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

2021 ◽  
Vol 11 (4) ◽  
pp. 413-425
Author(s):  
Anna Sominina ◽  
Daria Danilenko ◽  
Andrey Komissarov ◽  
Maria Pisareva ◽  
Tamila Musaeva ◽  
...  

AbstractThe 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.

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Neli Korsun ◽  
Svetla Angelova ◽  
Ivelina Trifonova ◽  
Silvia Voleva ◽  
Iliana Grigorova ◽  
...  

Нuman bocaviruses (hBoVs) are often associated with acute respiratory infections (ARIs). Information on the distribution and molecular epidemiology of hBoVs in Bulgaria is currently limited. The objectives of this study were to investigate the prevalence and genetic characteristics of hBoVs detected in patients with ARIs in Bulgaria. From October 2016 to September 2019, nasopharyngeal/oropharyngeal swabs were prospectively collected from 1842 patients of all ages and tested for 12 common respiratory viruses using a real-time RT-PCR. Phylogenetic and amino acid analyses of the hBoV VP1/VP2 gene/protein were performed. HBoV was identified in 98 (5.3%) patients and was the 6th most prevalent virus after respiratory-syncytial virus (20.4%), influenza A(H1N1)pdm09 (11.1%), A(H3N2) (10.5%), rhinoviruses (9.9%), and adenoviruses (6.8%). Coinfections with other respiratory viruses were detected in 51% of the hBoV-positive patients. Significant differences in the prevalence of hBoVs were found during the different study periods and in patients of different age groups. The detection rate of hBoV was the highest in patients aged 0–4 years (6.9%). In this age group, hBoV was the only identified virus in 9.7%, 5.8%, and 1.1% of the children diagnosed with laryngotracheitis, bronchiolitis, and pneumonia, respectively. Among patients aged ≥5 years, hBoV was detected as a single agent in 2.2% of cases of pneumonia. Phylogenetic analysis showed that all Bulgarian hBoV strains belonged to the hBoV1 genotype. A few amino acid substitutions were identified compared to the St1 prototype strain. This first study amongst an all-age population in Bulgaria showed a significant rate of hBoV detection in some serious respiratory illnesses in early childhood, year-to-year changes in the hBoV prevalence, and low genetic variability in the circulating strains.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Phuong Thai Truong ◽  
Shinji Saito ◽  
Ikuyo Takayama ◽  
Hiroyuki Furuya ◽  
Binh Gia Nguyen ◽  
...  

Abstract Background Acute respiratory tract infection (ARI) is a leading cause of hospitalization, morbidity, and mortality worldwide. Respiratory microbes that were simultaneously detected in the respiratory tracts of hospitalized adult ARI patients were investigated. Associations between influenza A(H1N1)pdm09 virus (H1N1pdm) detection and intensive care unit (ICU) admission or fatal outcome were determined. Methods This prospective observational study was conducted between September 2015 and June 2017 at Bach Mai Hospital, Hanoi, Vietnam. Inclusion criteria were hospitalized patients aged ≥15 years; one or more of symptoms including shortness of breath, sore throat, runny nose, headache, and muscle pain/arthralgia in addition to cough and fever > 37.5 °C; and ≤ 10 days from the onset of symptoms. Twenty-two viruses, 11 bacteria, and one fungus in airway specimens were examined using a commercial multiplex real-time PCR assay. Associations between H1N1pdm detection and ICU admission or fatal outcome were investigated by univariate and multivariate logistic regression analyses. Results The total of 269 patients (57.6% male; median age, 51 years) included 69 ICU patients. One or more microbes were detected in the airways of 214 patients (79.6%). Single and multiple microbes were detected in 41.3 and 38.3% of patients, respectively. Influenza A(H3N2) virus was the most frequently detected (35 cases; 13.0%), followed by H1N1pdm (29 cases; 10.8%). Hematological disease was associated with ICU admission (p < 0.001) and fatal outcomes (p < 0.001) using the corrected significance level (p = 0.0033). Sex, age, duration from onset to sampling, or number of detected microbes were not significantly associated with ICU admission or fatal outcomes. H1N1pdm detection was associated with ICU admission (odds ratio [OR] 3.911; 95% confidence interval [CI] 1.671–9.154) and fatal outcome (OR 5.496; 95% CI 1.814–16.653) after adjusting for the confounding factors of comorbidities, bacteria/Pneumocystis jirovecii co-detection, and age. Conclusions H1N1pdm was associated with severe morbidity and death in adult patients hospitalized with respiratory symptoms. The diagnosis of subtype of influenza virus may be epidemiologically important.


2021 ◽  
Vol 21 (3) ◽  
pp. 123-126
Author(s):  
Evgeniya Viktorovna Lelenkova ◽  
Alexandr Yurievich Markaryan

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.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Shirley Masse ◽  
Lisandru Capai ◽  
Alessandra Falchi

Background. The current study aims to describe the demographical and clinical characteristics of elderly nursing home (NH) residents with acute respiratory infections (ARIs) during four winter seasons (2013/2014–2016/2017), as well as the microbiological etiology of these infections. Methods. Seventeen NHs with at least one ARI resident in Corsica, France, were included. An ARI resident was defined as a resident developing a sudden onset of any constitutional symptoms in addition to any respiratory signs. Nasopharyngeal swabs from ARI residents were screened for the presence of 21 respiratory agents, including seasonal influenza viruses. Results. Of the 107 ARI residents enrolled from NHs, 61 (57%) were positive for at least one of the 21 respiratory pathogens. Forty-one (38.3%) of the 107 ARI residents had influenza: 38 (92%) were positive for influenza A (100% A(H3N2)) and three (8%) for influenza B/Victoria. Axillary fever (≥38°C) was significantly more common among patients infected with influenza A(H3N2). Conclusion. The circulation of seasonal respiratory viruses other than influenza A(H3N2) seems to be sporadic among elderly NH residents. Investigating the circulation of respiratory viruses in nonwinter seasons seems to be important in order to understand better the dynamic of their year-round circulation in NHs.


2014 ◽  
Vol 27 (3) ◽  
pp. 199-201
Author(s):  
Adrian Jarzynski ◽  
Agata Dubas ◽  
Malgorzata Polz-Dacewicz

ABSTRACT Viruses that cause respiratory tract infections are the most common agents of infectious diseases in humans throughout the world. A virus that infects the respiratory system, may induce various clinical symptoms. What is more, the same symptoms may be caused by different viruses. The aim of the study was to analyze the prevalence of enteroviruses that cause respiratory infections in patients with influenzavirus A/H1N1 hospitalized in the Lublin province. The experimental material was throat and nose swabs taken from patients hospitalized in Lublin and Tomaszow Lubelski. In the group of 44 patients (20 women and 24 men) infected with influenza A/H1N1, the genetic material of enteroviruses was detected in 13 patients (29.5%). Respiratory viruses co-infections are very common in hospitalized patients. Studies show that co-infection with influenza virus and enterovirus are more common in children than in adults. Moreover, viral respiratory tract infections are independent from the patients’ gender.


2011 ◽  
Vol 140 (9) ◽  
pp. 1551-1556 ◽  
Author(s):  
H. E. TANNER ◽  
M. D. CURRAN ◽  
E. H. BOXALL ◽  
H. OSMAN

SUMMARYIn spring 2009 a new strain of influenza A(H1N1) emerged and caused a worldwide pandemic. This study utilized a large collection of respiratory specimens from suspected cases of influenza A(H1N1) in the UK West Midlands during the pandemic in order to investigate which other respiratory viruses were circulating and whether they played any role in the increased hospitalization rates seen during that period. Study specimens were selected from community and hospitalized patients positive and negative for influenza A(H1N1) and tested by PCR for other respiratory viruses. A number of infections diagnosed as influenza during the summer influenza outbreak were found to be due to other virus infections (most commonly rhinovirus). No statistically significant difference was found between the rates of respiratory virus co-infection with H1N1 in patients from community or hospital locations suggesting underlying factors were likely to be more significant than viral co-infections in determining severity of influenza A(H1N1) disease.


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