COLUMBUS , Ohio People who have high cholesterol levels may be much more susceptible to a particular disease transmitted by the bites of ticks, a new study in mice suggests.
Scientists infected mice with Anaplasma phagocytophilum, the bacterium that causes human granulocytic anaplasmosis (HGA), a disease with flu-like symptoms. Bacteria levels were 10 times greater in mice that were genetically predisposed to high cholesterol levels and that were also fed a high-cholesterol diet.
The results confirmed what the researchers had suspected that A. phagocytophilum depends on its host's cholesterol stores for its survival.
The implication is that the higher a person's cholesterol levels, the more susceptible that person may be to developing a severe case of HGA, said Yasuko Rikihisa, the study's lead author and a professor of veterinary biosciences at Ohio State University.
Yet HGA is difficult to accurately diagnose, as symptoms are similar to those of the flu and include high fever, muscle aches, chills and headaches. But in some cases misdiagnosis can be devastating.
Young, healthy people probably don't develop very severe symptoms, Rikihisa said. But left undetected, the infection could kill an older person or someone with a weakened immune system.
She added that immune function slowly declines and blood cholesterol levels typically increase as we age.
The researchers report their findings in a recent issue of the Journal of Infectious Diseases. Rikihisa conducted the study with Qingming Xiong and Xueqi Wang, both graduate students in Rikihisa's laboratory.
Experts say that HGA is on the rise in the United States , where anywhere from 400 to more than 1,000 people contract the disease each year. It is transmitted by the bite of Ixodes scapularis, or deer tick. Deer ticks also spread Lyme disease, and are found primarily in the upper Midwest, New England, parts of the mid-Atlantic Stat
Contact: Yasuko Rikihisa
Ohio State University