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Zhang M, Zhou J, Ni R, Zhao X, Chen Y, Sun Y, Liu Z, Han X, Luo C, Fu X, Shao Y. Genomic Analyses Uncover Evolutionary Features of Influenza A/H3N2 Viruses in Yunnan Province, China, from 2017 to 2022. Viruses 2024; 16:138. [PMID: 38257838 PMCID: PMC10820241 DOI: 10.3390/v16010138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 01/13/2024] [Accepted: 01/16/2024] [Indexed: 01/24/2024] Open
Abstract
Influenza A viruses evolve at a high rate of nucleotide substitution, thereby requiring continuous monitoring to determine the efficacy of vaccines and antiviral drugs. In the current study, we performed whole-genome sequencing analyses of 253 influenza A/H3N2 strains from Yunnan Province, China, during 2017-2022. The hemagglutinin (HA) segments of Yunnan A/H3N2 strains isolated during 2017-2018 harbored a high genetic diversity due to heterogeneous distribution across branches. The mutation regularity of the predominant antigenic epitopes of HA segments in Yunnan was inconsistent in different years. Some important functional mutations in gene segments associated with viral adaptation and drug tolerance were revealed. The rapid genomic evolution of Yunnan A/H3N2 strains from 2017 to 2022 mainly concentrated on segments, i.e., matrix protein 2 (M2), non-structural protein 1 (NS1), neuraminidase (NA), NS2, and HA, with a high overall non-synonymous/synonymous substitution ratio (dN/dS). Our results highlighted a decline in vaccine efficacy against the A/H3N2 circulating strains, particularly against the Yunnan 2021-2022 A/H3N2 strains. These findings aid our understanding of evolutionary characteristics and epidemiological monitoring of the A/H3N2 viruses and provide in-depth insights into the protective efficacy of influenza vaccines.
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Affiliation(s)
- Meiling Zhang
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Jienan Zhou
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Ruize Ni
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Xiaonan Zhao
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Yaoyao Chen
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Yanhong Sun
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Zhaosheng Liu
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Xiaoyu Han
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Chunrui Luo
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Xiaoqing Fu
- Department of Acute Infectious Diseases Control and Prevention, Yunnan Center for Disease Control and Prevention, Kunming 650022, China; (M.Z.); (J.Z.); (R.N.); (X.Z.); (Y.C.); (Y.S.); (Z.L.); (X.H.); (C.L.)
| | - Yong Shao
- State Key Laboratory of Genetic Resources and Evolution, Chinese Academy of Sciences, Kunming Institute of Zoology, Kunming 650201, China
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Jia R, Jiang C, Li L, Huang C, Lu L, Xu M, Xu J, Liang X. Interleukin 16 Enhances the Host Susceptibility to Influenza A Virus Infection. Front Microbiol 2021; 12:736449. [PMID: 34630361 PMCID: PMC8496453 DOI: 10.3389/fmicb.2021.736449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 08/16/2021] [Indexed: 12/13/2022] Open
Abstract
Influenza A virus (IAV) is a major respiratory pathogen that causes seasonal and pandemic flu, being a threat to global health. Various viral and cellular factors have been characterized to support or limit IAV infection. Interleukin 16 (IL16) has been known as one of the blood signature biomarkers discriminating systemic inflammation due to viral infection vs. other etiologies. Here, we report that the level of IL16 was elevated in the serum samples, lung homogenates, and bronchoalveolar lavage fluid of IAV-infected mice. IL16 overexpression facilitated IAV replication. Conversely, loss of IL16 reduced the host susceptibility to IAV infection in vitro and in vivo. Furthermore, IL16 deficiency blocked IAV-induced body weight loss and attenuated lung injury in the infected mice. Molecular mechanism analyses further revealed that IL16 could directly inhibit IFN-β transcription and suppress the expression of IFN-β and IFN-stimulated gene. In conclusion, these findings demonstrate that IL16 is a supporting factor for IAV infection.
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Affiliation(s)
- Ran Jia
- Department of Clinical Laboratory, Children's Hospital of Fudan University, Shanghai, China
| | - Congwei Jiang
- Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Long Li
- Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Chenxu Huang
- Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Lijuan Lu
- Department of Clinical Laboratory, Children's Hospital of Fudan University, Shanghai, China
| | - Menghua Xu
- Department of Clinical Laboratory, Children's Hospital of Fudan University, Shanghai, China
| | - Jin Xu
- Department of Clinical Laboratory, Children's Hospital of Fudan University, Shanghai, China
| | - Xiaozhen Liang
- Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
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Development of cycling probe based real-time PCR methodology for influenza A viruses possessing the PA/I38T amino acid substitution associated with reduced baloxavir susceptibility. Antiviral Res 2021; 188:105036. [PMID: 33577807 DOI: 10.1016/j.antiviral.2021.105036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 02/04/2021] [Accepted: 02/06/2021] [Indexed: 02/02/2023]
Abstract
Baloxavir marboxil has been used for influenza treatment since March 2018 in Japan. After baloxavir treatment, the most frequently detected substitution is Ile38Thr in polymerase acidic protein (PA/I38T), and this substitution reduces baloxavir susceptibility in influenza A viruses. To rapidly investigate the frequency of PA/I38T in influenza A (H1N1)pdm09 and A (H3N2) viruses in clinical samples, we established a rapid real-time system to detect single nucleotide polymorphisms in PA, using cycling probe real-time PCR. We designed two sets of probes that were labeled with either 6-carboxyfluorescein (FAM) or 6-carboxy-X-rhodamine (ROX) to identify PA/I38 (wild type strain) or PA/I38T, respectively. The established cycling probe real-time PCR system showed a dynamic linear range of 101 to 106 copies with high sensitivity in plasmid DNA controls. This real-time PCR system discriminated between PA/I38T and wild type viruses well. During the 2018/19 season, 377 influenza A-positive clinical samples were collected in Japan before antiviral treatment. Using our cycling probe real-time PCR system, we detected no (0/129, 0.0%) influenza A (H1N1)pdm09 viruses with PA/I38T substitutions and four A (H3N2) (4/229, 1.7%) with PA/I38T substitution prior to treatment. In addition, we found PA/I38T variant in siblings who did not received baloxavir treatment during an infection caused by A (H3N2) that afflicted the entire family. Although human-to-human transmission of PA/I38T variant may have occurred in a closed environment, the prevalence of this variant in influenza A viruses was still limited. Our cycling probe-PCR system is thus useful for antiviral surveillance of influenza A viruses possessing PA/I38T.
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Kyaw Win SM, Saito R, Win NC, Lasham DJ, Kyaw Y, Lin N, Thein KN, Chon I, Odagiri T, Thein W, Kyaw LL, Tin OS, Saitoh A, Tamura T, Hirokawa C, Uchida Y, Saito T, Watanabe S, Odagiri T, Kamata K, Osada H, Dapat C, Watanabe H, Tin HH. Epidemic of influenza A(H1N1)pdm09 analyzed by full genome sequences and the first case of oseltamivir-resistant strain in Myanmar 2017. PLoS One 2020; 15:e0229601. [PMID: 32130243 PMCID: PMC7055873 DOI: 10.1371/journal.pone.0229601] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 02/10/2020] [Indexed: 12/16/2022] Open
Abstract
A community outbreak of human influenza A(H1N1)pdm09 virus strains was observed in Myanmar in 2017. We investigated the circulation patterns, antigenicity, and drug resistance of 2017 influenza A(H1N1)pdm09 viruses from Myanmar and characterized the full genome of influenza virus strains in Myanmar from in-patients and out-patients to assess the pathogenicity of the viruses. Nasopharyngeal swabs were collected from out-patients and in-patients with acute respiratory tract infections in Yangon and Pyinmana City in Myanmar during January-December 2017. A total of 215 out-patients and 18 in-patients infected with A(H1N1)pdm09 were detected by virus isolation and real-time RT-PCR. Among the positive patients, 90.6% were less than 14 years old. Hemagglutination inhibition (HI) antibody titers against A(H1N1)pdm09 viruses in Myanmar were similar to the recommended Japanese influenza vaccine strain for 2017–2018 seasons (A/Singapore/GP1908/2015) and WHO recommended 2017 southern hemisphere vaccine component (A/Michigan/45/2015). Phylogenetic analysis of the hemagglutinin sequence showed that the Myanmar strains belonged to the genetic subclade 6B.1, possessing mutations of S162N and S164T at potential antigenic sites. However, the amino acid mutation at position 222, which may enhance the severity of disease and mortality, was not found. One case with no prior history of oseltamivir treatment possessed H275Y mutated virus in neuraminidase (NA), which confers resistance to oseltamivir and peramivir with elevated IC50 values. The full genome sequence of Myanmar strains showed no difference between samples from in-patients and out-patients, suggesting no additional viral mutations associated with patient severity. Several amino acid changes were observed in PB2, PB1, and M2 of Myanmar strains when compared to the vaccine strain and other Asian strains. However, no mutations associated with pathogenicity were found in the Myanmar strains, suggesting that viral factors cannot explain the underlying reasons of the massive outbreak in Myanmar. This study reported the first detection of an oseltamivir-resistant influenza virus in Myanmar, highlighting the importance of continuous antiviral monitoring and genetic characterization of the influenza virus in Myanmar.
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Affiliation(s)
- Su Mon Kyaw Win
- Infectious Diseases Research Center of Niigata University in Myanmar (IDRC), Yangon, Yangon Region, Myanmar
| | - Reiko Saito
- Infectious Diseases Research Center of Niigata University in Myanmar (IDRC), Yangon, Yangon Region, Myanmar.,Division of International Health, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Niigata, Japan
| | - Nay Chi Win
- Infectious Diseases Research Center of Niigata University in Myanmar (IDRC), Yangon, Yangon Region, Myanmar
| | - Di Ja Lasham
- Infectious Diseases Research Center of Niigata University in Myanmar (IDRC), Yangon, Yangon Region, Myanmar
| | - Yadanar Kyaw
- Respiratory Medicine Department, Thingangyun Sanpya General Hospital, Yangon, Yangon Region, Myanmar
| | - Nay Lin
- Clinical Laboratory, Microbiology Section, Pyinmana General Hospital, Pyinmana Township, Nay Pyi Taw, Myanmar
| | - Khin Nyo Thein
- Pediatric Ward 1, Yankin Children Hospital, Yangon, Yangon Region, Myanmar
| | - Irina Chon
- Division of International Health, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Niigata, Japan
| | - Takashi Odagiri
- Department of Microbiology, Infectious diseases and Immunology, Iwate Medical University, Morioka, Iwate, Japan
| | - Win Thein
- National Health Laboratory, Department of Medical Services, Ministry of Health and Sports, Yangon, Yangon Region, Myanmar
| | - Latt Latt Kyaw
- National Health Laboratory, Department of Medical Services, Ministry of Health and Sports, Yangon, Yangon Region, Myanmar
| | - Ommar Swe Tin
- National Health Laboratory, Department of Medical Services, Ministry of Health and Sports, Yangon, Yangon Region, Myanmar
| | - Akihiko Saitoh
- Department of Pediatrics, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Niigata, Japan
| | - Tsutomu Tamura
- Division of Virology, Niigata Prefectural Institute of Public Health and Environmental Sciences, Niigata, Niigata, Japan
| | - Chika Hirokawa
- Division of Virology, Niigata Prefectural Institute of Public Health and Environmental Sciences, Niigata, Niigata, Japan
| | - Yuko Uchida
- Division of Transboundary Animal Disease, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Takehiko Saito
- Division of Transboundary Animal Disease, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Shinji Watanabe
- Laboratory of Influenza Virus Surveillance, Influenza Research Center, National Institute of Infectious Diseases, Sinjuku-ku, Tokyo, Japan
| | - Takato Odagiri
- Laboratory of Influenza Virus Surveillance, Influenza Research Center, National Institute of Infectious Diseases, Sinjuku-ku, Tokyo, Japan
| | - Kazuhiro Kamata
- Infectious Diseases Research Center of Niigata University in Myanmar (IDRC), Yangon, Yangon Region, Myanmar.,Institute of Medicine and Dentistry, Niigata University, Niigata, Japan
| | - Hidekazu Osada
- Infectious Diseases Research Center of Niigata University in Myanmar (IDRC), Yangon, Yangon Region, Myanmar.,Institute of Medicine and Dentistry, Niigata University, Niigata, Japan
| | - Clyde Dapat
- Department of Virology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Hisami Watanabe
- Infectious Diseases Research Center of Niigata University in Myanmar (IDRC), Yangon, Yangon Region, Myanmar.,Institute of Medicine and Dentistry, Niigata University, Niigata, Japan
| | - Htay Htay Tin
- National Health Laboratory, Department of Medical Services, Ministry of Health and Sports, Yangon, Yangon Region, Myanmar
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5
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Nagai E, Iwai M, Koketsu R, Okuno Y, Suzuki Y, Morimoto R, Sumitani H, Ohshima A, Enomoto T, Isegawa Y. Anti-Influenza Virus Activity of Adlay Tea Components. PLANT FOODS FOR HUMAN NUTRITION (DORDRECHT, NETHERLANDS) 2019; 74:538-543. [PMID: 31728799 DOI: 10.1007/s11130-019-00773-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Our previous study showed anti-influenza virus activity in adlay tea prepared from adlay seeds, naked barley seeds, soybean, and cassia seeds. In this study, we evaluated the anti-influenza virus activity of each component of this tea and analyzed their active ingredients. Each component was roasted and extracted in hot water; the extracts were tested for antiviral activity and their mechanisms of action were studied. All the tea components showed antiviral activity against the H1N1 and H3N2 influenza subtypes and against influenza B. The viral stages inhibited by the components were virus adsorption and replication in proliferative process, suggesting that the action mechanisms of the components might differ from those of oseltamivir acid. Of the tea components, soybean showed the strongest activity. Therefore, we analyzed its active ingredients by liquid chromatography quadruple time-of-flight mass spectrometry (LC/qTOF-MS) and daidzein and glycitein were detected as active ingredients. Here, anti-influenza virus action of glycitein was the first report.
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Affiliation(s)
- Emiko Nagai
- Department of Food Science, Ishikawa Prefectural University, Nonoichi, Ishikawa, 921-8836, Japan
| | - Miwa Iwai
- Department of Food Sciences and Nutrition, Mukogawa Women's University, Ikebiraki, Nishinomiya, Hyogo, 663-8558, Japan
| | - Ritsuko Koketsu
- Research Foundation for Microbial Diseases of Osaka University, Osaka University, Suita, Osaka, 565-0871, Japan
| | | | - Yuri Suzuki
- Department of Food Sciences and Nutrition, Mukogawa Women's University, Ikebiraki, Nishinomiya, Hyogo, 663-8558, Japan
| | - Ryosuke Morimoto
- Department of Food Sciences and Nutrition, Mukogawa Women's University, Ikebiraki, Nishinomiya, Hyogo, 663-8558, Japan
| | - Hidenobu Sumitani
- Toyo Institute of Food Technology, Kawanishi, Hyogo, 666-0026, Japan
| | - Atsushi Ohshima
- Genomics Program, Nagahamabio Institute of Bio-Science and Technology, Nagahama, Shiga, 526-0829, Japan
| | - Toshiki Enomoto
- Department of Food Science, Ishikawa Prefectural University, Nonoichi, Ishikawa, 921-8836, Japan
| | - Yuji Isegawa
- Department of Food Sciences and Nutrition, Mukogawa Women's University, Ikebiraki, Nishinomiya, Hyogo, 663-8558, Japan.
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Mawatari M, Saito R, Hibino A, Kondo H, Yagami R, Odagiri T, Tanabe I, Shobugawa Y. Effectiveness of four types of neuraminidase inhibitors approved in Japan for the treatment of influenza. PLoS One 2019; 14:e0224683. [PMID: 31697721 PMCID: PMC6837752 DOI: 10.1371/journal.pone.0224683] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 10/18/2019] [Indexed: 11/19/2022] Open
Abstract
Background Neuraminidase inhibitors (NAIs) effectively treat influenza. The clinical effectiveness of four NAIs (oseltamivir, zanamivir, laninamivir, and peramivir) was evaluated against influenza A/H1N1pdm09, A/H3N2, and B viruses. Additionally, fever duration in patients infected with oseltamivir-resistant influenza A/H1N1pdm09 with the H275Y mutation was evaluated. Methods Patients aged <20 years who visited outpatient clinics in Japan with influenza-like illnesses were enrolled during 4 influenza seasons from 2012/2013 to 2015/2016. After obtaining informed consent, patients who tested positive for influenza with rapid tests received one of the four NAIs. Patients recorded their body temperature daily for 8 days from the first visit. The influenza strain was identified using real-time polymerase chain reaction. Univariate and multivariable analyses were used to evaluate factors influencing fever duration. In children aged ≤5 years treated with oseltamivir, fever duration in oseltamivir-resistant A/H1N1pdm09-infected patients was compared to that in oseltamivir-sensitive A/H1N1pdm09-infected patients. Results Of the 1,368 patients analyzed, 297 (21.7%), 683 (49.9%), and 388 (28.4%) were infected with influenza A/H1N1pdm09, A/H3N2, and B, respectively. In multivariable analysis factors associated with significantly prolonged fever duration included: treatment with laninamivir (hazard ratio [HR]: 0.78, p = 0.006, compared to oseltamivir), influenza B (HR: 0.58, p<0.001, compared to influenza A/H1N1pdm09), and a higher body temperature at the clinic visit (HR: 0.87 per degree Celsius, p<0.001). Increasing age was associated with a significantly shorter duration of fever (HR: 1.31 for 6–9 years old, p<0.001; and HR: 1.65 for 10–19 years old, p<0.001, respectively, compared to 0–5 years old). Following treatment with oseltamivir, fever duration was significantly longer for oseltamivir-resistant A/H1N1pdm09-infected patients (n = 5) than for oseltamivir-sensitive A/H1N1pdm09 infected patients (n = 111) (mean, 89 versus 40 hours, p<0.001). Conclusions Our results revealed characteristic information on the effectiveness of the four NAIs and also on oseltamivir-resistant viruses that may affect patients’ clinical care.
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Affiliation(s)
- Momoko Mawatari
- Division of International Health (Public Health), Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
- * E-mail:
| | - Reiko Saito
- Division of International Health (Public Health), Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Akinobu Hibino
- Division of International Health (Public Health), Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Hiroki Kondo
- Division of International Health (Public Health), Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Ren Yagami
- Division of International Health (Public Health), Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Takashi Odagiri
- Division of International Health (Public Health), Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
- Division of Infectious Diseases and Immunology, Department of Microbiology, School of Medicine, Iwate Medical University, Iwate, Japan
| | - Ikumi Tanabe
- Division of International Health (Public Health), Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Yugo Shobugawa
- Division of International Health (Public Health), Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
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Njifon HLM, Monamele CG, Vernet MA, Njankouo MR, Deweerdt L, Nono R, Kenmoe S, Mbacham W, Njouom R. Genetic diversity of influenza A(H3N2) viruses in Northern Cameroon during the 2014-2016 influenza seasons. J Med Virol 2019; 91:1400-1407. [PMID: 30866072 DOI: 10.1002/jmv.25456] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/05/2019] [Accepted: 02/06/2019] [Indexed: 12/11/2022]
Abstract
In Cameroon, genome characterization of influenza virus has been performed only in the Southern regions meanwhile genetic diversity of this virus varies with respect to locality. The Northern region characterized by a Sudan tropical climate might have distinct genetic characterization. This study aimed to better understand the genetic diversity of influenza A(H3N2) viruses circulating in Northern Cameroon. Sequences of three gene segments (hemagglutinin (HA), neuraminidase (NA) and matrix (M) genes) were obtained from 16 A(H3N2) virus strains collected during the 2014 to 2016 influenza seasons in Garoua. The HA gene segments were analysed with respect to reference strains while the NA and M gene was analysed for reported genetic markers of resistance to antivirals. Analysis of the HA sequences revealed that majority of the virus strains grouped together with the 2016-2017 vaccine strain (3C.2a-A/Hong Kong/4801/2014) while 3/5 (60%) of the 2015 viral strains grouped together with the 2015-2016 vaccine strain 3C.3a-A/Switzerland/9715293/2013. Within clade 3C.2a, Northern Cameroon sequences mostly grouped in sub-clade A3 (10/16). Analysis of the coding regions of the NA and M genes showed that none had genetic markers of resistance to neuraminidase inhibitors but all strains possessed the S31N substitution of resistance to amantadine. Due to some discrepancies observed in this region with respect to the Southern regions of Cameroon, there is necessity of including all regions within a country in the sentinel surveillance of influenza. These data will enable to track changes in influenza viruses in Cameroon.
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Affiliation(s)
- Hermann Landry Munshili Njifon
- National Influenza Centre, Centre Pasteur of Cameroon, Yaoundé, Cameroon, PO Box 1274, Yaoundé, Cameroon.,Centre Pasteur of Cameroon, Annex of Garoua, PO Box 921, Garoua, Cameroon.,Faculty of Science, University of Yaoundé 1, P.O Box 812, Yaoundé, Cameroon
| | - Chavely Gwladys Monamele
- National Influenza Centre, Centre Pasteur of Cameroon, Yaoundé, Cameroon, PO Box 1274, Yaoundé, Cameroon
| | - Marie-Astrid Vernet
- National Influenza Centre, Centre Pasteur of Cameroon, Yaoundé, Cameroon, PO Box 1274, Yaoundé, Cameroon
| | - Mohamadou Ripa Njankouo
- National Influenza Centre, Centre Pasteur of Cameroon, Yaoundé, Cameroon, PO Box 1274, Yaoundé, Cameroon
| | - Louis Deweerdt
- Centre Pasteur of Cameroon, Annex of Garoua, PO Box 921, Garoua, Cameroon
| | - Raphael Nono
- Centre Pasteur of Cameroon, Annex of Garoua, PO Box 921, Garoua, Cameroon
| | - Sebastien Kenmoe
- National Influenza Centre, Centre Pasteur of Cameroon, Yaoundé, Cameroon, PO Box 1274, Yaoundé, Cameroon
| | - Wilfred Mbacham
- Faculty of Science, University of Yaoundé 1, P.O Box 812, Yaoundé, Cameroon
| | - Richard Njouom
- National Influenza Centre, Centre Pasteur of Cameroon, Yaoundé, Cameroon, PO Box 1274, Yaoundé, Cameroon
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8
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Ceramide Suppresses Influenza A Virus Replication In Vitro. J Virol 2019; 93:JVI.00053-19. [PMID: 30700605 DOI: 10.1128/jvi.00053-19] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 02/06/2023] Open
Abstract
Annual influenza outbreaks are associated with significant morbidity and mortality worldwide despite the availability of seasonal vaccines. Influenza pathogenesis depends on the manipulation of host cell signaling to promote virus replication. Ceramide is a sphingosine-derived lipid that regulates diverse cellular processes. Studies highlighted the differential role of ceramide de novo biosynthesis on the propagation of various viruses. Whether ceramide plays, a role in influenza virus replication is not known. In this study, we assessed the potential interplay between the influenza A (IAV) and ceramide biosynthesis pathways. The accumulation of ceramide in human lung epithelial cells infected with influenza A/H1N1 virus strains was evaluated using thin-layer chromatography and/or confocal microscopy. Virus replication was assessed upon the regulation of the de novo ceramide biosynthesis pathway. A significant increase in ceramide accumulation was observed in cells infected with IAV in a dose- and time-dependent manner. Inoculating the cells with UV-inactivated IAV did not result in ceramide accumulation in the cells, suggesting that the induction of ceramide required an active virus replication. Inhibiting de novo ceramide significantly decreased ceramide accumulation and enhanced virus replication. The addition of exogenous C6-ceramide prior to infection mediated an increase in cellular ceramide levels and significantly attenuated IAV replication and reduced viral titers (≈1 log10 PFU/ml unit). Therefore, our data demonstrate that ceramide accumulation through de novo biosynthesis pathway plays a protective and antiviral role against IAV infection. These findings propose new avenues for development of antiviral molecules and strategies.IMPORTANCE Understanding the effect of sphingolipid metabolism on viral pathogenesis provide important insights into the development of therapeutic strategies against microbial infections. In this study, we demonstrate a critical role of ceramide during influenza A virus infection. We demonstrate that ceramide produced through de novo biosynthesis possess an antiviral role. These observations unlock new opportunities for the development of novel antiviral therapies against influenza.
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Schaffner W, van Buynder P, McNeil S, Osterhaus ADME. Seasonal influenza immunisation: Strategies for older adults. Int J Clin Pract 2018; 72:e13249. [PMID: 30216647 DOI: 10.1111/ijcp.13249] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 07/31/2018] [Indexed: 02/06/2023] Open
Abstract
Adults over the age of 60-65 years suffer disproportionally from seasonal influenza, experiencing high rates of complications, exacerbation of underlying medical comorbidities, and excess mortality. Thus, older adults are an important priority for influenza immunisation campaigns. Unfortunately, older adults generally display lower immune responses to standard influenza vaccines because of immunosenescence, with resulting suboptimal vaccine effectiveness. Thus, the development of improved vaccines that heighten immune responses and improve effectiveness is an important medical need. To this end, enhanced influenza vaccines specifically targeting this age group have been developed, which seek to overcome the inherent limitations in the immune responses of older adults. Both the licensed high-dose trivalent influenza vaccine (hdTIV) containing fourfold higher antigen contents than standard vaccine, and the MF59® -adjuvanted trivalent influenza vaccine (aTIV) have been proven to be safe and well-tolerated while enhancing the immune response. Healthcare providers for populations of older adults should be advised to routinely use these enhanced influenza vaccines in seasonal immunisation campaigns to provide improved immunity against influenza and its consequences in this particularly susceptible age group.
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Affiliation(s)
| | - Paul van Buynder
- School of Medicine, Griffith University, Gold Coast, Qld, Australia
| | - Shelly McNeil
- Canadian Center for Vaccinology, IWK Health Center and Nova Scotia Health Authority, Dalhousie University, Halifax, NS, Canada
| | - Albert D M E Osterhaus
- Research Centre for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Hanover, LS, Germany
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10
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Strand-Specific Dual RNA Sequencing of Bronchial Epithelial Cells Infected with Influenza A/H3N2 Viruses Reveals Splicing of Gene Segment 6 and Novel Host-Virus Interactions. J Virol 2018; 92:JVI.00518-18. [PMID: 29976658 DOI: 10.1128/jvi.00518-18] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 05/24/2018] [Indexed: 02/08/2023] Open
Abstract
Host-influenza virus interplay at the transcript level has been extensively characterized in epithelial cells. Yet, there are no studies that simultaneously characterize human host and influenza A virus (IAV) genomes. We infected human bronchial epithelial BEAS-2B cells with two seasonal IAV/H3N2 strains, Brisbane/10/07 and Perth/16/09 (reference strains for past vaccine seasons) and the well-characterized laboratory strain Udorn/307/72. Strand-specific RNA sequencing (RNA-seq) of the infected BEAS-2B cells allowed for simultaneous analysis of host and viral transcriptomes, in addition to pathogen genomes, to reveal changes in mRNA expression and alternative splicing (AS). In general, patterns of global and immune gene expression induced by the three IAVs were mostly shared. However, AS of host transcripts and small nuclear RNAs differed between the seasonal and laboratory strains. Analysis of viral transcriptomes showed deletions of the polymerase components (defective interfering-like RNAs) within the genome. Surprisingly, we found that the neuraminidase gene undergoes AS and that the splicing event differs between seasonal and laboratory strains. Our findings reveal novel elements of the host-virus interaction and highlight the importance of RNA-seq in identifying molecular changes at the genome level that may contribute to shaping RNA-based innate immunity.IMPORTANCE The use of massively parallel RNA sequencing (RNA-seq) has revealed insights into human and pathogen genomes and their evolution. Dual RNA-seq allows simultaneous dissection of host and pathogen genomes and strand-specific RNA-seq provides information about the polarity of the RNA. This is important in the case of negative-strand RNA viruses like influenza virus, which generate positive (complementary and mRNA) and negative-strand RNAs (genome) that differ in their potential to trigger innate immunity. Here, we characterize interactions between human bronchial epithelial cells and three influenza A/H3N2 strains using strand-specific dual RNA-seq. We focused on this subtype because of its epidemiological importance in causing significant morbidity and mortality during influenza epidemics. We report novel elements that differ between seasonal and laboratory strains highlighting the complexity of the host-virus interplay at the RNA level.
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11
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Hurt A, Komadina N, Deng YM, Kaye M, Sullivan S, Subbarao K, Barr I. Detection of adamantane-sensitive influenza A(H3N2) viruses in Australia, 2017: a cause for hope? ACTA ACUST UNITED AC 2018; 22. [PMID: 29183552 PMCID: PMC5710658 DOI: 10.2807/1560-7917.es.2017.22.47.17-00731] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
For over a decade virtually all A(H3N2) influenza viruses have been resistant to the adamantane class of antivirals. However, during the 2017 influenza season in Australia, 15/461 (3.3%) adamantane-sensitive A(H3N2) viruses encoding serine at residue 31 of the M2 protein were detected, more than the total number identified globally during the last 6 years. A return to wide circulation of adamantane-sensitive A(H3N2) viruses would revive the option of using these drugs for treatment and prophylaxis.
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Affiliation(s)
- Aeron Hurt
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.,WHO Collaborating Centre for Reference and Research on Influenza, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Naomi Komadina
- WHO Collaborating Centre for Reference and Research on Influenza, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Yi-Mo Deng
- WHO Collaborating Centre for Reference and Research on Influenza, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Matthew Kaye
- WHO Collaborating Centre for Reference and Research on Influenza, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Sheena Sullivan
- School of Global and Population Health, The University of Melbourne, Victoria, Australia.,WHO Collaborating Centre for Reference and Research on Influenza, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Kanta Subbarao
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.,WHO Collaborating Centre for Reference and Research on Influenza, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Ian Barr
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.,WHO Collaborating Centre for Reference and Research on Influenza, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
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12
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Hibino A, Massaad E, Kondo H, Saito R, Odagiri T, Takemae N, Tsunekuni R, Saito T, Kyaw Y, Lin N, Myint YY, Tin HH, Le Khanh Hang N, Mai LQ, Yagami R, Shobugawa Y, Lam T, Zaraket H. Neuraminidase inhibitor susceptibility and evolutionary analysis of human influenza B isolates from three Asian countries during 2012-2015. INFECTION GENETICS AND EVOLUTION 2018; 62:27-33. [PMID: 29665435 DOI: 10.1016/j.meegid.2018.04.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 03/26/2018] [Accepted: 04/11/2018] [Indexed: 11/16/2022]
Abstract
Influenza B viruses of both the Yamagata and the Victoria lineages are implicated in a large proportion of the morbidity and mortality associated with influenza outbreaks. In this study, we characterized the full genomes of 53 influenza B viruses isolated during 2012-2015 in three Asian countries: Japan, Myanmar, and Vietnam. Analysis of the hemagglutinin (HA) genes revealed co-circulation of both the Yamagata and Victoria lineages within the same season in these countries. Our analysis revealed, that a large proportion of viruses circulating during 2013-2014 in Japan and Vietnam were mismatched to the vaccine supporting the rationale for using quadrivalent vaccines. Molecular analysis of the neuraminidase (NA) genes did not reveal any of the previously reported substitutions associated with reduced susceptibility to neuraminidase inhibitors (NAIs). However, one isolate from Nagasaki displayed reduced inhibition by NAIs, associated with an NA-M426I substitution (N2-numbering). Phylogenetic analysis of the eight genome segments identified a 6 + 2 reassortant strain belonging to the Victoria lineage that circulated in Japan during the 2013-2014 season. This strain appears to have evolved from a descendent of a B/Brisbane/60/2008-like strain in an intra-lineage reassortment event involving the nucleoprotein (NP) and nonstructural (NS) genes. Therefore, influenza B strains circulating worldwide continue to evolve via complex reassortment events, which contribute to their survival and the emergence of new strains. These findings highlight the need for ongoing genome-wide studies of circulating viruses and assessing the implications of these evolutionary events on the vaccines.
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Affiliation(s)
- Akinobu Hibino
- Division of International Health (Public Health), Graduate School of Medical and Dental Sciences, Niigata University, Japan; Department of Pathology, Immunology, and Microbiology, Faculty of Medicine American University of Beirut, Lebanon
| | - Elie Massaad
- Department of Pathology, Immunology, and Microbiology, Faculty of Medicine American University of Beirut, Lebanon; Center for Infectious Disease Research, Faculty of Medicine American University of Beirut, Beirut, Lebanon
| | - Hiroki Kondo
- Division of International Health (Public Health), Graduate School of Medical and Dental Sciences, Niigata University, Japan
| | - Reiko Saito
- Division of International Health (Public Health), Graduate School of Medical and Dental Sciences, Niigata University, Japan.
| | - Takashi Odagiri
- Division of International Health (Public Health), Graduate School of Medical and Dental Sciences, Niigata University, Japan
| | - Nobuhiro Takemae
- Influenza and Prion Disease Research Center, National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Ibaraki, Japan
| | - Ryota Tsunekuni
- Influenza and Prion Disease Research Center, National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Ibaraki, Japan
| | - Takehiko Saito
- Influenza and Prion Disease Research Center, National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Ibaraki, Japan
| | | | - Yadanar Kyaw
- Respiratory Medicine Department, Sanpya Hospital, Kyaikkasan Pagoda Road, Yangon, Myanmar
| | - Nay Lin
- Clinical Laboratory, Microbiology Section, Pyinmana Township Hospital, Naw Pyi Taw, Myanmar
| | - Yi Yi Myint
- Ministry of Health and Sports, Department traditional Medicine, Naw Pyi Taw, Myanmar
| | - Htay Htay Tin
- Ministry of Health and Sports, Department traditional Medicine, Naw Pyi Taw, Myanmar; National Health Laboratory, Ministry of Health and Sports, Yangon, Myanmar
| | | | - Le Quynh Mai
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam
| | - Ren Yagami
- Center for Infectious Disease Research, Faculty of Medicine American University of Beirut, Beirut, Lebanon
| | - Yugo Shobugawa
- Center for Infectious Disease Research, Faculty of Medicine American University of Beirut, Beirut, Lebanon
| | - Tommy Lam
- School of Public Health, the University of Hong Kong, Hong Kong, China
| | - Hassan Zaraket
- Department of Pathology, Immunology, and Microbiology, Faculty of Medicine American University of Beirut, Lebanon; Center for Infectious Disease Research, Faculty of Medicine American University of Beirut, Beirut, Lebanon.
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13
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Baicalin Downregulates RLRs Signaling Pathway to Control Influenza A Virus Infection and Improve the Prognosis. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2018; 2018:4923062. [PMID: 29681974 PMCID: PMC5846362 DOI: 10.1155/2018/4923062] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 01/23/2018] [Indexed: 12/31/2022]
Abstract
The objective of this study is to investigate the effects of baicalin on controlling the pulmonary infection and improving the prognosis in influenza A virus (IAV) infection. PCR and western blot were used to measure the changes of some key factors in RLRs signaling pathway. MSD electrochemiluminescence was used to measure the expression of pulmonary inflammatory cytokines including IFN-γ, TNF-α, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, and KC/GRO. Flow cytometry was used to detect the proportion of Th1, Th2, Th17, and Treg. The results showed that IAV infection led to low body weight and high viral load and high expression of RIG-I, IRF3, IRF7, and NF-κB mRNA, as well as RIG-I and NF-κB p65 protein. However, baicalin reduced the rate of body weight loss, inhibited virus replication, and downregulated the key factors of the RLRs signaling pathway. Besides, baicalin reduced the high expression inflammatory cytokines in lung and decreased the ratios of Th1/Th2 and Th17/Treg to arouse a brief but not overviolent inflammatory response. Therefore, baicalin activated a balanced host inflammatory response to limit immunopathologic injury, which was helpful to the improvement of clinical and survival outcomes.
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14
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Monamele GC, Vernet MA, Njankouo MR, Victoir K, Akoachere JF, Anong D, Njouom R. Genetic and antigenic characterization of influenza A(H3N2) in Cameroon during the 2014-2016 influenza seasons. PLoS One 2017; 12:e0184411. [PMID: 28877235 PMCID: PMC5587321 DOI: 10.1371/journal.pone.0184411] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/23/2017] [Indexed: 12/25/2022] Open
Abstract
The first outbreak of influenza A(H3N2) occurred in 1968 and caused the third flu pandemic of the 20th century. It has affected multiple countries over time. The best strategy to reduce the burden of influenza is through vaccination whose efficacy varies with respect to the circulating strains. This study was performed to better understand the molecular evolution of influenza A(H3N2) and assess vaccine efficacy in Cameroon. Complete sequences of three gene segments were obtained from 2014 to 2016 influenza seasons in Cameroon. Hemagglutinin (HA), Neuraminidase (NA) and matrix (M) genes of 35 A(H3N2) virus strains were amplified and sequenced. Predicted vaccine efficacy was measured using the Pepitope model. Phylogenetic analysis of the HA gene showed that all Cameroonian strains had evolved away from the 3C.1-A/Texas/50/2012-like clade. Globally, 2014 virus strains clustered with the 2015–2016 vaccine strain, 3C.3a-A/Switzerland/9715293/2013, whereas 2015 and 2016 virus strains clustered with the 2016–2017 vaccine strain, 3C.2a-A/HongKong/4801/2014. In order to determine the genotypic drug susceptibility to neuraminidase inhibitors and amantadine, the NA and M2 protein coding sequences were analyzed. There was no strain with characteristic mutation for resistance to neuraminidase inhibitors, per contra; all strains possessed the substitution S31N, peculiar of resistance to adamantanes. There was drift in influenza A(H3N2) dominant epitopes B (2014 and 2015) to epitopes A (2016) with a theoretical efficiency in vaccine ranging from low to moderate. The presence of several antigenic site mutations among H3N2 virus strains between 2014–2016 influenza seasons in Cameroon confirms the progressing evolution of circulating H3N2 strains.
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Affiliation(s)
- Gwladys C. Monamele
- National Influenza Centre, Centre Pasteur du Cameroun, Yaoundé, Cameroon
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
| | | | | | - Kathleen Victoir
- International Director, Institut Pasteur de Paris, Paris, France
| | | | - Damian Anong
- Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
| | - Richard Njouom
- National Influenza Centre, Centre Pasteur du Cameroun, Yaoundé, Cameroon
- * E-mail:
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15
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Molecular characterization of neuraminidase genes of influenza A(H3N2) viruses circulating in Southwest India from 2009 to 2013. Arch Virol 2017; 162:1887-1902. [DOI: 10.1007/s00705-017-3306-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 02/15/2017] [Indexed: 12/22/2022]
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16
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Zaraket H, Saito R. Japanese Surveillance Systems and Treatment for Influenza. CURRENT TREATMENT OPTIONS IN INFECTIOUS DISEASES 2016; 8:311-328. [PMID: 28035195 PMCID: PMC5155020 DOI: 10.1007/s40506-016-0085-5] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Influenza management and surveillance programs in Japan possess several unique features. The national influenza surveillance is affiliated with National Epidemiological Surveillance for Infectious Diseases (NESID) and features sentinel outpatient surveillance, virological surveillance, and reports on hospitalization, mortality, and influenza-associated encephalopathy. Of note, information on the number of student absences and class/grade/school closures due to influenza are also reported to the government and made publically available. A private online influenza surveillance portal by volunteer doctors provides a real-time information source for the Japanese clinicians and the general public. For influenza treatment, three classes of drugs are approved and covered by national medical insurance in Japan: M2 inhibitors, neuraminidase inhibitors (NAIs), and a polymerase inhibitor. Four NAIs, oseltamivir, zanamivir, laninamivir, and peramivir, are licensed in Japan and are prescribed to seven to eight million patients annually. NAIs are prescribed to any influenza outpatient rather than being limited to severe cases. The majority (80-95 %) of patients start the treatment within 48 h of onset. Laninamivir and peramivir were used almost solely in Japan, until the approval of the latter drug by the FDA. Observational studies showed that the two drugs have equal effectiveness as oseltamivir and zanamivir. The Japanese approach to influenza surveillance and management has facilitated bringing new influenza antivirals to the markets and has driven innovative research in this field. New classes of antivirals, including polymerase inhibitors and cap-dependent endonuclease inhibitor, provide novel tools for treatment of influenza in Japan and the rest of the world.
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Affiliation(s)
- Hassan Zaraket
- Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Center for Infectious Diseases Research, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Reiko Saito
- Division of International Health, Graduate School of Medical and Dental Sciences, Niigata University, 1-757, Asahimachi-dori, Chuo-ku, Niigata City, Niigata Prefecture 951-8510 Japan
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