Stochastic simulation of endemic Salmonella enterica serovar Typhi: the importance of long lasting immunity and the carrier state.
Stochastic simulation of endemic Salmonella enterica serovar Typhi: the importance of long lasting immunity and the carrier state.
复制标题
DOI：
10.1371/journal.pone.0074097
复制
发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Maire N
中科院分区：
文献类型：
--
作者：
Saul A;Smith T;Maire N
伤寒沙门氏菌引起的伤寒仍然是一种严重的疾病负担，特别是在亚洲和非洲的发展中国家。据估计，它每年造成20万人死亡，主要是儿童。伤寒沙门氏菌是人类的一种专性病原体，尽管它的生活史相对复杂，携带者状态较长，但非人类宿主的缺乏表明，良好的针对性控制方法应该对疾病产生重大影响。包括新一代疫苗在内的较新的控制方法带来了希望，但它们的实施将受益于指导最具成本效益的战略的量化模型。本文提出了伤寒疾病、免疫和传播的量化模型，作为这一过程的第一步。基于随机智能体的模型结合了伤寒生物学的已知特征，包括感染的概率、感染的后果、治疗选择、感染和疫苗接种导致的免疫获得和丧失、携带者状态的发展以及环境或行为因素对传播的影响。模型已被参数化，在可能的情况下，从文献中获得的值，在这是不可能的情况下，通过敏感性分析确定了可行的参数空间，将模拟与现场数据的年龄分布相匹配。该模型能够很好地预测伤寒在两种环境下的年龄分布。该模型强调了婴幼儿在不同环境中对感染暴露/抵抗力变化的重要性，特别是这对控制程序的设计产生了影响；它预测了对伤寒的自然诱导临床和无菌免疫是长期存在的，并强调了携带者状态的重要性，特别是在低传播率地区。
Typhoid fever caused by Salmonella enterica serovar Typhi (S. Typhi) remains a serious burden of disease, especially in developing countries of Asia and Africa. It is estimated that it causes 200,000 deaths per year, mainly in children. S. Typhi is an obligate pathogen of humans and although it has a relatively complex life cycle with a long lived carrier state, the absence of non-human hosts suggests that well targeted control methods should have a major impact on disease. Newer control methods including new generations of vaccines offer hope but their implementation would benefit from quantitative models to guide the most cost effective strategies. This paper presents a quantitative model of Typhoid disease, immunity and transmission as a first step in that process. A stochastic agent-based model has been developed that incorporates known features of the biology of typhoid including probability of infection, the consequences of infection, treatment options, acquisition and loss of immunity as a result of infection and vaccination, the development of the carrier state and the impact of environmental or behavioral factors on transmission. The model has been parameterized with values derived where possible from the literature and where this was not possible, feasible parameters space has been determined by sensitivity analyses, fitting the simulations to age distribution of field data. The model is able to adequately predict the age distribution of typhoid in two settings. The modeling highlights the importance of variations in the exposure/resistance of infants and young children to infection in different settings, especially as this impacts on design of control programs; it predicts that naturally induced clinical and sterile immunity to typhoid is long lived and highlights the importance of the carrier state especially in areas of low transmission.
登录
查看更多内容
影响因子：
6.4
作者：
LEVINE, MM;BLACK, RE;LANATA, C
通讯作者：
LANATA, C
影响因子：
--
作者：
MARMION, DE;NAYLOR, GRE;STEWART, IO
通讯作者：
STEWART, IO
DOI：
10.4269/ajtmh.2000.62.644
发表时间：
2000-05-01
影响因子：
3.3
作者：
Lin, FYC;Ho, VA;Robbins, JB
通讯作者：
Robbins, JB
影响因子：
3.1
作者：
Kossaczka, Z;Lin, FYC;Szu, SC
通讯作者：
Szu, SC
影响因子：
5.5
作者：
Klugman, KP;Koornhof, HJ;LeCam, NN
通讯作者：
LeCam, NN