2009-2015 年越南临床疟疾疾病模式和趋势分析。

Analysis of clinical malaria disease patterns and trends in Vietnam 2009-2015.

机构信息

Department of Global Health, Research School of Population Health, Australian National University, Canberra, Australia.

Vysnova Partners, Inc, Bethesda, MD, USA.

出版信息

Malar J. 2018 Sep 17;17(1):332. doi: 10.1186/s12936-018-2478-z.

DOI:10.1186/s12936-018-2478-z

PMID:30223843

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6142383/

Abstract

BACKGROUND

Viet Nam has made tremendous progress towards reducing mortality and morbidity associated with malaria in recent years. Despite the success in malaria control, there has been a recent increase in cases in some provinces. In order to understand the changing malaria dynamics in Viet Nam and measure progress towards elimination, the aim of this study was to describe and quantify spatial and temporal trends of malaria by species at district level across the country.

METHODS

Malaria case reports at the Viet Nam National Institute of Malariology, Parasitology, and Entomology were reviewed for the period of January 2009 to December 2015. The population of each district was obtained from the Population and Housing Census-2009. A multivariate (insecticide-treated mosquito nets [ITN], indoor residual spraying [IRS], maximum temperature), zero-inflated, Poisson regression model was developed with spatial and spatiotemporal random effects modelled using a conditional autoregressive prior structure, and with posterior parameters estimated using Bayesian Markov chain Monte Carlo simulation with Gibbs sampling. Covariates included in the models were coverage of intervention (ITN and IRS) and maximum temperature.

RESULTS

There was a total of 57,713 Plasmodium falciparum and 32,386 Plasmodium vivax cases during the study period. The ratio of P. falciparum to P. vivax decreased from 4.3 (81.0% P. falciparum; 11,121 cases) in 2009 to 0.8 (45.0% P. falciparum; 3325 cases) in 2015. Coverage of ITN was associated with decreased P. falciparum incidence, with a 1.1% (95% credible interval [CrI] 0.009%, 1.2%) decrease in incidence for 1% increase in the ITN coverage, but this was not the case for P. vivax, nor was it the case for IRS coverage. Maximum temperature was associated with increased incidence of both species, with a 4% (95% CrI 3.5%, 4.3%) and 1.6% (95% CrI 0.9%, 2.0%) increase in P. falciparum and P. vivax incidence for a temperature increase of 1 °C, respectively. Temporal trends of P. falciparum and P. vivax incidence were significantly higher than the national average in Central and Central-Southern districts.

CONCLUSION

Interventions (ITN distribution) and environmental factors (increased temperature) were associated with incidence of P. falciparum and P. vivax during the study period. The factors reviewed were not exhaustive, however the data suggest distribution of resources can be targeted to areas and times of increased malaria transmission. Additionally, changing distribution of the two predominant malaria species in Viet Nam will require different programmatic approaches for control and elimination.

摘要

背景

近年来，越南在降低与疟疾相关的死亡率和发病率方面取得了巨大进展。尽管在疟疾控制方面取得了成功，但最近一些省份的病例有所增加。为了了解越南疟疾动态的变化情况，并衡量消除疟疾的进展，本研究旨在描述和量化全国各地区按物种划分的疟疾时空趋势。

方法

对 2009 年 1 月至 2015 年期间越南国家疟疾、寄生虫学和昆虫学研究所的疟疾病例报告进行了回顾。每个地区的人口数从 2009 年人口和住房普查中获得。采用多元（经杀虫剂处理的蚊帐 [ITN]、室内滞留喷洒 [IRS]、最高温度）、零膨胀、泊松回归模型，使用条件自回归先验结构对空间和时空随机效应进行建模，并使用贝叶斯马尔可夫链蒙特卡罗模拟和吉布斯抽样对后验参数进行估计。模型中包含的协变量包括干预措施（ITN 和 IRS）的覆盖范围和最高温度。

结果

在研究期间，共发生 57713 例恶性疟原虫和 32386 例间日疟原虫病例。2009 年恶性疟原虫与间日疟原虫的比例为 4.3（81.0%恶性疟原虫；11121 例），2015 年降至 0.8（45.0%恶性疟原虫；3325 例）。ITN 覆盖率与恶性疟发病率下降有关，ITN 覆盖率每增加 1%，恶性疟发病率下降 1.1%（95%可信区间 [CrI]0.009%，1.2%），但间日疟原虫和 IRS 覆盖率并非如此。最高温度与两种疟原虫的发病率增加有关，温度升高 1°C，恶性疟原虫和间日疟原虫的发病率分别增加 4%（95% CrI 3.5%，4.3%）和 1.6%（95% CrI 0.9%，2.0%）。恶性疟原虫和间日疟原虫发病率的时间趋势明显高于全国平均水平。