Stability Analysis of Bubonic Plague Model with the Causing Pathogen Yersinia pestis in the Environment

Bubonic plague is a serious bacterial disease, mainly transmitted to human beings and rodents through flea bite. However, the disease may also be transmitted upon the interaction with the infected materials or surfaces in the environment. In this study, a deterministic model for bubonic plague disease with Yersinia pestis in the environment is developed and analyzed. Conditions for existence and stability of the equilibrium points are established. Using Jacobian method disease free equilibrium (DFE) point, E0 was proved to be locally asymptotically stable. The Metzler matrix method was used to prove that the DFE was globally asymptotically stable when R0 < 1. By applying Lyapunov stability theory and La Salles invariant principle, we prove that the endemic equilibrium point of system is globally asymptotically stable when R0 > 1. Numerical simulations are done to verify the analytical predictions. The results show that bubonic plague can effectively be controlled or even be eradicated if efforts are made to ensure that there are effective and timely control strategies.

Single-cell transcriptomics of immune cells in lymph nodes reveals their composition and alterations in functional dynamics during the early stages of bubonic plague

Bubonic plague caused by Yersinia pestis is highly infectious and often fatal.Characterization of the host immune response and its subsequent suppression by Y.pestis is critical to understanding the pathogenesis of Y.pestis.Here,we utilized single-cell RNA sequencing to systematically profile the transcriptomes of immune cells in draining lymph nodes(d LNs)during the early stage of Y.pestis infection.Dendritic cells responded to Y.pestis within 2 h post-infection(hpi),followed by the activation of macrophages/monocytes(Mφs/Mons)and recruitment of polymorphonuclear neutrophils(PMNs)to d LNs at 24 hpi.Analysis of cell-to-cell communication suggests that PMNs may be recruited to lymph nodes following the secretion of CCL9 by Mφs/Mons stimulated through CCR1-CCL9 interaction.Significant functional suppression of all the three innate immune cell types occurred during the early stage of infection.In summary,we present a dynamic immune landscape,at single-cell resolution,of murine d LNs involved in the response to Y.pestis infection,which may facilitate the understanding of the plague pathogenesis of during the early stage of infection.

Epidemiological features of four human plague cases in the Inner Mongolia Autonomous Region, China in 2019

This study aims to investigate cases of human plague in the Inner Mongolia Autonomous Region (IMAR), China, and to inform the development of plague prevention and control strategies. On 12th of November 2019, two herdsmen from Sunitezuo Banner, Xilingol League were diagnosed with pneumonic plague in Beijing, China. On November 16th, one resident of Xianghuang Banner, Xilingol League was diagnosed with bubonic plague in Huade County Hospital, Ulanqab, China. On 27th of November, one resident of Siziwang Banner was diagnosed with bubonic plague. In total, 78 close contacts were monitored over a period, but none of them developed symptoms. Plague outbreaks in animals had been reported in Sunitezuo Banner, Xianghuang Banner, and Siziwang Banner in 2019. Two of the four cases were related (husband and wife), but not the other two. All the cases may be associated with contact with rodents (hare) or infected fleas. The cases highlight the importance of early identification of plague cases in humans in order to stop further infection. This demonstrates the value of monitoring and ongoing vigilance on endemic diseases, the importance of updating medical training and raising public awareness about infectious diseases that even have not been observed over decades.