Bug Zappers
by Paul Karr
Researchers at the UGA Center for Tropical
and Emerging Global Diseases study a host of parasite-borne diseases some well
known, some youve probably never heard of, but all a threat
to global health.
Julie Moore, who joined the team last year as an assistant professor
of medical microbiology and parasitology, deals with one of the
most challenging and pernicious: malaria, which occurs in high
incidence in sub-Saharan Africa and other lesser-developed nations.
She spends up to four months each year in Kenya, India and other
affected areas trying to understand the complexities of the disease.
Spread by mosquitoes, malaria is an especially
tricky infection: It can take many different forms, depending
on the region of the
globe and the quantity of infection. Worldwide, it kills about
3 million people a year 90 percent of them African and
afflicts many more. The mosquitoes that carry the disease were
nearly eradicated during the 1960s by DDT spraying programs, but
now they have rebounded stronger than ever. Yet it is only beginning
to capture research attention and funding.
Four babies die from malaria each minute, yet there is no
vaccine for it, Moore said. Thats true for a
very simple reason: People in the United States rarely get malaria,
and so the research money goes toward other diseases.
Moore studies successful immune responses to the disease, reasoning
that an understanding of what responses work well will be critical
to the later development of a vaccine.
Also on the centers hit list are:
- African sleeping sickness: Often
fatal, this disease takes two forms that are passed on
by the bite
of the tsetse fly as
it feeds on human or animal blood. The first form is exceptionally
painful and often kills its victims within several weeks;
the other causes an infection and slower decline lasting
several
years but it is also often fatal. Associate cellular
biology professor Kojo Mensa-Wilmot is probing the biology
of the two
Trypansoma brucei parasites that cause the disease in the
hope that it will lead to a vaccine or other preventative
measures.
- Insect saliva: To combat diseases,
researchers are learning how insects transmit them in the
first place.
Donald Champagne,
an assistant entomology professor, studies the polypeptides
in insect saliva and the ways in which those substances
alter the
blood of an infected human or animal host so that the parasite
can be transmitted. Some insects inject an anticoagulant
and an immunosupressant that alter and affect the hosts response
to parasites, which means the insect is actually helping the
parasite create infection. Eventually, work like Champagnes
may help scientists develop defenses to infectious bites.
- Schistosomiasis: Cellular biologist Raymond Damian has studied
a range of problems relating to this disease of the intestinal
and urinary tracts. Schistosomiasis affects more than 200 million
people in Africa, South America, and the Middle and Far East,
not to mention millions of livestock.
- Toxoplasma gondii: This parasite is mainly transmitted through
cat feces and causes toxoplasmosis, which is why pregnant women
should avoid exposure to cat litter during their first trimester.
To learn how the infection spreads, assistant cellular biology
professor Boris Striepen applies substances to pathogenic cells,
then uses dyes and time-lapse video microscopy to document the
infection process in slow-motion detail.
For more information about the CTEGD, access http://www.uga.edu/ctegd/.
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