The efficacy of insecticide-treated nets (ITNs) is increasingly compromised by the prevalence of malaria vectors resistant to pyrethroids. In response to this issue, a new generation of ITNs has been developed that in...The efficacy of insecticide-treated nets (ITNs) is increasingly compromised by the prevalence of malaria vectors resistant to pyrethroids. In response to this issue, a new generation of ITNs has been developed that incorporate synergistic components, such as piperonyl butoxide (PBO). The purpose of this study is to provide entomological evidence for the efficacy of a PBO-based ITN brand at the village level, serving as a basis for decision-making before large-scale net deployment. During the high malaria transmission period, ITNs were distributed in each group and vector sampling was conducted biweekly in selected households. Bionomic data were collected to assess the resistance of wild An. gambiae populations to various chemical insecticides. There was a significant disparity in total An. gambiae sl. collected between the ITN arms, the intervention arm (ITN arms), and the control arm (P = 0.003). An. coluzzi was identified as the predominant species in the study area, as confirmed by PCR analysis. Analysis of the blood-feeding inhibition rate revealed that 100% permethrin + PBO ITN exhibited significantly greater inhibition than 66.81% permethrin only ITN. According to the log-time probit regression analysis, permethrin exhibited a knockdown time of 256 min without synergists, while it decreased to 139 min (P = 0.001) when pre-exposed to PBO. The evidence from this trial supports the use of PBO ITNs over standard ITNs for pyrethroids to combat pyrethroid resistance and improve protection against malaria for both individuals and communities, particularly in areas with high pyrethroid resistance.展开更多
In this study, we develop an SIS model for two types of mosquitoes, a traditional one and one that is resistant to IRS and ITNs. The resistant mosquito develops behavioral adaptation to control measures put in place t...In this study, we develop an SIS model for two types of mosquitoes, a traditional one and one that is resistant to IRS and ITNs. The resistant mosquito develops behavioral adaptation to control measures put in place to reduce their biting rate. They also bite early before dusk and later after dark when people are outside the houses and nets. We determine the effect of the two types of mosquitoes on malaria transmission in Kenya. The basic reproduction number R <sub>0</sub> is established as a sharp threshold that determines whether the disease dies out or persists in the population. Precisely, if R <sub>0</sub> ≤ 1, the disease-free equilibrium is globally asymptotically stable and the disease always dies out and if R <sub>0</sub> > 1, there exists a unique endemic equilibrium which is globally stable and the disease persists. The contribution of the two types of mosquitoes to the basic reproduction number and to the level of the endemic equilibrium is analyzed.展开更多
Malaria is the leading cause of morbidity and mortality in Kenya, with close to 70 percent (24 million) of the population at risk of infection. It affects people of all age groups: children under five years of age and...Malaria is the leading cause of morbidity and mortality in Kenya, with close to 70 percent (24 million) of the population at risk of infection. It affects people of all age groups: children under five years of age and pregnant women living in malaria endemic regions who are vulnerable. The main objective was to assess the utilization of the insecticide treated bed nets among the mothers attending MCH/FP in Webuye District Hospital, Bungoma County, Kenya. This research was based at the Webuye District Hospital, Bungoma County, Kenya from February to May, 2013. Sample size included 40 adult mothers attending MCH/FP aged 18 years and above during the study period. The design of the study was cross-sectional where sampling technique employed was non-probabilistic, purposive sampling. Data was collected by interviews using structured questionnaire which was administered by the researchers. SPSS version 16 was employed in Data analysis. The association between the overall knowledge about ITN use and malaria attack and level of education was tested and correlation between knowledge about malaria and ITNs utilization was calculated. Nearly all mothers attending MCH/FP had knowledge about ITNs nets and used it, with majority, 82.5% of the respondents used it for protection and 75% knew the importance of ITNs which were for malaria prevention. A majority of mothers attending MCH/FP were aware of ITNs and used it. Malaria morbidity was influenced by various factors including frequency of ITN use and most respondents interviewed had contracted malaria once before. The difference was found to be highly statistically significant between the overall knowledge about ITN use and malaria attack and level of education (χ2 = 58.7, p = 0.000). There was a significantly moderate positive correlation between total knowledge and ITN utilization (r = 0.449 & p = 0.000). The same was for the frequency of use but it was found to be in a weak magnitude, (r = 0.223 & p = 0.000). There was a strong positive correlation between knowledge abou展开更多
Background:<span> </span><span>Intermittent prevention of malaria is a key strategy adopted globally to ensure the wellbeing of pregnant women. By extension, these strategies enhance the healthy...Background:<span> </span><span>Intermittent prevention of malaria is a key strategy adopted globally to ensure the wellbeing of pregnant women. By extension, these strategies enhance the healthy development of the fetus. This study assesses the knowledge and practices of pregnant women towards intermittent malaria </span><span>prevention strategies in the Juaben Government Hospital of Ghana.</span><span> </span><span>Methods: A cross-sectional</span><span>,</span><span> quantitative</span><span>,</span><span> descriptive survey was conducted among 1</span><span>20 pregnant women at the antenatal clinic of the Juaben Government hospital in the Ashanti region of Ghana using a simple random sampling technique in selecting the study participants. The participant response rate was 94.5%. Data w</span><span>ere</span><span> analyzed using Statistical Package for the Social Sciences (SPSS) version 22.0.</span><span> </span><span>Results:</span><span> </span><span>Majority (54.2%) of respondents were between 20</span><span> </span><span>-</span><span> </span><span>29 years of age. Majority of study respondents attended Antenatal visits in their first trimester of pregnancy. Majority (69.2%) have knowledge of malaria preventive strategies in pregnancy, with about 70% of respondents stating these strategies were designed only for pregnant women. Only 37.5% of study respondents could rightly identify the chemoprophylaxis indicated for malaria prevention in pregnancy. Whereas majority (93.3%) of respondents owned insecticide-treated mosquito nets, only 63.3% utilized these nets for their purpose. Barriers to utilization of insecticide-treated nets include difficulty in setting up the nets (26.7%), using mosquito coils (10.8%), and feeling uncomfortable sleeping in the nets (36.7%). Barriers to taking malaria prophylaxis include distance to health facilities (28.3%), thoughts of not being sick with malaria (55.8%), using herbs (10.0%), and not being aware of the essence </span><span>of prophylaxis (7.5%). Conclusion:展开更多
The large-scale use of insecticide-treated bednets(ITNs)and indoor residual spraying(IRS),over the last two decades,has resulted in a dramatic reduction of malaria incidence globally.However,the effectiveness of these...The large-scale use of insecticide-treated bednets(ITNs)and indoor residual spraying(IRS),over the last two decades,has resulted in a dramatic reduction of malaria incidence globally.However,the effectiveness of these interventions is now being threatened by numerous factors,such as resistance to insecticide in the mosquito vector and their preference to feed and rest outdoors or early in the evening(when humans are not protected by the bednets).This study presents a new deterministic model for assessing the population-level impact of mosquito insecticide resistance on malaria transmission dynamics.A notable feature of the model is that it stratifies the mosquito population in terms of type(wild or resistant to insecticides)and feeding preference(indoor or outdoor).The model is rigorously analysed to gain insight into the existence and asymptotic stability properties of the various disease-free equilibria of the model namely the trivial diseasefree equilibrium,the non-trivial resistant-only boundary disease-free equilibrium and a non-trivial disease-free equlibrium where both the wild and resistant mosquito geneotypes co-exist).Simulations of the model,using data relevant to malaria transmission dynamics in Ethiopia(a malaria-endemic nation),show that the use of optimal ITNs alone,or in combination with optimal IRS,is more effective than the singular implementation of an optimal IRS-only strategy.Further,when the effect of the fitness cost of insecticide resistance with respect to fecundity(i.e.,assuming a decrease in the baseline birth rate of new resistant-type adult female mosquitoes)is accounted for,numerical simulations of the model show that the combined optimal ITNs-IRS strategy could lead to the effective control of the disease,and insecticide resistance effectively managed during the first 8 years of the 15-year implementation period of the insecticides-based anti-malaria control measures in the community.展开更多
Background:The high prevalence of malaria in endemic areas generally stems from recurrence events,characterized by the appearance of malaria symptoms at the time of examination;nearly every resident is at risk of expe...Background:The high prevalence of malaria in endemic areas generally stems from recurrence events,characterized by the appearance of malaria symptoms at the time of examination;nearly every resident is at risk of experiencing such a recurrence.The verified presence of Plasmodium sp is referred to as the Confirmed state,while the condition without confirmed P.falciparum is called the Undetected Parasitaemia state.After malaria treatment,a person can be in Aparasitaemic state or return to an Undetected Parasitaemia or Confirmed state due to non-adherence in complying with malaria therapy.In this study,we evaluate the characteristics of malaria recurrence in Timika,Indonesia,using the Markovian multiple-state model.In addition,we also simulate the probability of malaria recurrence after the implementation of several control strategies,including prevention strategies using insecticide-treated nets(ITNs)and indoor residual spraying(IRS).Objective:This study aims to identify the transition probabilities of malaria recurrence with and without control strategies.Methods:We use data from the medical records of malaria patients from the Naena Muktipura sub-health center in Timika,Papua,Indonesia,from March 2020 to March 2021.The data were grouped into two age categories:those under or over 24 years.The incidence of malaria in this area was modeled using a Markovian multiple-state model,dividing the incidence data based on the character of the patient's condition(Undetected Parasitaemia,Confirmed,or Aparasitaemic states)in order to obtain the patient's transition probabilities in each state.Furthermore,we simulate the recurrence probability given specific control strategies.Results:There were 964 visits to the sub-health center at Naena Muktipura in which symptoms of malaria were reported.Specifically,the number of the malaria incidences in the groups under and over age 24 were 456 and 508,respectively.The modeling results indicate that the probability of recurrence in the over-24 age group is generally higher than that in 展开更多
文摘The efficacy of insecticide-treated nets (ITNs) is increasingly compromised by the prevalence of malaria vectors resistant to pyrethroids. In response to this issue, a new generation of ITNs has been developed that incorporate synergistic components, such as piperonyl butoxide (PBO). The purpose of this study is to provide entomological evidence for the efficacy of a PBO-based ITN brand at the village level, serving as a basis for decision-making before large-scale net deployment. During the high malaria transmission period, ITNs were distributed in each group and vector sampling was conducted biweekly in selected households. Bionomic data were collected to assess the resistance of wild An. gambiae populations to various chemical insecticides. There was a significant disparity in total An. gambiae sl. collected between the ITN arms, the intervention arm (ITN arms), and the control arm (P = 0.003). An. coluzzi was identified as the predominant species in the study area, as confirmed by PCR analysis. Analysis of the blood-feeding inhibition rate revealed that 100% permethrin + PBO ITN exhibited significantly greater inhibition than 66.81% permethrin only ITN. According to the log-time probit regression analysis, permethrin exhibited a knockdown time of 256 min without synergists, while it decreased to 139 min (P = 0.001) when pre-exposed to PBO. The evidence from this trial supports the use of PBO ITNs over standard ITNs for pyrethroids to combat pyrethroid resistance and improve protection against malaria for both individuals and communities, particularly in areas with high pyrethroid resistance.
文摘In this study, we develop an SIS model for two types of mosquitoes, a traditional one and one that is resistant to IRS and ITNs. The resistant mosquito develops behavioral adaptation to control measures put in place to reduce their biting rate. They also bite early before dusk and later after dark when people are outside the houses and nets. We determine the effect of the two types of mosquitoes on malaria transmission in Kenya. The basic reproduction number R <sub>0</sub> is established as a sharp threshold that determines whether the disease dies out or persists in the population. Precisely, if R <sub>0</sub> ≤ 1, the disease-free equilibrium is globally asymptotically stable and the disease always dies out and if R <sub>0</sub> > 1, there exists a unique endemic equilibrium which is globally stable and the disease persists. The contribution of the two types of mosquitoes to the basic reproduction number and to the level of the endemic equilibrium is analyzed.
文摘Malaria is the leading cause of morbidity and mortality in Kenya, with close to 70 percent (24 million) of the population at risk of infection. It affects people of all age groups: children under five years of age and pregnant women living in malaria endemic regions who are vulnerable. The main objective was to assess the utilization of the insecticide treated bed nets among the mothers attending MCH/FP in Webuye District Hospital, Bungoma County, Kenya. This research was based at the Webuye District Hospital, Bungoma County, Kenya from February to May, 2013. Sample size included 40 adult mothers attending MCH/FP aged 18 years and above during the study period. The design of the study was cross-sectional where sampling technique employed was non-probabilistic, purposive sampling. Data was collected by interviews using structured questionnaire which was administered by the researchers. SPSS version 16 was employed in Data analysis. The association between the overall knowledge about ITN use and malaria attack and level of education was tested and correlation between knowledge about malaria and ITNs utilization was calculated. Nearly all mothers attending MCH/FP had knowledge about ITNs nets and used it, with majority, 82.5% of the respondents used it for protection and 75% knew the importance of ITNs which were for malaria prevention. A majority of mothers attending MCH/FP were aware of ITNs and used it. Malaria morbidity was influenced by various factors including frequency of ITN use and most respondents interviewed had contracted malaria once before. The difference was found to be highly statistically significant between the overall knowledge about ITN use and malaria attack and level of education (χ2 = 58.7, p = 0.000). There was a significantly moderate positive correlation between total knowledge and ITN utilization (r = 0.449 & p = 0.000). The same was for the frequency of use but it was found to be in a weak magnitude, (r = 0.223 & p = 0.000). There was a strong positive correlation between knowledge abou
文摘Background:<span> </span><span>Intermittent prevention of malaria is a key strategy adopted globally to ensure the wellbeing of pregnant women. By extension, these strategies enhance the healthy development of the fetus. This study assesses the knowledge and practices of pregnant women towards intermittent malaria </span><span>prevention strategies in the Juaben Government Hospital of Ghana.</span><span> </span><span>Methods: A cross-sectional</span><span>,</span><span> quantitative</span><span>,</span><span> descriptive survey was conducted among 1</span><span>20 pregnant women at the antenatal clinic of the Juaben Government hospital in the Ashanti region of Ghana using a simple random sampling technique in selecting the study participants. The participant response rate was 94.5%. Data w</span><span>ere</span><span> analyzed using Statistical Package for the Social Sciences (SPSS) version 22.0.</span><span> </span><span>Results:</span><span> </span><span>Majority (54.2%) of respondents were between 20</span><span> </span><span>-</span><span> </span><span>29 years of age. Majority of study respondents attended Antenatal visits in their first trimester of pregnancy. Majority (69.2%) have knowledge of malaria preventive strategies in pregnancy, with about 70% of respondents stating these strategies were designed only for pregnant women. Only 37.5% of study respondents could rightly identify the chemoprophylaxis indicated for malaria prevention in pregnancy. Whereas majority (93.3%) of respondents owned insecticide-treated mosquito nets, only 63.3% utilized these nets for their purpose. Barriers to utilization of insecticide-treated nets include difficulty in setting up the nets (26.7%), using mosquito coils (10.8%), and feeling uncomfortable sleeping in the nets (36.7%). Barriers to taking malaria prophylaxis include distance to health facilities (28.3%), thoughts of not being sick with malaria (55.8%), using herbs (10.0%), and not being aware of the essence </span><span>of prophylaxis (7.5%). Conclusion:
基金The authors are grateful to National Institute for Mathematical and Biological Synthesis(NIMBioS)for funding theWorking Group on Climate Change and Vector-borne Diseases(VBDs)held from 2013 to 2015.NIMBioS is an Institute sponsored by the National Science Foundation,the U.S.Department of Homeland Security,and the U.S.Department of Agriculture through NSF Award#EF-0832858with additional support from The University of Tennessee,Knoxville.The authors are grateful to the anonymous reviewers for their constructive comments.
文摘The large-scale use of insecticide-treated bednets(ITNs)and indoor residual spraying(IRS),over the last two decades,has resulted in a dramatic reduction of malaria incidence globally.However,the effectiveness of these interventions is now being threatened by numerous factors,such as resistance to insecticide in the mosquito vector and their preference to feed and rest outdoors or early in the evening(when humans are not protected by the bednets).This study presents a new deterministic model for assessing the population-level impact of mosquito insecticide resistance on malaria transmission dynamics.A notable feature of the model is that it stratifies the mosquito population in terms of type(wild or resistant to insecticides)and feeding preference(indoor or outdoor).The model is rigorously analysed to gain insight into the existence and asymptotic stability properties of the various disease-free equilibria of the model namely the trivial diseasefree equilibrium,the non-trivial resistant-only boundary disease-free equilibrium and a non-trivial disease-free equlibrium where both the wild and resistant mosquito geneotypes co-exist).Simulations of the model,using data relevant to malaria transmission dynamics in Ethiopia(a malaria-endemic nation),show that the use of optimal ITNs alone,or in combination with optimal IRS,is more effective than the singular implementation of an optimal IRS-only strategy.Further,when the effect of the fitness cost of insecticide resistance with respect to fecundity(i.e.,assuming a decrease in the baseline birth rate of new resistant-type adult female mosquitoes)is accounted for,numerical simulations of the model show that the combined optimal ITNs-IRS strategy could lead to the effective control of the disease,and insecticide resistance effectively managed during the first 8 years of the 15-year implementation period of the insecticides-based anti-malaria control measures in the community.
基金The authors would like to thank all of the staff at the Naena Muktipura Community Health Center,the head of the Limau Asri Public Health Center,and the Timika Health Office,who have assisted tremendously in performing this researchThe authors also express their gratitude for the research grant provided by the Faculty of Medicine,Universitas Islam Indonesia Number 600/Dek/70/Adm.Jur/VI/2021 for funding this research.
文摘Background:The high prevalence of malaria in endemic areas generally stems from recurrence events,characterized by the appearance of malaria symptoms at the time of examination;nearly every resident is at risk of experiencing such a recurrence.The verified presence of Plasmodium sp is referred to as the Confirmed state,while the condition without confirmed P.falciparum is called the Undetected Parasitaemia state.After malaria treatment,a person can be in Aparasitaemic state or return to an Undetected Parasitaemia or Confirmed state due to non-adherence in complying with malaria therapy.In this study,we evaluate the characteristics of malaria recurrence in Timika,Indonesia,using the Markovian multiple-state model.In addition,we also simulate the probability of malaria recurrence after the implementation of several control strategies,including prevention strategies using insecticide-treated nets(ITNs)and indoor residual spraying(IRS).Objective:This study aims to identify the transition probabilities of malaria recurrence with and without control strategies.Methods:We use data from the medical records of malaria patients from the Naena Muktipura sub-health center in Timika,Papua,Indonesia,from March 2020 to March 2021.The data were grouped into two age categories:those under or over 24 years.The incidence of malaria in this area was modeled using a Markovian multiple-state model,dividing the incidence data based on the character of the patient's condition(Undetected Parasitaemia,Confirmed,or Aparasitaemic states)in order to obtain the patient's transition probabilities in each state.Furthermore,we simulate the recurrence probability given specific control strategies.Results:There were 964 visits to the sub-health center at Naena Muktipura in which symptoms of malaria were reported.Specifically,the number of the malaria incidences in the groups under and over age 24 were 456 and 508,respectively.The modeling results indicate that the probability of recurrence in the over-24 age group is generally higher than that in
