Is it flu or malaria? New disease testing Micro-chip has answer
Pastor Dale Morgan
Is it flu or malaria? New disease testing Micro-chip has answer*
By Maggie Fox, Health and Science Editor
Reuters
Wednesday, December 6, 2006; 12:17 AM
WASHINGTON (Reuters) - A new diagnostic tool called a gene chip can tell
with a single test if a patient has malaria, Ebola, influenza or a
bacterial infection, researchers said on Wednesday.
The so-called GreeneChip can quickly diagnose infectious diseases caused
by viruses, bacteria, fungi or parasites, using tissue, blood, urine and
stool, the international team of researchers report in the journal
Emerging Infectious Diseases.
So when a patient comes in with flu-like symptoms, such as fever, a sore
throat, a cough and muscle aches, a doctor armed with such a chip can
quickly tell if it is a dangerous strain of flu or a relatively harmless
virus.
The GreeneChip is a glass slide with row after row of DNA or RNA samples
from nearly 30,000 different viruses, bacteria, fungi and parasites.
"When human fluid and tissue samples are applied to the chip, these
probes will stick to any closely related genetic material in the
samples," the U.S. National Institute of Allergy and Infectious
Diseases, which helped develop the chip, said in a statement.
Doctors have been asking for such a tool for years, although widespread
availability of the chip will require more work. An estimated half of
all upper respiratory infections in the United States are never
diagnosed, in part because it is so cumbersome, expensive and
time-consuming to test patients for every single virus or bacteria that
might be the cause.
Dr. Ian Lipkin, director of the Greene Infectious Disease Laboratory at
Columbia University in New York, noted that hundreds of different
infectious agents all can cause similar symptoms.
"Methods that simultaneously screen for multiple agents are important,
particularly when early accurate diagnosis can alter treatment or assist
in containment of an outbreak," Lipkin said in a statement. The chip is
named for his lab.
The researchers tested their chip on samples from patients with
respiratory disease, hemorrhagic fever, tuberculosis and urinary tract
infections.
The GreeneChip diagnosed the infectious agent as accurately as older and
slower methods, such as culturing or growing the bacteria or virus, or
using polymerase chain reaction to look at the genetic material and
identify the infectious agent that way.
"In addition, the GreeneChip was used in the analysis of an unknown
sample from a patient with a viral hemorrhagic fever (VHF)-like
syndrome," Columbia University wrote in a statement.
The researchers tested samples from a health care worker who died during
an outbreak of deadly Marburg virus in Angola, which ended up killing 90
percent of its 252 victims.
A PCR test showed no evidence of Marburg virus, and neither did the
GreeneChip. But the chip then identified Plasmodium -- the parasite that
causes malaria.
Had the GreeneChip been available then, the worker could have been
treated for malaria.