Surveillance of SARS-CoV-2 virus circulation using Acute Respiratory Infections sentinel system of Catalonia (PIDIRAC) during the 2019-2020 season: A retrospective observational study.

BACKGROUND: In the context of COVID-19 pandemic in Catalonia (Spain), the present study analyses respiratory samples collected by the primary care network using Acute Respiratory Infections Sentinel Surveillance System (PIDIRAC) during the 2019-2020 season to complement the pandemic surveillance system in place to detect SARS-CoV-2. The aim of the study is to describe whether SARS-CoV-2 was circulating before the first confirmed case was detected in Catalonia, on February 25th, 2020. METHODS: The study sample was made up of all samples collected by the PIDIRAC primary care network as part of the Influenza and Acute Respiratory Infections (ARI) surveillance system activities. The study on respiratory virus included coronavirus using multiple RT-PCR assays. All positive samples for human coronavirus were subsequently typed for HKU1, OC43, NL63, 229E. Every respiratory sample was frozen at-80°C and retrospectively studied for SARS-CoV-2 detection. A descriptive study was performed, analysing significant differences among variables related to SARS-CoV- 2 cases comparing with rest of coronaviruses cases through a bivariate study with Chi-squared test and statistical significance at 95%. RESULTS: Between October 2019 and April 2020, 878 respiratory samples from patients with acute respiratory infection or influenza syndrome obtained by PIDIRAC were analysed. 51.9% tested positive for influenza virus, 48.1% for other respiratory viruses. SARS-CoV-2 was present in 6 samples. The first positive SARS-CoV-2 case had symptom onset on 2 March 2020. These 6 cases were 3 men and 3 women, aged between 25 and 50 years old. 67% had risk factors, none had previous travel history nor presented viral coinfection. All of them recovered favourably. CONCLUSION: Sentinel Surveillance PIDIRAC enhances global epidemiological surveillance by allowing confirmation of viral circulation and describes the epidemiology of generalized community respiratory viruses' transmission in Catalonia. The system can provide an alert signal when identification of a virus is not achieved in order to take adequate preparedness measures.

Whole-Genome Analysis Surveillance of Influenza A Virus Resistance to Polymerase Complex Inhibitors in Eastern Spain from 2016 to 2019.

Molecular surveillance by whole-genome sequencing was used to monitor the susceptibility of circulating influenza A viruses to three polymerase complex inhibitors. A total of 12 resistance substitutions were found among 285 genomes analyzed, but none were associated with high levels of resistance. Natural resistance to these influenza A antivirals is currently uncommon.

Evaluation of a new, rapid, simple test for the detection of influenza virus.

BACKGROUND: Influenza virus infections are responsible for significant morbidity and mortality in both pediatric and adult populations worldwide. Rapid and accurate diagnosis of influenza is necessary for appropriate patient management during the influenza season and for optimal utilization of anti-influenza therapy. We prospectively tested the accuracy of a simple and rapid diagnostic method. METHODS: Ninety-eight samples (nasal and pharyngeal swabs) from patients with upper respiratory tract infection symptoms who presented to primary healthcare centres in Barcelona (Spain) were prospectively analyzed. The samples were collected as part of influenza surveillance program. Samples that had enough volume to make the new test after aliquoting the amount needed to perform routine tests were included. None of the samples were pre-selected as a result of their status in relation to influenza virus. Samples were analyzed by in-house real-time PCR and Alere i Influenza A & B (Alere i), which uses isothermal amplification of nucleic acids for the qualitative detection of influenza A and B in nasal swabs transported in viral transport media. The two techniques were compared by positive percent agreement (PPA) and negative percent agreement (NPA). Statistical analysis was performed with Stata. RESULTS: Of the 98 samples analysed 90 were concordant; 46 (46.9%) were positive and 44 (44.9%) were negative. Five samples showed invalid results with the Alere i test and could be not re-tested due to insufficient sample volume and were not included in the final statistical analysis. In the 93 remaining samples, the Alere i test showed 97% of accuracy having correctly classified 90 samples. We obtained discordant results in 3 samples (3%). The PPA was 93.8% for influenza A and 94.1% for influenza B, and NPA was 100% for influenza A and influenza B virus. In addition, the Alere i was very rapid (15 minutes or less) and extremely easy to use. CONCLUSIONS: The Alere i test provided a good correlation compared to the real-time PCR test for the diagnosis of influenza. Since this method can be performed in minutes, it allows immediate, accurate clinical decisions to prescribe appropriate antiviral treatment or isolation of patients.

Immunogenicity and acceptance of influenza A (H1N1) vaccine in a cohort of chronic hepatitis C patients receiving pegylated-interferon treatment.

UNLABELLED: BACKGROUND #ENTITYSTARTX00026; AIMS: Individuals at risk of (H1N1) influenza A infection are recommended to receive vaccination. Chronic hepatitis C (CHC) patients receiving treatment might be at a higher risk of respiratory bacterial infections after influenza infection. However, there are no observational studies evaluating the immunogenicity, tolerance and acceptance of 2009 influenza A vaccine in CHC patients. METHODS: We evaluated the immunogenicity of influenza A vaccine (Pandemrix®) by using the hemagglutination inhibition (HI) titers method in a well defined cohort of CHC patients receiving or not receiving pegylated-interferon and ribavirin, and compared it with healthy subjects (controls). A group of patients with inflammatory bowel disease (IBD) under immunosuppression, thought to have a lower immune response to seasonal influenza vaccine, were also included as a negative control group. In addition, tolerance to injection site reactions and acceptance was assessed by a validated questionnaire (Vaccinees' perception of injection-VAPI-questionnaire). RESULTS: Of 114 subjects invited to participate, 68% accepted and, after exclusions, 72 were included. Post-vaccination geometric mean titers and seroprotection/seroconversion rates were optimal in CHC patients with ongoing treatment (n = 15; 232, CI95% 46-1166; 93%; 93%), without treatment (n = 10; 226, CI95% 69-743: 100%; 100%) and controls (n = 15;168, CI95% 42-680; 93%; 86%) with no differences between groups (P = 0.8). In contrast, IBD patients had a significantly lower immunogenic response (n = 27; 60, CI95% 42-680;66%;66%; P = 0.006). All the groups showed a satisfactory tolerance although CHC patients with ongoing treatment showed more local discomfort after vaccine injection. CONCLUSION: There appeared to be no differences between CHC patients and healthy controls in serological response and acceptance of (H1N1) influenza vaccination.

Influenza C virus surveillance during the first influenza A (H1N1) 2009 pandemic wave in Catalonia, Spain.

Although particular attention is paid to influenza A and B virus isolates during influenza surveillance, influenza C virus (FLUCV) coexisted during the first influenza A (H1N1) 2009 pandemic wave during the 2009-2010 season. From 27 April 2009 to 9 May 2010, 12 strains of FLUCV were detected in specimens collected from 1713 nonhospitalized patients with upper respiratory tract illness using a molecular method. Half of the patients with FLUCV infection were older than 14 years. The most frequent symptoms were cough and fever, similar to other viral respiratory infections. Phylogenetic analysis of the hemagglutinin-esterase gene revealed that the strains belonged to the C/Kanagawa/1/76-related and C/Sao Paulo/378/82-related lineages, demonstrating their co-circulation in Catalonia. In addition to regular virological surveillance that provides information about the incidence and the exact role of FLUCV in acute viral respiratory infections in the general population, the genetic lineage identification offers additional data for epidemiological purposes.

D225G mutation in the hemagglutinin protein found in 3 severe cases of 2009 pandemic influenza A (H1N1) in Spain.

From 27 April to 16 December 2009, we analyzed the hemagglutinin gene sequence of 2009 pandemic influenza A (H1N1) virus in 189 respiratory specimens. We only found the D225G mutation in 3 severe cases. However, it was not found in samples from other cases with or without clinical criteria of severity. The biologic significance of this mutation remains still unclear.

Double (V27A/S31N) mutant 2009 pandemic influenza A (H1N1) virus isolated from adamantane non-treated inmunocompetent child.

We report the first strain of 2009 pandemic influenza A (H1N1) virus with V27A mutation in addition to S31N substitution in M2 gen. It was isolated from adamantane non-treated child.