Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Elsayed Elsayed Wagih wikipedia , lookup
Taura syndrome wikipedia , lookup
Hepatitis B wikipedia , lookup
Orthohantavirus wikipedia , lookup
Canine distemper wikipedia , lookup
Marburg virus disease wikipedia , lookup
Canine parvovirus wikipedia , lookup
Henipavirus wikipedia , lookup
Swine influenza wikipedia , lookup
Influenza C in Alberta TARRANT Symposium 2012 Kanti Pabbaraju Lab Scientist ProvLab [email protected] Matsuzaki et al., JID, 2006 Tested 84946 patients from 1990 to 2004 170 (0.22%) were positive for FluC Excluded all co-infections Retrospective chart review Studied symptoms and compared hospitalized Vs non-hospitalized patients Clinical features associated with influenza C virus infection. Matsuzaki Y et al. J Infect Dis. 2006;193:1229-1235 © 2006 by the Infectious Diseases Society of America Clinical diagnoses in influenza C virus–infected children. Matsuzaki Y et al. J Infect Dis. 2006;193:1229-1235 © 2006 by the Infectious Diseases Society of America Comparison of clinical features of type C and A influenza virus infections at Katsushima Pediatric Clinic during January–March 2002. Matsuzaki Y et al. J Infect Dis. 2006;193:1229-1235 © 2006 by the Infectious Diseases Society of America Results 92% were less than 6 years old Fever, cough and rhinorrhea were the most common symptoms 29 were hospitalized and 21 of these had LRT such as pneumonia, bronchitis and brochiolitis Rate of hospitalization was significantly higher in <2 year olds In addition A case of acute encephalopathy associated with influenza C has been reported (Takayanagi, 2009). Documented as the etiological cause of several outbreaks in schools and the community (Ramos 2008, Matsuzaki 2007, Matsuzaki 2002, GreenBaum 1998, Katagiri 1987, Katagiri 1983) Thus overall burden of Influenza C infections should not be underestimated Why is FluC under-diagnosed Few reports describing its clinical features Difficulty in isolating it (No suitable cell lines) Amniotic inoculation of embryonated hen's eggs has been employed to isolate the virus from clinical specimens. Attributable to mild pathogenecity Important epidemiological features Antigenically and genetically different strains co-circulate in a community Genetic re-assorting occurs frequently among strains Newly emergent re-assortant viruses become predominant Humans with antibodies to FluC can be repeatedly infected Pigs and dogs have been reported to have antibodies against Influenza C, thus it can cause zoonooses Re-assortants with pig and human FluC genes reported Design of RT-PCR assay Assay Design Real-time PCR assay using labelled probes on the Taqman platform Target the conserved matrix gene Strong pos Weak pos Neg Sensitivity, dynamic range, reproducibility, linearity Limit-of-detection was determined using quantified Influenza C RNA prepared in-vitro Copy number for in-vitro RNA Average Ct SD %CV 4.51E+08 11.52 0.08 0.68 4.51E+07 14.89 0.07 0.44 4.51E+06 18.24 0.05 0.25 4.51E+05 21.67 0.04 0.19 4.51E+04 25.07 0.07 0.28 4.51E+03 28.63 0.07 0.26 4.51E+02 31.91 0.10 0.32 4.51E+01 35.39 0.44 1.24 4.51E+00 39.18 0.89 2.28 Sensitivity, dynamic range, reproducibility, linearity Detection of a range of FluC viral loads - replicates 45 R2 = 0.9998 40 y = -3.4407x + 41.18 R2 = 0.9998 35 30 25 20 15 10 5 0 0.00E+00 1.00E+00 2.00E+00 3.00E+00 4.00E+00 5.00E+00 6.00E+00 Good linearity over a large dynamic range 7.00E+00 8.00E+00 9.00E+00 1.00E+01 Specificity Test high copy number samples of common respiratory pathogens different strains of influenza virus A and B, parainfluenza virus 1, 2, 3, 4A and 4B, RSV A and B, human coronaviruses 229E, NL63, HKU1 and OC43 human bocavirus, coxsackievirus A16 and B6, echovirus 2, human metapneumovirus, rhinovirus type 1B, adenovirus type 4, Legionella pneumophila, Mycoplasma pneumoniae, Bordetella bronchiseptica, B. holmseii, B. parapertussis, B. pertussis, Hemophilus influenzae, Neisseria meningitidis Streptococcus pneumoniae. Population screened From Sept 1, 2010 to April 30, 2011 Children less than 10 years during hospital visits (n=427) Respiratory outbreaks (n=47) Randomly selected to include 55 samples per month Multiple samples from the same patient were excluded All specimens had tested negative for influenza A and B, RSV, human metapneumovirus, parainfluenza types 1 to 4, coronavirus 229E, OC43, NL65 and HKUI, adenovirus, entero/rhinovirus Positive sample types Specimen type Total tested Total positive % positive in specimen type Nasopharyngeal swab 313 7 2.24 Auger suction fluid 67 3 4.48 Nasopharyngeal fluid 45 1 2.22 Throat swab 24 0 0.00 Others 25 0 0.00 Nasopharyngeal swab Nasopharyngeal fluid Others n=45 Positive=1 n=24 Positive=0 Auger suction fluid Throat swab n=25 Positive=0 n=314 Positive=7 n=67 Positive=3 Age distribution 300 # of Samples tested 2.76 3.00 % positve 250 254 2.50 2.41 2.15 200 2.00 150 1.50 100 1.00 93 83 44 50 2 7 2 0.50 0 0 0.00 <1 1 to 5 Age in years 5 to 10 10 to 100 Percent positive Number of samples # of Positives detected Seasonality 80 7.00 Total tested 5.66 6.00 %positive 60 5.00 50 3.77 4.00 40 3.00 30 2.00 1.56 20 1.79 1.00 10 1 1 3 4 2 0 0.00 Sep 10 Oct 10 Nov 10 Dec 10 Jan 11 Month-Year Feb 11 Mar 11 Apr 11 Percent positive Total positives 70 Number of samples 6.25 Monthly isolation of influenza C virus between December 1990 and November 2004. Matsuzaki Y et al. J Infect Dis. 2006;193:1229-1235 © 2006 by the Infectious Diseases Society of America Phylogenetic tree for HE gene Aichi_81 Kansas_79 C/Aichi/1/81 Georgia_69 Johannesburg_66 Aichi_99 93% identity C11VC3502 SaoPaulo82 C/Sao Paulo/378/82 Yamagata93 42 isolates (1947-1993) revealed six lineages co-circulation was detected Paris_67 Taylor_47 C/Taylor/1233/47 M11VC4753 M11VC10161 C11VC2921 C/ Kanagawa/1/76 Catalonia2009 M11VC4941 >98% identity Singapore_2006 C11VC3087 Yamagata_2004 Kanagawa_76 Fukuoka_2004 Yamagata_98 Miyagi_92 England_83 Pig_Beijing_81 Yamagata_88 C/Yamagata/26/81 Yamagata_81 NewJersey_76 Kyoto_79 Sapporo_71 Greece_79 Mississipi_80 C/Mississippi/80 5.8 4 2 Nucleotide Substitutions (x100) 0 Co-circulation of different lineages Leads to re-assortment and epidemics of the new strain Phylogenetic tree for M gene Aichi_81 Kansas_79 Johannesburg_66 Mississippi_80 Greece_79 Taylor_47 Sao Yamagata_93 Kanagawa_76 Kyoto_79 C/Yamagata/26/81NewJersey_76 Yamagata_81 related lineage Yamagata_88 C/Aichi/1/81- or C/Mississippi/80related lineage Pig_Beijing_81 Aichi_99 England_83 M11VC002193 M11VC004941 M11VC010161 C11VC002921 C11VC004753 M10VC021100 C11VC003087 >98% identity Miyagi_92 2.6 C11VC002616 C11VC003502 C11VC004406 C/Aomori/74 2 0 Nucleotide Substitutions (x100) Conclusions Sensitive and specific for the detection of Influenza C Good reproducibility Is linear over a large dynamic range Will facilitate for testing of influenza C viruses in respiratory samples in a high throughput fashion Future work screening of patient samples including children and adults Influenza C in outbreaks of unknown etiology Studying the epidemiology Are FluC infections cyclical or endemic Role of FluC in hemopoeitic dysfunctions Better strain characterization of Influenza C isolates in the community Acknowledgements Dr. Kevin Fonseca Dr. Raymond Tellier Sallene Wong Anita Wong Vinod Khurana and the MOD group