Cross-protective immunity can account for the alternating epidemic pattern of dengue virus serotypes circulating in Bangkok
Cross-protective immunity can account for the alternating epidemic pattern of dengue virus serotypes circulating in Bangkok
复制标题
DOI：
10.1073/pnas.0602768103
复制
发表时间：
2006-09-19
影响因子：
11.1
通讯作者：
Boots, M.
中科院分区：
文献类型：
--
作者：
Adams, B.;Holmes, E. C.;Boots, M.
登革病毒是登革热及其更严重的登革出血热的病原体，在整个热带和亚热带地区广泛传播。该病毒有四种不同的血清型，所有这些血清型都已在曼谷共同传播了数十年，每 8-10 年就会爆发一次流行病。我们分析了每月感染发病率的时间序列数据，揭示了一种独特的模式，即血清型 1、2 和 3 的流行病几乎同时发生，而血清型 4 的流行病则在其间的年份中发生。对同一时期收集的病毒样本的系统发育分析表明，进化枝替换事件与流行周期有关，并表明存在血清型免疫反应。使用显示 8 至 10 年流行病振荡的随机季节性强迫的流行病模型，我们证明适度的交叉保护免疫会引起与数据中观察到的类似的持续异相振荡，但强或弱的交叉保护或交叉增强只会产生同相模式。这种行为表明，在曼谷观察到的流行模式是交叉保护性免疫的结果，并且可能会因血清型免疫反应的变化而显着改变。
Dengue virus, the causative agent of dengue fever and its more serious manifestation dengue hemorrhagic fever, is widespread throughout tropical and subtropical regions. The virus exists as four distinct serotypes, all of which have cocirculated in Bangkok for several decades with epidemic outbreaks occurring every 8-10 years. We analyze time-series data of monthly infection incidence, revealing a distinctive pattern with epidemics of serotypes 1, 2, and 3 occurring at approximately the same time and an isolated epidemic of serotype 4 occurring in the intervening years. Phylogenetic analysis of virus samples collected over the same period shows that clade replacement events are linked to the epidemic cycle and indicates that there is an interserotypic immune reaction. Using an epidemic model with stochastic seasonal forcing showing 8- to 10-year epidemic oscillations, we demonstrate that moderate cross-protective immunity gives rise to persistent out-of-phase oscillations similar to those observed in the data, but that strong or weak cross-protection or cross-enhancement only produces in-phase patterns. This behavior suggests that the epidemic pattern observed in Bangkok is the result of cross-protective immunity and may be significantly altered by changes in the interserotypic immune reaction.