Optimal control analysis for the Nipah infection with constant and time-varying vaccination and treatment under real data application.

In the last two decades, Nipah virus (NiV) has emerged as a significant paramyxovirus transmitted by bats, causing severe respiratory illness and encephalitis in humans. NiV has been included in the World Health Organization's Blueprint list of priority pathogens due its potential for human-to-human transmission and zoonotic characteristics. In this paper, a mathematical model is formulated to analyze the dynamics and optimal control of NiV. In formulation of the model we consider two modes of transmission: human-to-human and food-borne. Further, the impact of contact with an infected corpse as a potential route for virus transmission is also consider in the model. The analysis identifies the model with constant controls has three equilibrium states: the NiV-free equilibrium, the infected flying foxes-free equilibrium, and the NiV-endemic equilibrium state. Furthermore, a theoretical analysis is conducted to presents the stability of the model equilibria. The model fitting to the reported cases in Bangladesh from 2001 to 2015, and the estimation of parameters are performed using the standard least squares technique. Sensitivity analysis of the model-embedded parameters is provided to set the optimal time-dependent controls for the disease eradication. The necessary optimality conditions are derived using Pontryagin's maximum principle. Finally, numerical simulation is performed to determine the most effective strategy for disease eradication and to confirm the theoretical results.

Bionomics of the unexplored sand flies fauna of District Mohmand, Khyber Pakhtunkhwa, Pakistan: assessing risk factors associated with cutaneous leishmaniasis.

BACKGROUND: Sand flies are of considerable public health importance in Pakistan because these insects are vectors of leishmaniasis. The current study explores the bionomics of sand flies, their spatial distribution pattern and cutaneous leishmaniasis-associated risk factors in District Mohmand, Khyber Pakhtunkhwa, Pakistan. METHODS: Sand flies were collected from indoor and outdoor habitats in 69 villages of five tehsils in Mohmand during July-October 2019. Risk factor data were recorded for 829 households in 94 villages. RESULTS: In total, 2065 sand flies were captured. Phlebotomus (Paraphlebotbmus) sergenti was the most abundant species. Relative density for P. sergenti and Phlebotomus papatasi was highest in Prang Ghar and lowest in Safi. Sand flies abundance peaked in August and September, corresponding to maximum relative humidity, temperature and rainfall. Relative density for P. sergenti and P. papatasi was highest in combined dwellings (indoor) and cattle corrals (outdoor). Phlebotomus sergenti and P. papatasi were abundant at an elevation of 283-1140 m on agricultural land and rangelands. Both species were recorded abundantly on Carbontites, Mesozoic and Indus suture Melange rock formations. Presence of domestic animals, ownership of pet dogs, presence of muddy dunes in the village, knowledge of sandflies and use of mosquitoes spray remained significant risk factors. CONCLUSIONS: The study reports sand fly bionomics in District Mohmand. Risk identified for cutaneous leishmaniasis are significant in strategising control methods for Health authorities can allocate localized control means to high-risk areas using these findings.