Molecular epidemiological analysis of three hepatitis C virus outbreaks in Jammu and Kashmir State, India.

Outbreaks of hepatitis C virus (HCV) infection are associated with unsafe injection practices, intravenous drug abuse and other exposure to blood and body fluids. We report here three outbreaks of HCV infection from Jammu and Kashmir (J&K) State, India, which occurred over a period of 3 years and in which molecular epidemiological investigations identified a presumptive common source of infection, most likely a single healthcare venue. Representative blood samples collected from cases of hepatitis C were sent to the National Centre for Disease Control (NCDC) for molecular characterization. These samples were positive by HCV ELISA. Subsequently, specimens were also tested for the presence of HCV RNA by RT-PCR. Sequencing was carried out for all positive samples. A total of 812 cases were laboratory confirmed by HCV ELISA; a total of 115 samples were sent to the NCDC for RT-PCR, and 77 were positive. Subtype 3a of HCV was found in all samples from Anantnag (February 2013); and for subtype 3b, in all samples from Srinagar (May 2015). Subtypes 3a and 3g were identified from two samples from the Kulgam outbreak (July 2014). A detailed epidemiological investigation should be conducted whenever a cluster of HCV cases is revealed, as this potentially allows for the identification of larger outbreaks. Epidemiological investigations of outbreaks should be further supported by inclusion of molecular tests. Efforts to limit therapeutic injections to only those cases having strong medical/surgical indications and to restrict the use of non-sterile needles are essential to prevent transmission of HCV.

Continued persistence of a single genotype of dengue virus type-3 (DENV-3) in Delhi, India since its re-emergence over the last decade.

BACKGROUND/PURPOSE: The re-emergence of an epidemic strain of dengue virus type-3 (DENV-3) in Delhi in 2003 and its persistence in subsequent years marked a changing trend in dengue virus circulation in this part of India. Its evolving phylogeny over the past decade has not been studied in detail as yet. METHODS: Reverse transcription polymerase chain reaction and sequencing of the CprM gene junction of DENV-3 from different outbreaks since 2003 was carried out. Thirty CprM DENV-3 sequences from this study were compared with 46 other previously reported CprM DENV-3 sequences from India and other countries. Multiple sequence alignment and phylogenetic trees were constructed to determine the extent of genetic heterogeneity and trace the phylogeny of DENV-3. RESULTS: Thirty CprM DENV-3 sequences (Accession numbers AY706096-99, DQ645945-52, EU181201-14, and EU846234-36) were submitted to GenBank. The CprM junction was found to be AT rich (approximately 53%). Nucleotide sequence alignment revealed only nucleotide substitutions. Phylogenetic analysis indicated sustained evolution of a distinct Indian lineage of DENV-3 genotype III in Delhi. CONCLUSION: Active circulation of DENV-3 genotype III over the last decade in Delhi was evident and worrying. This genotype has been implicated in several outbreaks in South-East Asia and other parts of the world.

Phylogenetic studies reveal existence of multiple lineages of a single genotype of DENV-1 (genotype III) in India during 1956-2007.

BACKGROUND: Dengue virus type 1 (DENV-1) have been mostly circulating silently with dominant serotypes DENV-2 and DENV-3 in India. However recent times have marked an increase in DENV-1 circulation in yearly outbreaks. Many studies have not been carried out on this virus type, leaving a lacunae pertaining to the circulating genotypes, since its earliest report in India. In the present study, we sequenced CprM gene junction of 13 DENV-1 isolated from Delhi and Gwalior (North India) between 2001-2007 and one 1956 Vellore isolate as reference. For comparison, we retrieved 11 other Indian and 70 global reference sequences from NCBI database, making sure that Indian and global isolates from all decades are available for comparative analysis. RESULTS: The region was found to be AT rich with no insertion or deletion. Majority of the nucleotide substitutions were silent, except 3 non-conservative amino acid changes (I --> T, A --> T and L --> S at amino acid positions 59,114 and 155 respectively) in the Indian DENV-1 sequences, sequenced in this study. Except two 1997-98 Delhi isolates, which group in genotype I; all other Indian isolates group in genotype III. All Indian genotype III DENV-1 exhibited diversity among them, giving rise to at least 4 distinct lineages (India 1-4) showing proximity to isolates from diverse geographic locations. CONCLUSION: The extensive phylogenetic analysis revealed consistent existence of multiple lineages of DENV-1 genotype III during the last 5 decades in India.

Impact of HIV on genomic variability in the 5'UTR of HCV in Indian patients with HCV/HIV co-infection.

BACKGROUND: The impact of HIV on hepatitis C virus (HCV) genome during HCV/HIV co-infection is poorly understood. The present study was intended to unveil nucleotide sequence variability in the 5'-untranslated region (5'UTR) of HCV in co-infected cases. METHODS: Automated nucleotide sequencing of the 5'UTR of HCV from both mono- and co-infected cases was performed. RESULTS: Data analysis revealed deletion of a continuous stretch of 12 nucleotides (nt 240-251) from domain IIIc in 20% co-infected cases, but no long-stretch deletion was observed in HCV from mono-infected cases. On the contrary, there was no insertion in the 5'UTR of HCV from co-infectedcases, but there were insertions in domain II and III (3 mononucleotides and 2 dinucleotides) of the 5'UTR in mono-infected cases. CONCLUSION: Since domain III is known to be important for binding of 40S ribosomal subunit, deletion of a single stretch of 12 nucleotides in HCV from co-infected cases observed in the present study may have implications during HCV replication with or without HIV infection. Although this is the first report on genomic heterogeneity in the 5'UTR of HCV from HCV/HIV co-infected Indian patients, it would be worthwhile to study if similar changes are observed in other genes of HCV during co-infection.

Emergence of an independent lineage of dengue virus type 1 (DENV-1) and its co-circulation with predominant DENV-3 during the 2006 dengue fever outbreak in Delhi.

OBJECTIVES: The sudden emergence of dengue virus type 1 (DENV-1) and its co-circulation with predominant DENV-3 was the hallmark of the 2006 dengue fever outbreak in Delhi. Viruses that circulated between 1996 and 2005 in the City have been well characterized, but the genomic diversity in 2006 strains is not known. The present study was undertaken to reveal the emerging molecular genotype(s) and evolutionary trend of the viruses responsible for the dengue fever outbreak in Delhi during 2006. STUDY DESIGN: The CprM gene junction of the DENV isolates from the 2006 Delhi dengue fever outbreak were subjected to nucleotide sequencing. Comparative phylogenetic analysis was done using DENV-1 and DENV-3 sequences retrieved from the global database. RESULTS: Multiple sequence alignment revealed only substitutions, with no insertions or deletions. A dendrogram indicated emergence of a distinct lineage of DENV-1 (having similarity with the Comoros/Singapore 1993 and Delhi 1982 strains, but quite different from the Delhi 2005 lineage) and microevolution of the pre-circulating DENV-3. These findings point towards the circulation of two independent lineages of DENV-1 in Delhi during 2005 and 2006. CONCLUSIONS: It is feared that the introduction of an independent lineage of the outbreak-associated strain of DENV-1 and its co-circulation with the deeply-rooted strain of DENV-3 in Delhi may result in yet another, possibly more severe outbreak in the near future.