Researchers recently discovered a previously unknown strain of rabies in Lincoln County, New Mexico. The strain was identified in a rabid fox that bit a 78-year-old woman in April, NBC reported.

A genetic sequencing test conducted by the U.S. Centers for Disease Control and Prevention confirmed that the strain had never been seen before. The strain does not pose a threat to public health, but is one of the first new strains of rabies to be found in the country, officials said.

According to NBC, state officials believe the fox became a carrier of the virus after coming in contact with an infected bat. State public health veterinarian Paul Ettestad said he believes the strain has existed for some time, and was discovered by chance. He added that no one has looked very hard for new strains of the virus. He said the strain is similar to other strains, and that the reservoir for the new strain has yet to be identified.

Dr. Retta Ward from the New Mexico Department of Health confirmed that the new strain is related to other strains found in bats. In addition, Ward revealed that state health officials plan to work with other agencies to collect dead foxes from Lincoln County and test them for the presence of the virus.

According to the World Health Organization, rabies kills more than 50,000 people annually. Anti-rabies vaccine shots easily prevent the disease.