Phylogenetic analysis of NS5B gene of classical swine fever virus isolates indicates plausible Chinese origin of Indian subgroup 2.2 viruses.

Twenty-three CSFV isolates recovered from field outbreaks in various parts of India during 2006-2009 were used for genetic analysis in the NS5B region (409 nts). Seventeen of these were studied earlier [16] in the 5'UTR region. Phylogenetic analysis indicated the continued dominance of subgroup 1.1 strains in the country. Detailed analysis of a subgroup 2.2 virus indicated the plausible Chinese origin of this subgroup in India and provided indirect evidence of routes of CSFV movement within South East Asia region.

Environmental factors of households in five districts of Kerala affected by the epidemic of chikungunya fever in 2007.

BACKGROUND: Two epidemics of chikungunya fever were reported from Kerala in 2006 and 2007. We aimed to investigate the environmental factors of households affected by chikungunya fever and to estimate the proportion of population that suffered from the disease during the epidemic in 2007. METHODS: A cross-sectional survey was conducted in the 5 heavily affected districts of Kerala during October-November 2007. The 2-stage sampling technique was used to collect data from 10 clusters, each having 18 houses from every district, by interviewing the subjects using a structured questionnaire. The sample size was 900. RESULTS: The proportion of the population affected by chikungunya fever was 57.1% (95% CI: 52.8%-61.4%). There was a significant association between location of houses and disease status. Houses located near a public conveyance facility (within 250 m) were relatively protected from the disease (OR 0.19 [0.06-0.60]). About 69% of the households perceived mosquito infestation as a problem and 46.6% used fumes to avoid mosquitoes. More than 42% of households were not using any anti-mosquito measures at the time of the survey. Stored drinking water was the most common potential breeding source in the houses (23.5%). Households which did not store water inside were protected from the disease (OR 0.22 [0.08-0.65]). CONCLUSION: The study indicated the persistence of favourable domestic and environmental factors after the epidemic, reflecting the necessity to strengthen anti-mosquito campaigns.

Genetic typing of recent classical swine fever isolates from India.

Seventeen classical swine fever virus (CSFV) isolates recovered during the period of 3 years (2006-2008) from India were subjected to nucleotide sequencing in the 5' untranslated region (UTR). For genetic typing, 150 nucleotides within this region were used. For better epizootiological understanding, 39 nucleotide sequences of the above region, including 13 Indian CSFV sequences, available either in the Genbank or published literature were also included in the study. Based on the phylogenetic analysis, the Indian isolates could be grouped in to two subgroups, viz., 1.1 and 2.2. The study also revealed predominance of subgroup 1.1 and involvement of viruses of more than one subgroup in an outbreak.