INDIANAPOLIS (AP) — The Indianapolis Zoo says the fourth elephant to test positive for a virus that killed two other members of its herd is responding well to treatment.

The Zoo said Friday that 12-year-old female Zahara tested positive last week for elephant endotheliotropic herpes virus. They add the African elephant is expected to fully recover.

Zoo staff say that 13-year-old male Kedar has recovered from his recent bout with the virus. Two others, Nyah and Kalina, died in March.

Zahara represents the fourth case in less than nine weeks.

The zoo says humans and other animal species cannot contract the virus, which causes fatal hemorrhagic disease. Officials say in a release that prompt action “is the only hope for treatment and survival.”

The Indianapolis Zoo has encouraged other zoos to test elephants.