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The interplay of vaccination and vector control on small dengue networks

View Article: PubMed Central - PubMed

ABSTRACT

Dengue fever is a major public health issue affecting billions of people in over 100 countries across the globe. This challenge is growing as the invasive mosquito vectors, Aedes aegypti and Aedes albopictus, expand their distributions and increase their population sizes. Hence there is an increasing need to devise effective control methods that can contain dengue outbreaks. Here we construct an epidemiological model for virus transmission between vectors and hosts on a network of host populations distributed among city and town patches, and investigate disease control through vaccination and vector control using variants of the sterile insect technique (SIT). Analysis of the basic reproductive number and simulations indicate that host movement across this small network influences the severity of epidemics. Both vaccination and vector control strategies are investigated as methods of disease containment and our results indicate that these controls can be made more effective with mixed strategy solutions. We predict that reduced lethality through poor SIT methods or imperfectly efficacious vaccines will impact efforts to control disease spread. In particular, weakly efficacious vaccination strategies against multiple virus serotype diversity may be counter productive to disease control efforts. Even so, failings of one method may be mitigated by supplementing it with an alternative control strategy. Generally, our network approach encourages decision making to consider connected populations, to emphasise that successful control methods must effectively suppress dengue epidemics at this landscape scale.

No MeSH data available.


Related in: MedlinePlus

Schematic diagram representing infections through host class infected by two different dengue serotypes. A susceptible host may progress through one of two possible routes, depending on which serotype is carried by the infected vector that first bites them. X mosquitoes carry serotype A, and Y carry B. If bitten by X, hosts will move from the susceptible class, S, to primarily infected, IA, and then on to recovered, RA. Then, following a period of cross-immunity , hosts become susceptible to a second serotype, SB2, at which point another biting event can move hosts into a secondarily infected class, IB2, before another immune response brings them into the fully recovered class, RAB. Circles within the grey rectangles indicate that progression to these classes is dependent on interactions with vectors.
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f0005: Schematic diagram representing infections through host class infected by two different dengue serotypes. A susceptible host may progress through one of two possible routes, depending on which serotype is carried by the infected vector that first bites them. X mosquitoes carry serotype A, and Y carry B. If bitten by X, hosts will move from the susceptible class, S, to primarily infected, IA, and then on to recovered, RA. Then, following a period of cross-immunity , hosts become susceptible to a second serotype, SB2, at which point another biting event can move hosts into a secondarily infected class, IB2, before another immune response brings them into the fully recovered class, RAB. Circles within the grey rectangles indicate that progression to these classes is dependent on interactions with vectors.

Mentions: To describe the dynamics of these secondary infections, additional classes were added to the model. Rather than simply one infection type occurring, any given susceptible host may be bitten by an infected mosquito, X, carrying serotype A or another mosquito, Y, carrying serotype B. Thus from an individual host's perspective, if they are bitten at least once they will track through one of two trajectories, as illustrated in Fig. 1.


The interplay of vaccination and vector control on small dengue networks
Schematic diagram representing infections through host class infected by two different dengue serotypes. A susceptible host may progress through one of two possible routes, depending on which serotype is carried by the infected vector that first bites them. X mosquitoes carry serotype A, and Y carry B. If bitten by X, hosts will move from the susceptible class, S, to primarily infected, IA, and then on to recovered, RA. Then, following a period of cross-immunity , hosts become susceptible to a second serotype, SB2, at which point another biting event can move hosts into a secondarily infected class, IB2, before another immune response brings them into the fully recovered class, RAB. Circles within the grey rectangles indicate that progression to these classes is dependent on interactions with vectors.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5016021&req=5

f0005: Schematic diagram representing infections through host class infected by two different dengue serotypes. A susceptible host may progress through one of two possible routes, depending on which serotype is carried by the infected vector that first bites them. X mosquitoes carry serotype A, and Y carry B. If bitten by X, hosts will move from the susceptible class, S, to primarily infected, IA, and then on to recovered, RA. Then, following a period of cross-immunity , hosts become susceptible to a second serotype, SB2, at which point another biting event can move hosts into a secondarily infected class, IB2, before another immune response brings them into the fully recovered class, RAB. Circles within the grey rectangles indicate that progression to these classes is dependent on interactions with vectors.
Mentions: To describe the dynamics of these secondary infections, additional classes were added to the model. Rather than simply one infection type occurring, any given susceptible host may be bitten by an infected mosquito, X, carrying serotype A or another mosquito, Y, carrying serotype B. Thus from an individual host's perspective, if they are bitten at least once they will track through one of two trajectories, as illustrated in Fig. 1.

View Article: PubMed Central - PubMed

ABSTRACT

Dengue fever is a major public health issue affecting billions of people in over 100 countries across the globe. This challenge is growing as the invasive mosquito vectors, Aedes aegypti and Aedes albopictus, expand their distributions and increase their population sizes. Hence there is an increasing need to devise effective control methods that can contain dengue outbreaks. Here we construct an epidemiological model for virus transmission between vectors and hosts on a network of host populations distributed among city and town patches, and investigate disease control through vaccination and vector control using variants of the sterile insect technique (SIT). Analysis of the basic reproductive number and simulations indicate that host movement across this small network influences the severity of epidemics. Both vaccination and vector control strategies are investigated as methods of disease containment and our results indicate that these controls can be made more effective with mixed strategy solutions. We predict that reduced lethality through poor SIT methods or imperfectly efficacious vaccines will impact efforts to control disease spread. In particular, weakly efficacious vaccination strategies against multiple virus serotype diversity may be counter productive to disease control efforts. Even so, failings of one method may be mitigated by supplementing it with an alternative control strategy. Generally, our network approach encourages decision making to consider connected populations, to emphasise that successful control methods must effectively suppress dengue epidemics at this landscape scale.

No MeSH data available.


Related in: MedlinePlus