Molecular characterization of imported and autochthonous dengue in northeastern spain

Dengue is the most significant arbovirus worldwide and a public health threat to nonendemic areas in which Aedes vectors are present. Autochthonous dengue transmission has been reported in several European countries in the last decade. Infected travelers from endemic regions arriving to areas colonized by Aedes albopictus in Europe need to be monitored in surveillance and control programs. We aimed to perform molecular characterization of RT-PCR-positive dengue cases detected in Catalonia, northeastern Spain, from 2013 to 2018. The basic demographic information and the geographical regions of importation were also analyzed. One-hundred four dengue cases were studied (103 imported infections and the first autochthonous case in our region). The dengue virus strains detected were serotyped and genotyped using molecular methods, and phylogenetic analyses were conducted. All four dengue serotypes were detected in travelers, including up to 10 different genotypes, reflecting the global circulation of dengue in endemic areas. The primary travel-related case of the 2018 autochthonous transmission was not identified, but the molecular analysis revealed dengue serotype 1, genotype I of Asian origin. Our results highlight the diversity of imported dengue virus strains and the role of molecular epidemiology in supporting arbovirus surveillance programs

First Report of Sylvatic DENV-2-Associated Dengue Hemorrhagic Fever in West Africa

Dengue virus (DENV) circulates in human and sylvatic cycles. Sylvatic strains are both ecologically and evolutionarily distinct from endemic viruses. Although sylvatic dengue cycles occur in West African countries and Malaysia, only a few cases of mild human disease caused by sylvatic strains and one single case of dengue hemorrhagic fever in Malaysia have been reported. Here we report a case of dengue hemorrhagic fever (DHF) with thrombocytopenia (13000/µl), a raised hematocrit (32% above baseline) and mucosal bleeding in a 27-year-old male returning to Spain in November 2009 after visiting his home country Guinea Bissau. Sylvatic DENV-2 West African lineage was isolated from blood and sera. This is the first case of DHF associated with sylvatic DENV-2 in Africa and the second case worldwide of DHF caused by a sylvatic strain

Geographical Variability Affects CCHFV Detection by RT-PCR: A Tool for In-Silico Evaluation of Molecular Assays

The Crimean-Congo hemorrhagic fever virus (CCHFV) is considered to be a major emerging infectious threat, according to the WHO R&D blueprint. A wide range of CCHFV molecular assays have been developed, employing varied primer/probe combinations. The high genetic variability of CCHFV often hampers the efficacy of available molecular tests and can affect their diagnostic potential. Recently, increasing numbers of complete CCHFV genomic sequences have become available, allowing a better appreciation of the genomic evolution of this virus. We summarized the current knowledge on molecular methods and developed a new bioinformatics tool to evaluate the existing assays for CCHFV detection, with a special focus on strains c

Rapid detection of important human pathogenic Phleboviruses

Background: Rapid diagnostics are not available for several human pathogens in the genus Phlebovirus of the Bunyaviridae. Objectives: To develop RT-PCR assays for Sandfly Fever Sicilian virus (SFSV), Sandfly Fever Naples virus (SFNV), Toscana virus (TOSV) and Rift Valley Fever virus (RVFV). Study design: RNA standards were generated and used to test the performance of the assays. Results: A detection limit of 10-100 RNA molecules was determined for the SFSV, TOSV and RVFV assays. The sensitivity of the SFNV assay was not determined. The TOSV and the RVFV assays detected recent isolates from Spain and Africa, respectively. Conclusion: The assays should help to improve surveillance of pathogenic Phleboviruses

Geographical Variability Affects CCHFV Detection by RT-PCR: A Tool for In-Silico Evaluation of Molecular Assays

The Crimean-Congo hemorrhagic fever virus (CCHFV) is considered to be a major emerging infectious threat, according to the WHO R&D blueprint. A wide range of CCHFV molecular assays have been developed, employing varied primer/probe combinations. The high genetic variability of CCHFV often hampers the efficacy of available molecular tests and can affect their diagnostic potential. Recently, increasing numbers of complete CCHFV genomic sequences have become available, allowing a better appreciation of the genomic evolution of this virus. We summarized the current knowledge on molecular methods and developed a new bioinformatics tool to evaluate the existing assays for CCHFV detection, with a special focus on strains circulating in different geographical areas. Twenty-two molecular methods and 181 sequences of CCHFV were collected, respectively, from PubMed and GenBank databases. Up to 28 mismatches between primers and probes of each assay and CCHFV strains were detected through in-silico PCR analysis. Combinations of up to three molecular methods markedly decreased the number of mismatches within most geographic areas. These results supported the good practice of CCHFV detection of performing more than one assay, aimed for different sequence targets. The choice of the most appropriate tests must take into account patient's travel history and geographic distribution of the different CCHFV strains.Funding: This research was supported by the following funds: Italian Ministry of Health, grants Ricerca Corrente–Linea 1; European Union, Joint Action Consumers, Health, Agriculture, and Food Executive Agency for E cient response to highly dangerous and emerging pathogens at EU level no. 677066 (EMERGE); European Centre for Disease Prevention and Control (ECDC), EVD-LabNet Framework contract ECDC/2016/00; European Union, Horizon 2020 research and innovation program “European Virus Archive goes Global” no. 653316 (EVAg).S

Screening for Zika virus infection in 1057 potentially exposed pregnant women, Catalonia (northeastern Spain)

Dear editor: A recent editorial in Travel Medicine and Infectious Diseases highlighted the lack of studies about Zika virus (ZIKV) in pregnancy and its implications in many countries [1]. Zika virus infection can induce congenital defects in the newborn such as microcephaly and miscarriage when mothers are infected during pregnancy [2]. However, relevant questions remain to be completely understood, such as the risk of infection for pregnant women and of subsequent congenital defects, and the ratio between symptomatic and asymptomatic ZIKV infections in the general population and in pregnant women. Here, we describe the results of a ZIKV screening of pregnant women in Catalonia, northeastern Spain. Testing for ZIKV was recommended for all pregnant women with history of travel to ZIKV endemic areas during pregnancy or in the 8 weeks before conception [3]. Symptomatic patients were screened by serological methods from day four after the onset of symptoms and by molecular methods within the first week (serum) and two weeks (urine) after illness. Asymptomatic patients were tested by serological methods. Seroneutralization assay for ZIKV was perfomed in samples positive for antibodies. Commercial diagnostic assays were used (RT-PCR, Altona Diagnostics and IIFT, Euroimmun). Neutralization titers ≥1/32 were considered indicative of the presence of ZIKV neutralizing antibodies. Follow up at two designated reference obstetrical departments for early detection of microcephaly or other malformations was offered to pregnant women with laboratory evidence of ZIKV infection. When available, amniotic fluid and placental tissue samples were tested for ZIKV by RT-PCR in cases of microcephaly or miscarriage, respectively

Numbers of SNPs identified in VEEV genomes, by gene region.

<p>Numbers of SNPs identified in VEEV genomes, by gene region.</p

Status, quality and specific needs of Zika virus (ZIKV) diagnostic capacity and capability in National Reference Laboratories for arboviruses in 30 EU/EEA countries, MAY 2016

With international travel, Zika virus (ZIKV) is introduced to Europe regularly. A country’s ability to robustly detect ZIKV introduction and local transmission is important t