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Seasonal Genetic Drift of Human Influenza A Virus Quasispecies Revealed by Deep Sequencing.

After a pandemic wave in 2009 following their introduction in the human population, the H1N1pdm09 viruses replaced the previously circulating, pre-pandemic H1N1 virus and, along with H3N2 viruses, are now responsible for the seasonal influenza type A epidemics. So far, the evolutionary potential of influenza viruses has been mainly documented by consensus sequencing data. However, like other RNA viruses, influenza A viruses exist as a population of diverse, albeit related, viruses, or quasispecies. Interest in this quasispecies nature has increased with the development of next generation seque…

Influenza A virus infections in swine: pathogenesis and diagnosis.

Influenza has been recognized as a respiratory disease in swine since its first appearance concurrent with the 1918 "Spanish flu" human pandemic. All influenza viruses of significance in swine are type A, subtype H1N1, H1N2, or H3N2 viruses. Influenza viruses infect epithelial cells lining the surface of the respiratory tract, inducing prominent necrotizing bronchitis and bronchiolitis and variable interstitial pneumonia. Cell death is due to direct virus infection and to insult directed by leukocytes and cytokines of the innate immune system. The most virulent viruses consistently express the…

Seasonality of respiratory viral identification varies with age and Aboriginality in metropolitan Western Australia.

BACKGROUND: Viral respiratory infections are a major cause of pediatric illness. It is not known whether seasonality of viruses differs between Aboriginal and non-Aboriginal children of varying ages. METHODS: We extracted data on respiratory syncytial virus (RSV), influenza viruses A and B, parainfluenza virus types 1, 2, and 3 and adenovirus identified through cell culture or direct immunofluorescence between 1997 and 2005 from nasopharyngeal or throat specimens at Western Australia's only pediatric hospital. We used harmonic analysis in generalized linear models to examine the variations in…

[Highly pathogenic avian influenza in poultry (fowl plague); implications for human health].

Since 1997, high-pathogenicity avian influenza (HPAI) virus infection in poultry "avian plague" has emerged as a potential threat to human health, with some fatal cases of bird-to-human transmission. These sporadic infections are caused by H7N7 and H5N1 viruses in Europe and Asia, respectively. The persistence of H5N1 viruses in poultry in several Asian countries, and their appearance in Europe, has raised concerns that the virus might mutate or recombine to create a human pandemic influenza A virus. Wild waterfowl are the natural reservoir of all influenza A viruses, and rarely develop the di…

Blood donor testing for HIV-I/II and HTLV-I/II.

In 1985, serologic testing became available to screen blood donors for the viruses associated with the acquired immunodeficiency syndrome; these viruses are now called human immunodeficiency viruses I and II. In 1989, blood donor screening for other retroviruses, human T-cell lymphotropic viruses I and II, was initiated. This article describes the evolution of testing protocols for blood donors for these viruses, disease manifestations associated with seropositivity, the efficacy of donor screening including testing for these retroviruses, and counseling recommendations for positive blood dono…

Synaptic Plasticity and Neurological Disorders in Neurotropic Viral Infections.

Based on the type of cells or tissues they tend to harbor or attack, many of the viruses are characterized. But, in case of neurotropic viruses, it is not possible to classify them based on their tropism because many of them are not primarily neurotropic. While rabies and poliovirus are considered as strictly neurotropic, other neurotropic viruses involve nervous tissue only secondarily. Since the AIDS pandemic, the interest in neurotropic viral infections has become essential for all clinical neurologists. Although these neurotropic viruses are able to be harbored in or infect the nervous sys…

Распространение и клиническое значение вируса SEN-H для хронических инфекций гепатита В, С и дельты в Турции.

ВИДЫ СЭН передаются материнско и могут вызывать гепатит после трансмиссии. Вопрос о распространенности и клинической значимости вирусов СЭН изучался у пациентов с хроническим гепатитом С и В, но не в D. Мы стремились определить распространенность и клиническое значение вирусов СЭН - H у пациентов с хроническим гепатитом С, В и дельтой в Турции. МЕТОДЫ: Вирусы SEN-H были проанализированы у 85 пациентов с хроническим вирусным гепатитом (30 HCV, 30 HBV и 25 HDV) и у 43 непрофессиональных доноров крови. ДНК HBV, HCV RNA и HDV RNA были положительными у пациентов с гепатитом B, C и D, соответственно

Совпадение в аннотации оригинала
BACKGROUND/AIMS: SEN viruses are transmitted parenterally and can cause post-transfusion hepatitis. The prevalence and clinical significance of SEN viruses have been investigated in patients with chronic hepatitis C and B but not in D. We aimed to determine the prevalence and clinical significance of SEN viruses- H in patients with chronic hepatitis C, B and…

Random selection: a model for poliovirus infection of the central nervous system.

Mixed infections occur in the natural environment, and also result from the use of mixed live vaccines. Some recipients of the trivalent oral poliovirus vaccine develop vaccine-associated paralytic poliomyelitis (VAPP). Numerous serotypes and recombinant genotypes of vaccine-derived polioviruses may be found in stool samples from such cases. To investigate the relationship between the multiplication of various genotypes at the primary replication site in the gut and the infection outcome in the central nervous system (CNS), the viruses excreted on consecutive days by two patients with VAPP wer…

Medically important arboviruses of the United States and Canada.

Of more than 500 arboviruses recognized worldwide, 5 were first isolated in Canada and 58 were first isolated in the United States. Six of these viruses are human pathogens: western equine encephalitis (WEE) and eastern equine encephalitis (EEE) viruses (family Togaviridae, genus Alphavirus), St. Louis encephalitis (SLE) and Powassan (POW) viruses (Flaviviridae, Flavivirus), LaCrosse (LAC) virus (Bunyaviridae, Bunyavirus), and Colorado tick fever (CTF) virus (Reoviridae, Coltivirus). Their scientific histories, geographic distributions, virology, epidemiology, vectors, vertebrate hosts, transm…

Arboviruses causing neurological disorders in the central nervous system.

Arthropod-borne viruses are important causes of diseases of the central nervous system. In addition to the tick-borne encephalitis viruses, other arboviruses in Europe are known to cause neurological disorders. Among them are West Nile, California group, Bhanja, Erve, Kemerovo group, Eyach, and Thogoto viruses. The ecologies and epidemiologies of these viruses are presented and their medical importance as travel-related diseases is discussed.

Development of new vaccines against dengue fever and Japanese encephalitis.

Mosquito-borne dengue (DEN) and Japanese encephalitis (JE) viruses are the leading causes of arthropod-transmitted viral disease in humans. A licensed tetravalent vaccine that provides effective, long-term immunity against all four serotypes of DEN virus is needed, but is currently unavailable. Improvements to currently available JE vaccines are also needed. Past and recent strategies for the development of new DEN and JE vaccines include inactivated and live attenuated viruses, engineered viruses and chimeric viruses derived from infectious cDNA clones of DEN or JE virus, recombinant poxvirus…

Phylogenetic and Pathogenic Analysis of H5N1 and H5N6 High Pathogenicity Avian Influenza Virus Isolated from Poultry Farms (Layer and Broiler Chickens) in Japan in the 2023/2024 Season.

During the 2023-2024 winter, 11 high pathogenicity avian influenza (HPAI) outbreaks caused by clade 2.3.4.4b H5N1 and H5N6 HPAI viruses were confirmed in Japanese domestic poultry among 10 prefectures (n = 10 and 1, respectively). In this study, we aimed to genetically and pathologically characterize these viruses. Phylogenetic analysis revealed that H5N1 viruses were classified into the G2d-0 genotype, whereas the H5N6 virus was a novel genotype in Japan, designated as G2c-12. The G2c-12 virus shared PB2, PB1, PA, HA, and M genes with previous G2c viruses, but had NP and NS genes originating …

Position Paper on Road Map for RNA Virus Research in India.

The Indian subcontinent with its population density, climatic conditions, means of subsistence, socioeconomic factors as well as travel and tourism presents a fertile ground for thriving of RNA viruses. Despite being pathogens of huge significance, there is very little focus on research into the biology and pathogenesis of RNA viruses in India. Studies on epidemiology and disease burden, risk factors, the immune response to RNA viruses, circulating virus strains and virus evolution, animal models of disease, antivirals and vaccines are strikingly absent. Emerging RNA viruses such as Zika virus…

Use of ethidium monoazide and propidium monoazide to determine viral infectivity upon inactivation by heat, UV- exposure and chlorine.

Despite the great sensitivity of PCR in monitoring enteric viruses in an aquatic environment, PCR detects viral nucleic acids of both infectious and noninfectious viruses, limiting the conclusions regarding significance for public health. Ethidium monoazide (EMA) and propidium monoazide (PMA) are closely related membrane impermeant dyes that selectively penetrate cells with compromised membranes. Inside the cells, the dye can intercalate into nucleic acids and inhibit PCR amplification. To assess whether EMA and PMA pretreatment is a suitable approach to inhibit DNA amplification from noninfec…

Mosquito-borne arboviruses in Uganda: history, transmission and burden.

Mosquito-transmitted arboviruses constitute a large proportion of emerging infectious diseases that are both a public health problem and a threat to animal populations. Many such viruses were identified in East Africa, a region where they remain important and from where new arboviruses may emerge. We set out to describe and review the relevant mosquito-borne viruses that have been identified specifically in Uganda. We focused on the discovery, burden, mode of transmission, animal hosts and clinical manifestation of those previously involved in disease outbreaks. A search for mosquito-borne arb…

Nucleotide sequence variation of the envelope protein gene identifies two distinct genotypes of yellow fever virus.

The evolution of yellow fever virus over 67 years was investigated by comparing the nucleotide sequences of the envelope (E) protein genes of 20 viruses isolated in Africa, the Caribbean, and South America. Uniformly weighted parsimony algorithm analysis defined two major evolutionary yellow fever virus lineages designated E genotypes I and II. E genotype I contained viruses isolated from East and Central Africa. E genotype II viruses were divided into two sublineages: IIA viruses from West Africa and IIB viruses from America, except for a 1979 virus isolated from Trinidad (TRINID79A). Unique …

Virus-host studies in human seminal and mouse testicular cells.

Virological studies were performed for male infertility and repeated abortions. It was found that in about 40% of infertile males infectious adeno- or herpes simplex virus is present in the semen, while the same viruses are present in 60% of the cells in a latent form. In the aborted fetuses the same viruses could be observed as in the father's cells. Due to semen added to tissue cultures the latent presence also of other viruses could be supposed. The affinity of adeno- and herpes viruses to urogenital organs was confirmed by animal experiments, where a new method was applied for in vivo infe…

Amino-terminal amino acid sequences of structural proteins of three flaviviruses.

N-terminal amino acid sequences of structural proteins of three flaviviruses, yellow fever, St. Louis encephalitis, and dengue-2 viruses, have been obtained. The glycoproteins of these three viruses are 52-60% conserved in the region sequenced, depending upon which pair of viruses are compared, and 40% of the amino acids are invariant in all three viruses. Thus, flaviviruses are closely related and have in all probability descended from a common ancestor. Furthermore, residues important in the secondary structure of proteins are conserved, suggesting that the overall conformation of the glycop…

Nation-wide surveillance of human acute respiratory virus infections between 2013 and 2015 in Korea.

The prevalence of eight respiratory viruses detected in patients with acute respiratory infections (ARIs) in Korea was investigated through analysis of data recorded by the Korea Influenza and Respiratory Viruses Surveillance System (KINRESS) from 2013 to 2015. Nasal aspirate and throat swabs specimens were collected from 36 915 patients with ARIs, and viral nucleic acids were detected by real-time (reverse-transcription) polymerase chain reaction for eight respiratory viruses, including human respiratory syncytial viruses (HRSVs), influenza viruses (IFVs), human parainfluenza viruses (HPIVs),…

Antigenic analysis of yellow fever virus glycoproteins: use of monoclonal antibodies in enzyme-linked immunosorbent assays.

A sensitive enzyme-linked immunosorbent assay with biotin and streptavidin (B/SA ELISA) was developed for the specific detection of yellow fever (YF) viruses. Monoclonal antibodies (MCA) specific for the envelope (E) glycoprotein or the non-structural glycoprotein (NV3) of YF virus-infected cell lysates were tested by antigen and antibody capture B/SA ELISA against YF viruses and a large number of other flaviviruses. In an antigen capture assay, with suckling mouse brain antigens, MCA directed against the envelope glycoprotein clearly differentiated YF viruses from any other flaviviruses, wild…