Sixteen patients at the Neshoba County Nursing Home have been treated for hepatitis B since November and state health officials are trying to find out what caused the outbreak.
There are two investigations. Epidemiologists are attempting to determine the cause while the Health Department's Office of Licensure is reviewing procedures at the nursing home.
The nursing home is publicly owned but privately managed.
State Department of Health spokeswoman Liz Sharlot said this week that under federal regulations, the nursing home was cited with a deficiency related to infection control.
Dr. Risa Webb, infectious disease consultant for the Health Department, said as part of the investigation, nursing home employees as well as residents and anyone who could have been exposed to the virus would be tested.
Hepatitis B is part of a class of viruses that strike the liver. It can lead to cirrhosis and liver cancer. It's transmitted through blood, bodily fluids, shared needles and from mother to child.