New optical tool promises rapid and accurate diagnosis of malaria

   Apr 20, 1:04 am

Washington, Apr 19 (ANI): A potential new optical imaging system may make the diagnosis of malaria much easier, faster and more accurate, a new study has revealed.

The new system, developed by an international team of researchers, uses "speckle imaging," an optical sensing technique that measures the differences in how laser light bounces off the membranes of healthy and infected red blood cells.

By comparing the apparently random scattering (speckling) of light as it builds up from multiple images, a clear statistical pattern emerges that identifies cells that harbor the parasite responsible for malaria.

The team's preliminary results involved 25 cell samples (12 healthy, 13 infected).

"A new diagnostic tool is urgently needed," noted Dan Cojoc, Ph.D., lead author of the study and a researcher at the Materials Technology Institute, National Research Council in Trieste, Italy.

"With a fast, portable, low-cost, and accurate diagnostic tool, physicians can confidently and quickly administer the correct therapy."

According to the researchers, this timely diagnosis maximizes the likelihood of successful, life-saving treatment. It also minimizes the chances that inappropriate therapy will be given, which would help combat the growing problem of drug resistant malaria.

The current diagnostic gold standard for malaria, Giemsa-stained blood smear, uses optical microscopy to identify different species of the malaria agent, Plasmodium, in blood samples.

This technique requires skilled medical professionals trained to identify the telltale signs of the parasite throughout its life cycle and its population density in the bloodstream.

In an effort to find a more effective means of detection, Cojoc's team of biophysics researchers in Italy joined forces with malaria experts from Israel and Spain.

Together they turned to speckle imaging, because of its ability to construct a statistically significant picture, as a new way to improve the diagnosis of malaria. It's called speckling because of light's wave-like ability to brighten as waves combine and fade as they cancel. The resulting patterns have a distinctive speckled pattern.

The specific technique the researchers used is called Secondary Speckle Sensing Microscopy.

By applying this imaging technique to an automated high-throughput system, the researchers were able to deliver results in as little as 30 minutes.

They did so with a high rate of accuracy and without the need for highly trained technicians and a well-equipped hospital laboratory. The current time to diagnosis in most African medical centers is typically between 8-10 hours.

Secondary Speckle Sensing Microscopy begins with illuminating red blood cells with a tilted laser beam. This produces a time-varied speckle pattern field based on the cells' thermal vibration and the movement of their membranes - traits that differ in healthy and diseased states.

The speckle patterns are inspected under the microscope and recorded on a camera at a high frame rate.

Using two automated analytical methods - "fuzzy logic" and "principal component analysis" - scientists scour a set of speckle parameters to extract statistical information about changes in red blood cells' membranes and their flickering movements.

Scientists then make a diagnosis based on statistical correlations in speckle patterns between healthy and diseased cells.

While these preliminary results are encouraging, the investigators noted that further study is needed to validate the results and further refine the technique. If the positive outcomes hold up, field studies or clinical trials of the new method might be deployed as early as 2013.

The study has been published in the Optical Society's (OSA) open-access journal Biomedical Optics Express. (ANI)

Pakistan airstrikes kill 17 militants in Khyber Agency Nov 28, 8:26 am
Peshawar, Nov. 28 (ANI): In an airstrike carried out by the Pakistan Air Force near the Afghan border, 17 militants have been killed.
Full Story
Colorado: A cop, two people killed in birth control clinic shootout Nov 28, 7:59 am
London, Nov. 28 (ANI): An officer and two people were after a shootout inside a 'Planned Parenthood' clinic in Colorado Springs took place and the gunman has surrendered.
Full Story
Indian-American offloaded from international flight in Islamabad over 'bomb hoax' Nov 27, 7:04 pm
Islamabad, Nov. 27 (ANI): An Indian-American man on board the Qatar Airways flight to Washington via Doha was offloaded at the Benazir International Airport in Islamabad around 3 a.m. on Friday after he claimed that there was a bomb on the aircraft, which later turned out to be a hoax.
Full Story