Plasmodium Falciparum (stained green)
amidst red blood cells
***
Malaria
Wikipedia
200,000,000 people infected yearly.
Of those, c. 1,000,000 die.
Richard T. Ellison III, MD
A novel transdermal laser technique can detect malaria noninvasively,
without the need for chemical reagents or blood samples.
http://www.jwatch.org/content/
The need for sophisticated blood testing for diagnosis has hampered efforts
to control malaria. However, all blood-stage malaria parasites produce
nanocrystals of a unique compound — hemozoin — as they digest hemoglobin,
and researchers have now developed a technique that appears to be able to
detect these nanoparticles transdermally.
Hemozoin has high optical absorbance, and the heat generated when
hemozoin nanocrystals are exposed to a picosecond pulse from a
near-infrared laser evaporates liquid around them, producing transient
vapor nanobubbles (VNBs). The explosive generation and subsequent
collapse of these VNBs generate characteristic optical and acoustic
signals, and researchers were able to define these signals in studies
of isolated hemozoin nanocrystals in water. Subsequent experiments
confirmed that such VNBs could be generated and detected within
Plasmodium falciparum–infected human red blood cells, but not in
uninfected red blood cells. In studies involving malaria-infected mice,
a transdermal laser probe applied to the ear could detect hemozoin VNBs
at a 0.00034% level of parasitemia without any apparent discomfort or
morphological damage to ear skin or blood vessels.
Comment
This technique needs to be tested in humans to define its
sensitivity, specificity, and safety. However, assuming no safety
concerns, it could potentially revolutionize the diagnosis of
malaria and greatly improve clinical management, as well as
surveillance and eradication efforts.
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