ABSTRACT
Due to the existence and variation of various viruses, an epidemic in which different strains spread at the same time will occur. here, an avian–human epidemic model with two strain viruses are established and analyzed. Both theoretical and simulation results reveal that the mixed infections intensify the epidemic and the dynamics become more complex and sensitive. There are six equilibria. The trivial equilibrium point is a high-order singular point and will undergo the transcritical bifurcations to bifurcate three equilibria. The existence and stability of equilibria mainly depend on five thresholds. A bifurcation portrait for the existence and stability of equilibria is presented. Simulations suggest that the key control measure is to develop the identification technology to eliminate the poultry infected with a high pathogenic virus preferentially, then the infected poultry with a low pathogenic virus in the recruitment and on farms. Controlling contact between human and poultry can effectively restrain the epidemic and controlling contagions in poultry can avoid great infection in humans.
ABSTRACT
At the end of December 2019, acute respiratory infectious diseases caused by a new type of coronavirus were prevalent in Wuhan and other cities of China. Different from radiology examinations, the protocols of nuclear medical imaging examinations are complicated, in which more workplaces and staff are needed, resulting more complex management of patients and higher protection requirements. Combined with the characteristics of SPECT and PET imaging procedures, this paper puts forward some suggestions on the protective process of imaging examinations for patients with confirmed or suspected novel coronavirus infection. The main purpose is to protect medical staff from virus infection, effectively reduce the risk of virus transmission during the examination process, and ensure the medical quality and safety.