# Modeling and control of Chikungunya with chronic infection

## TL;DR

This study models the spread of Chikungunya fever in China, incorporating chronic infection, and identifies the most cost-effective control strategies.

## Contribution

The study introduces a novel dynamical model with a chronic infection stage and evaluates cost-effective intervention strategies for Chikungunya.

## Key findings

- The model estimates key transmission parameters and validates the stability of disease-free and endemic equilibria.
- Personal protection is identified as the most economically efficient intervention strategy.
- Mosquito biting rate and mortality rate are the most influential factors in disease transmission.

## Abstract

Recognized globally as a major public health concern in the tropics and subtropics, Chikungunya fever also poses a potential epidemic risk in areas of China such as Guangdong Province, where suitable mosquito vector habitats exist. Based on a Chikungunya fever outbreak in Shunde District, Foshan City, this study develops a dynamical model incorporating a chronic infection stage. We derive R0 and perform a thorough stability analysis of all equilibria. Using daily reported case data from Shunde District, model fitting yields estimates for three key transmission parameters (β, ρ1, ρ2), the total mosquito population (Tv), and the initial number of infected mosquitoes (Iv(0)). Sensitivity analysis identifies that the primary positive and negative parameters on disease transmission are mosquito biting rate (β) and mosquito mortality rate (ϵv), respectively. Accordingly, five types of intervention measures are designed: personal protection, screening and detection, treatment of acute patients, management of chronic cases, and mosquito vector control measures. Based on these findings, we formulate a control framework to optimize intervention strategies. Numerical simulations not only validate the global asymptotic stability of the disease-free equilibrium when R0 < 1 and that of the endemic equilibrium when R0 > 1, but also assess the effectiveness of different control strategies. Strategy A, which emphasizes personal protection, emerges as the most economically efficient option in the cost-effectiveness analysis. It not only effectively interrupts virus transmission but also optimally reduces the burden of chronic cases, thereby offering a scientifically sound and economically feasible approach for public health resource allocation.