Forough Tavakoli; Afagh Moattari; Mahmoud Shamsi Shahr Abadi; Mohammad Rahim Kadivar; Nastaran Khodadad; Neda Pirbonyeh; Amir Emami
Volume 12, Issue 3 , September 2015, , Pages 198-208
Abstract
Background: A new pandemic influenza A (H1N1) emerged in April 2009, causing considerable morbidity and mortality. Since mutations in the haemagglutinin (HA) may influence the antigenicity and pathogenicity of the virus, continued epidemiological and molecular characterization for the effective control ...
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Background: A new pandemic influenza A (H1N1) emerged in April 2009, causing considerable morbidity and mortality. Since mutations in the haemagglutinin (HA) may influence the antigenicity and pathogenicity of the virus, continued epidemiological and molecular characterization for the effective control of pandemic flu and developing of more appropriate vaccine is crucial. Objective: To monitor the molecular evolution of A (H1N1) pdm09 viruses in a specific time period in Shiraz, Southern Iran. Methods: A total of 200 samples were collected from February-April 2013. HA gene of the isolates was amplified and sequenced. Phylogenetic analysis of the HA gene was performed. Results: Out of 200 samples, a total of 77 (38.5%) samples were confirmed as A (H1N1) pdm09 virus using Real-time PCR method. Nucleotide similarity of our study strains with respect to reference strain A/California/07/2009 (H1N1) was 97.5%-98.5%. Phylogenetic analysis of our study strains indicated that the dominant A (H1N1) pdm09 clade was clade 7 and the dominant genetic group in circulating strains in Shiraz was genetic group 6. Some of our study strains showed substitutions at or in the vicinity of the antigenic sites of the HA1 region which may affect the efficacy of the vaccine. Conclusion: Our study strains showed a high homology to the vaccine strain. Our findings confirm the genetic variability of influenza A (H1N1) pdm09 and highlight the necessity of continuous molecular study of the virus for effective management of influenza.
Mohsen Moghadami; Afagh Moattari; Hamid Reza Tabatabaee; Alireza Mirahmadizadeh; Abbas Rezaianzadeh; Jafar Hasanzadeh; Mostafa Ebrahimi; Nima Zamiri; Abdolvahab Alborzi; Kamran Bagheri Lankarani
Volume 7, Issue 1 , March 2010, , Pages 39-48
Abstract
Background: Pandemic flu had at least two waves in Iran. Knowing how many of the general population were already exposed to this infection has a major impact on na-tional preventive measures. As of December 30, 2009, a total of 3672 confirmed cases of human infection with a novel Influenza A (2009 H1N1) ...
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Background: Pandemic flu had at least two waves in Iran. Knowing how many of the general population were already exposed to this infection has a major impact on na-tional preventive measures. As of December 30, 2009, a total of 3672 confirmed cases of human infection with a novel Influenza A (2009 H1N1) virus had been reported in Iran with 140 deaths. Objective: In this study we aim to measure, as a pilot study, the seroprevalence of positive antibody titer (humoral immunity) against 2009 H1N1 virus in Iranian population in Shiraz, Southern Iran. Methods: Through cluster random sam-pling of families residing in Shiraz, 2553 subjects were selected and after a medical in-terview blood samples were taken and checked for polyclonal antibody against 2009 H1N1 antigen using hemagglutination inhibition assay. An antibody titer of more than 1:40 dilution was considered positive. Data were analyzed considering the demographic characteristics of the population and were compared among different age groups. Results: 1504 (58.91%) samples were tested positive for the presence of polyclonal an-tibody against 2009 H1N1 virus. The prevalence of positive titers were significantly higher in 60 to 64 years old group and significantly lower in 20 to 24 years old group (p<0.05). Data did not differ based on other demographic characteristics or the history of flu like illnesses in the past 6 months. Conclusion: High seroprevalence of antibody against 2009 H1N1 in the sera of our subjects describes either a high level of pre-existing immunity against H1N1 in Iranian population or a high rate of asymptomatic infection in our area compared to other countries.
