Genetic diversity of hepatitis E virus (HEV) in imported and domestic camels in Saudi Arabia.

Camels gained attention since the discovery of MERS-CoV as intermediary hosts for potentially epidemic zoonotic viruses. DcHEV is a novel zoonotic pathogen associated with camel contact. This study aimed to genetically characterize DcHEV in domestic and imported camels in Saudi Arabia. DcHEV was detected by RT-PCR in serum samples, PCR-positive samples were subjected to sequencing and phylogenetic analyses. DcHEV was detected in 1.77% of samples with higher positivity in domestic DCs. All positive imported dromedaries were from Sudan with age declining prevalence. Domestic DcHEV sequences clustered with sequences from Kenya, Somalia, and UAE while imported sequences clustered with one DcHEV isolate from UAE and both sequences clustered away from isolates reported from Pakistan. Full-genome sequences showed 24 amino acid difference with reference sequences. Our results confirm the detection of DcHEV in domestic and imported DCs. Further investigations are needed in human and camel populations to identify DcHEV potential zoonosis threat.

Diversity of dengue virus-3 genotype III in Jeddah, Saudi Arabia.

BACKGROUND: Dengue is the most important arboviral disease in tropical and subtropical countries. Dispersal of the vector and an increase in migratory flow between countries have led to large epidemics and severe clinical outcomes. Over the past 20 years, dengue epidemics have become more wide-spread and frequent. Previous studies have shown that dengue is endemic in Jeddah, Makkah and Al-Madinah in western Saudi Arabia as well as in Jazan region in the southern part of the country. The four serotypes of dengue virus (DENV) have been reported from western Saudi Arabia. It has been suggested that pilgrims could play a significant and unique role in DENV-1 and DENV-2 introduction into Saudi Arabia, especially in the cities of Jeddah, Makkah and Al-Madinah during Hajj and Umrah seasons. However, only limited data on DENV-3 in Saudi Arabia are available. METHODS: All available DENV-3 sequences published and unpublished from Saudi Arabia and other countries were retrieved from Genbank and gene sequence repository and phylogenetically analyzed to examine the diversity of DENV-3 into the city of Jeddah. RESULTS: Based on the analysis of the envelope gene and non-structural 1 (E/NS1) junction sequences, we show that there were at least four independent introductions of DENV-3, all from genotype III into Jeddah. The first introduction was most probably before 1997 as Saudi virus isolates from 1997 formed a cluster without any close relationship to other globally circulating isolates, suggesting their local circulation from previous introduction events. Two introductions were most probably in 2004 with isolates closely-related to isolates from Africa and India (Asia), in addition to another introduction in 2014 with isolates clustering with those from Singapore (Asia). CONCLUSIONS: Our data shows that only genotype III isolates of DENV-3 are circulating in Jeddah and highlights the potential role of pilgrims in DENV-3 importation into western Saudi Arabia and subsequent exportation to their home countries during Hajj and Umrah seasons. Therefore, it is highly recommended to establish DENV sentinel surveillance programs targeting clinical cases and the mosquito vector in the country to implement effective control measures and to minimize the burden of the disease in the kingdom.