Health officials in Nigeria have revealed that the total number of confirmed cases of Ebola infection in the country has risen to 14 after two more people tested positive for the virus.
"Nigeria has now recorded the first two cases of Ebola Virus Disease in secondary contacts of the index case," Health Minister Onyebuchi Chukwu told a news conference in Abuja.
"The two patients are spouses of primary contacts of the Liberian American," the minister said, referring to Patrick Sawyer, who died in a private Lagos hospital on July 25.
Chukwu said the two new cases were the husband and the wife of two primary contacts who died of the disease.
"They were quarantined two days ago. But the other ones that were quarantined along with them have been released," he added.
"Those on treatment (in isolation) currently are four -- two primary contacts, two secondary contacts. Presently altogether we have 213 on surveillance."
Six of the 213 are under watch in the eastern city of Enugu, where a nurse who had treated Sawyer travelled before falling sick and was returned to Lagos, the minister said.
Sawyer, a 40-year-old Liberian finance ministry consultant, was taken for treatment after arriving at Lagos airport visibly unwell on a flight from Monrovia.
Two doctors and two nurses who treated Sawyer, as well as an official from the West African regional bloc ECOWAS who picked him up from the airport died from the disease.
The World Health Organization said on Tuesday that it was encouraged by the situation in Nigeria, given that all of the confirmed cases came from a single chain of transmission.
Five people confirmed to have the virus have been "successfully managed and discharged".
Ebola has killed 1,350 people this year, with most deaths in Guinea, Liberia and Sierra Leone.