ABSTRACT
Influenza surveillance was conducted in Pune, India in 2003. A total of 573 throat swabs/ nasal swabs (TS/NS) and 190 nasopharyngeal aspirates (NPA) were collected from 763 in- and out-patients who were mostly children aged 0-16 years. TS/NS (507/573) and NPA (42/190) specimens were processed in MDCK cell cultures and identified with the hemagglutination inhibition test (HI). A total of 37 influenza viruses was isolated: twenty-three type A (H3N2) and 14 type B of the Yamagata lineage were isolated from 29 children and 8 adults. Three type A (H3N2) isolates were characterized as being similar to A/Panama/2007/99 like, A/Korea/770/2000 like, and B/Sichuan/379/99 like strains.
Subject(s)
Disease Outbreaks , Influenza A Virus, H3N2 Subtype/isolation & purification , Influenza B virus/isolation & purification , Influenza, Human/epidemiology , Influenza, Human/virology , Population Surveillance , Child , Child, Preschool , Female , Humans , India/epidemiology , Infant , Infant, Newborn , Male , Time FactorsABSTRACT
Mink lung epithelial cells (Mv-1-Lu) were tested for their ability to support the growth and serial passage of respiratory syncytial virus (RSV) in vitro. Indian isolates of RSV induced distinctive cytopathic effect with typical rounding of cells followed by detachment with more than 50 per cent cells showing bright fluorescence using anti-RSV monoclonal antibodies in immunofluorescence test. Serial passage of RSV was possible in Mv-1-Lu cells without loss of sensitivity of the cells for virus growth. Titration of cell associated virus and virus released in the supernatant indicated that 60 per cent of the virus was released in the supernatant, and 40 per cent remained cell associated. Transmission electron microscopic studies of negatively stained RSV particles and ultra-thin sections of RSV infected Mv-1-Lu cells showed roughly spherical particles with club shaped projections, budding from the cytoplasmic membrane. These results indicate that Mv-1-Lu cell line is suitable for the growth and propagation of RSV.
Subject(s)
Respiratory Mucosa/virology , Respiratory Syncytial Viruses/growth & development , Animals , Cell Line , Cell Size , Child, Preschool , Cytopathogenic Effect, Viral , Female , Humans , India , Infant , Male , Mink , Respiratory Mucosa/cytology , Respiratory Mucosa/metabolism , Respiratory Syncytial Viruses/metabolism , Respiratory Syncytial Viruses/ultrastructure , Virus CultivationABSTRACT
BACKGROUND & OBJECTIVES: Influenza viruses cause frequent epidemics and periodic pandemics throughout the world due to antigenic variations. Serological data can be useful to determine the disease burden and population immunity and for predicting the likelihood of occurrence and potential severity of subsequent epidemics. We undertook a serological analysis of antibodies against ten influenza virus strains in Pune, India. METHODS: Haemagglutination inhibition (HI) test was done on 619 sera collected between 1997-99 during an age-stratified serosurvey in Pune, India against 10 strains of influenza virus. Overall prevalence and spectrum of HI antibodies against these strains was determined. RESULTS: Antibodies to at least one influenza virus strain was seen in 62 per cent (116/188) of the sera from individuals in the age group 5-15 yr, 77 per cent (85/111) in sera from 16-25 yr, 78 per cent (93/119) from 26-35 yr, 84 per cent (77/92) from 36-45 yr and 93 per cent (101/109) in sera from individuals aged > 45 yr. The antibody spectrum progressively increased with age. Antibodies to the pandemic strain A(H2N2) were absent in the age groups < 25 yr. INTERPRETATION & CONCLUSION: The results indicate that influenza virus infection occurs in a large proportion of individuals in our community and may be responsible for a considerable amount of morbidity and mortality. The study also demonstrates the absence of antibody to A/Singapore/1/57 (H2N2) strain in younger persons < 25 yr of age. The potential of its reintroduction cannot be ruled out as H2 variants are circulating in wild birds and population immunity in humans is decreasing.
Subject(s)
Influenza, Human/epidemiology , Adolescent , Adult , Antibodies, Viral/blood , Child , Child, Preschool , Hemagglutination Tests , Humans , India/epidemiology , Influenza, Human/diagnosis , Influenza, Human/mortality , Middle Aged , Orthomyxoviridae/immunology , Seroepidemiologic Studies , Species SpecificityABSTRACT
Monoclonal antibodies (MAbs) against an Indian strain (804994) and an Egyptian strain (E 101) of West Nile virus (WNV) were prepared in mice. Nine MAbs against the 804994 strain and 5 MAbs against E 101 strain were obtained. All 14 MAbs reacted with the envelope (E) protein of WNV in an immunoblot assay. They were tested by an enzyme-linked immunosorbent assay (ELISA) for their cross-reactivity with WNV, Japanese encephalitis virus (JEV) and Dengue-2 virus (DEN-2), and for their reactivity in haemagglutination-inhibition (HAI) test. Based on these results MAbs were broadly grouped into three groups, namely WNV-specific HAI-positive, WNV-JEV cross-reactive HAI-positive, and WNV-JEV cross-reactive HAI-negative MAbs. The antigenic cross-reactivity between twelve WNV strains isolated from different geographical regions and their respective hosts was assessed using these MAbs in HAI and complement fixation (CF) tests. The strain analysis by CF distinguished Indian from South African strains. However, a similarity between some Indian and South African strains in HAI was observed. E 101 strain appeared to have antigenic similarity with Indian as well as South African strains. Overall it appears that antigenically similar strains of WNV are prevalent in India. A single heterogenous domain was apparent on the epitope map of WNV deduced by ELISA additivity test.
Subject(s)
Antibodies, Monoclonal/immunology , Antigenic Variation/immunology , Antigens, Viral/immunology , Epitopes/analysis , West Nile virus/immunology , Animals , Animals, Suckling , Antibodies, Monoclonal/biosynthesis , Antibodies, Monoclonal/classification , Cell Line , Cross Reactions/immunology , Dengue Virus/immunology , Encephalitis Virus, Japanese/immunology , Enzyme-Linked Immunosorbent Assay , Epitope Mapping/methods , Female , Mice , Mice, Inbred BALB C , West Nile virus/classificationABSTRACT
A focal outbreak of hepatitis was detected in a day-care centre for children centrally located in Pune. The source of infection was suspected to be an 11-year-old child who probably got the infection from his school. Seven out of 15 children from day-care centre developed clinical hepatitis. Two cases of secondary infection were identified among the family contacts of infected children. Sera from all the nine sick children were positive for anti-hepatitis A virus-IgM antibodies. A stool sample from a case of secondary infection showed presence of HAV-RNA by RT-nested PCR. These findings proved that the outbreak was caused by hepatitis A virus.
Subject(s)
Child Day Care Centers , Disease Outbreaks , Hepatitis A/epidemiology , Adolescent , Child , Child, Preschool , Female , Hepatitis A/diagnosis , Hepatitis A/transmission , Humans , India , MaleABSTRACT
ISCOMs (immunostimulating complexes) were prepared from envelope glycoprotein (Egp) of Japanese encephalitis (JE) virus. ISCOMs showed a single band of the viral Egp in SDS-PAGE, which reacted with polyclonal and monoclonal antibody (MAb) raised against Egp. Comparison between the epitopes exposed on JE virion and JE ISCOMs, by antigen capture ELISA, utilizing a panel of domain-specific MAbs, revealed identical epitopes exposed on the Egp incorporated in ISCOMs and the whole virion. Electron micrographs of ISCOMs showed spherical cage-like structures of 35 nm. ISCOMs with Egp were good immunogenes, which stimulated high titres of neutralizing antibodies, both in mice and rabbits.
Subject(s)
Encephalitis Virus, Japanese/immunology , ISCOMs/biosynthesis , ISCOMs/chemistry , Adjuvants, Immunologic , Animals , Antibodies, Viral/biosynthesis , Antigens, Viral/immunology , Electrophoresis, Polyacrylamide Gel , Encephalitis Virus, Japanese/genetics , Encephalitis Virus, Japanese/ultrastructure , Enzyme-Linked Immunosorbent Assay , ISCOMs/ultrastructure , Mice , Mice, Inbred BALB C , Polymerase Chain Reaction , Quillaja Saponins , RNA, Viral/analysis , Rabbits , SaponinsABSTRACT
Immunogenicity of immunostimulating complexes (ISCOMs) of Japanese encephalitis virus (JEV) were studied in mice, rabbits and monkeys. Two doses of JE ISCOMs elicited a strong immune response in mice with an uniform distribution in IgG subclasses. Different time intervals between the two doses of ISCOMs led to similar titers of antibodies. Rabbits and monkeys immunized with ISCOMs developed strong neutralizing immune, response. Mice immunized with ISCOMs demonstrated cell-mediated immunity (CMI) as evidenced by T cell proliferation and macrophage migration inhibition (MMI) assays.
