Frequent detection of monkeypox virus DNA in saliva, semen, and other clinical samples from 12 patients, Barcelona, Spain, May to June 2022.

A monkeypox (MPX) outbreak has expanded worldwide since May 2022. We tested 147 clinical samples collected at different time points from 12 patients by real-time PCR. MPX DNA was detected in saliva from all cases, sometimes with high viral loads. Other samples were frequently positive: rectal swab (11/12 cases), nasopharyngeal swab (10/12 cases), semen (7/9 cases), urine (9/12 cases) and faeces (8/12 cases). These results improve knowledge on virus shedding and the possible role of bodily fluids in disease transmission.

Diagnostic Performance of Six Rapid Antigen Tests for SARS-CoV-2.

Microbiological diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a challenge. Although real-time reverse transcription PCR (RT-PCR) represents the gold standard method, strategies that allow rapid and simple diagnosis are necessary for the early identification of cases. In this study, we evaluated the diagnostic performance of six different commercial rapid antigen tests (Coronavirus antigen [Ag] rapid test cassette [Healgen Scientific, Houston, TX, USA], COVID-19 Ag FIA [Vircell, SD Biosensor Inc., Gyeonggi-do, Republic of Korea], Clinitest rapid COVID-19 antigen test [Siemens, Healthineers, Erlangen, Germany], SARS-CoV-2 rapid antigen test [SD Biosensor; Roche Diagnostics, Basel, Switzerland], Panbio COVID-19 Ag rapid test device [Abbott, Chicago, IL, USA], and SARS-CoV-2 test [MonLab, Barcelona, Spain]) in 130 nasopharyngeal swab samples tested previously by RT-PCR. The overall sensitivity of the rapid tests ranged from 65% to 79%, and the specificity was 100% for all of them. The sensitivity was higher for those samples with RT-PCR cycle threshold (CT) values below 25 and those from patients presenting within the first week of symptoms. The Siemens test showed the highest sensitivity for patients with high viral loads while the Vircell test performed better than the rest for CT values of ≥25. IMPORTANCE The rapid detection of people infected with SARS-CoV-2 is essential for a correct and effective control of the disease it causes. This process must be sensitive, fast, and simple, and it must be possible to carry out in any type of health center. Rapid antigen tests are the answer to this need. Knowing its ability to detect the virus in different stages of the disease is essential for a correct diagnosis, which is why this study has been carried out to evaluate the sensitivity and specificity of 6 different antigens tests in nasopharyngeal smear samples.

Molecular Characterization of Imported and Autochthonous Dengue in Northeastern Spain.

Dengue is the most significant arbovirus worldwide and a public health threat to non-endemic 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.

Evaluation of a novel microfluidic immuno-magnetic agglutination assay method for detection of dengue virus NS1 antigen.

BACKGROUND: Dengue virus (DENV) is the most important arbovirus worldwide, causing infections in endemic countries and returning travellers from these areas. Rapid diagnostic tests are needed to improve patient management and monitor local transmission. The detection of DENV non-structural protein 1 (NS1) is a useful tool for the diagnosis, but the currently available methods can be time consuming or lack sensitivity. The objective of our study was to evaluate a new rapid and semi-quantitative microfluidic DENV NS1 immuno-magnetic agglutination assay based on aggregation of magnetic nanoparticles detected by an electronic reader (Virotrack Dengue Acute and Blubox, Blusense diagnostics, Copenhagen, Denmark). METHODOLOGY/PRINCIPAL FINDINGS: A panel of 135 serum samples from travelers returning from dengue endemic countries was analyzed (74 DENV positive samples including the four DENV serotypes, 26 Zika virus positive samples, 25 chikungunya virus positive samples, 5 malaria positive samples and 5 negative samples). Samples were tested by three different antigen detection methods: SD Dengue NS1 Ag ELISA, SD BIOLINE Dengue Duo and ViroTrack Dengue Acute. The sensitivity observed for SD Dengue NS1 Ag ELISA, ViroTrack Dengue Acute and SD BIOLINE Dengue Duo was 97.2%, 91.1% and 68.1%, respectively. All methods showed high specificity (98.4% for ViroTrack Dengue Acute and 100% for both SD Dengue NS1 Ag ELISA and SD BIOLINE Dengue Duo). SD Dengue NS1 Ag ELISA and ViroTrack Dengue Acute only failed to detect samples positive for DENV-2. CONCLUSIONS/SIGNIFICANCE: ViroTrack Dengue Acute is a sensitive and specific assay for DENV NS1 detection. It provides faster results than the ELISA method and a better performance than the rapid immunochromatographic tests. ViroTrack Dengue Acute could represent a valuable tool for rapid diagnosis of DENV infections in returning travellers from endemic countries.

Persistence of Zika virus in semen 93 days after the onset of symptoms / Persistencia del virus Zika en semen 93 días tras el comienzo de los síntomas

Introduction: Zika virus is mainly transmitted through the bites of infected Aedes mosquitoes, although mother-to-child and sexual transmission have also been described. The presence of Zika virus in semen after infection seems to be not uncommon, but the duration of viral persistence has not been well-determined. Methods: Molecular, serological and cell culture methods were used for the diagnosis and follow up of a case of Zika virus infection imported from Venezuela. Serial samples of serum, urine and semen were analyzed to investigate the persistence of the Zika virus. Results: Zika virus was detected in semen samples up to 93 days after the onset of symptoms. Conclusions: Our results confirm the persistence of Zika virus in semen samples for long periods after infection (AU)

Introducción: El virus Zika se transmite fundamentalmente por la picadura de mosquitos Aedes infectados, aunque también es posible la transmisión de madre a hijo y la transmisión sexual. La presencia del virus Zika en semen tras la infección parece ser algo relativamente frecuente, pero la duración de la persistencia viral no es bien conocida. Métodos: Mediante técnicas moleculares, serológicas y cultivo celular se diagnosticó un caso de Zika importado de Venezuela y se tomaron muestra seriadas de suero, orina y semen para investigar la persistencia del virus. Resultados: El virus Zika fue detectado en muestras de semen recogidas 93días después del inicio de los síntomas. Conclusiones: Nuestros resultados confirman la persistencia del virus Zika en semen por períodos prolongados de tiempo después de la infección (AU)

Persistence of Zika virus in semen 93 days after the onset of symptoms.

INTRODUCTION: Zika virus is mainly transmitted through the bites of infected Aedes mosquitoes, although mother-to-child and sexual transmission have also been described. The presence of Zika virus in semen after infection seems to be not uncommon, but the duration of viral persistence has not been well-determined. METHODS: Molecular, serological and cell culture methods were used for the diagnosis and follow up of a case of Zika virus infection imported from Venezuela. Serial samples of serum, urine and semen were analyzed to investigate the persistence of the Zika virus. RESULTS: Zika virus was detected in semen samples up to 93 days after the onset of symptoms. CONCLUSIONS: Our results confirm the persistence of Zika virus in semen samples for long periods after infection.