Hat tip to Alert
By Dr. Sanjay Gupta and Danielle
Dellorto, CNN
updated 11:17 AM EDT, Wed July 11, 2012Phnom Penh, Cambodia
(CNN) --
The cause of a mysterious illness that has claimed the lives of more
than 60 Cambodian children has been determined, medical doctors familiar with
the investigation told CNN on Wednesday.A combination of pathogens,
disease-causing micro-organisms, is to blame for the illness, the World Health
Organization, in conjunction with the Cambodian Ministry of Health, has
concluded, the doctors said.
The pathogens include
enterovirus 71,
which is known to cause neurological disease; streptococcus suis, which can
cause infections like bacterial meningitis in people who have close contact with
pigs or with pork products; and dengue, which is transmitted by
mosquitoes.
The
inappropriate use of steroids, which can
suppress the immune system, worsened the illness in a majority of the
patients, the doctors said. The World Health Organization (WHO) is expected to
advise health care workers to refrain from using steroids in patients with signs
and symptoms of the infection, which include severe fever, encephalitis and
breathing difficulties.
While not all the microorganisms were present in
each patient, doctors concluded the illness was caused by a combination of them
and worsened by steroid use.
The WHO sources did not want to be
identified because the results of the health organization's investigation have
not yet been made public.
"
I'm very confident for the reason of the
epidemic," said Dr. Phillipe Buchy, chief of virology at the Institut Pasteur in
Cambodia and one of the doctors who cracked the case.
"The first
thing that goes through your mind is, is this one of the usual suspects you
haven't detected before?" said Dr. Arnaud Tarantola, chief of epidemiology and
public health at the Institut Pasteur. "If it is, has it mutated, or changed in
a way that it causes more severe disease? Or is it something completely
new?"
On the steroids issue, Tarantola said, "When you have a dying
child, you try to use what you have at hand, and they were right to try that."
But, he acknowledged, "from the cases we reviewed, almost all of the children
died, and almost all of them had steroids."
Parents face anxious wait
over mystery illness
"I think we can close the case and move ahead asking
different questions," Buchy said. "Not what is the illness, but now, how long
has the virus been circulating? What is the extent of the circulation of the
virus? How many mild diseases are we missing? That's the next step."
Over
the past four months, doctors at Kantha Bopha Children's Hospitals in Phnom Penh
have been faced with the mysterious syndrome, which kills children so fast that
nearly all of those infected with it die within a day or two of being admitted
to the hospital.
Dr. Beat Richner, head of the children's hospitals --
which cared for 66 patients affected by the illness, 64 of whom died -- said
that no new cases of the illness had been confirmed since Saturday.
Other
hospitals in the country have reported similar cases, but far fewer than the
children's hospitals in the capital, which are the most popular.
In the
last hours of their life, the children experienced a "total destruction of the
alveola(e) in the lungs," Richner said. Alveolae are the air sacs where oxygen
enters the bloodstream.
Most of the children who have contracted the
illness have come from the south of the country, though health officials cannot
find what is known as a cluster -- a lot of cases coming from one specific
area.
By June 29, the WHO had been contacted and Cambodian officials were
scrambling to instruct health providers across the country to spread information
about the illness as quickly as possible.
Officials search for clues in
disease killing Cambodia's children
The WHO and the Cambodian
authorities' announcement of the situation drew criticism from Richner, who said
they were "causing unnecessary panic."
The WHO said the unexplained
nature of the outbreak obliged it to communicate the information.
Over
the weekend, lab tests linked enterovirus 71 (EV71) to some of the cases. But
the tests didn't solve the whole puzzle and health officials continued their
investigations, noting the detection of other elements like streptococcus suis
and dengue.
The link to EV71 does not particularly help in the treatment
of the illness, as there is no effective antiviral treatment for severe EV71
infections and no vaccine is available.
In milder cases, EV71 can cause
coldlike symptoms, diarrhea and sores on the hands, feet and mouth, according to
the journal Genetic Vaccines and Therapy. But more severe cases can cause fluid
to accumulate on the brain, resulting in polio-like paralysis and
death.
Outbreaks of the enterovirus "occur periodically in the
Asia-Pacific region," according to the CDC. Brunei had its first major outbreak
in 2006. China had an outbreak in 2008.
Adults' well-developed immune
systems usually can fend off the virus, but children are vulnerable to it,
according to the CDC.
"It looks like (EV71) has emerged strongly,
probably because it hadn't circulated with the same intensity in the past
years," Tarantola said.
Reported cases of streptococcus suis have risen
significantly in recent years, notably in Southeast Asia, according to a paper
that appeared last year in Emerging Infectious Diseases, a journal published by
the Centers for Disease Control and Prevention in Atlanta.
The rainy
season in Cambodia, which lasts from May to October, is a key problem in trying
to control diseases like dengue. Because of a lack of indoor plumbing in many
homes, people collect rainwater in vats, creating potential breeding grounds for
mosquitoes.
In Cambodia, as with many places around the world, parents
first try treating their child at home. If that doesn't work, they typically
then go to a local clinic. A hospital visit, which often involves a long trip,
is a last resort.
