Dengue fever (DF) is an arthropod-borne disease caused by dengue virus (DENV). DENV is a member of the genus Flavivirus in the family Flaviviridae. Recently, DENV has been reported as an important emerging infectious viral pathogen in Sudan. Multiple outbreaks and sporadic cases of DF have been frequently reported in the eastern region of Sudan. The present study was conducted to confirm DENV outbreak in Kassala State, eastern Sudan, 2019, and to provide some information on the molecular characterization of the DENV isolate associated with the disease outbreak. A hundred serum samples were collected during the outbreak from residents of Kassala State, Sudan, 2019. ELISA was used to detect DENV non structural protein NS1 (DENV-NS1) in acute phase sera sampled during the disease outbreak. RT-PCR assays were used to amplify a fragment of the capsid/pre-membrane region (CprM) of the viral polyprotein gene. The PCR products of the amplified CprM region of the viral polyprotein gene were purified and partial sequences were generated and used to confirm the specificity of DENV sequences and to identify the virus serotype. Phylogenetic tree was constructed to determine the genotype of DENV associated with the outbreak. Using DENV-NS1 ELISA assay, DENV infection was confirmed in 23% sampled sera. The detection of DENV RNA was made possible using group-specific RT-PCR assay. The virus was serotyped as DENV serotype 3 (DENV-3) using DENV serotype-specific RT-PCR assay. Phylogenetic analysis of the partial CprM sequences of the viral polyprotein gene indicates that the virus belonged to genotype III of DENV-3. The scientific data presented in this investigation confirmed that genotype III of DENV-3 was associated with the disease outbreak in eastern Sudan, 2019. The study represents the first report on molecular characterization of DENV-3 in Sudan.

中文翻译：

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登革病毒血清型3的基因型III与苏丹东部疾病暴发的关联，2019年。

登革热（DF）是由登革热病毒（DENV）引起的节肢动物传播的疾病。DENV是黄病毒科黄病毒属的成员。最近，据报道DENV是苏丹重要的新兴传染性病毒病原体。苏丹东部地区经常报告多次暴发和DF的零星病例。进行本研究是为了确定2019年苏丹东部卡萨拉州的DENV暴发，并提供与该疾病暴发相关的DENV分离株的分子表征的一些信息。暴发期间在苏丹卡萨拉州居民中采集了100个血清样本，2019年。ELISA用于检测疾病暴发期间所采集的急性期血清中的DENV非结构蛋白NS1（DENV-NS1）。RT-PCR测定法用于扩增病毒多蛋白基因的衣壳/前膜区域（CprM）的片段。纯化病毒多蛋白基因的扩增的CprM区的PCR产物，并产生部分序列，并用于证实DENV序列的特异性并鉴定病毒血清型。建立了系统进化树来确定与暴发有关的DENV的基因型。使用DENV-NS1 ELISA分析，在23％的采样血清中证实了DENV感染。DENV RNA的检测使用组特异性RT-PCR测定法成为可能。使用DENV血清型特异性RT-PCR分析将该病毒血清型定为DENV血清型3（DENV-3）。对病毒多蛋白基因的部分CprM序列进行系统进化分析表明，该病毒属于DENV-3的基因型III。