6 mayo 1987 año - April - July 1987
- Outbreak in Oyo state
- Ogbomosho became the epicentre
- 805 cases and 416 deaths reported
- CFR 52%
- Real incidence estimated (by serological testing)
to be around 800,000 cases (20% of the pop)
- 19 laboratory confirmed by viral insulation (5)
and serology (4)
- Aedes aegypti incriminated
