Hellenic Centre for Diseases Control and Prevention, Marousi, Greece.
Malar J. 2013 Dec 27;12:463. doi: 10.1186/1475-2875-12-463.
Plasmodium vivax malaria was common in Greece until the 1950s with epidemics involving thousands of cases every year. Greece was declared free of malaria by the World Health Organization in 1974. From 1974 to 2010, an average of 39 cases per year were reported, which were mainly imported. However, in 2009 and 2010 six and one autochthonous cases were reported culminating with a total of 40 autochthonous cases reported in 2011, of which 34 originated from a single region: Laconia of Southern Peloponnese. In this study the genotypic complexity of the P. vivax infections from the outbreak in Greece during 2011 is described, to elucidate the possible origin and spread of the disease.
Three polymorphic markers of P. vivax were used; Pvmsp-3α and the microsatellites m1501 and m3502 on P. vivax isolates sampled from individuals diagnosed in Greece. Thirty-nine isolates were available for this study (20 autochthonous and 19 imported), mostly from Evrotas municipality in Laconia region, in southern Greece, (n = 29), with the remaining representing sporadic cases originating from other areas of Greece.
Genotyping the Evrotas samples revealed seven different haplotypes where the majority of the P. vivax infections expressed two particular Pvmsp-3α-m1501-m3502 haplotypes, A10-128-151 (n = 14) and A10-121-142 (n = 7). These haplotypes appeared throughout the period in autochthonous and imported cases, indicating continuous transmission. In contrast, the P. vivax autochthonous cases from other parts of Greece were largely comprised of unique haplotypes, indicating limited transmission in these other areas.
The results indicate that several P. vivax strains were imported into various areas of Greece in 2011, thereby increasing the risk of re-introduction of malaria. In the region of Evrotas ongoing transmission occurred exemplifying that further control measures are urgently needed in this region of southern Europe. In circumstances where medical or travel history is scarce, methods of molecular epidemiology may prove highly useful for the correct classification of the cases.
在 20 世纪 50 年代以前，疟原虫疟疾在希腊很常见，每年都会爆发数千例病例。1974 年，世界卫生组织宣布希腊无疟疾。1974 年至 2010 年，每年平均报告 39 例病例，主要为输入性病例。然而，2009 年和 2010 年分别报告了 6 例和 1 例本地感染病例，最终 2011 年共报告了 40 例本地感染病例，其中 34 例来自一个单一地区：伯罗奔尼撒半岛南部的拉科尼亚。本研究描述了 2011 年希腊疫情中疟原虫感染的基因复杂性，以阐明疾病的可能起源和传播。
对来自希腊诊断为疟疾病例的疟原虫分离株使用了三个疟原虫 vivax 的多态性标记；Pvmsp-3α 和微卫星 m1501 和 m3502。本研究共获得 39 个分离株（20 个本地和 19 个输入），主要来自希腊南部拉科尼亚地区的埃夫罗塔斯市（n=29），其余代表来自希腊其他地区的散发病例。
对埃夫罗塔斯样本进行基因分型显示了七种不同的单倍型，其中大多数疟原虫 vivax 感染表达两种特定的 Pvmsp-3α-m1501-m3502 单倍型，A10-128-151（n=14）和 A10-121-142（n=7）。这些单倍型在本地和输入病例中均出现，表明持续传播。相比之下，来自希腊其他地区的疟原虫 vivax 本地病例主要由独特的单倍型组成，表明在这些其他地区的传播有限。
结果表明，2011 年有几株疟原虫 vivax 被输入到希腊的不同地区，从而增加了疟疾再次传入的风险。在埃夫罗塔斯地区，持续发生传播，表明在欧洲南部的这一地区急需进一步采取控制措施。在医疗或旅行史稀少的情况下，分子流行病学方法可能对正确分类病例非常有用。
