Cincinnati--Carl J. Fichtenbaum, MD, associate professor of
infectious diseases, University of Cincinnati (UC) College of Medicine,
said recent research done by himself and his colleagues shows "the drug
rifabutin, commonly used to prevent bacterial infection, also prevents
infection from the one-cell parasite called Cryptosporidium (or Crypto)
in advanced HIV patients." Cryptosporidiosis infection is caused by
ingesting water or food that harbors Crypto.
contaminated water from rivers, lakes, swimming pools, and hot tubs,
places one at greater risk for Crypto infection, but even consuming
unfiltered drinking water can be risky, because chlorine treatment
doesn't always kill Crypto. In a healthy adult, Crypto-infected water
causes acute diarrhea for one to four weeks. In people with AIDS, the
illness often becomes chronic, severe, and sometimes fatal.
Fichtenbaum's research findings into prevention of Crypto was reported
in the December 22, 2000 issue of AIDS and the January 12 Reuters Health Information.
"Rifabutin but not clarithromycin (an antibiotic) is effective in
preventing cryptosporidiosis in patients with advanced HIV infection
who are not receiving potent combination antiviral therapy,"
Fichtenbaum and his colleagues performed a
cross-protocol analysis of 2,288 patients with advanced HIV infection.
The subjects were enrolled in two prospective clinical trials between
December 1992 and June 1995 to prevent specific bacterial and viral
infections. While those receiving rifabutin "had about a 50 percent
reduction in risk of developing Crypto, clarithromycin showed no
effect," Fichtenbaum said.
People with immune systems compromised
by anti-rejection drugs (used in transplants), chemotherapy, or HIV
infection are at increased risk of severe cryptosporidiosis. The best
way to prevent exposure to Crypto is to drink only boiled, filtered, or
bottled water, and to make sure raw fruits and vegetables have been
peeled, properly washed, and/or disinfected.
"Rifabutin is an inexpensive and effective medication for use in
developing countries where there is no access to potent antiviral
drugs." He cautioned that rifabutin should not be given by itself when
a patient has tuberculosis (TB) as it may lead to an
antibiotic-resistant form of TB.