The Role of Punctuated Evolution in the Pathogenicity of Influenza Viruses

2016 ◽  
pp. 121-130
Author(s):  
Jonathan A. McCullers
Keyword(s):  
Influenza Viruses ◽  
Punctuated Evolution

The Seasonal End of Human Coronavirus Hospital Admissions with Implications for SARS-CoV-2 (Preprint)

2020 ◽  
Author(s):  
Alan T Evangelista
Keyword(s):  
Hospital Admissions ◽  
Disease Incidence ◽  
Influenza Viruses ◽  
Seasonal Effects ◽  
Human Coronavirus ◽  
Enveloped Virus ◽  
Multiplex Pcr Assay ◽  
Contact Transmission ◽  
Human Coronaviruses

UNSTRUCTURED The seasonality of influenza viruses and endemic human coronaviruses was tracked over an 8-year period to assess key epidemiologic reduction points in disease incidence for an urban area in the northeast United States. Patients admitted to a pediatric hospital with worsening respiratory symptoms were tested using a multiplex PCR assay from nasopharyngeal swabs. The additive seasonal effects of outdoor temperatures and indoor relative humidity (RH) were evaluated. The 8-year average peak activity of human coronaviruses occurred in the first week of January, when droplet and contact transmission was enabled by the low indoor RH of 20-30%. Previous studies have shown that an increase in RH to 50% has been associated with markedly reduced viability and transmission of influenza virus and animal coronaviruses. As disease incidence was reduced by 50% in early March, to 75% in early April, to greater than 99% at the end of April, a relationship was observed from colder temperatures in January with a low indoor RH to a gradual increase in outdoor temperatures in April with an indoor RH of 45-50%. As a lipid-bound, enveloped virus with similar size characteristics to endemic human coronaviruses, SARS-CoV-2 should be subject to the same dynamics of reduced viability and transmission with increased humidity. In addition to the major role of social distancing, the transition from lower to higher indoor RH with increasing outdoor temperatures could have an additive effect on the decrease in SARS-CoV-2 cases in May. Over the 8-year period of this study, human coronavirus activity was either zero or >99% reduction in the months of June through September, and the implication would be that SARS-Cov-2 may follow a similar pattern. INTERNATIONAL REGISTERED REPORT RR2-doi.org/10.1101/2020.05.15.20103416

scholarly journals Sialic Acids as Receptors for Pathogens

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 831
Author(s):  
Patrycja Burzyńska ◽  
Łukasz F. Sobala ◽  
Krzysztof Mikołajczyk ◽  
Marlena Jodłowska ◽  
Ewa Jaśkiewicz
Keyword(s):  
Malaria Parasite ◽  
Sialic Acids ◽  
Influenza Viruses ◽  
Disease Vectors ◽  
Animal Disease ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum ◽  
Infection Biology ◽  
Species Specific

Carbohydrates have long been known to mediate intracellular interactions, whether within one organism or between different organisms. Sialic acids (Sias) are carbohydrates that usually occupy the terminal positions in longer carbohydrate chains, which makes them common recognition targets mediating these interactions. In this review, we summarize the knowledge about animal disease-causing agents such as viruses, bacteria and protozoa (including the malaria parasite Plasmodium falciparum) in which Sias play a role in infection biology. While Sias may promote binding of, e.g., influenza viruses and SV40, they act as decoys for betacoronaviruses. The presence of two common forms of Sias, Neu5Ac and Neu5Gc, is species-specific, and in humans, the enzyme converting Neu5Ac to Neu5Gc (CMAH, CMP-Neu5Ac hydroxylase) is lost, most likely due to adaptation to pathogen regimes; we discuss the research about the influence of malaria on this trait. In addition, we present data suggesting the CMAH gene was probably present in the ancestor of animals, shedding light on its glycobiology. We predict that a better understanding of the role of Sias in disease vectors would lead to more effective clinical interventions.

scholarly journals COVID-19 Shuts Doors to Flu but Keeps Them Open to Rhinoviruses

Biology ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 733
Author(s):  
Irina Kiseleva ◽  
Andrey Ksenafontov
Keyword(s):  
Influenza Pandemic ◽  
Age Groups ◽  
Influenza Viruses ◽  
Interferon Response ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Mild Disease ◽  
Viral Interference ◽  
The Common

It is well known that rhinoviruses are distributed across the globe and are the most common cause of the common cold in all age groups. Rhinoviruses are widely considered to be harmless because they are generally perceived as respiratory viruses only capable of causing mild disease. However, they may also infect the lower respiratory tract, inducing chronic obstructive pulmonary disease and exacerbations of asthma, bronchiolitis, etc. The role of rhinoviruses in pathogenesis and the epidemiological process is underestimated, and they need to be intensively studied. In the light of recent data, it is now known that rhinoviruses could be one of the key epidemiological barriers that may influence the spread of influenza and novel coronaviruses. It has been reported that endemic human rhinoviruses delayed the development of the H1N1pdm09 influenza pandemic through viral interference. Moreover, human rhinoviruses have been suggested to block SARS-CoV-2 replication in the airways by triggering an interferon response. In this review, we summarized the main biological characteristics of genetically distinct viruses such as rhinoviruses, influenza viruses, and SARS-CoV-2 in an attempt to illuminate their main discrepancies and similarities. We hope that this comparative analysis will help us to better understand in which direction research in this area should move.

scholarly journals The Central Role of Non-Structural Protein 1 (NS1) in Influenza Biology and Infection

2020 ◽  
Vol 21 (4) ◽  
pp. 1511 ◽  
Author(s):  
Nícia Rosário-Ferreira ◽  
António J. Preto ◽  
Rita Melo ◽  
Irina S. Moreira ◽  
Rui M. M. Brito
Keyword(s):  
Viral Disease ◽  
Influenza Viruses ◽  
World Health ◽  
World Population ◽  
Structural Protein ◽  
Human Respiratory Tract ◽  
Host Interactions ◽  
The World ◽  
Health Organization

Influenza (flu) is a contagious viral disease, which targets the human respiratory tract and spreads throughout the world each year. Every year, influenza infects around 10% of the world population and between 290,000 and 650,000 people die from it according to the World Health Organization (WHO). Influenza viruses belong to the Orthomyxoviridae family and have a negative sense eight-segment single-stranded RNA genome that encodes 11 different proteins. The only control over influenza seasonal epidemic outbreaks around the world are vaccines, annually updated according to viral strains in circulation, but, because of high rates of mutation and recurrent genetic assortment, new viral strains of influenza are constantly emerging, increasing the likelihood of pandemics. Vaccination effectiveness is limited, calling for new preventive and therapeutic approaches and a better understanding of the virus–host interactions. In particular, grasping the role of influenza non-structural protein 1 (NS1) and related known interactions in the host cell is pivotal to better understand the mechanisms of virus infection and replication, and thus propose more effective antiviral approaches. In this review, we assess the structure of NS1, its dynamics, and multiple functions and interactions, to highlight the central role of this protein in viral biology and its potential use as an effective therapeutic target to tackle seasonal and pandemic influenza.

scholarly journals Correlation of Cellular Immune Responses with Protection against Culture-Confirmed Influenza Virus in Young Children

2008 ◽  
Vol 15 (7) ◽  
pp. 1042-1053 ◽  
Author(s):  
Bruce D. Forrest ◽  
Michael W. Pride ◽  
Andrew J. Dunning ◽  
Maria Rosario Z. Capeding ◽  
Tawee Chotpitayasunondh ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Young Children ◽  
Immune Responses ◽  
Virus Vaccine ◽  
Elispot Assay ◽  
Influenza Virus Vaccine ◽  
The Philippines ◽  
Influenza Viruses ◽  
Ifn Γ

ABSTRACT The highly sensitive gamma interferon (IFN-γ) enzyme-linked immunosorbent spot (ELISPOT) assay permits the investigation of the role of cell-mediated immunity (CMI) in the protection of young children against influenza. Preliminary studies of young children confirmed that the IFN-γ ELISPOT assay was a more sensitive measure of influenza memory immune responses than serum antibody and that among seronegative children aged 6 to <36 months, an intranasal dose of 107 fluorescent focus units (FFU) of a live attenuated influenza virus vaccine (CAIV-T) elicited substantial CMI responses. A commercial inactivated influenza virus vaccine elicited CMI responses only in children with some previous exposure to related influenza viruses as determined by detectable antibody levels prevaccination. The role of CMI in actual protection against community-acquired, culture-confirmed clinical influenza by CAIV-T was investigated in a large randomized, double-blind, placebo-controlled dose-ranging efficacy trial with 2,172 children aged 6 to <36 months in the Philippines and Thailand. The estimated protection curve indicated that the majority of infants and young children with ≥100 spot-forming cells/106 peripheral blood mononuclear cells were protected against clinical influenza, establishing a possible target level of CMI for future influenza vaccine development. The ELISPOT assay for IFN-γ is a sensitive and reproducible measure of CMI and memory immune responses and contributes to establishing requirements for the future development of vaccines against influenza, especially those used for children.

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