Vaccine effectiveness against severe acute respiratory infections (SARI) COVID-19 hospitalisations estimated from real-world surveillance data, Slovenia, October 2021

We estimated vaccine effectiveness (VE) against severe COVID-19 during October 2021, using Slovenian surveillance data. For people fully vaccinated with any vaccine in age groups 18–49, 50–64, ≥ 65 years, VE was 86% (95% CI: 79–90), 89% (85–91), and 77% (74–81). Among ≥ 65 year-olds fully vaccinated with mRNA vaccines, VE decreased from 93% (95% CI: 88–96) in those vaccinated ≤ 3 months ago to 43% (95% CI: 30–54) in those vaccinated ≥ 6 months ago, suggesting the need for early boosters.

Etiology of severe acute respiratory infections in Ekaterinburg in different epidemic seasons

BACKGROUND: Acute respiratory viral infections are ubiquitous. Part of the cases are severe and require hospital treatment. AIM: Studying the etiology of severe acute respiratory infections in patients of Ekaterinburg hospitals in different epidemic seasons (from 2017 to 2020). MATERIALS AND METHODS: 1,132 cases of severe acute respiratory infection were assessed. The structure of laboratory-confirmed cases was determined. RESULTS: In the assessed seasons, the proportion of respiratory viruses in the etiological structure of severe acute respiratory infections was 56.0% on average. B/Yamagata lineage of influenza viruses was predominant in the season of 2017/2018 (23.9% from the total number of respiratory viruses), influenza А (H1N1)pdm09 viruses were predominant in the season of 2018/2019 (27.7%), and influenza A and B viruses were identified in 2019/2020 (39.4% and 31.7%, respectively). СONCLUSIONS: The obtained results confirm a key role of influenza viruses in the etiology of severe acute respiratory infections among the hospital patients in different epidemic seasons.

Age-Specific Etiology of Severe Acute Respiratory Infections and Influenza Vaccine Effectivity in Prevention of Hospitalization in Russia, 2018–2019 Season

The expansion and standardization of clinical trials, as well as the use of sensitive and specific molecular diagnostics methods, provide new information on the age-specific roles of influenza and other respiratory viruses in development of severe acute respiratory infections (SARI). Here, we present the results of the multicenter hospital-based study aimed to detect age-specific impact of influenza and other respiratory viruses (ORV). The 2018–2019 influenza season in Russia was characterized by co-circulation of influenza A(H1N1)pdm09 and A(H3N2) virus subtypes which were detected among hospitalized patients with SARI in 19.3% and 16.4%, respectively. RSV dominated among ORV (15.1% of total cases and 26.8% in infants aged ≤ 2 years). The most significant SARI agents in intensive care units were RSV and influenza A(H1N1)pdm09 virus, (37.3% and 25.4%, respectively, of PCR-positive cases). Hyperthermia was the most frequently registered symptom for influenza cases. In contrast, hypoxia, decreased blood O2 concentration, and dyspnea were registered more often in RSV, rhinovirus, and metapneumovirus infection in young children. Influenza vaccine effectiveness (IVE) against hospitalization of patients with PCR-confirmed influenza was evaluated using test-negative case–control design. IVE for children and adults was estimated to be 57.0% and 62.0%, respectively. Subtype specific IVE was higher against influenza A(H1N1)pdm09, compared to influenza A(H3N2) (60.3% and 45.8%, respectively). This correlates with delayed antigenic drift of the influenza A(H1N1)pdm09 virus and genetic heterogeneity of the influenza A(H3N2) population. These studies demonstrate the need to improve seasonal influenza prevention and control in all countries as states by the WHO Global Influenza Strategy for 2019–2030 initiative.

Enhanced national surveillance of severe acute respiratory infections (SARI) within COVID-19 surveillance, Slovenia, weeks 13 to 37 2021

We monitored trends of severe COVID-19 morbidity in Slovenia during weeks 13 to 37 2021. National weekly rates of severe acute respiratory infections (SARI) cases testing positive for SARS-CoV-2 at admission in all hospitals varied between 0.2 and 16.3 cases per 100,000 population. Of those without previous COVID-19 diagnosis, SARI COVID-19 admission rates ranged between 0.3 and 17.5 per 100,000 unvaccinated, and 0.0 and 7.3 per 100,000 fully vaccinated individuals. National SARI COVID-19 surveillance is essential in informing COVID-19 response.

Spotlight influenza: Extending influenza surveillance to detect non-influenza respiratory viruses of public health relevance: analysis of surveillance data, Belgium, 2015 to 2019

Background Seasonal influenza-like illness (ILI) affects millions of people yearly. Severe acute respiratory infections (SARI), mainly influenza, are a leading cause of hospitalisation and mortality. Increasing evidence indicates that non-influenza respiratory viruses (NIRV) also contribute to the burden of SARI. In Belgium, SARI surveillance by a network of sentinel hospitals has been ongoing since 2011. Aim We report the results of using in-house multiplex qPCR for the detection of a flexible panel of viruses in respiratory ILI and SARI samples and the estimated incidence rates of SARI associated with each virus. Methods We defined ILI as an illness with onset of fever and cough or dyspnoea. SARI was defined as an illness requiring hospitalisation with onset of fever and cough or dyspnoea within the previous 10 days. Samples were collected in four winter seasons and tested by multiplex qPCR for influenza virus and NIRV. Using catchment population estimates, we calculated incidence rates of SARI associated with each virus. Results One third of the SARI cases were positive for NIRV, reaching 49.4% among children younger than 15 years. In children younger than 5 years, incidence rates of NIRV-associated SARI were twice that of influenza (103.5 vs 57.6/100,000 person-months); co-infections with several NIRV, respiratory syncytial viruses, human metapneumoviruses and picornaviruses contributed most (33.1, 13.6, 15.8 and 18.2/100,000 person-months, respectively). Conclusion Early testing for NIRV could be beneficial to clinical management of SARI patients, especially in children younger than 5 years, for whom the burden of NIRV-associated disease exceeds that of influenza.

Study to determine the correlation of platelet-lymphocyte ratio in COVID 19 positive and negative severe acute respiratory infections cases

Background: Severity of COVID 19 disease is related to the systemic inflammatory response triggered by the respiratory virus. Hematological alterations triggered by inflammation can be used as a marker to predict the severity of COVID 19 infection.Methods: 155 patients of severe acute respiratory infections (SARI) defined by World Health Organization (WHO) criteria of which 65 were COVID positive and 90 COVID negative were taken for the study. Demographic profile of the population and platelet count, lymphocyte count and platelet lymphocyte ratio was compared between COVID 19 positive and negative SARI cases using appropriate descriptive statistics. Correlation analysis done for the same parameters between severe and moderate COVID 19 SARI cases.Results: Median platelet count in COVID positive group (2.47 L) was lower than that of COVID negative group (2.65 L) and was not statistically significant between 2 groups. Median lymphocyte count in COVID positive group (651) was lower compared to the negative group (1250) and difference was statistically significant. PLR in COVID positive group was higher (353) than COVID negative group (198) and was statistically significant (p value 0.00). PLR was higher in severe COVID disease compare to moderate disease but difference was not statistically significant. No significant correlation was found in platelet count, lymphocyte count in moderate and severe COVID positive SARI cases.Conclusions: Lower lymphocyte counts was observed in SARI caused by COVID 19 infection than other causes of SARI. No significant correlation was found in platelet count between COVID positive and negative SARI cases. PLR was significantly higher in COVID positive SARI cases as compared to COVID negative SARI cases. Platelet lymphocyte ratio (PLR) was higher in severe COVID disease when compared to moderate disease but levels did not reach statistical significance.

Molecular Typing and Epidemiology Profiles of Human Metapneumovirus Infection Among Children With Severe Acute Respiratory Infection in Huzhou, China

Background: Severe acute respiratory infections (SARI) threaten human health and cause a large number of hospitalized patients every year. However, as one of the most common pathogen that cause acute respiratory tract infection, the molecular epidemiological information relating to hMPV among patients with SARI is limited. Here, we evaluate the epidemiological and molecular characteristics of hMPV infections among children hospitalized patients with SARI from January 2016 to December 2020 in Huzhou, China.Methods: From January 2016 to December 2020, a total of 1133 nasopharyngeal swabs collected from children inpatients with SARI were screened for hMPV by real-time PCR. All samples that tested positive for hMPV were further typed by sequencing partial sequences of hexon gene. Genotypes of hMPV were confirmed by phylogenetic analysis. Epidemiological data were analyzed using Microsoft Excel 2010 and service solutions (SPSS) 21.0 software.Results: 56 (4.94%) samples were positive for hMPV, children under 5 years old accounted for 85.71% (48/56) of the infections. Higher activity of hMPV infection could be seen in the period in Spring and Winter. 3 different types of hMPV were identified in hospitalized SARI cases, with hMPV-B1 (42.86 %) was the most prevalent types, followed by HAdV-B2 (35.71 %) and hMPV-A1(21.42 %). The predominant genotypes of hMPV during our study period varied according to surveillance year. Overall, 1 type (hMPV-B1) were detected in 2016, 2 different types(hMPV-B1 and HAdV-A1) were detected in 2017, 3 different types(hMPV-B1, hMPV-B2 and hMPV-A1) were detected in 2018, 2 different types(hMPV-B1 and hMPV-B2) were detected in 2019, 1 type (hMPV-B2) were detected in 2020.Conclusions: This study revealed the prevalence and the molecular epidemiological characteristics of hMPV infections among children hospitalized patients with SARI in Huzhou from January 2016 to December 2020. The hMPV prevalence is related to age and season. As the most prevalent hMPV types, hMPV-B1 was co-circulating with other types and presented an alternate prevalence pattern.

Surveillance for Severe Acute Respiratory Infections among Hospitalized Subjects from 2015/2016 to 2019/2020 Seasons in Tuscany, Italy

In Italy, the influenza season lasts from October until April of the following year. Influenza A and B viruses are the two viral types that cocirculate during seasonal epidemics and are the main causes of respiratory infections. We analyzed influenza A and B viruses in samples from hospitalized patients at Le Scotte University Hospital in Siena (Central Italy). From 2015 to 2020, 182 patients with Severe Acute Respiratory Infections were enrolled. Oropharyngeal swabs were collected from patients and tested by means of reverse transcriptase-polymerase chain reaction to identify influenza A(H3N2), A(H1N1)pdm09 and B. Epidemiological and virological surveillance remain an essential tool for monitoring circulating viruses and possible mismatches with seasonal vaccine strains, and provide information that can be used to improve the composition of influenza vaccines.