This paper presents a deterministic model for Neisseria meningitidis,a bacterium that causes meningitis.The model was parameterized using data from the 2017 meningitis outbreak in Nigeria.Optimal control theory was ap...This paper presents a deterministic model for Neisseria meningitidis,a bacterium that causes meningitis.The model was parameterized using data from the 2017 meningitis outbreak in Nigeria.Optimal control theory was applied to investigate the optimal strategy for curtailing the spread of the disease using control variables determined from sensitivity analysis.These control variables are personal-protection such as the use of facial masks,and vaccination.The results show that the two controls avert more infections at low costs.Furthermore,a reciprocal relationship exists between the use of facial masks and vaccine.That is,when the use of facial masks is high,the use of vaccine is low and vice versa.Cost-effective analysis was applied to investigate the most cost-effective strategy from various combination of control strategies.The results show that strategy combining all the control variables is the most cost-effective strategy followed by the strategy involving both personal-protection,the vaccination-only strategy was the least cost-effective.Although vaccination strategy is not cost-effective in this study,it is as effective in curtailing the infection as the other two control strategies.The study suggests that governments of communities with limited resources should consider complementing the use of vaccine with the use of facial mask particularly in hard-to-reach places in their communities.展开更多
Zika is a flavivirus transmitted to humans through either the bites of infected Aedes mosquitoes or sexual transmission.Zika has been linked to congenital anomalies such as microcephaly.In this paper,we analyze a new ...Zika is a flavivirus transmitted to humans through either the bites of infected Aedes mosquitoes or sexual transmission.Zika has been linked to congenital anomalies such as microcephaly.In this paper,we analyze a new system of ordinary differential equations which incorporates human vertical transmission of Zika virus,the birth of babies with microcephaly and asymptomatically infected individuals.The Zika model is locally and globally asymptotically stable when the basic reproduction number is less than unity.Our model shows that asymptomatic individuals amplify the disease burden in the community,and the most important parameters for ZIKV spread are the death rate of mosquitoes,the mosquito biting rate,the mosquito recruitment rate,and the transmission per contact to mosquitoes and to adult humans.Scenario exploration indicates that personal-protection is a more effective control strategy than mosquito-reduction strategy.It also shows that delaying conception reduces the number of microcephaly cases,although this does little to prevent Zika transmission in the broader community.However,by coupling aggressive vector control and personal protection use,it is possible to reduce both microcephaly and Zika transmission.2000 Mathematics Subject Classifications:92B05,93A30,93C15.展开更多
文摘This paper presents a deterministic model for Neisseria meningitidis,a bacterium that causes meningitis.The model was parameterized using data from the 2017 meningitis outbreak in Nigeria.Optimal control theory was applied to investigate the optimal strategy for curtailing the spread of the disease using control variables determined from sensitivity analysis.These control variables are personal-protection such as the use of facial masks,and vaccination.The results show that the two controls avert more infections at low costs.Furthermore,a reciprocal relationship exists between the use of facial masks and vaccine.That is,when the use of facial masks is high,the use of vaccine is low and vice versa.Cost-effective analysis was applied to investigate the most cost-effective strategy from various combination of control strategies.The results show that strategy combining all the control variables is the most cost-effective strategy followed by the strategy involving both personal-protection,the vaccination-only strategy was the least cost-effective.Although vaccination strategy is not cost-effective in this study,it is as effective in curtailing the infection as the other two control strategies.The study suggests that governments of communities with limited resources should consider complementing the use of vaccine with the use of facial mask particularly in hard-to-reach places in their communities.
文摘Zika is a flavivirus transmitted to humans through either the bites of infected Aedes mosquitoes or sexual transmission.Zika has been linked to congenital anomalies such as microcephaly.In this paper,we analyze a new system of ordinary differential equations which incorporates human vertical transmission of Zika virus,the birth of babies with microcephaly and asymptomatically infected individuals.The Zika model is locally and globally asymptotically stable when the basic reproduction number is less than unity.Our model shows that asymptomatic individuals amplify the disease burden in the community,and the most important parameters for ZIKV spread are the death rate of mosquitoes,the mosquito biting rate,the mosquito recruitment rate,and the transmission per contact to mosquitoes and to adult humans.Scenario exploration indicates that personal-protection is a more effective control strategy than mosquito-reduction strategy.It also shows that delaying conception reduces the number of microcephaly cases,although this does little to prevent Zika transmission in the broader community.However,by coupling aggressive vector control and personal protection use,it is possible to reduce both microcephaly and Zika transmission.2000 Mathematics Subject Classifications:92B05,93A30,93C15.
