Johannesburg, South Africa ? International medical personnel and supplies are being airlifted to a remote region of central Congo to combat what threatens to become the world’s most serious outbreak of the deadly Ebola virus in years.

Only nine cases of the disease have been confirmed by laboratory tests. But medical authorities suspect the virus has killed 168 people and sickened 375 others across a heavily forested region where villages are linked only by deeply rutted dirt roads. Health officials say it’s possible that new cases will continue to emerge in the coming months.

“It’s a serious outbreak,” said Peter Kilmarx, an official with the U.S. Centers for Disease Control and Prevention who toured the area last weekend. “Every day, there is a new town with a reported suspect case.”

The epicenter of the outbreak, which is serviced by a single dirt-and-grass airstrip, consists of three towns in Congo’s Kasai Occidental province, but the affected area appears to stretch for more than 100 miles.

Kilmarx, who was speaking from the Congolese capital of Kinshasa, said that one village market he visited had been abandoned and that many Congolese in the area appeared reluctant to shake hands for fear of contracting the highly contagious disease.

Efforts to control Ebola depend on identifying and isolating those already infected. There is no cure, and most who contract the virus die. The disease typically produces acute flu-like symptoms, such as high fever, headaches and diarrhea. Hemorrhaging also is common, and bodily fluids containing the virus are the main source of transmission. In previous outbreaks, caretakers and those burying victims were susceptible.