Unité Emergence des maladies virales, Centre International de Recherches Médicales de Franceville, 769, Franceville, BP, Gabon.
Unité Evolution Epidémiologie et Résistances Parasitaires (UNEEREP), Centre International de Recherches Médicales de Franceville, 769, Franceville, BP, Gabon.
BMC Infect Dis. 2019 Jan 25;19(1):90. doi: 10.1186/s12879-019-3731-y.
Measles is one of the most infectious diseases with a high mortality rate worldwide. It is caused by the measles virus (MeV) which is a single stranded RNA virus with genetic diversity based on the nucleoprotein gene, including 24 genotypes. In Gabon, several outbreaks occurred in the past few years, especially in 2016 in Libreville and Oyem. A surveillance network of infectious diseases highlighted a measles outbreak which occurred in the south of Gabon from April to June 2017.
Clinical specimens of urine, blood, throat and nasal swabs were collected in the two main cities of the Haut-Ogooue province, Franceville and Moanda. Virological investigations based on real-time polymerase chain reaction for molecular diagnosis and conventional PCR for genotype identification were done.
Specimens were collected from 139 suspected measles patients. A total of 46 (33.1%) children and adults were laboratory-confirmed cases among which 16 (34.8%) were unvaccinated, 16 (34.8%) had received one dose, and 11 (23.9%) had received two doses of the measles vaccine. Phylogenetic analysis revealed that all the sequences of the nucleoprotein gene belonged to genotype B3.
Measles infection was more commonly confirmed among those with one recorded dose compared to suspect cases with none, unknown or two recorded doses. The molecular characterization of the strains showed the circulation of the B3 genotype which is endemic on the African continent, thirty years after the B2 genotype was described in an outbreak in Libreville, the capital of Gabon. These findings highlight that surveillance and molecular investigation of measles should be continued in Gabon.
麻疹是全球死亡率较高的最具传染性疾病之一。它是由麻疹病毒（MeV）引起的，麻疹病毒是一种具有遗传多样性的单链 RNA 病毒，基于核蛋白基因，包括 24 种基因型。在加蓬，过去几年发生了几起麻疹疫情，特别是 2016 年在利伯维尔和奥耶姆。传染病监测网络突出了 2017 年 4 月至 6 月在加蓬南部发生的麻疹疫情。
在 Haut-Ogooue 省的两个主要城市，弗朗斯维尔和莫安达，采集了尿液、血液、喉咙和鼻腔拭子的临床标本。进行了基于实时聚合酶链反应的分子诊断和用于基因型鉴定的常规 PCR 的病毒学调查。
从 139 名疑似麻疹患者中采集了标本。在总共 46 名（33.1%）实验室确诊的儿童和成年人中，有 16 名（34.8%）未接种疫苗，16 名（34.8%）接种了 1 剂，11 名（23.9%）接种了 2 剂麻疹疫苗。系统进化分析显示，核蛋白基因的所有序列均属于基因型 B3。
与未记录剂量的疑似病例相比，记录有 1 剂的麻疹感染更常见。病毒株的分子特征表明，B3 基因型在非洲大陆流行，在加蓬首都利伯维尔暴发的 B2 基因型 30 年后，B3 基因型仍在传播。这些发现强调，加蓬应继续进行麻疹监测和分子调查。
