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Assessing the Role of Voluntary Self-Isolation in the Control of Pandemic Influenza Using a Household Epidemic Model.

Zhang Q, Wang D - Int J Environ Res Public Health (2015)

Bottom Line: We used a household model to assess the effect of voluntary self-isolation on outbreak control when antiviral drugs are not provided sufficiently early.We found that the early initiation of voluntary self-isolation can overcome the negative effects caused by a delay in antiviral drug distribution when enough symptomatic individuals comply with home confinement at symptom onset.In addition, the effect of voluntary self-isolation decreases substantially with the proportion of asymptomatic infections increasing.

View Article: PubMed Central - PubMed

Affiliation: School of Mathematical Sciences, University of Electronic Science and Technology of China, No. 2006, Xiyuan Avenue, West Hi-Tech Zone, Chengdu 611731, China. zqx121981@126.com.

ABSTRACT
In the absence of effective vaccines, antiviral drugs and personal protective measures, such as voluntary self-isolation, have been a part of preparedness plans for the next influenza pandemic. We used a household model to assess the effect of voluntary self-isolation on outbreak control when antiviral drugs are not provided sufficiently early. We found that the early initiation of voluntary self-isolation can overcome the negative effects caused by a delay in antiviral drug distribution when enough symptomatic individuals comply with home confinement at symptom onset. For example, for the baseline household reproduction number RH0 = 2:5, if delays of one or two days occur between clinical symptom development and the start of antiviral prophylaxis, then compliance rates of q ≥ 0:41 and q ≥ 0:6, respectively, are required to achieve the same level of effectiveness as starting antiviral prophylaxis at symptom onset. When the time to beginning voluntary self-isolation after symptom onset increases from zero to two days, this strategy has a limited effect on reducing the transmission of influenza; therefore, this strategy should be implemented as soon as possible. In addition, the effect of voluntary self-isolation decreases substantially with the proportion of asymptomatic infections increasing.

No MeSH data available.


Related in: MedlinePlus

The impact of asymptomatic infected individuals.
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ijerph-12-09750-f004: The impact of asymptomatic infected individuals.

Mentions: Figure 4 illustrates how asymptomatic infections influence the effectiveness of voluntary self-isolation. Four scenarios were considered: (i) no intervention, (ii) and , (iii) and and (iv) and . For each curve in Figure 4, when the parameters lie below the curve and when the parameters lie above the curve. From Figure 4, we can see that as the value of the parameter α decreases, the curve moves down. This phenomenon implies that the decrease in the probability that an infected individual develops symptoms shrinks the set of scenarios in which containment is possible. In short, the effectiveness of voluntary self-isolation decreases as the probability of developing symptoms after infection decreases. For example, if an individual only has a one in four chance of developing symptoms after infection, voluntary self-isolation of symptomatic individuals with a compliance rate of did not substantially reduce disease transmission. Assuming no voluntary self-isolation, when the values of are calculated for the parameter pairs on Curve (iv), values are approximately . From this, we can see that voluntary self-isolation has only a limited effect on reducing the values of if a high proportion of asymptomatic infections does indeed exist and if asymptomatic infected people have the same infectiousness as those with obvious clinical symptoms.


Assessing the Role of Voluntary Self-Isolation in the Control of Pandemic Influenza Using a Household Epidemic Model.

Zhang Q, Wang D - Int J Environ Res Public Health (2015)

The impact of asymptomatic infected individuals.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555310&req=5

ijerph-12-09750-f004: The impact of asymptomatic infected individuals.
Mentions: Figure 4 illustrates how asymptomatic infections influence the effectiveness of voluntary self-isolation. Four scenarios were considered: (i) no intervention, (ii) and , (iii) and and (iv) and . For each curve in Figure 4, when the parameters lie below the curve and when the parameters lie above the curve. From Figure 4, we can see that as the value of the parameter α decreases, the curve moves down. This phenomenon implies that the decrease in the probability that an infected individual develops symptoms shrinks the set of scenarios in which containment is possible. In short, the effectiveness of voluntary self-isolation decreases as the probability of developing symptoms after infection decreases. For example, if an individual only has a one in four chance of developing symptoms after infection, voluntary self-isolation of symptomatic individuals with a compliance rate of did not substantially reduce disease transmission. Assuming no voluntary self-isolation, when the values of are calculated for the parameter pairs on Curve (iv), values are approximately . From this, we can see that voluntary self-isolation has only a limited effect on reducing the values of if a high proportion of asymptomatic infections does indeed exist and if asymptomatic infected people have the same infectiousness as those with obvious clinical symptoms.

Bottom Line: We used a household model to assess the effect of voluntary self-isolation on outbreak control when antiviral drugs are not provided sufficiently early.We found that the early initiation of voluntary self-isolation can overcome the negative effects caused by a delay in antiviral drug distribution when enough symptomatic individuals comply with home confinement at symptom onset.In addition, the effect of voluntary self-isolation decreases substantially with the proportion of asymptomatic infections increasing.

View Article: PubMed Central - PubMed

Affiliation: School of Mathematical Sciences, University of Electronic Science and Technology of China, No. 2006, Xiyuan Avenue, West Hi-Tech Zone, Chengdu 611731, China. zqx121981@126.com.

ABSTRACT
In the absence of effective vaccines, antiviral drugs and personal protective measures, such as voluntary self-isolation, have been a part of preparedness plans for the next influenza pandemic. We used a household model to assess the effect of voluntary self-isolation on outbreak control when antiviral drugs are not provided sufficiently early. We found that the early initiation of voluntary self-isolation can overcome the negative effects caused by a delay in antiviral drug distribution when enough symptomatic individuals comply with home confinement at symptom onset. For example, for the baseline household reproduction number RH0 = 2:5, if delays of one or two days occur between clinical symptom development and the start of antiviral prophylaxis, then compliance rates of q ≥ 0:41 and q ≥ 0:6, respectively, are required to achieve the same level of effectiveness as starting antiviral prophylaxis at symptom onset. When the time to beginning voluntary self-isolation after symptom onset increases from zero to two days, this strategy has a limited effect on reducing the transmission of influenza; therefore, this strategy should be implemented as soon as possible. In addition, the effect of voluntary self-isolation decreases substantially with the proportion of asymptomatic infections increasing.

No MeSH data available.


Related in: MedlinePlus