Do you have a source for that? Why would Nigeria close its borders - it does not share a border with any affected country?
Implying that since Nigeria dopes not share a border with a now-affected country does not mean that Nigeria didn’t do what it did.
An Ebola-infected man (Patrick Sawyer) landed in Lagos and Nigeria moved swiftly to try and stop the spread from this Patient Zero. Nigeria has been declared Ebola-free since August 31st and implemented all of the aforementioned steps.
WaPo, Wash Times and many others reported on this.
Nigerian officials took contact tracing to the max to end any chance of Ebola spreading within Nigeria.