Dynamics of Mpox in an HIV endemic community: A mathematical modelling approach

During the 2022 monkeypox (Mpox) outbreak in non-endemic countries, sexual transmission was identified as the dominant mode of transmission, and particularly affected the community of men who have sex with men (MSM). This community experienced the highest incidence of Mpox cases, exacerbating the public health burden they already face due to the disproportionate impact of HIV. Given the simultaneous spread of HIV and Mpox within the MSM community, it is crucial to understand how these diseases interact. Specifically, since HIV is endemic within this population, understanding its influence on the spread and control of Mpox is essential. In this study, we analyze a mechanistic mathematical model of Mpox to explore the potential impact of HIV on the dynamics of Mpox within the MSM community. The model considered in this work incorporates the transmission dynamics of the two diseases, including antiretroviral therapy (ART) for HIV. We assumed that HIV was already endemic in the population at the onset of the Mpox outbreak. Through our analysis, we derived the Mpox invasion reproduction number within an HIV-endemic setting and established the existence and local asymptotic stability of the Mpox-free equilibrium under these conditions. Furthermore, we demonstrated the existence and local asymptotic stability of an Mpox-endemic equilibrium in an HIV-endemic regime. Notably, our findings revealed that the model exhibits a backward bifurcation, a phenomenon that may not have occurred in the absence of HIV within the population. The public health significance of our results is that the presence of HIV in the MSM community could hinder efforts to control Mpox, allowing the disease to become endemic even when its invasion reproduction number is below one. Additionally, we found that Mpox might be more challenging to control in scenarios where HIV increases susceptibility to Mpox. Finally, consistent with previous studies, our analysis confirms that reducing sexual contact can be effective for controlling the spread of Mpox within the MSM community.