scholarly journals THE QUANTITATIVE DETERMINATION OF INFLUENZA VIRUS AND ANTIBODIES BY MEANS OF RED CELL AGGLUTINATION

1942 ◽  
Vol 75 (1) ◽  
pp. 49-64 ◽  
Author(s):  
George K. Hirst
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Allantoic Fluid ◽  
Red Cells ◽  
Virus Neutralization ◽  
Influenza B ◽  
Logarithmic Scale ◽  
Neutralization Titer ◽  
Cell Agglutination ◽  
Agglutination Titer

1. The agglutination titer for chicken red cells of freshly prepared or carefully stored suspensions of PR8 influenza virus, that is to say virus of maximum pathogenicity, was found to be proportional to the mouse lethal titer of the same preparations. 2. The agglutination titer of infected allantoic fluid procured in a standard way is relatively constant, regardless of the influenza strain used and its pathogenicity for mice. 3. Virus preparations inactivated by heat or storage may retain their agglutinating power. 4. Certain animal sera contain a partially heat-labile factor which, in low dilution, inhibits the agglutination of chicken red cells by influenza A and influenza B viruses. 5. The agglutination inhibition test, using ferret and human sera, gives qualitative data regarding influenza antibodies which are similar to the information obtained on the same sera by means of the virus neutralization test. 6. There is a definite relationship between the agglutination inhibition titer and the virus neutralization titer of a serum. On a logarithmic scale of both variables, this relationship is essentially linear within the range investigated. 7. The agglutination inhibition titer of immune ferret serum is inversely proportional to the amount of virus used in the test.

scholarly journals INFLUENZA VIRUS INFECTION IN THE HAMSTER

1948 ◽  
Vol 88 (3) ◽  
pp. 343-353 ◽  
Author(s):  
William F. Friedewald ◽  
Edward W. Hook
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A ◽  
High Titer ◽  
Influenza Virus Infection ◽  
The Body ◽  
Red Cells ◽  
Influenza B Virus ◽  
Influenza B ◽  
Lung Lesions

A study of influenza virus infection in the hamster has yielded the following results: 1. Two influenza A strains (Ga. 47 and PR8) multiplied readily in the hamster lung, although no lung lesions were produced during six serial passages. On further passage both viruses abruptly acquired the capacity to produce pulmonary consolidation and death of the animals. 2. Extracts of the lungs during the early passages contained complement-fixing antigen and infectious virus, as revealed by titration in mice and embryonated eggs. Agglutinins for chicken, human, and guinea pig red cells, however, were not demonstrable at this time. With further passage a close correlation was observed between the capacity of the virus to produce lung lesions in the hamster and to agglutinate mammalian types of red cells. In addition, quantitative changes in the virus population were demonstrated in the lung extracts by complement fixation tests and titrations in mice and eggs. 3. Incubation at 37°C. was effective in bringing out agglutinins in high titer for chicken red cells in lung extracts, which originally failed to agglutinate chicken cells but agglutinated mammalian red cells. This method did not increase the titers of mammalian cell agglutinins. 4. The body temperature of the hamster was found to decrease within 1 to 4 days after inoculation of influenza virus. In the early passages the temperature returned to normal within 24 hours, but with the development of the pathogenic strain of virus the temperature remained at subnormal levels until death. 5. The Lee strain of influenza B virus produced pulmonary lesions in the hamster on the first passage and no increase in pathogenicity of the virus occurred during eleven serial passages. Virus was demonstrable in extracts of the lungs by all the methods used and no difference was observed in its capacity to agglutinate fowl and mammalian types of red cells. The implications of these findings are considered briefly in the discussion.

scholarly journals The memberane Piece Technique for in Vitro Infectivity Titrations of Influenza Virus

1957 ◽  
Vol 55 (3) ◽  
pp. 434-456 ◽  
Author(s):  
N. B. Finter ◽  
P. Armitage
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Technical Assistance ◽  
Allantoic Fluid ◽  
Test Tube ◽  
Influenza B Virus ◽  
Influenza B ◽  
Experimental Conditions ◽  
Set Up

1. The membrane piece technique for in vitro titrations of the infectivity of influenza virus is described. Rectangles of shell, about 8 × 25 mm., with the chorio-allantoic membrane still attached (membrane pieces) are cut from thirteenth-day fertile eggs. One piece in a test-tube with glucose-buffered salt solution forms an individual assay unit. Five or more tubes are inoculated with each virus dilution. After incubation at 37° C. for 72 hr., with agitation for the first 24 hr. the fluid in each tube is tested for haemagglutinins. From the results at each dilution, an estimate of the 50% membrane piece (MP50) infectivity titre is obtained.2. Six hundred assay units, with pieces cut from twenty eggs, can be set up by two workers in 1 hr. and used for titration of between three and twenty-four individual virus preparations, depending on the reliability desired for the 50% end-point estimates.3. With the D.S.P. and PR 8 strains of influenza A virus, the MP50 titres parallel the EID50 titres from egg titrations, but are eight times and twenty times lower, respectively. The MP50: EID50 ratio is the same for various preparations of the same strain, including standard allantoic fluid and chorio-allantoic membrane virus, incomplete virus, and inactivated (heated) allantoic fluid virus. Preliminary experiments with Lee influenza B virus show that slightly different experimental conditions are required, and the MP50 titres are about fifty times less than the EID50 titres.4. Consistent results have been obtained on titration of samples of the same virus preparation on a number of occasions over a period of several months.5. A large number of membrane pieces can be used to test each virus dilution, and sampling variations in the MP50 estimates thus made quite small. Statistical data on the reliability of a 50 % titration result, and on the minimum significant differences between two end-points, are given for different values of n, the number of membrane pieces used to test each virus dilution, and of d, the log dilution step.We are grateful to Mr J. Collins for invaluable technical assistance, and also to Miss I. Allen for help with the computations.

scholarly journals Influenza: An Emerging and Re-emerging Public Health Threat in Nepal

2018 ◽  
Vol 3 (2) ◽  
pp. 1-2
Author(s):  
Bishnu Prasad Upadhyay
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Winter Season ◽  
Emerging Infectious Diseases ◽  
Influenza Viruses ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Influenza A H1n1 ◽  
New Variant ◽  
Seasonal Epidemics

Influenza virus type A and B are responsible for seasonal epidemics as well as pandemics in human. Influenza A viruses are further divided into two major groups namely, low pathogenic seasonal influenza (A/H1N1, A/H1N1 pdm09, A/H3N2) and highly pathogenic influenza virus (H5N1, H5N6, H7N9) on the basis of two surface antigens: hemagglutinin (HA) and neuraminidase (NA). Mutations, including substitutions, deletions, and insertions, are one of the most important mechanisms for producing new variant of influenza viruses. During the last 30 years; more than 50 viral threat has been evolved in South-East Asian countriesof them influenza is one of the major emerging and re-emerging infectious diseases of global concern. Similar to tropical and sub-tropical countries of Southeast Asia; circulation of A/H1N1 pdm09, A/H3N2 and influenza B has been circulating throughout the year with the peak during July-November in Nepal. However; the rate of infection transmission reach peak during the post-rain and winter season of Nepal.

scholarly journals REACTIONS BETWEEN INFLUENZA VIRUS AND A COMPONENT OF ALLANTOIC FLUID

1948 ◽  
Vol 88 (4) ◽  
pp. 463-484 ◽  
Author(s):  
Paul H. Hardy ◽  
Frank L. Horsfall
Keyword(s):  
Influenza Virus ◽  
Influenza A Virus ◽  
Influenza A ◽  
Allantoic Fluid ◽  
Partial Dissociation

Evidence is presented which shows that there is a component present in normal allantoic fluid, probably mucoprotein in nature, capable of combining with influenza A virus (PR8), and that following combination between this component and the virus only partial dissociation of the complex occurs. Evidence is also presented which strongly suggests that the component is present in virus-infected allantoic fluid in which it is in part combined with the virus and in part free although altered by viral action. The probability that the component is present as well in highly purified preparations of influenza virus, and its effect upon various reactions obtained with this agent are discussed.

scholarly journals QUALITATIVE DIFFERENCES IN THE ANTIGENIC COMPOSITION OF INFLUENZA A VIRUS STRAINS

1944 ◽  
Vol 79 (6) ◽  
pp. 633-647 ◽  
Author(s):  
William F. Friedewald
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Serum Antibody ◽  
Allantoic Fluid ◽  
Influenza B Virus ◽  
Influenza B ◽  
Red Cell ◽  
Homologous Virus ◽  
Cell Adsorption ◽  
Virus Strains

A study of the PR8, Christie, Talmey, W.S., and swine strains of influenza A virus by means of antibody absorption tests revealed the following findings: 1. Serum antibody could be specifically absorbed with allantoic fluid containing influenza virus or, more effectively, with concentrated suspensions of virus obtained from allantoic fluid by high-speed centrifugation or by the red cell adsorption and elution technique. Normal allantoic fluid, or the centrifugalized sediment therefrom, failed to absorb antibodies. Influenza B virus (Lee) caused no detectable absorption of antibody from antisera directed against influenza A virus strains, but it specifically absorbed antibody from Lee antisera. 2. The neutralizing, agglutination-inhibiting, and complement-fixing anti-bodies in ferret antisera were completely absorbed only by the homologous virus strain, even though 2 absorptions were carried out with large amounts of heterologous virus strains. 3. PR8 virus appeared to have the broadest range of specific antigenic components for it completely absorbed the heterologous antibodies in Christie and W.S. antisera and left only those antibodies which reacted with the respective homologous strains. The other virus strains (Christie, Talmey, W.S., swine) were more specific in the absorption of heterologous antibodies and completely removed only those antibodies which reacted with the absorbing virus. 4. The absorption tests revealed a higher degree of specificity and individuality of the virus strains than the various cross reactions previously reported. The strain specificity of PR8 virus was equally manifest in absorption tests with ferret sera and with human sera following vaccination. 5. The amount of homologous antibody remaining in a PR8 ferret serum after absorption with PR8 virus, obtained by the red cell adsorption and elution method, varied inversely as the concentration of virus used for absorption. A given concentration of virus, however, absorbed a greater percentage of neutralizing antibodies than either agglutination-inhibiting or complement-fixing antibodies.

Severe Influenza Virus Infection in Children Admitted to the PICU: Comparison of Influenza A and Influenza B Virus Infection

2021 ◽  
Author(s):  
Pınar YAZICI ÖZKAYA ◽  
Eşe Eda TURANLI ◽  
Hamdi METİN ◽  
Ayça Aydın UYSAL ◽  
Candan ÇİÇEK ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Influenza B Virus ◽  
Influenza B ◽  
Severe Influenza ◽  
B Virus

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

1978 ◽  
Vol 80 (1) ◽  
pp. 13-19 ◽  
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.

scholarly journals Serum High-Mobility-Group Box 1 as a Biomarker and a Therapeutic Target during Respiratory Virus Infections

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Mira C. Patel ◽  
Kari Ann Shirey ◽  
Marina S. Boukhvalova ◽  
Stefanie N. Vogel ◽  
Jorge C. G. Blanco
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
High Mobility ◽  
Influenza B Virus ◽  
Influenza B ◽  
Lung Pathology ◽  
B Virus ◽  
Cotton Rats

ABSTRACT Host-derived “danger-associated molecular patterns” (DAMPs) contribute to innate immune responses and serve as markers of disease progression and severity for inflammatory and infectious diseases. There is accumulating evidence that generation of DAMPs such as oxidized phospholipids and high-mobility-group box 1 (HMGB1) during influenza virus infection leads to acute lung injury (ALI). Treatment of influenza virus-infected mice and cotton rats with the Toll-like receptor 4 (TLR4) antagonist Eritoran blocked DAMP accumulation and ameliorated influenza virus-induced ALI. However, changes in systemic HMGB1 kinetics during the course of influenza virus infection in animal models and humans have yet to establish an association of HMGB1 release with influenza virus infection. To this end, we used the cotton rat model that is permissive to nonadapted strains of influenza A and B viruses, respiratory syncytial virus (RSV), and human rhinoviruses (HRVs). Serum HMGB1 levels were measured by an enzyme-linked immunosorbent assay (ELISA) prior to infection until day 14 or 18 post-infection. Infection with either influenza A or B virus resulted in a robust increase in serum HMGB1 levels that decreased by days 14 to 18. Inoculation with the live attenuated vaccine FluMist resulted in HMGB1 levels that were significantly lower than those with infection with live influenza viruses. RSV and HRVs showed profiles of serum HMGB1 induction that were consistent with their replication and degree of lung pathology in cotton rats. We further showed that therapeutic treatment with Eritoran of cotton rats infected with influenza B virus significantly blunted serum HMGB1 levels and improved lung pathology, without inhibiting virus replication. These findings support the use of drugs that block HMGB1 to combat influenza virus-induced ALI. IMPORTANCE Influenza virus is a common infectious agent causing serious seasonal epidemics, and there is urgent need to develop an alternative treatment modality for influenza virus infection. Recently, host-derived DAMPs, such as oxidized phospholipids and HMGB1, were shown to be generated during influenza virus infection and cause ALI. To establish a clear link between influenza virus infection and HMGB1 as a biomarker, we have systematically analyzed temporal patterns of serum HMGB1 release in cotton rats infected with nonadapted strains of influenza A and B viruses and compared these patterns with a live attenuated influenza vaccine and infection by other respiratory viruses. Towards development of a new therapeutic modality, we show herein that blocking serum HMGB1 levels by Eritoran improves lung pathology in influenza B virus-infected cotton rats. Our study is the first report of systemic HMGB1 as a potential biomarker of severity in respiratory virus infections and confirms that drugs that block virus-induced HMGB1 ameliorate ALI.

scholarly journals Performance of the Molecular Alere i Influenza A&B Test Compared to That of the Xpert Flu A/B Assay

2014 ◽  
Vol 53 (2) ◽  
pp. 706-709 ◽  
Author(s):  
Kimberle C. Chapin ◽  
Estefany J. Flores-Cortez
Keyword(s):  
Influenza Virus ◽  
Sensitivity And Specificity ◽  
Influenza A ◽  
Point Of Care ◽  
Type A ◽  
Influenza B ◽  
Clinical Sensitivity ◽  
Transport Medium ◽  
The Poor ◽  
B Test

Data on the performance of rapid molecular point-of-care use platforms for diagnosis of influenza are lacking. We validated nasopharyngeal (NP) flocked specimens in universal transport medium (UTM) and evaluated the clinical sensitivity and specificity of the Alere i influenza A&B test compared to those of the Xpert flu A/B assay. The Alere i influenza A&B test had an overall sensitivity and specificity of 93.8% and 62.5% for influenza A, respectively, and of 91.8% and 53.6% for influenza B, respectively. The poor specificity was due to influenza virus samples determined positive for both type A and B.

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

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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