Liberia has seen more than 10,000 Ebola cases and more than 4,000 deaths since the West Africa outbreak began in 2013. The World Health Organization (WHO) has twice declared Liberia to be Ebola-free, once in May and again in September. Africa Live: BBC news updates The teenage boy's mother and two other siblings have also been admitted to the treatment centre to be monitored, health ministry spokesman Sorbor George said. He told the BBC that eight healthcare workers "who are at high risk because they came in direct contact with the boy" were also under surveillance. The BBC's Jonathan Paye-Layleh in Monrovia says nearly 160 people are now being monitored since the new cases were confirmed last week. Radio and television stations have resumed broadcasting Ebola awareness messages, he says.