Descriptive epidemiology of monkeypox in Nigeria, September 2017–June 2019
S. Akar, Sevda Akar, Y.-O. Adesola, S. Akar, Sevda Akar, Joel Burga, B. Oluwafemi, Jessica Akinrogbe, Chikwe Ihekweazu
Abstract
Background: Human monkeypox is a rare zoonotic infection caused by an orthopoxvirus and characterized by smallpox-like signs and symptoms. Reported outbreaks have occurred mainly in rural rainforest areas of the Congo basin and West Africa. In September 2017, Nigeria experienced a resurgence of monkeypox. Prior to this, the last of three cases recorded was in 1978. Since then sporadic cases have continued to occur, especially in the Southern part of the country. We present a descriptive epidemiology of monkeypox outbreak in Nigeria from September 2017 to June 2019. Methods and materials: A retrospective review of monkeypox cases reported to the Nigeria Centre for Disease Control over the period was conducted. Data was cleaned and analyzed for socio-demographic characteristics and signs and symptoms using Microsoft Office Excel version 2010. Counts, frequencies and proportions were determined. Results: Of 370 suspected cases reported in 30 states, 165 (45.8%) were confirmed in 17 states. Five cases had both monkeypox and chickenpox. Males constituted 115 (70.1%) of cases with mean age of 29.3 + 11 years. Those most affected were 31–40 years old. 9 deaths were recorded (CFR-5.5%), 67% in known immune-compromised patients). Case reporting was highest within the first two months of the outbreak; but have continued to occur since then. Most common clinical presentations include rash (all cases), fever (n = 106, 64.8%) and headache (n = 78, 47.3%). Fever preceded rash in 59 (35.8%) of cases. Most common lesions include facial (n = 100, 60.6%), leg (n = 90, 54.5%), hand and thoracic (n = 84, 50.9%). Cases were mostly confined to the southern and central parts of the country. Conclusion: Since the largest outbreak of monkeypox in 2017, sporadic cases have continue to occur in Nigeria pointing to endemicity of the disease. Unlike the central african clade cases are mostly seen in urban dwellers, especially among active young males.