Environmental Persistence of Influenza Viruses Is Dependent upon Virus Type and Host Origin

ABSTRACT Highly transmissible influenza viruses (IV) must remain stable and infectious under a wide range of environmental conditions following release from the respiratory tract into the air. Understanding how expelled IV persist in the environment is critical to limiting the spread of these viruses. Little is known about how the stability of different IV in expelled aerosols is impacted by exposure to environmental stressors, such as relative humidity (RH). Given that not all IV are equally capable of efficient airborne transmission in people, we anticipated that not all IV would respond uniformly to ambient RH. Therefore, we have examined the stability of human-pathogenic seasonal and avian IV in suspended aerosols and stationary droplets under a range of RH conditions. H3N2 and influenza B virus (IBV) isolates are resistant to RH-dependent decay in aerosols in the presence of human airway surface liquid, but we observed strain-dependent variations in the longevities of H1N1, H3N2, and IBV in droplets. Surprisingly, low-pathogenicity avian influenza H6N1 and H9N2 viruses, which cause sporadic infections in humans but are unable to transmit person to person, demonstrated a trend toward increased sensitivity at midrange to high-range RH. Taken together, our observations suggest that the levels of vulnerability to decay at midrange RH differ with virus type and host origin. IMPORTANCE The rapid spread of influenza viruses (IV) from person to person during seasonal epidemics causes acute respiratory infections that can lead to hospitalizations and life-threatening illness. Atmospheric conditions such as relative humidity (RH) can impact the viability of IV released into the air. To understand how different IV are affected by their environment, we compared the levels of stability of human-pathogenic seasonal and avian IV under a range of RH conditions and found that highly transmissible seasonal IV were less sensitive to decay under midrange RH conditions in droplets. We observed that certain RH conditions can support the persistence of infectious viruses on surfaces and in the air for extended periods of time. Together, our findings will facilitate understanding of factors affecting the persistence and spread of IV in our environment.

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Influenza Viral Infections Surveillance and Clinical Presentations in Hospitalized Children: A Cross-Sectional Study

Current Respiratory Medicine Reviews ◽

10.2174/1573398x17666210319094524 ◽

2021 ◽

Vol 17 ◽

Author(s):

Montaha Al-Iede ◽

Lena Sarhan ◽

Leen Abushanab ◽

Tamara Ayasrah ◽

Rafaa Al Maani ◽

...

Keyword(s):

Respiratory Infections ◽

Respiratory Viruses ◽

Influenza Viruses ◽

University Hospital ◽

Severe Illness ◽

Influenza B Virus ◽

Influenza B ◽

Hospitalized Children ◽

Acute Respiratory Infections ◽

Clinical Presentations

Background: Influenza virus and other respiratory viruses have been identified as an essential cause of acute respiratory infections (ARIs) in children worldwide. However, there are few data on its frequency and clinical presentation in Jordan. Objectives: We aimed to identify the viral etiology of acute respiratory infections and the various clinical presentations in hospitalized children, especially those with influenza viruses compared to other respiratory viruses. Methods: A retrospective study that was conducted at the Jordan university hospital. All the positive nasopharyngeal aspirates that were collected from hospitalized children aged 0-19 years from January 2017 to January 2019 were reviewed. Results: A total of 338 nasopharyngeal aspirates (NPAs) with positive viral serology results were reviewed. Among the patients younger than four years, the RSV virus was the most frequently detected. However, the Influenza B virus was the most commonly seen in patients older than 5 years, H1N1 was more frequent in autumn (29.5%), and RSV was the most frequent virus in winter. Bronchopneumonia was the most frequent diagnosis among all hospitalized patients, followed by bronchiolitis. Out of 338 patients, 50.3 % had tachypnea, 70.7% of patients were admitted to the pediatric floor, while 18.6% presented with a severe illness and required admission to the pediatric intensive care unit (PICU). Infants under the age of one were more likely to have higher co-infection rates with other viruses compared to children over five years that had influenza. Conclusion: Presentations of influenza and other respiratory viruses vary between different age groups, such as sepsis in children younger than one year.

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Influenza A and B viruses in the population of Vojvodina, Serbia

Archives of Biological Sciences ◽

10.2298/abs1401043r ◽

2014 ◽

Vol 66 (1) ◽

pp. 43-50 ◽

Cited By ~ 2

Author(s):

J. Radovanov ◽

V. Milosevic ◽

I. Hrnjakovic ◽

V. Petrovic ◽

M. Ristic ◽

...

Keyword(s):

Influenza A ◽

Respiratory Infections ◽

Influenza Viruses ◽

Influenza B Virus ◽

Nasopharyngeal Swab ◽

Influenza B ◽

Influenza A Viruses ◽

B Virus ◽

Life Threatening ◽

Seasonal Epidemic

At present, two influenza A viruses, H1N1pdm09 and H3N2, along with influenza B virus co-circulate in the human population, causing endemic and seasonal epidemic acute febrile respiratory infections, sometimes with life-threatening complications. Detection of influenza viruses in nasopharyngeal swab samples was done by real-time RT-PCR. There were 60.2% (53/88) positive samples in 2010/11, 63.4% (52/82) in 2011/12, and 49.9% (184/369) in 2012/13. Among the positive patients, influenza A viruses were predominant during the first two seasons, while influenza B type was more active during 2012/13. Subtyping of influenza A positive samples revealed the presence of A (H1N1)pdm09 in 2010/11, A (H3N2) in 2011/12, while in 2012/13, both subtypes were detected. The highest seroprevalence against influenza A was in the age-group 30-64, and against influenza B in adults aged 30-64 and >65.

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Inhibitory effects of aprotinin on influenza A and B viruses in vitro and in vivo

Scientific Reports ◽

10.1038/s41598-021-88886-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Eun-Jung Song ◽

Erica Españo ◽

Sang-Mu Shim ◽

Jeong-Hyun Nam ◽

Jiyeon Kim ◽

...

Keyword(s):

Influenza Virus ◽

Influenza A ◽

Lethal Dose ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

Inhibitory Effects ◽

Compound Libraries ◽

Wide Range

AbstractInfluenza viruses cause significant morbidity and mortality worldwide. Long-term or frequent use of approved anti-influenza agents has resulted in drug-resistant strains, thereby necessitating the discovery of new drugs. In this study, we found aprotinin, a serine protease inhibitor, as an anti-influenza candidate through screening of compound libraries. Aprotinin has been previously reported to show inhibitory effects on a few influenza A virus (IAV) subtypes (e.g., seasonal H1N1 and H3N2). However, because there were no reports of its inhibitory effects on the other types of influenza viruses, we investigated the inhibitory effects of aprotinin in vitro on a wide range of influenza viruses, including avian and oseltamivir-resistant influenza virus strains. Our cell-based assay showed that aprotinin had inhibitory effects on seasonal human IAVs (H1N1 and H3N2 subtypes), avian IAVs (H5N2, H6N5, and H9N2 subtypes), an oseltamivir-resistant IAV, and a currently circulating influenza B virus. We have also confirmed its activity in mice infected with a lethal dose of influenza virus, showing a significant increase in survival rate. Our findings suggest that aprotinin has the capacity to inhibit a wide range of influenza virus subtypes and should be considered for development as a therapeutic agent against influenza.

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Comparison of Pathogenicity and Transmissibility of Influenza B and D Viruses in Pigs

Viruses ◽

10.3390/v11100905 ◽

2019 ◽

Vol 11 (10) ◽

pp. 905 ◽

Cited By ~ 8

Author(s):

Jinhwa Lee ◽

Liping Wang ◽

Rachel Palinski ◽

Tim Walsh ◽

Dongchang He ◽

...

Keyword(s):

Influenza A ◽

Animal Health ◽

Influenza Virus Infection ◽

Swine Influenza ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

Wide Range ◽

Influenza C Virus ◽

Limited Host Range

Influenza viruses are important pathogens causing respiratory disease in humans and animals. In contrast to influenza A virus (IAV) that can infect a wide range of animal species, other influenza viruses, including influenza B virus (IBV), influenza C virus (ICV), and influenza D virus (IDV) have a limited host range. Swine can be infected with all four different genera of influenza viruses. IAV infection of pigs causes the well-known swine influenza that poses significant threats to human and animal health. However, influenza virus infection of pigs with IBV, ICV, and IDV are not well-characterized. Herein, we compared pathogenicity of IBV and IDV using intratracheal and intranasal infection of pigs, which are IAV seropositive, and commingled naïve pigs with the infected animals to determine their transmissibility. Both viruses caused fever and some lung lesions, replicated in the lungs of infected pigs, but only IDV transmitted to the contact animals. Although IBV and IDV displayed differing levels of replication in the respiratory tract of infected pigs, no significant differences in pathogenicity of both viruses were observed. These results indicate that both IBV and IDV can replicate, and are pathogenic in pigs.

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Clinical Investigations. Comparison of Directigen Flu A+B with Real Time PCR in the Diagnosis of Influenza / Сравнение Иммунохроматографического Метода (Directigen Flu A+B) И Теста RT-PCR При Инфекциях Гриппа

Folia Medica ◽

10.1515/folmed-2015-0027 ◽

2015 ◽

Vol 57 (2) ◽

pp. 104-110 ◽

Cited By ~ 4

Author(s):

Golubinka Bosevska ◽

Nikola Panovski ◽

Elizabeta Janceska ◽

Vladimir Mikik ◽

Irena Kondova Topuzovska ◽

...

Keyword(s):

Real Time ◽

Influenza A Virus ◽

Real Time Pcr ◽

Influenza A ◽

Age Groups ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

B Virus ◽

Nose And Throat

AbstractEarly diagnosis and treatment of patients with influenza is the reason why physicians need rapid high-sensitivity influenza diagnostic tests that require no complex lab equipment and can be performed and interpreted within 15 min. The Aim of this study was to compare the rapid Directigen Flu A+B test with real time PCR for detection of influenza viruses in the Republic of Macedonia. MATERIALS AND METHODS: One-hundred-eight respiratory samples (combined nose and throat swabs) were routinely collected for detection of influenza virus during influenza seasons. Forty-one patients were pediatric cases and 59 were adult. Their mean age was 23 years. The patients were allocated into 6 age groups: 0 - 4 yrs, 5 - 9 yrs, 10 - 14 yrs, 15 - 19 yrs, 20-64 yrs and > 65 yrs. Each sample was tested with Directigen Flu A+B and CDC real time PCR kit for detection and typisation/subtypisation of influenza according to the lab diagnostic protocol. RESULTS: Directigen Flu A+B identified influenza A virus in 20 (18.5%) samples and influenza B virus in two 2 (1.9%) samples. The high specificity (100%) and PPV of Directigen Flu A+B we found in our study shows that the positive results do not need to be confirmed. The overall sensitivity of Directigen Flu A+B is 35.1% for influenza A virus and 33.0% for influenza B virus. The sensitivity for influenza A is higher among children hospitalized (45.0%) and outpatients (40.0%) versus adults. CONCLUSION: Directigen Flu A+B has relatively low sensitivity for detection of influenza viruses in combined nose and throat swabs. Negative results must be confirmed.

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Haemagglutination-inhibition antibodies against influenza A and influenza B in maternal and neonatal sera

Journal of Hygiene ◽

10.1017/s0022172400053353 ◽

1978 ◽

Vol 80 (1) ◽

pp. 13-19 ◽

Cited By ~ 6

Author(s):

N. Masurel ◽

J. I. de Bruijne ◽

H. A. Beuningh ◽

H. J. A. Schouten

Keyword(s):

Influenza Virus ◽

Maternal Age ◽

Influenza A ◽

Haemagglutination Inhibition ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

B Virus ◽

Duration Of Pregnancy ◽

Pregnancy And Birth

SUMMARYHaemagglutination inhibition (HI) antibodies against the influenza viruses A/Hong Kong/8/68 (H3N2) and B/Nederland/77/66 were determined in 420 paired sera from mothers and newborns (umbilical cord sera), sampled in 1970–1.A higher concentration of antibodies against influenza A virus was found more frequently in neonatal than in maternal sera. By contrast, low titres against influenza B virus were more frequently observed in neonatal than in maternal sera. Maternal age, duration of pregnancy, and birth-weight did not affect the results of the tests.It is suggested that the titre of the newborn against an epidemic influenza virus can be predicted from that of the mother. Furthermore, the maternal titre may be an indication of the susceptibility of the newborn infant to influenza infections.

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Epidemiology of Respiratory Pathogens among Elderly Nursing Home Residents with Acute Respiratory Infections in Corsica, France, 2013–2017

BioMed Research International ◽

10.1155/2017/1423718 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Shirley Masse ◽

Lisandru Capai ◽

Alessandra Falchi

Keyword(s):

Nursing Home ◽

Influenza A ◽

Respiratory Infections ◽

Nursing Home Residents ◽

Respiratory Viruses ◽

Sudden Onset ◽

Influenza Viruses ◽

Influenza B ◽

Acute Respiratory Infections ◽

Respiratory Pathogens

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.

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Triazavirin might be the new hope to fight Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

Česká a slovenská farmacie ◽

10.5817/csf2021-1-18 ◽

2021 ◽

Vol 70 (1) ◽

pp. 18-25

Author(s):

Malík Ivan ◽

Čižmárik Jozef ◽

Kováč Gustáv ◽

Pecháčová Mária ◽

Hudecová Lucia

Keyword(s):

Influenza Virus ◽

Severe Acute Respiratory Syndrome ◽

Rift Valley Fever Virus ◽

Encephalitis Virus ◽

Influenza Viruses ◽

Swine Flu ◽

Influenza B Virus ◽

Influenza B ◽

Antiviral Compound ◽

Virus Influenza

Since the beginning of the outbreak, a large number of clinical trials have been registered worldwide, and thousands of drugs have been investigated to face new health emergency of highly contagious COVID-19 caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Drug repurposing, i.e., utilizing an approved drug for a different indication, offers a time- and cost-efficient alternative for making new (relevant) therapies available to physicians and patients. Considering given strategy, many approved and investigational antiviral compounds, alone or in various relevant combinations, used in the past to fight Severe Acute Respiratory Syndrome Coronavirus-1, Middle East Respiratory Syndrome Coronavirus, Human Immunodeficiency Virus type 1, or Influenza viruses are being evaluated against the SARS-CoV-2. Triazavirin (TZV), a non-toxic broad--spectrum antiviral compound, is efficient against various strains of the Influenza A virus (Influenza Virus A, Orthomyxoviridae), i.e., swine flu (H1N1, or H3N2), avian influenza (H5N1, H5N2, H9N2, or highly pathogenic H7N3 strain), Influenza B virus (Influenza Virus B, Orthomyxoviridae), Respiratory Syncytial Virus (Orthopneumovirus, Pneumoviridae), Tick-Borne Encephalitis Virus (known as Forest-Spring Encephalitis Virus; Flavivirus, Flaviviridae), West Nile Virus (Flavivirus, Flavaviridae), Rift Valley Fever Virus (Phlebovirus, Bunyaviridae), and Herpes viruses (Simplexviruses, Herpesviridae) as well. In regard to COVID-19, the molecule probably reduced inflammatory reactions, thus limiting the damage to vital organs and reducing the need for therapeutic support, respectively. In addition, in silico computational methods indicated relatively satisfactory binding affinities of the TZV ligand to both structural (E)- and (S)-proteins, non-structural 3-chymotrypsin-like protease (3-CLpro) of SARS-CoV-2 as well as human angiotensin-I converting enzyme-2 (ACE-2). The interactions between TZV and given viral structures or the ACE-2 receptor for SARS-CoV-2 might effectively block both the entry of the pathogen into a host cell and its replication. Promising treatment patterns of COVID-19 positive patients might be also based on a suitable combination of a membrane fusion inhibitor (umifenovir, for example) with viral RNA synthesis and replication inhibitor (TZV).

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Non-Uniform and Non-Random Binding of Nucleoprotein to Influenza A and B Viral RNA

Viruses ◽

10.3390/v10100522 ◽

2018 ◽

Vol 10 (10) ◽

pp. 522 ◽

Cited By ~ 10

Author(s):

Valerie Le Sage ◽

Adalena Nanni ◽

Amar Bhagwat ◽

Dan Snyder ◽

Vaughn Cooper ◽

...

Keyword(s):

Influenza A ◽

Gene Segment ◽

Influenza Viruses ◽

Viral Rna ◽

Influenza B Virus ◽

Viral Gene ◽

Influenza B ◽

Influenza A Viruses ◽

Binding Profile ◽

Random Manner

The genomes of influenza A and B viruses have eight, single-stranded RNA segments that exist in the form of a viral ribonucleoprotein complex in association with nucleoprotein (NP) and an RNA-dependent RNA polymerase complex. We previously used high-throughput RNA sequencing coupled with crosslinking immunoprecipitation (HITS-CLIP) to examine where NP binds to the viral RNA (vRNA) and demonstrated for two H1N1 strains that NP binds vRNA in a non-uniform, non-random manner. In this study, we expand on those initial observations and describe the NP-vRNA binding profile for a seasonal H3N2 and influenza B virus. We show that, similar to H1N1 strains, NP binds vRNA in a non-uniform and non-random manner. Each viral gene segment has a unique NP binding profile with areas that are enriched for NP association as well as free of NP-binding. Interestingly, NP-vRNA binding profiles have some conservation between influenza A viruses, H1N1 and H3N2, but no correlation was observed between influenza A and B viruses. Our study demonstrates the conserved nature of non-uniform NP binding within influenza viruses. Mapping of the NP-bound vRNA segments provides information on the flexible NP regions that may be involved in facilitating assembly.

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Detection of severe acute respiratory syndrome coronavirus 2 and influenza viruses based on CRISPR-Cas12a

Experimental Biology and Medicine ◽

10.1177/1535370220963793 ◽

2020 ◽

pp. 153537022096379

Author(s):

Oraphan Mayuramart ◽

Pattaraporn Nimsamer ◽

Somruthai Rattanaburi ◽

Naphat Chantaravisoot ◽

Kritsada Khongnomnan ◽

...

Keyword(s):

Influenza Virus ◽

Severe Acute Respiratory Syndrome ◽

Influenza A ◽

Limit Of Detection ◽

Cross Reactivity ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

Influenza Virus A ◽

B Virus

Due to the common symptoms of COVID-19, patients are similar to influenza-like illness. Therefore, the detection method would be crucial to discriminate between SARS-CoV-2 and influenza virus-infected patients. In this study, CRISPR-Cas12a-based detection was applied for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus, and influenza B virus which would be a practical and attractive application for screening of patients with COVID-19 and influenza in areas with limited resources. The limit of detection for SARS-CoV-2, influenza A, and influenza B detection was 10, 103, and 103 copies/reaction, respectively. Moreover, the assays yielded no cross-reactivity against other respiratory viruses. The results revealed that the detection of influenza virus and SARS-CoV-2 by using RT-RPA and CRISPR-Cas12a technology reaches 96.23% sensitivity and 100% specificity for SARS-CoV-2 detection. The sensitivity for influenza virus A and B detections was 85.07% and 94.87%, respectively. In addition, the specificity for influenza virus A and B detections was approximately 96%. In conclusion, the RT-RPA with CRISPR-Cas12a assay was an effective method for the screening of influenza viruses and SARS-CoV-2 which could be applied to detect other infectious diseases in the future.

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