(Image courtesy of Andrew Brooks via Getty Images)
One Oregon county has reported three cases of a disease similar to mad cow disease, with a 100% fatality rate.
In the past eight months, health officials have confirmed one case and identified two possible cases of the rare brain disorder, according to a statement released by the Hood River County Health Department on April 14. Hood River County is south of the Columbia River, on the border with Washington and Oregon. Two of the people affected have died, the department said.
One case has been confirmed through an autopsy, and the other two are considered presumptive, The Oregonian reported. Trish Elliott, director of the Department of Health, told The Oregonian that presumptive cases can only be confirmed after death through testing of brain tissue and cerebrospinal fluid — the clear fluid that surrounds the brain and spinal cord — adding that the process could take months.
“At this time, no links have been established between the three cases,” the health department added.
The mad cow-like disease reported in Oregon is called Creutzfeldt-Jakob disease (CJD), named after two German doctors who first described the condition in the 1920s. The disease affects about 1 to 2 people per million worldwide, with about 350 cases reported in the United States each year. Hood River County has a census population of about 23,000 to 24,000, so three cases of CJD are statistically unusual.
Like mad cow disease, Creutzfeldt-Jakob disease is a prion disease, meaning it is caused by abnormally folded proteins that damage brain tissue; in the case of CJD, this results in spongy holes in the brain. Prions also cause normal proteins in the brain to degenerate, turning them into prions, which then continue to cause damage.
Symptoms of the disease can vary, including confusion, disorientation, hallucinations, problems with coordination, muscle rigidity, and personality changes that first manifest as psychological disturbances and seizures. Symptoms progress rapidly, causing those with the disease to lose awareness of their surroundings and be unable to communicate. The disease is inevitably fatal, with about 70% of those affected dying within a year of diagnosis.
The most common variant of CJD is “sporadic,” meaning that normal proteins in the brain spontaneously transform into prions for unknown reasons. The second most common is a genetic variant caused by inherited mutations in the PRNP gene. This gene is responsible for producing the prion protein (PrP) that is active in the brain, but its normal functions are not yet fully understood. Some studies suggest that the normal version of PrP may help protect neurons from damage and form connections between them.
The best-known form of CJD is also the rarest, accounting for less than 1% of cases. It is caused by the introduction of prions into the body from external sources. For example, this can occur if a person eats beef from cows affected by bovine spongiform encephalopathy (BSE), more commonly known as mad cow disease; only seven cases of BSE have been reported in cows in the United States. Another potential source of prions is medical interventions, such as transplants or transfusions from donors with CJD.
To prevent cases of “acquired” CJD in the United States, strict agricultural regulations have been in place since the 1990s to prevent the consumption of beef contaminated with mad cow disease. There are also infection control guidelines to minimize the risk of CJD transmission through medical procedures.
The Hood River County Health Department has not specified what type of CJD is likely linked to
Sourse: www.livescience.com
