But Emilio Nsue and Victor Casadesus turned things around for the visitors and Valencia ended the match with 10 men after Costa was dismissed for a two-footed challenge.
Diosdado Nsue-Micawg, the WHO representative in the Angolan capital of Luanda, said the health agency does not know the source of the virus, but fears that hunters and women who visit the forest might have been in contact with infected monkeys.