Time series modelling and forecasting of mpox incidence and mortality in Nigeria.

Abstract

The World Health Organization (WHO) declared mpox a Public Health Emergency of International Concern (PHEIC) twice, in response to the global outbreak, first in May 2022 and again in August 2024, after a span of 2 years and 3 months. African countries continue to be a hotspot for the ongoing mpox outbreaks and Nigeria has contributed substantially in exporting the virus to other countries, highlighting the need for an in-depth analysis of outbreak patterns and forecasting to inform public health policy. This study used the Auto-Regressive Integrated Moving Average (ARIMA) model to perform a 14-month forecast of mpox cases and mortality in Nigeria using mpox monthly routine data. The data were split into two portions; 70% for training, used to estimate the parameters of the forecasting model and 30% for testing, used to evaluate the model's accuracy. Wavelet analysis was used to decompose the time series into its various frequency components, enabling a multi-resolution analysis of the data. The ARIMA model forecasted an average of 13 mpox cases per month and zero mortality over a 14-month period. The wavelet power spectrum revealed a strong annual cycle between June 2022 and June 2023. In order to sustain the forecasted downward trend in mpox cases in the coming months, it is essential that the National Mpox Technical Working Group (TWG) of Nigeria Centre for Disease Control and Prevention (NCDC) continue to coordinate scale up of vaccine coverage and improve surveillance especially in high risk area. The findings will ultimately improve focused interventions and knowledge of mpox outbreak patterns by guiding public health policy, allocating resources optimally, and preparing health systems for potential outbreaks.