MERCED COUNTY, Calif. (KSEE/KGPE) - Merced County officials are warning the community of fake letters that are telling residents they have positive STI results. This week, the Merced County Public Health Department received a notice about a fake letter diagnosing an individual with HIV, syphilis, and chlamydia. The letter urged immediate medical treatment and warned of severe health complications if untreated. "We don't know exactly how many letters have gone out or to whom," said Mike North, Public Information Officer for Merced County.  "Our team has reached out previously to offer guidance on treatment options, but it appears that no action has been taken at this time," a portion of the letter said. Although only one person has reported receiving such a letter, the county is taking the matter seriously due to the use of a counterfeit letterhead. "When somebody counterfeits county letterhead, we take that seriously, and we want to make sure that the public is aware that this is happening and just really get ahead of it," North said.  The letterhead had the real phone number and address of the Merced County Public Health Department. "We don't know the intent of a letter, this is something that, you know, would likely concern someone if they got a letter, you know, of this nature," North said.  The county has not launched an investigation, but Fresno Criminal Defense Attorney Mark King said the counterfeiter could face real consequences if they do. "It is a federal crime to misuse the mail, it's called mail fraud, and the federal system, it can get you as much as twenty years in prison," King said.  In the State of California, impersonating a public official can result in up to six months behind bars. If the Merced Public Health Department ever did need to reach you, officials say they may send a letter requesting a phone call back. "We would never disclose any medical information in mail letters," North said. If anybody has also received a letter of this nature, the public health department asks people to call and report it.