Doctors currently have a difficult time diagnosing human forms of mad cow disease, a rare but fatal neurological disorder caused by an accumulation of misfolded proteins. Patients suspected of having the disease must undergo painful  and distressing procedures so that doctors can look for the aberrant proteins in the fluid that circulates through their brain. However, two new studies published this week in the New England Journal of Medicine show that researchers are on the road toward much more accurate and much less invasive tests.

Mad cow disease is one of several forms of transmissible spongiform encephalopathy caused by misfolded proteins called prions that can be transmitted among cattle and potentially transmitted to humans who consume beef from an infected animal. A form of the disease called chronic wasting disease occurs in deer, and the human form is called Creutzfeldt-Jakob disease, or CJD. Sporadic CJD has no known cause, whereas variant CJD is what humans can acquire from eating tainted beef.

One test is based on finding prions in nasal swabs, and the other utilizes a powerfully sensitive technique that can detect trace amounts of prions in human urine. Both tests are easily administered compared with the current method for CJD diagnosis. However, better tests cannot decrease the mortality of CJD since there are no cures or treatments. Still, the tests can be used to find early cases and guide efforts to minimize transmission of the disease.

“We also need rapid, sensitive and specific tests to help us make the correct diagnosis for people presenting with dementia,” said Dr. Colin Masters, a prion disease researcher at the University of Melbourne, in Australia. “It is sometimes very difficult to be sure of the correct diagnosis using just (signs and symptoms),” said Masters, who wrote an editorial published with the studies.

The nasal swab-based test was able to identify 30 of 31 patients with CJD. The urine-based test found 13 of 14 people with variant CJD. Both tests were perfect in correctly identifying people who did not have either sporadic or variant CJD.

“Variant CJD and sporadic CJD are different diseases,” said Claudio Soto of the University of Texas Health Science Center in Houston.