Evaluating The Impact of Potential Interventions on The Tuberculosis Epidemic in Taiwan
Date Issued
2014
Date
2014
Author(s)
Fu, Han
Abstract
Background:
The relative contribution of recent infection and remote reactivation to the current tuberculosis (TB) epidemiology remains unclear and has important implications for the design of TB control policy. As one of the main active case finding strategies for TB control, contact tracing can improve case detection of active TB and prevent disease progression of latent TB. However, the impact of contact tracing on TB epidemic has not been well evaluated.
Methods:
We built an age-structured compartmental model of TB transmission to capture the transmission dynamic of TB in Taiwan over the past decades. We calibrated the model to reflect the declining trend of TB prevalence observed in the eight national prevalence surveys (1957-1993) and the age-specific notification rate (2010). Based on the calibrated model, we further estimated the relative contributions of recent and remote transmission and evaluated the impact of contact tracing on the annual declining rate in notified rate.
Results:
In order to fit the age pattern of TB incidence in Taiwan, we assigned an age-dependent gradient for the parameters of primary progression rate and reactivation rate in the model. Using the calibrated model, we found that the proportion of remote reactivation among incident cases increased gradually with the declining TB prevalence, and reached 58.2% in 2010. The implementation of contact tracing for finding active TB cases had contributed to the decline in TB incidence in the past decade. With the combined scenarios for ageing trend, DM control and LTBI prophylaxis under the best-case scenario, the proportion of TB incidence reduction by 2025 was 18.6%.
Discussion:
The model-based analysis revealed a strong age-dependent pattern in the risk of disease infection and progression, indicating the potential high TB risk caused by comorbidities among elders. Although reactivation has contributed to the majority of TB incident cases, recent transmission still accounts for a substantial proportion of TB epidemic. To intensify the interventions for TB control, DM control among the elders and expanding the latent TB treatment to older adults were the potential approaches. However, the hepatotoxicity of preventive treatment in older adults should be carefully evaluated and monitored before scaling up the program.
The relative contribution of recent infection and remote reactivation to the current tuberculosis (TB) epidemiology remains unclear and has important implications for the design of TB control policy. As one of the main active case finding strategies for TB control, contact tracing can improve case detection of active TB and prevent disease progression of latent TB. However, the impact of contact tracing on TB epidemic has not been well evaluated.
Methods:
We built an age-structured compartmental model of TB transmission to capture the transmission dynamic of TB in Taiwan over the past decades. We calibrated the model to reflect the declining trend of TB prevalence observed in the eight national prevalence surveys (1957-1993) and the age-specific notification rate (2010). Based on the calibrated model, we further estimated the relative contributions of recent and remote transmission and evaluated the impact of contact tracing on the annual declining rate in notified rate.
Results:
In order to fit the age pattern of TB incidence in Taiwan, we assigned an age-dependent gradient for the parameters of primary progression rate and reactivation rate in the model. Using the calibrated model, we found that the proportion of remote reactivation among incident cases increased gradually with the declining TB prevalence, and reached 58.2% in 2010. The implementation of contact tracing for finding active TB cases had contributed to the decline in TB incidence in the past decade. With the combined scenarios for ageing trend, DM control and LTBI prophylaxis under the best-case scenario, the proportion of TB incidence reduction by 2025 was 18.6%.
Discussion:
The model-based analysis revealed a strong age-dependent pattern in the risk of disease infection and progression, indicating the potential high TB risk caused by comorbidities among elders. Although reactivation has contributed to the majority of TB incident cases, recent transmission still accounts for a substantial proportion of TB epidemic. To intensify the interventions for TB control, DM control among the elders and expanding the latent TB treatment to older adults were the potential approaches. However, the hepatotoxicity of preventive treatment in older adults should be carefully evaluated and monitored before scaling up the program.
Subjects
結核病
傳染病數理模型
介入措施
臺灣
SDGs
Type
thesis
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