Research Article Mathematical Modeling and Analysis of TB and COVID- 19 Coinfection Kassahun Getnet Mekonen , 1 Shiferaw Feyissa Balcha, 1 Legesse Lemecha Obsu , 1 and Abdulkadir Hassen 2 1 Department of Applied Mathematics, Adama Science and Technology University, Adama, Ethiopia 2 Department of Mathematics, Rowan University, Glassboro, NY, USA Correspondence should be addressed to Kassahun Getnet Mekonen; kassaget15@gmail.com Received 27 September 2021; Accepted 24 February 2022; Published 27 March 2022 Academic Editor: Bruno Carpentieri Copyright © 2022 Kassahun Getnet Mekonen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Tuberculosis (TB) and coronavirus (COVID-19) are both infectious diseases that globally continue affecting millions of people every year. They have similar symptoms such as cough, fever, and difficulty breathing but differ in incubation periods. This paper introduces a mathematical model for the transmission dynamics of TB and COVID-19 coinfection using a system of nonlinear ordinary differential equations. The well-posedness of the proposed coinfection model is then analytically studied by showing properties such as the existence, boundedness, and positivity of the solutions. The stability analysis of the equilibrium points of submodels is also discussed separately after computing the basic reproduction numbers. In each case, the disease-free equilibrium points of the submodels are proved to be both locally and globally stable if the reproduction numbers are less than unity. Besides, the coinfection disease-free equilibrium point is proved to be conditionally stable. The sensitivity and bifurcation analysis are also studied. Different simulation cases were performed to supplement the analytical results. 1. Introduction The outbreak of coronavirus (COVID-19) was first reported by the World Health Organization (WHO) as pneumonia of unknown cause on December 31, 2019, observed in Wuhan, China. However, on the 10 th of January 2020, the virus was determined to be the new family of novel coronavirus with the same category as the severe acute respiratory syndrome virus (SARS-CoV) and the Middle Eastern Respiratory Syn- drome virus (MERS-CoV) that occurred, respectively, in Asia and Saudi Arabia [1]. COVID-19 is a respiratory virus that transmits mainly through droplets of saliva generated from an infected person through coughing or sneezing. The rapid expansion of the virus forced the WHO to declare it as a pandemic on March 11, 2020 [2]. The WHO report of COVID-19 indicated that on 10 August 2021, more than 202.14 million people were infected with the virus, and over 4.28 million have died. Different variants of COVID-19 occur in different countries, namely, α, β, γ, and δ. The δ variant is the highest contagion, which is 40 − 60% more transmissible than the α variant and with a higher risk of hospitalization [3]. Tuberculosis (TB) is a communicable disease which is caused by Mycobacterium tuberculosis. It is a major cause of death from a single infectious agent. The bacteria that cause TB are usually spread when an infected person coughs, sneezes, or any other forceful expiratory maneuver that shears respiratory secretions. It mostly affects the lungs but can also affect other organs such as bones, brain, kidneys, and glands [4]. About a quarter of the worldwide population is infected with Mycobacterium tuberculosis and thus at risk of developing TB disease. Globally, approximately 10 million people fell ill with TB, and 1.45 million people died from TB in 2018 [5]. Both TB and COVID-19 are infectious diseases that are transmitted mainly via close contact. The growing clinical evidence suggests that TB diseases are associated with COVID-19 outcomes, including an approximately two to Hindawi Journal of Applied Mathematics Volume 2022, Article ID 2449710, 20 pages https://doi.org/10.1155/2022/2449710