A University of Montana student infected with hantavirus in early March returned to class Tuesday, though he continues to recover from the virus that nearly killed him. Antonio Morsette, a 20-year-old environmental studies student, believes he contracted the virus while power-washing recycled items at the university’s recycling center.

Montana ranks fifth in the number of reported hantavirus cases within the US, with 35. Between 1993 and 2013, 606 cases were reported nationally, resulting in 217 deaths.

According to the CDC, certain rodents, such as deer mice in the West, shed the virus in their urine, droppings and saliva. The virus is mainly transmitted to people when they breathe air contaminated with the virus. Guinea pigs, hamsters, gerbils and rodents from pet stores are not known to carry hantavirus, the CDC said.