Fungal meningitis outbreak in United States continues to grow, with at least seven people being killed and 65 cases reported in nine states, according to officials on Saturday.

The outbreak itself is linked to steroid injections that were manufactured in a pharmaceutical plant based in Massachusetts. Most of the people received the injections in order to treat their back pain problems. However, some patients later suffered from a wide range of symptoms, including fever, headache and nausea.

Fungal meningitis causes damage to the membrane layer of the brain as well as spinal cord, even though it is not transmitted from human to human. If not treated property, the disease can cause permanent damage to the nervous system and death.

The states in which fungal meningitis cases were reported are Florida, Indiana, Maryland, Michigan, North Carolina, Tennessee and Virginia. Tennessee had the largest number of cases of 29, while there are 11 in Virginia, eight in Indiana, four in Florida, three in Maryland, two in Minnesota and North Carolina as well as one in Ohio. So far three deaths have been reported in Tennessee, two in Michigan, and one each in Maryland and Virginia.

According to the U.S. Centers for Disease Control, more cases are likely to be found in other U.S. states, due to the fact that the steroids were transported to 23 states and thousands of patients may already have been injected.