Worries have widened in recent days over the number of people in who may have been exposed to the country’s first case in more than two weeks, a street vendor who lived in a one-bathroom house shared with 52 others in a Monrovia suburb and who had sold food at a school where more than 1,900 students are enrolled.
The patient, identified as Ruth Tugbah, 44, had been in contact with a range of people, including her children and a pastor who had sought to comfort her, after she developed a and was contagious, aid workers said Tuesday.
Ms. Tugbah received a diagnosis of Ebola on Friday, ending a that Liberia would be the first of three afflicted West African countries to emerge from the worst epidemic of the deadly virus in history.
More than 10,000 people have died in the past year from Ebola, nearly all of them in Liberia, Guinea and Sierra Leone. Liberia has made the most progress toward recovery.
On Tuesday the patient’s 18-year-old daughter, Beneta Kun, developed a and weakness and was taken to an Ebola treatment unit for testing, aid workers in Liberia reported.
“She was crying, especially when she had to enter the ambulance,” said Iris Martor, program director of the charity , which operates the school Ms. Kun attended. “It was so sad. It was the only thing we could do.”
Ms. Martor said the girl, who bathed her mother when she was ill, and other family members considered high-risk contacts were isolated Monday and were being monitored.
“They were paying attention to her and asking her all the right questions,” Katie Meyler, founder of More Than Me, said in a telephone interview.
She said her school had gone the entire outbreak without an illness in any of its 124 students. It had been closed during most of the epidemic, and like other schools had recently been allowed to reopen. The school has a special program to aid 30 children whose parents died of Ebola. “We’ve been taking every single precaution we can,” she said.
Parents of students at the school gathered for an emergency meeting and were reassured that Ms. Kun had been absent since last week, before she developed symptoms.
“We concealed the information initially,” Ms. Martor said. “We wanted to do our own investigation before reaching out to the parents or students, because we didn’t want them to panic.”
However, Ebola response officials in Liberia expressed concern about the possible exposure of students at a different school where Ms. Tugbah sold food last Wednesday after she developed a fever. According to the officials, the school has 1,904 enrolled students.
They also said children from one other school could possibly be at risk, an elementary school where students who had visited Ms. Tugbah’s house were enrolled.
Officials involved in the Ebola response gathered on Saturday to discuss the new case. Some suggested it showed a need to change the country’s approach to ending the epidemic. Others pointed out that the entire country had one known patient and plenty of resources to respond.
That was evident on Monday at the patient’s home, Ms. Martor said, which had five to seven other families living in it and sharing a water well, and was located in the Caldwell suburb of the capital. She said Ms. Kun, her younger sister and another child were overwhelmed by the number of agencies and individuals who responded.
Officials said Tuesday they had still not determined how Ms. Tugbah had contracted Ebola. Her only known risk factor was a boyfriend who was described by acquaintances as an Ebola survivor. “Since she got sick he ran away,” said Ms. Martor.
The Liberian government said Friday that its initial suspicion was that the patient had been infected from sex with an Ebola survivor.
Studies from two decades ago documented the Ebola virus in the semen of survivors, including one case in which Ebola was isolated 86 days after the onset of symptoms. When patients are discharged from treatment units, they are urged to remain abstinent for three months or to use .
“That kind of recommendation is based on the little evidence we have,” said Nathalie Jeanne Nicole Broutet, a medical officer with the World Health Organization’s Department of Reproductive Health and Research in Geneva. “Now what we have to do is of course get more evidence.”
A technical advisory committee at the W.H.O. is in the process of finishing work on recommendations for countries to follow after an Ebola outbreak has been declared ended, 42 days after the last patient has died or undergone two negative tests.
The guidance calls for countries to “maintain a system of heightened surveillance for a further 90 days,” including swabbing and testing all dead bodies for Ebola; keeping an active alert system for potential cases; and periodically surveying pregnant women and blood donors.
Dr. Philderald E. Pratt, assistant representative in Liberia of the United Nations Population Fund, said there was also a need to enhance the public messaging about the potential risks of spreading Ebola through sex.
Currently it is mainly survivors who are told of the risks as they are discharged from treatment. The messages are not generally broadcast to the public, in part because of the risk of further stigmatizing survivors.
“We have to intensify those efforts,” Dr. Pratt said. “I think we allowed that to slip through the cracks.”