This study analyzes the transmission of typhoid fever caused by Salmonella typhi using a mathematical model thathighlights the significance of delay in its effectiveness.Time delays can affect the nature of patterns and slow downthe emergence of patterns in infected population density.The analyzed model is expanded with the equilibriumanalysis,reproduction number,and stability analysis.This study aims to establish and explore the non-standardfinite difference(NSFD)scheme for the typhoid fever virus transmission model with a time delay.In addition,the forward Euler method and Runge-Kutta method of order 4(RK-4)are also applied in the present research.Some significant properties,such as convergence,positivity,boundedness,and consistency,are explored,and theproposed scheme preserves all the mentioned properties.The theoretical validation is conducted on how NSFDoutperforms other methods in emulating key aspects of the continuous model,such as positive solution,stability,and equilibrium about delay.Hence,the above analysis also shows some of the limitations of the conventional finitedifference methods,such as forward Euler and RK-4 in simulating such critical behaviors.This becomes moreapparent when using larger steps.This indicated that NSFD is beneficial in identifying the essential characteristicsof the continuous model with higher accuracy than the traditional approaches.
Muhammad TashfeenFazal DayanMuhammad Aziz Ur RehmanThabet AbdeljawadAiman Mukheimer
Rationale:Salmonella is a common etiological agent behind the tropical fever syndrome in the Indian subcontinent.Its prevalence in India remains high due to a lack of proper sanitation services in large parts of the country.Its neuropsychiatric manifestations is rare and the understanding on their pathophysiology is still poor.Patient concerns:A 19-year-old male,presented with a 10-day history of altered mental status,high-grade fever and violent behaviour.2 Days prior to admission,he developed decreased responsiveness and a muttering delirium with self-talking.Diagnosis:Coma vigil secondary to salmonellosis.Interventions:Intravenous ceftriaxone and dexamethasone.Outcomes:The resolution of the coma vigil and the associated Salmonella infection were observed;however,the patient developed residual mutism.Lessons:The atypical presentation of a globally obtunded state followed by mutism in typhoid coma in this case should be brought to the attention of clinicians worldwide.Additionally,the enduring speech limitations and potential psychiatric consequences may be linked to the prolonged duration of the infection.
Prashant BadoleJivtesh SinghPreetam N WasnikRohini Rokkam
