
"It's a serious problem. Any pediatric complication of
influenza is a big
concern because, obviously, that's a dangerous situation."
In Massachusetts, two of the four children who succumbed to flu
this year
also harbored MRSA.
A 15-year-old Newton boy and a 12-year-old Worcester County girl
who died
of flu had also developed MRSA infections. Health agencies such as
DeMaria's are more closely tracking such cases.
In New Hampshire, the state Department of Health & Human
Services now
reviews death certificates as soon as they're filed, looking for
evidence
of flu and MRSA, said Dr. Jose Montero, the state's public health
director.
One New Hampshire child died this winter of the flu, but did not
have MRSA.
While MRSA infections can't be treated with the most common
antibiotics,
they may respond to higher-powered drugs. Also, flu vaccine may
help limit
the severity of illness, DeMaria said.
At the CDC, investigators decided to review the medical charts
of nearly
all children admitted to Atlanta-area hospitals with the flu in the
winter
of 2006-2007. They found that 11 percent of the youngsters also
suffered
from staph infections, with a little more than half caused by the
drug-resistant type.
"There are so many unanswered questions," said Carrie Reed, an
epidemiologist in the agency's flu surveillance branch who reported
the
findings last week at a scientific conference. "It's something
we're going
to continue looking at and, hopefully, come up with some better
conclusions
soon."
Stephen Smith can be reached at stsmith@globe.com.
c.2008 The Boston Globe