Yellow fever outbreak in Plateau state, Nigeria: A re-emerging disease or a case of misdiagnosis over the years?

Background: The first reported Yellow fever outbreak in Nigeria occurred in 1931.The latest outbreak in Nigeria, commenced in September 2017. It is active in seven states and suspected cases have been reported in sixteen states, inclusive of Plateau state. The last reported outbreak in Plateau state occurred in Jos in 1969 with an estimated 100,000 cases.Materials and Methods: The cases and health workers involved in management were interviewed. Hospital records, laboratory and surveillance data were reviewed.Results: Case 1: A 6-year-old girl from Tudun-Wada, Jos Plateau state presented with fever (38.6oC), abdominal pain, sore throat and jaundice. Liver function test (AST: 398U/L, ALT: 96U/L). Treatment included ribavirin, ceftriaxone, anti-oxidants, intravenous fluids, blood transfusion. ELISA-IgM was positive for YF, but negative on PNRT.Case 2: A 10-year-old boy from the same family with case 1 presented with fever (39.0oC), abdominal pain, diarrhoea and jaundice.  Liver function test (AST: 315 U/L, ALT: 126U/L). Treatment is same as case 1 plus metronidazole. ELISA-IgM was positive for YF, but negative on PNRT, while PCR was positive for Lassa fever.Twenty-three contacts (17 healthcare workers, 6 family members) were traced and daily monitoring instituted.Conclusion: The potential for a major urban outbreak of Yellow Fever in Plateau state and Nigeria is already present. Advocacy, health education and enforcement of vector control measures need to be intensified by the State Ministry of Health. Surveillance for rapid case finding and proactive vaccination also need to be intensified to forestall a disaster.