Doug Stanglin

USA TODAY

Liberian authorities said Thursday they will prosecute Dallas Ebola patient Thomas Eric Duncan when he returns home for allegedly lying on his airport departure screening questionnaire about whether he had had contact with a person infected with the virus.

The latest Ebola outbreak has killed 3,338 in Guinea, Sierra Leone, Liberia, Senegal and Nigeria, the World Health Organization says, prompting several West African countries to closely monitor travelers in and out of the country.

On the form obtained by the Associated Press and confirmed by a Liberian government official, Duncan answered "no" to questions about whether he had cared for an Ebola patient or touched the body of someone who had died in an area affected by Ebola.

"He will be prosecuted" when he returns to Liberia, Binyah Kesselly, chairman of the board of directors of the Liberia Airport Authority, told reporters.

He said that people like Duncan and Patrick Sawyer, a Liberian-American with Ebola who traveled to Nigeria and infected people there, have brought a "stigma" upon Liberians living abroad.

Duncan is in serious condition in a Dallas hospital.

On Sept. 15, days before he left Liberia for the United States, Duncan -- a LIberian national -- helped carry 19-year-old Marthalene Williams into a taxi to go to the hospital after her family was unable to get an ambulance, The New York Times reports, quoting family and neighbors.

Williams, who was seven months pregnant, was turned away at the hospital because of lack of space in the Ebola ward, the Times reports. She re

turned home that evening, hours before she died.

It is not clear whether Duncan knew of the woman's diagnosis, which initially appeared to be pregnancy related, at the time he left the country. Officials in Liberia said Duncan showed no symptoms when he boarded the plane and he was therefore not contagious.

Ebola can only be spread through the bodily fluids of people showing signs of the disease.

The Daily Observer newspaper in Monrovia reported that a source close to Duncan said that he "did not leave Liberia sick," but that before flying off to Dallas he may have come in contact with people who had symptoms.

Until being terminated in early September, he had worked as a personal driver for the general manager of Safeway Cargo, a FedEx contractor in Liberia. He did not work for FedEx, as earlier reported, the company said Thursday.

Liberia's information minister, Lewis Brown, said stringent screening measures at Roberts International Airport were preventing the disease from spreading by air travel.

"These screening programs are monitored regularly," he said.

Jens David Ohlin, a professor of law at Cornell Law School in New York, said it's unusual to prosecute someone for this sort of infraction.

"Prosecuting an Ebola patient for lying on his screening form represents a particularly harsh treatment for someone on the precipice of death," Ohlin said. "Usually, compassion is the order of the day for Ebola patients. However, the Liberian government is clearly concerned that members of the public will not take their screening protocols seriously. If Ebola patients know that there are no legal consequences for lying on these forms, they will not take the screening seriously. And if travelers don't take the screening seriously, other countries will respond by closing air travel to Liberia."

Contributing: Liz Szabo, Michael Winter, Associated Press.