Transmission dynamics of novel influenza A/H1N1 2009 outbreak in a residential school in India

Transmission dynamics of an outbreak of novel influenza A/H1N1 (2009) in June-July 2009 in a residential school in Maharashtra, India has been studied. A mathematical model of the type susceptible-exposedinfectious- asymptomatic-recovered has been adopted for the purpose. Analyses of epidemiological data revealed that close clustering within population resulted in high transmissibility with basic reproduction number R0 = 2.61 and transmission rate (β) being 0.001566. Model has successfully described the dynamics of transmission in a residential school setting and helped in ascertaining the epidemiological parameters for asymptomatic cases and the effectiveness of the control measures. Our study presents a framework for studying similar outbreaks of influenza involving clustered populations

Experimental transmission of Chandipura virus by Phlebotomus argentipes (Diptera: Psychodidae)

Experiments were carried out to demonstrate the susceptibity and transmission potential of Phlebotomus argentipes (Annandale & Brunetti) for Chandipura virus (CHPV). In India, P. argentipes is one of the predominant species found in many areas endemic for CHPV. Although its laboratory colonization is difficult, we have demonstrated that 65% of P. argentipes were susceptible to CHPV infection by the oral route. Transmission experiments were carried out by intrathoracic inoculation because of re-feeding problems with this species. After incubation for 24 hours, efficient transmission of CHPV to mice was observed. The estimated minimum transmission rate among the inoculated flies was 32%. CHPV in sand flies as well as in mice was detected and confirmed by immunofluorescent antibody assay and reverse transcription-polymerase chain reaction, respectively. The susceptibility of P. argentipes to CHPV and its potential to transmit the virus by bite has importance in epidemiology of CHPV

Surveillance in eastern India (2007-2009) revealed reassortment event involving ns and PB1-F2 gene segments among co-circulating influenza a subtypes

<p>Abstract</p> <p>Background</p> <p>Influenza A virus encodes for eleven proteins, of which HA, NA, NS1 and PB1-F2 have been implicated in viral pathogenicity and virulence. Thus, in addition to the HA and NA gene segments, monitoring diversity of NS1 and PB1-F2 is also important.</p> <p>Methods</p> <p>55 out of 166 circulating influenza A strains (31 H1N1 and 24 H3N2) were randomly picked during 2007-2009 and NS and PB1-F2 genes were sequenced. Phylogenetic analysis was carried out with reference to the prototype strains, concurrent vaccine strains and other reference strains isolated world wide.</p> <p>Results</p> <p>Comparative analysis of both nucleotide and deduced amino acid sequences, revealed presence of NS gene with A/PR/8/34(H1N1)-like mutations (H4N, Q21R, A22V, K44R, N53D, C59R, V60A, F103S and M106I) in both RNA-binding and effector domain of NS1 protein, and G63E, the HPAI-H5N1-like mutation in NEP/NS2 of five A/H1N1 strains of 2007 and 2009. NS1 of other A/H1N1 strains clustered with concurrent A/H1N1 vaccine strains. Of 31 A/H1N1 strains, five had PB1-F2 similar to the H3N2 strains; six had non-functional PB1-F2 protein (11 amino acids) similar to the 2009 pandemic H1N1 strains and rest 20 strains had 57 amino acids PB1-F2 protein, similar to concurrent A/H1N1 vaccine strain. Interestingly, three A/H1N1 strains with H3N2-like PB1-F2 protein carried primitive PR8-like NS gene. Full gene sequencing of PB1 gene confirmed presence of H3N2-like PB1 gene in these A/H1N1 strains.</p> <p>Conclusion</p> <p>Overall the study highlights reassortment event involving gene segments other than HA and NA in the co-circulating A/H1N1 and A/H3N2 strains and their importance in complexity of influenza virus genetics. In contrast, NS and PB1-F2 genes of all A/H3N2 eastern India strains were highly conserved and homologous to the concurrent A/H3N2 vaccine strains suggesting that these gene segments of H3N2 viruses are evolutionarily more stable compared to H1N1 viruses.</p

Genetic Characterization of the Influenza A Pandemic (H1N1) 2009 Virus Isolates from India

Background: The Influenza A pandemic H1N1 2009 (H1N1pdm) virus appeared in India in May 2009 and thereafter outbreaks with considerable morbidity and mortality have been reported from many parts of the country. Continuous monitoring of the genetic makeup of the virus is essential to understand its evolution within the country in relation to global diversification and to track the mutations that may affect the behavior of the virus. Methods: H1N1pdm viruses were isolated from both recovered and fatal cases representing major cities and sequenced. Phylogenetic analyses of six concatenated whole genomes and the hemagglutinin (HA) gene of seven more isolates from May-September 2009 was performed with reference to 685 whole genomes of global isolates available as of November 24, 2009. Molecular characterization of all the 8 segments was carried out for known pathogenic markers. Results: The first isolate of May 2009 belonged to clade 5. Although clade 7 was the dominant H1N1pdm lineage in India, both clades 6 and 7 were found to be co-circulating. The neuraminidase of all the Indian isolates possessed H275, the marker for sensitivity to the neuraminidase inhibitor Oseltamivir. Some of the mutations in HA are at or in the vicinity of antigenic sites and may therefore be of possible antigenic significance. Among these a D222G mutation in the HA receptor binding domain was found in two of the eight Indian isolates obtained from fatal cases. Conclusions: The majority of the 13 Indian isolates grouped in the globally most widely circulating H1N1pdm clade 7

Genetic divergence of Chikungunya viruses in India (1963-2006) with special reference to the 2005-2006 explosive epidemic

Re-emergence of Chikungunya (CHIK), caused by CHIK virus, was recorded in India during 2005-2006 after a gap of 32 years, causing 1.3 million cases in 13 states. Several islands of the Indian Ocean reported similar outbreaks in the same period. These outbreaks were attributed to the African genotype of CHIK virus. To examine relatedness of the Indian isolates (IND-06) with Reunion Island isolates (RU), full-genome sequences of five CHIK virus isolates representative of different Indian states were determined. In addition, an isolate obtained from mosquitoes in the year 2000 (Yawat-2000), identified as being of the African genotype, and two older strains isolated in 1963 and 1973 (of the Asian genotype), were sequenced. The IND-06 isolates shared 99.9 % nucleotide identity with RU isolates, confirming involvement of the same strain in these outbreaks. The IND-06 isolates shared 98.2 % identity with the Yawat-2000 isolate. Of two crucial substitutions reported for RU isolates in the E1 region, M269V was noted in the Yawat-2000 and IND-06 isolates, whereas D284E was seen only in the IND-06 isolates. The A226V shift observed with the progression of the epidemic in Reunion Island, probably associated with adaptation to the mosquito vector, was absent in all of the Indian isolates. Three unique substitutions were noted in the IND-06 isolates: two (T128K and T376M) in the Nsp1 region and one (P23S) in the capsid protein. The two Asian strains showed 99.4 % nucleotide identity to each other, indicating relative stability of the virus. No evidence of recombination of the Asian and African genotypes, or of positive selection was observed. The results may help in understanding the association, if any, of the unique mutations with the explosive nature of the CHIK outbreak

Environmentally sound system for E-waste: Biotechnological perspectives

The rapid e-waste volume is generating globally. At the same time, different recycling technologies, mainly the mechanical and chemical methods well studied, while the biological method is the most promising approach. Therefore, this article provides a comprehensive information about extracting valuable metals from e-waste. In addition, this article outlines the process and key opportunity for extraction of metals, identifies some of the most critical challenges for e-waste environmentally sound management practices, and opinions on possible solutions for exiting challenges, and emphasis on importance of advanced recycling technologies that can be utilized, in order to minimize the environmental impact causes due to improper recycling of e-waste

Avian Influenza H9N2 Seroprevalence among Poultry Workers in Pune, India, 2010

Avian influenza (AI) H9N2 has been reported from poultry in India. A seroepidemiological study was undertaken among poultry workers to understand the prevalence of antibodies against AI H9N2 in Pune, Maharashtra, India. A total of 338 poultry workers were sampled. Serum samples were tested for presence of antibodies against AI H9N2 virus by hemagglutination inhibition (HI) and microneutralization (MN) assays. A total of 249 baseline sera from general population from Pune were tested for antibodies against AI H9N2 and were negative by HI assay using ≥40 cut-off antibody titre. Overall 21 subjects (21/338 = 6.2%) were positive for antibodies against AI H9N2 by either HI or MN assays using ≥40 cut-off antibody titre. A total of 4.7% and 3.8% poultry workers were positive for antibodies against AI H9N2 by HI and MN assay respectively using 40 as cut-off antibody titre. This is the first report of seroprevalence of antibodies against AI H9N2 among poultry workers in India

A unique influenza A (H5N1) virus causing a focal poultry outbreak in 2007 in Manipur, India

<p>Abstract</p> <p>Background</p> <p>A focal H5N1 outbreak in poultry was reported from Manipur, a north-eastern state, of India, in 2007. The aim of this study was to genetically characterize the Manipur isolate to understand the relationship with other H5N1 isolates and to trace the possible source of introduction of the virus into the country.</p> <p>Results</p> <p>Characterization of the complete genome revealed that the virus belonged to clade 2.2. It was distinctly different from viruses of the three EMA sublineages of clade 2.2 but related to isolates from wild migratory waterfowl from Russia, China and Mongolia. The HA gene, had the cleavage site GERRRRKR, earlier reported in whooper swan isolates from Mongolia in 2005. A stop codon at position 29 in the PB1-F2 protein could have implications on the replication efficiency. The acquisition of polymorphisms as seen in recent isolates of 2005–07 from distinct geographical regions suggests the possibility of transportation of H5N1 viruses through migratory birds.</p> <p>Conclusion</p> <p>Considering that all eight genes of the earlier Indian isolates belonged to the EMA3 sublineage and similar strains have not been reported from neighbouring countries of the subcontinent, it appears that the virus may have been introduced independently.</p

Pandemic influenza A(H1N1) 2009 outbreak in a residential school at Panchgani, Maharashtra, India

Background &amp; objectives: An outbreak of influenza was investigated between June 24 and July 30, 2009 in a residential school at Panchgani, Maharashtra, India. The objectives were to determine the aetiology, study the clinical features in the affected individuals and, important epidemiological and environmental factors. The nature of public health response and effectiveness of the control measures were also evaluated. Methods: Real time reverse transcriptase polymerase chain reaction was performed on throat swabs collected from 82 suspected cases to determine the influenza types (A or B) and sub-types [pandemic (H1N1) 2009, as well as seasonal influenza H1N1, H3N2]. Haemagglutination inhibition assay was performed on serum samples collected from entire school population (N = 415) to detect antibodies for pandemic (H1N1) 2009, seasonal H1N1, H3N2 and influenza B/Yamagata and B/Victoria lineages. Antibody titres ≥ 10 for pandemic (H1N1) 2009 and ≥ 20 for seasonal influenza A and B were considered as positive for these viruses. Results: Clinical attack rate for influenza-like illness was 71.1 per cent (295/415). The attack rate for pandemic (H1N1) 2009 cases was 42.4 per cent (176/415). Throat swabs were collected from 82 cases, of which pandemic (H1N1) 2009 virus was detected in 15 (18.3%), influenza type A in (6) 7.4 per cent and influenza type B only in one case. A serosurvey carried out showed haemagglutination inhibition antibodies to pandemic (H1N1) 2009 in 52 per cent (216) subjects in the school and 9 per cent (22) in the community. Interpretation &amp; conclusion: Our findings confirmed an outbreak of pandemic (H1N1) 2009 due to local transmission among students in a residential school at Panchgani, Maharashtra, India