Unité des Maladies Virales Emergentes, Centre International de Recherches Médicales de Franceville, Franceville, Gabon.
PLoS One. 2010 Feb 9;5(2):e9126. doi: 10.1371/journal.pone.0009126.
To better understand Zaire ebolavirus (ZEBOV) circulation and transmission to humans, we conducted a large serological survey of rural populations in Gabon, a country characterized by both epidemic and non epidemic regions. The survey lasted three years and covered 4,349 individuals from 220 randomly selected villages, representing 10.7% of all villages in Gabon. Using a sensitive and specific ELISA method, we found a ZEBOV-specific IgG seroprevalence of 15.3% overall, the highest ever reported. The seroprevalence rate was significantly higher in forested areas (19.4%) than in other ecosystems, namely grassland (12.4%), savannah (10.5%), and lakeland (2.7%). No other risk factors for seropositivity were found. The specificity of anti-ZEBOV IgG was confirmed by Western blot in 138 individuals, and CD8 T cells from seven IgG+ individuals were shown to produce IFN-gamma after ZEBOV stimulation. Together, these findings show that a large fraction of the human population living in forested areas of Gabon has both humoral and cellular immunity to ZEBOV. In the absence of identified risk factors, the high prevalence of "immune" persons suggests a common source of human exposure such as fruits contaminated by bat saliva. These findings provide significant new insights into ZEBOV circulation and human exposure, and raise important questions as to the human pathogenicity of ZEBOV and the existence of natural protective immunization.
为了更好地了解扎伊尔埃博拉病毒（ZEBOV）在人类中的传播和传播，我们对加蓬农村人口进行了大规模血清学调查，该国既有流行地区也有非流行地区。该调查持续了三年，覆盖了来自 220 个随机选择的村庄的 4349 个人，占加蓬所有村庄的 10.7%。使用敏感和特异的 ELISA 方法，我们发现总体上 ZEBOV 特异性 IgG 血清阳性率为 15.3%，这是有史以来报道的最高水平。森林地区（19.4%）的血清阳性率明显高于其他生态系统，即草原（12.4%）、热带稀树草原（10.5%）和湖泊地区（2.7%）。未发现其他血清阳性的危险因素。在 138 个人中通过 Western blot 证实了抗 ZEBOV IgG 的特异性，并且来自七个 IgG+个体的 CD8 T 细胞在 ZEBOV 刺激后产生 IFN-γ。这些发现表明，居住在加蓬森林地区的很大一部分人口对 ZEBOV 具有体液和细胞免疫。在没有确定的危险因素的情况下，“免疫”人群的高患病率表明人类接触的共同来源，例如被蝙蝠唾液污染的水果。这些发现为 ZEBOV 的传播和人类接触提供了重要的新见解，并提出了有关 ZEBOV 的人类致病性和自然保护免疫存在的重要问题。
