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Fragmentation of influenza surveillance in Australia.

Watts C, Kelly H.

Victorian Infectious Diseases Reference Laboratory, Carlton South. Caroline.Watts mh.org.au

Monitoring of community influenza through sentinel practice networks is essential to track the onset and progress of epidemics. In 1999, the Influenza Pandemic Planning Committee of the Communicable Diseases Network Australia New Zealand (CDNANZ) recommended that a national surveillance system be established comprising both community-based and institutional surveillance. In 2001, however, influenza surveillance remains fragmented in Australia and mainly restricted to major cities. Methods of surveillance and reporting of influenza activity vary between States and even within States. Three disparate case definitions are in use for reporting influenza-like illnesses. Many sentinel sites do not have laboratory support for confirmation of influenza or identification of circulating strains. Dissemination of information is uncoordinated and without a standardised reporting format for collation at a national level. Prompt attention to these issues is important to ensure an adequate public health response to future influenza virus epidemics or a pandemic.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11950209&dopt=Abstract flu, influenza



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Effect of immunomodulator adamantylamide dipeptide on antibody response to influenza subunit vaccines and protection against aerosol influenza infection.

Masihi KN, Lange W, Schwenke S, Gast G, Huchshorn P, Palache A, Masek K.

Robert Koch Institute, Federal Health Office, Berlin, FRG.

Adamantylamide dipeptide (AdDP) is a novel synthetic compound combining the antiviral properties of amantadine and the essential adjuvant activity of immunomodulator muramyl dipeptide. Mice were immunized with influenza A/Taiwan/1/86 (H1N1), A/Sichuan/2/87 (H3N2) and influenza B/Beijing/1/87 subunit vaccines containing AdDP or aluminium hydroxide (Al(OH)3). Induction of homologous haemagglutination-inhibition (HI) antibodies and correlation to protection against lethal aerosol influenza A/PR/8/34 (H1N1) infection were investigated. Subunit vaccine containing A/Sichuan (H3N2) and Al(OH)3 stimulated high HI antibody titres but failed to provide protection against heterologous influenza A (H1N1) challenge infection following either the primary or the secondary immunizations. In contrast, similar treatment with A/Sichuan subunit vaccine containing AdDP conferred significant protection against heterologous challenge despite low levels of circulating antibody. Primary immunization with even influenza B/Beijing subunit vaccine containing AdDP, but not Al(OH)3, provided partial protection against influenza A challenge. These results suggest that appropriate immunomodulators like AdDP can convert restricted homotypic immunity induced by inactivated influenza subunit vaccines to advantageous cross-reacting type of heterologous response.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2336875&dopt=Abstract flu, influenza



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Fusion characteristics of influenza C viruses.

Formanowski F, Wharton SA, Calder LJ, Hofbauer C, Meier-Ewert H.

Abteilung fur Virologie, Technische Universitat Munchen, F.R.G.

A number of different influenza C virus strains were tested for their fusion properties using a resonance energy assay which allows direct monitoring of fusion between virus membranes and artificial lipid vesicles. The fusion pH of various strains was found to range between 5.6 and 6.1. Haemolytic activity of the different strains with chicken erythrocytes was observed at slightly lower pH values and varied between 5.1 and 5.7. Studies of the kinetics of influenza C virus fusion showed distinct characteristics in fusion activity. A lag before onset of fusion was found with influenza C virus which was not observed for influenza A or B viruses. In addition, studies on the rate of conformational change of the influenza C virus glycoprotein, as determined by morphological changes and endogenous tryptophan fluorescence, suggest that the conformational change is rate-limiting in the fusion process, whereas for influenza A viruses the glycoprotein conformational change is fast and a later step in the fusion process is rate-limiting. Monitoring the conformational change of influenza C virus glycoprotein by the onset of trypsin susceptibility showed, however, that membrane fusion occurred in some cases without onset of trypsin susceptibility, indicating that the trypsin-susceptible conformation is a post-fusogenic conformation.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2345368&dopt=Abstract flu, influenza



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Enhancement of DTH response by cholera toxin B subunit inoculated intranasally together with influenza HA vaccine.

Kikuta K, Kurata H, Nagamine T, Aizawa C, Ueno Y, Kurata T, Tamura S.

Department of Pathology, National Institute of Health, Tokyo.

The effects of B subunit of cholera toxin (CTB) on delayed-type hypersensitivity (DTH) response to influenza vaccine derived from influenza virus A/PR/8/34 (PR-8, HlNl) virus were investigated in B10 mice that were immunized intranasally with both influenza vaccine and CTB. The result showed that intranasal inoculation of this combination augmented DTH response to influenza vaccine, which reached its peak 6 days after inoculation, and also induced accelerated DTH response upon a second inoculation of influenza vaccine alone 4 weeks later, that the cross-reactive DTH response to PR-8 vaccine was elicited by the injection of the different influenza A-type virus vaccine into the footpad of the vaccinated mice, but was not by influenza B-type virus vaccine, that the DTH-mediating T cells were detected selectively in the lungs of mice that received the nasal inoculation of the vaccine and CTB together, but that subcutaneous inoculation of this combination failed to induce DTH-mediating T cells in the lungs. These results, together with the previous papers (Tamura et al, Vaccine 7: 257-262; 314-320, 1989), suggest that CTB could augment both humoral and DTH responses against influenza vaccine in the respiratory mucosal tract.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2352500&dopt=Abstract flu, influenza



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Antigenic reactivity and electrophoretic migrational heterogeneity of the three polymerase proteins of type A human and animal influenza viruses.

Akkina RK.

Department of Microbiology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins.

Antigenic reactivity of the three polymerase proteins PB1, PB2, and PA of type A influenza viruses of animal and human origin were analysed by radioimmunoprecipitation using monospecific antisera. Each of the polymerase monospecific antisera made against the polymerase proteins of the human A/WSN/33 (H1N1) influenza virus reacted efficiently with the homologous proteins of all the known thirteen HA subtype viruses of avian influenza virus, three subtypes of human influenza virus, swine and equine influenza viruses. This broad reactivity of each of the antisera indicated that the polymerase proteins are antigenically related among the type A influenza viruses and therefore can be considered as type specific antigens similar to the other viral internal proteins nucleoprotein (NP) and matrix protein (M). No electrophoretic migrational heterogeneity was found among the PB2 proteins of different subtype viruses, whereas PB1 protein exhibited minor variation. However, PA protein from among various viral subtypes showed considerable heterogeneity. Each of the polymerase antisera also immunoprecipitated additional antigenically related polypeptides with distinct electrophoretic mobilities from cells infected with each of the influenza viral subtypes.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2353872&dopt=Abstract flu, influenza



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[The use of immunoenzyme analysis in studying the etiologic structure of influenza morbidity in 1985-1988]

[Article in Russian]

Isaeva EI, Rovnova ZI, Poliakova TG, Stakhanova VM.

In the periods of epidemic increases in the incidence of influenza in 1985-1988, approximately 600 patients with clinical diagnoses of ARVI and influenza were examined for the presence of viral antigen in nasopharyngeal washings by solid-phase enzyme-immunoassay and for antibody rises in paired blood sera. The use of modified SPEIA and original test sera for influenza type A and B viruses in rapid diagnosis of influenza made it possible to decode the etiology of the epidemic situations in 1985-1988. Influenza A and B virus antigens were detected in a high portion of the examined nasopharyngeal washings. The analysis of the distribution of positive results in the detection of viral antigen in the clinical specimens and in influenza serodiagnosis demonstrated a high correlation of the results (93.9%). The etiological pattern of influenza in recent years is characterized by simultaneous circulation in the human population of influenza A (H1N1, H3N2) and B viruses, as reflected by detection of mixed infections in 1-3% of the cases.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2389565&dopt=Abstract flu, influenza



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The effect of virus particle size on chemiluminescence induction by influenza and Sendai viruses in mouse spleen cells.

Peterhans E, Mettler F, Manser E.

Institute of Veterinary Virology, University of Berne.

Suspensions of orthomyxo- and paramyxoviruses are composed of pleomorphic particles ranging from large filaments to small spheres. Influenza and Sendai viruses were separated according to size by gel filtration and the induction of luminol-dependent chemiluminescence (CL) by particles of similar size was studied in suspensions of mouse spleen cells known to contain phagocytes. CL reflects the generation by the cells of reactive oxygen species. CL induction decreased with particle size for both viruses. Compared with small spheres, large influenza filaments were approximately 10 times as efficient in activating cellular light emission while the ratio between large and small Sendai viruses was 3:1. Small Sendai virus particles were also less efficient in lysing red cells and had lower neuraminidase activity. By contrast, with influenza virus, only neuraminidase and not the hemolytic activity decreased with the virus size. When influenza virus filaments were broken into smaller particles by sonication, the capacity to induce chemiluminescence dropped markedly while the hemolytic and hemagglutinating activities increased and neuraminidase activity remained unaltered. These results suggest that the presentation of influenza virus hemagglutinin and neuraminidase glycoproteins in a large particle, leading to extensive receptor crosslinking, may be an important factor in the efficient activation of CL by filamentous influenza virus. We suggest that radical generation as reflected in cellular CL may relate to the toxic in vivo effects that contribute to the pathogenesis of influenza and infections with paramyxoviruses.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1963614&dopt=Abstract flu, influenza



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[The incidence of exacerbations in chronic diseases in patients hospitalized with influenza and para-influenza]

[Article in Russian]

Bondarenko SS, Tumanov FA.

A retrospective analysis was made of the case reports of 829 patients admitted to the infectious department with a diagnosis of influenza (592) and parainfluenza (237). In all the patients, the diagnosis was supported serologically with the aid of the hemagglutination inhibition test, with the antibody titer in the serum rising 4-fold and more. In part of the patients the indicated test was used in combination with the immunofluorescence test in studying nasopharyngeal smears, whereas in part of the patients, it was coupled with virological tests. It has been revealed that in addition to the most frequently occurring complications on the part of the bronchopulmonary system and ENT organs caused by the pneumococcal and streptococcal flora, there were complications on the part of the endocrine, urogenital, nervous and gastrointestinal systems, equally in patients with influenza and parainfluenza. In patients with postinfarction cardiosclerosis, influenza B and mixed influenza run the most unfavourable course, provoking deterioration of coronary heart disease in every other patient. In 66.6% of cases, exacerbation of coronary heart disease fell within the period of early convalescence of patients with influenza and parainfluenza.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1965617&dopt=Abstract flu, influenza



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[Properties of influenza A and B, isolated from chick embryos and in MDCK cell culture]

[Article in Russian]

Burtseva EI, Ivanova VT, Oskerko TA, Slepushkin AN.

MDCK culture was used along with the traditional chicken embryonated eggs (CEE) for improving the efficiency of isolation of epidemic influenza A and B viruses from clinical material. The number of influenza viruses isolated in both systems in epidemic seasons of 1997-1998 and 1998-1999 was as follows: 1 in MDCK and 21 in CEE for influenza A(H1N1), 56 and 7, respectively, for influenza A(H3N2), and 4 and 2 strains, respectively, for influenza B viruses. Influenza A viruses were heterogeneous by sensitivity to various erythrocytes, thermal stability of hemagglutinins, and transfer to another culturing system. Unlike the strains isolated in CEE, cultural viruses possessed a thermolabile hemagglutinin and more actively reacted with human and guinea pig erythrocytes. Evolution of influenza A(H3N2) viruses which is due mainly to changes in the hemagglutinin structure seems to be directed towards greater tropism to mammalian but not avian cells. Influenza B viruses are more homogeneous by antigenic and biological properties.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11233284&dopt=Abstract flu, influenza



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Thoracic lymphatic pumping and the efficacy of influenza vaccination in healthy young and elderly populations.

Breithaupt T, Harris K, Ellis J, Purcell E, Weir J, Clothier M, Boesler D.

Department of Biochemistry, Des Moines University Osteopathic Medical Center, 3200 Grand Ave, Des Moines, IA 50312, USA. thomas.breithaupt dmu.edu

The authors investigated whether thoracic lymphatic pumping (TLP) after FluShield vaccination enhanced the production of anti-influenza immunoglobulins in elderly individuals, who are at particular risk for influenza. Osteopathic students and non-TLP-treated elderly subjects served as controls. Serum antibody titers were quantified with enzyme-linked immunosorbent assay, and hemagglutination inhibition assay, both of which generated comparable results. While approximately 70% of the younger controls had increased anti-influenza immunoglobulin production on vaccination, only 30% to 35% of the aged population had increased antibody production. There was no significant enhancement in anti-influenza immunoglobulin production in the TLP-treated subjects. The authors' findings suggest that TLP in conjunction with influenza vaccination does not enhance immunization against influenza in otherwise healthy and active populations. However, such techniques may be of value when applied in conjunction with vaccination to nonambulatory patients or on actual influenza exposure of at-risk individuals.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11234217&dopt=Abstract flu, influenza



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[Adequacy of the term "influenza" in disease reporting]

[Article in Spanish]

Baena Jimenez M, Montero Perez FJ, Calvo-Rubio Burgos M, Calderon de la Barca Gazquez JM.

To evaluate the real incidence rate of influenza in our community, we have assessed all those illnesses considered to be influenza-like in a population of 2,700 persons in Cordoba during a 7 month period (December 1986-June 1987). A complete clinical, virological and serological evaluation was carried out in 31 of the first 51 cases. Of these, 15 had positive serological tests for influenza A or B viruses and 4 for the other viruses. In none of the cases the isolation of influenza virus was achieved after cell culture of the pharyngeal exudate. The observed incidence rate in our study, on the basis of predefined clinical criteria, was 1.8%. This was significantly lower (p less than 0.001) than the rate of reported influenza cases in the province (11.6%). It was concluded that the expression "influenza-like syndrome" should be substituted for "influenza" in the official reportings of this disease, which, on the other hand, should always be carried out following strict clinical criteria.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2518985&dopt=Abstract flu, influenza