Detection of DENV-2 and Insect-Specific Flaviviruses in Mosquitoes Collected From Jeddah, Saudi Arabia

Abstract

BackgroundMosquito-borne diseases are rapidly spreading due to increasing international travel and trade. Routine mosquito surveillance and screening for mosquito-borne pathogens can be early indicators for local disease transmission and outbreaks. However, arbovirus detection in mosquito vectors has rarely been reported in Saudi Arabia.MethodsA total of 769,541 Aedes and Culex mosquitoes were collected by Black Hole traps during routine mosquito surveillance in the first half of 2016. Culex. quinquefasciatus and Ae. aegypti were the most prevalent species observed. Twenty-five and 24 randomly selected pools of Ae. aegypti and Cx. quinquefasciatus, respectively, were screened for arboviruses by RT-PCR.ResultsDengue 2 (DENV-2) and four strains of insect-specific flaviviruses, including one of cell-fusing agent virus (CFAV) and three of Phlebotomus-associated flavivirus (PAFV) were detected in pools of Ae. aegypti. We also detected 10 strains of Culex flavivirus (CxFV) in pools of Cx. quinquefasciatus. Phylogenetic analysis using whole genome sequences placed the DENV strain into the cosmopolitan 1 sub-DENV-2 genotype, and the CxFVs into the African/Caribbean/Latin American genotype. These analyses also showed that the DENV-2 strain detected in the present study was closely related to strains detected in China in 2014 and in Japan in 2018, which suggests frequent movement of DENV-2 strains among these countries. Furthermore, the phylogenetic analysis suggested at least five introductions of DENV-2 into Saudi Arabia from 2014 through 2018, most probably from India.ConclusionsTo our knowledge, this study reports the first detection of four arboviruses DENV, CFAV, PAFV, and CxFV in mosquitoes in Saudi Arabia, which shows that they are co-circulating in Jeddah. Our findings show a need for widespread mosquito-based arbovirus surveillance programs in Saudi Arabia, which will improve our understanding of the transmission dynamics of the mosquito-borne arboviruses within the country and help early predict and mitigate the risk of human infections and outbreaks.

Molecular Analysis of Targeted Insecticide Resistance Gene Mutations in Field-Caught Mosquitos of Medical Importance From Saudi Arabia

“…Mosquitoes were collected with Black Hole strap (BioTrap Co., Ltd, Seoul, South Korea) during routine mosquito surveillance in 2016. More details about the collection method and the results of mosquito diversity and seasonal density are were reported by in Fang et al (2021) . A total of 25 Ae.…”

“…aegypti , and 10 strains of Culex flavivirus were detected in pools of Cx. quinquefasciatus from Jeddah ( Fang et al 2021 ).…”

Insect‐specific viruses used in biocontrol of mosquito‐borne diseases

“…Concurrently, about 31% of negative female mosquitoes can be infected by CFAV‐positive males during copulation, and the CFAV maternal vertical transmission rate can reach 93% 21 . Nevertheless, the mosquito's co‐infection with CFAV and DENV/WNV can be detected in some areas, and the dynamic trend of this co‐infection needs to be monitored 22,23 …”

“…21 Nevertheless, the mosquito's co-infection with CFAV and DENV/WNV can be detected in some areas, and the dynamic trend of this coinfection needs to be monitored. 22,23 Nhumirim virus (NHUV) is a flavivirus originally isolated from Culex mosquito pools in Brazil. 24 Compared with the cells infected with WNV, JEV, or Saint Louis Encephalitis virus (SLEV) alone, prior to or concurrent infection of NHUV in C6/36 cells significantly reduces the replication of these mosquito-borne flaviviruses, 25 which is consistent with the results using WNV to infect C7/10 cells.…”

Monitoring Mosquito-Borne Arbovirus in Various Insect Regions in China in 2018

“…RNA extraction, cDNA synthesis, and RNA integrity assessment were performed as previously described (Fang et al, 2018). PCR amplification to detect alphaviruses, flaviviruses, and orthobunyaviruses was performed as described by Fang et al (2021a). For additional genotype identification, the primer sets JEV-Ef/JEV-Er (Gao et al, 2013) and CxFV-E-F/CxFV-E-R (Saiyasombat et al, 2010) amplified the E genes of JEV and CxFV, respectively.…”