RESUMO
Background & objectives: Influenza virological surveillance is an essential tool for the early detection of novel genetic variants of epidemiologic and clinical significance. This study was aimed to genetically characterize A(H1N1)pdm09 virus circulating in 2017 and to compare it with the global data. Methods: The regional/State Viral Research and Diagnostic Laboratories (VRDLs) provided influenza diagnosis for referred clinical samples and shared influenza A(H1N1)pdm09 positives with the Indian Council of Medical Research-National Institute of Virology (ICMR-NIV), Pune, India, for hemagglutinin (HA) gene phylogenetic analysis. Sites at Manipal, Jaipur and Dibrugarh performed the sequencing and shared the sequence data for analysis. The antiviral susceptibility of influenza viruses was assessed for known molecular marker H275Y at the ICMR-NIV, Pune. Results: All the eight VRDLs had well-established influenza diagnostic facilities and showed increased activity of influenza A(H1N1)pdm09 during 2017. Phylogenetic analysis showed that the viruses from the different regions of the country were similar to A/Michigan/45/2015 strain which was the 2017-2018 recommended vaccine strain and were clustered with the globally circulating clade 6B.1 with signature mutations S84N, S162N and I216T. The clade 6B.1 showed further subgrouping with additional mutations S74R, S164T and I295V; however, there was no significant association between the presence of these mutations and severity of disease due to influenza. All the study viruses were sensitive to oseltamivir. Interpretation & conclusions: During the study period, all the study sites reported globally circulating A/Michigan/45/2015 vaccine strain of influenza A(H1N1)pdm09 viruses and remained sensitive to oseltamivir. Further genetic and antigenic characterization of influenza viruses is recommended to address public health concerns.
RESUMO
Background & objectives: Dengue virus infection is endemic in India with all the four serotypes of dengue virus in circulation. This study was aimed to determine the geographic distribution of the primary and secondary dengue cases in India. Methods: A multicentre cross-sectional study was conducted at Department of Health Research / Indian Council of Medical Research (DHR)/(ICMR) viral research and diagnostic laboratories (VRDLs) and selected ICMR institutes located in India. Only laboratory-confirmed dengue cases with date of onset of illness less than or equal to seven days were included between September and October 2017. Dengue NS1 antigen ELISA and anti-dengue IgM capture ELISA were used to diagnose dengue cases while anti-dengue IgG capture ELISA was used for identifying the secondary dengue cases. Results: Of the 1372 dengue cases, 897 (65%) were classified as primary dengue and 475 (35%) as secondary dengue cases. However, the proportion varied widely geographically, with Theni, Tamil Nadu; Tirupati, Andhra Pradesh and Udupi-Manipal, Karnataka reporting more than 65 per cent secondary dengue cases while Srinagar, Jammu and Kashmir reporting as low as 10 per cent of the same. The median age of primary dengue cases was 25 yr [interquartile range (IQR 17-35] while that of secondary dengue cases was 23 yr (IQR 13.5-34). Secondary dengue was around 50 per cent among the children belonging to the age group 6-10 yr while it ranged between 20-43 per cent among other age groups. Interpretation & conclusions: Our findings showed a wide geographical variation in the distribution of primary and secondary dengue cases in India. It would prove beneficial to include primary and secondary dengue differentiation protocol in the national dengue surveillance programme.
RESUMO
Introduction: Influenza A(H1N1)pdm09 virus, since its identification in April 2009, has continued to cause significant outbreaks of respiratory tract infections including pandemics in humans. In the course of its evolution, the virus has acquired many mutations with an ability to cause increased disease severity. A regular molecular surveillance of the virus is essential to mark the evolutionary changes that may cause a shift to the viral behavior. Materials and Methods: Samples of Throat/Nasal swabs were collected from a total of 3715 influenza-like illness cases and screened by Real-time Reverse Transcription-Polymerase Chain Reaction for influenza viruses. Nucleotide sequence analysis was done to identify changes in antigenicity of the virus strains. Results: The present study describes the molecular characteristics of influenza A(H1N1)pdm09 viruses detected in Assam of Northeast India during 2009�15. Influenza A viruses were detected in 11.4% (425/3715), of which influenza A(H1N1)pdm09 viruses were detected in 41.4% (176/425). The nucleotide sequencing of influenza A(H1N1)pdm09 viruses revealed a total of 17 and 22 amino acid substitutions in haemagglutinin (HA) and neuraminidase (NA) genes of the virus, respectively, compared to contemporary vaccine strain A/California/07/2009. The important mutations detected in HA genes of A/Assam(H1N1)pdm09 strains included E391K, K180Q and S202T. Mutation 'N248D' which has an ability to develop oseltamivir resistance was also detected in NA gene of A/Assam(H1N1)pdm09 strains. Conclusions: Regular molecular surveillance of influenza A(H1N1)pdm09 is important to monitor the viral behavior in terms of increase virulence, drug resistance pattern and emergence of novel strains.
RESUMO
Background and Objectives: Dengue is one of the most prevalent arboviral diseases in the world with 390 million dengue infections per year. In this study, we report the molecular characterisation of dengue outbreak in Pasighat, Arunachal Pradesh, Northeast India during 2015. Subjects and Methods: A total of 613 dengue-suspected cases were screened for dengue virus by dengue NS1 Ag and anti-dengue IgM antibody depending on the duration of sample collection and onset of symptom. Further, molecular characterisation was done by amplifying the C-PrM region by real-time polymerase chain reaction followed by phylogenetic analysis. Results: Molecular characterisation revealed that the dengue outbreak was predominantly due to dengue virus serotype-1 (DENV-1) (90.9%) while DENV-2 was detected in 7.5% of samples. Co-infection of DENV-1 and DENV-2 was detected in one case. Phylogenetic analysis of the DENV-1 strains with the prototype revealed that the DENV-1 strains were grouped within genotype III. Similarly, DENV-2 strains were clustered within genotype IV. The study revealed a change in the predominant serotype in recent years with DENV-3 in 2012 to DENV-1, 2, 3 and 4 in 2014 to DENV-1 in 2015 in the study region. A unique L24M mutation was observed in the DENV-1 strains of Arunachal Pradesh which was absent in all the circulating strains in India except one strain from the state of Kerala in South India. Marked variation within the DENV-2 strains was observed at A102V and I163V in one strain similar to earlier circulating isolates in India. Conclusions: The present study reveals a shift in the serotype dominance in the study region. As serotype shifts and secondary infection with a heterologous DENV serotype are frequently associated with disease severity, there is an urgent need for sustained monitoring of the circulating serotypes and enhanced surveillance operations, especially in the monsoon and post-monsoon periods to prevent large-scale, severe dengue outbreaks in this region.
RESUMO
BACKGROUND & OBJECTIVE: Prevalence of injection drug users (IDUs) is high in the northeastern region of India. This coupled with unsafe injecting practices as well as practice of tattooing in remote tribal areas call for baseline data on the prevalence of parentally transmitted viral diseases. In the present study we aimed to measure the risk behaviours and seroprevalence of hepatitis C virus (HCV) antibodies amongst IDUs of Mizoram, a State of the northeast India. METHODS: A cross-sectional study was conducted in 2004-2005 amongst IDUs (including female sex workers) who had injected in the past six months and were unaware of their HCV/HIV status. They were recruited from various drop-in centers from Aizawl, Mizoram, and screened for anti-HCV antibodies using 3(rd) generation HCV EIA and recombinant immunoblot assay (RIBA). RESULTS: The prevalence of HCV antibodies was 71.2 per cent among the active IDUs. On univariate analysis increasing duration of injection, syringe sharing and heroin (diacetylmorphine) injectors were at a significantly higher risk of acquiring HCV antibodies (P<0.001). On multivariate analysis, HCV antibody prevalence showed a strong association with the type of drugs injected (P=0.001), frequency of injecting (P=0.013), multiplicity of drugs abused (P=0.004), and needle syringe sharing (P=0.003). INTERPRETATION & CONCLUSION: Unsafe injecting practices were found to be associated with a higher risk of acquiring hepatitis C infection. Our findings showed that syringe and needle exchange programme alone was not sufficient as a preventive strategy for control of hepatitis C infection among IDUs of Aizawl.
Assuntos
Adolescente , Adulto , Feminino , Hepatite C/etiologia , Anticorpos Anti-Hepatite C/sangue , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Abuso de Substâncias por Via Intravenosa/complicaçõesRESUMO
Background & objectives: Prevalence of injection drug users (IDUs) is high in the northeastern region of India. This coupled with unsafe injecting practices as well as practice of tattooing in remote tribal areas call for baseline data on the prevalence of parentally transmitted viral diseases. In the present study we aimed to measure the risk behaviours and seroprevalence of hepatitis C virus (HCV) antibodies amongst IDUs of Mizoram, a State of the northeast India. Methods: A cross-sectional study was conducted in 2004-2005 amongst IDUs (including female sex workers) who had injected in the past six months and were unaware of their HCV/HIV status. They were recruited from various drop-in centers from Aizawl, Mizoram, and screened for anti-HCV antibodies using 3rd generation HCV EIA and recombinant immunoblot assay (RIBA). Results: The prevalence of HCV antibodies was 71.2 per cent among the active IDUs. On univariate analysis increasing duration of injection, syringe sharing and heroin (diacetylmorphine) injectors were at a significantly higher risk of acquiring HCV antibodies (P<0.001). On multivariate analysis, HCV antibody prevalence showed a strong association with the type of drugs injected (P=0.001), frequency of injecting (P=0.013), multiplicity of drugs abused (P=0.004), and needle syringe sharing (P=0.003). Interpretation & conclusions: Unsafe injecting practices were found to be associated with a higher risk of acquiring hepatitis C infection. Our findings showed that syringe and needle exchange programme alone was not sufficient as a preventive strategy for control of hepatitis C infection among IDUs of Aizawl.
RESUMO
BACKGROUND & OBJECTIVE: There is a paucity of information on distribution of hepatitis B genotypes from northeastern part of India. Arunachal Pradesh, one of the northeastern State of India bordering Bhutan, China and Myanmar, reported abnormally high numbers of hepatitis B surface antigen (HBsAg) positive cases in one of its districts during January-June 2005. We conducted this study in the subsequent months (August-December 2005) to know the prevalent genotypes by a rapid and specific method based on type-specific primers in Upper Dibang valley of Arunachal Pradesh. METHODS: A total of 438 randomly selected individual were screened for HBsAg positivity. Of the 93 HBsAg positive individuals, 36 HBsAg and HBV DNA positive samples were processed for HBV genotyping using type-specific primer based nested PCR (TSP-PCR). Representative samples were retested with RFLP-PCR based genotyping and nucleotide sequencing. RESULTS: Of the 36 samples, 29 (80.1%) could be genotyped by the TSP-PCR based method used. The predominant genotype was genotype A (41.6%) followed by genotypes C (27.8%) and D (11.1%). Seven isolates (19.9%) could not be genotyped by this method. INTERPRETATION & CONCLUSION: The presence of genotype C in this part of the country needs attention as genotype C takes a more aggressive disease course. Also, detection of genotype C in this isolated community bordering Tibet suggests viral gene flow from Tibet or other South-east Asian countries where genotype C of HBV is predominant.
Assuntos
Genótipo , Vírus da Hepatite B/classificação , Índia , Filogenia , Reação em Cadeia da PolimeraseRESUMO
AIM: To study the prevalence of hepatitis B virus (HBV) infection among an isolated tribe of Northeast India that migrated long back from Tibet. METHODS AND MATERIALS: Randomly selected 438 subjects from Idu Mishmi tribe of Arunachal Pradesh were screened for hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), hepatitis B surface antibody (anti-HBs), envelope antigen (HBeAg) using ELISA kits. RESULTS: The point prevalence of HBsAg was found to be 21.2% (93/438). Anti-HBc prevalence was 92.3% (193/209). Anti-HBs above 10 IU/ml were detected in 48% (96/200). Prevalence of HBeAg was higher (42.1%, 16/38) in children (less than 15 years) compared to adolescent and adults (32.7%, 18/55). History of hepatitis was significantly associated with positive HBsAg status (p < 0.000). CONCLUSION: Hepatitis B virus infection is hyperendemic among Idu Mishmi tribe of Arunachal Pradesh, India. Though, the route of transmission could not be ascertained, but the high HBV infection (78.6%) among less than 5 yrs and the finding of 58.4% of HBsAg positive mothers bearing HBsAg positive child indicates possibility of vertical transmission in this setting.