Foot-and Mouth Disease Ecological Studies In Endemic Settings: Ongoing Studies in Vietnam and Pakistan

Transcription

1 Foot-and Mouth Disease Ecological Studies In Endemic Settings: Ongoing Studies in Vietnam and Pakistan Luis Rodriguez (Jonathan Arzt) Research leader, USDA-ARS Plum Island 1

2 PAKISTAN CHARACTERIZATION OF LOCAL ISOLATES OF FMDV AND DEVELOPMENT OF VECTOR BASED VACCINES F; S 9/1/2007-8/31/2012 REAL TIME DATA ANALYSIS AND RESEARCH CAPACITY BUILDING TOWARDS FMD CONTROL IN PAKISTAN S 09/27/ /27/2014 Dr. Khalid Naeem NARC Dr. Umer Farooq NARC Dr. Muhammadimam Afzal, FAO Dr. Manzoor Hussain, NVL Dr. Zaheer Ahmed Dr. Anna Ludi

3 Study Design Acute Clinical Samples Clinical case reports, geographic location, demographics, etc Clinical samples, viruses, sequence Longitudinal Field Study Population: buffalo premises all located near Islamabad Serological survey of 40 farms for NSP positive animals, probang, history Selection of 29 farms (300 buffalo) for sampling (serum and probang) 4X year for 1 year NSP-ELISA, RT-PCR and virus isolation Establish panel of reference sera for in country vaccine evaluation Vaccination of 10 cattle and 10 buffalo with commercial vaccine to be used in field Serum collection at 0, 21 dpv, boost vaccination Serum collection at 42 dpv Carry out vaccine matching studies

4 Significant amino acid and nucleotide variation, wide spatial distribution of genetic lineages, no with differences in host species, all consistent with frequent multispecies infection of this serotype O FMDV in a highly mobile population

5

6 Obtained multiple viral strains from persistent buffalo opportunity to look mechanism of strain emergence 8 /22 Animals 2 viruses of same serotype isolated at different sampling time points from same animal [8x2=16 viruses] ASIA 1 = 14 O = 2 TOTAL = 16 22/51 Animals VI positive 2 or more times, yielding 47 virus isolates 3/22 Animals 3 viruses of same serotype isolated from each Id at different sampling time points [3x3=9 viruses isolated] 9/22 Animals 2 viruses of 2 different serotypes isolated from each animal at different sampling time points [9x2=18 viruses isolated] ASIA 1 = 9 TOTAL = 9 ASIA 1/A 8X2=16 ASIA 1/O 1X2=2 TOTAL =18 1/22 Animal (3 viruses of 2 different serotypes isolated from each Id at different sampling time points) [1x3=3 viruses isolated] ASIA 1/A =3

7 Phylogeny of Carrier vs Clinical Serotype A Viruses Green: Carrier viruses Red: Clinical local Blue: Clinical non-local Found close relationship between persistent and acute lineages suggesting transmission Directionality of transmission not yet determined

8 ME-SA PanAsia PanAsia 2 Vaccine Evaluation Serotype O FMDV Pak-O 2010, 2012, 2012 SGD/PAK/19/2011 JX KHI/PAK/42/2011 JX ISR/7/2007 AJ OKAB/AFG/L2826/2009 HQ MAY/2/2004 HQ MAY/2/2006 HQ PAK/39/2008 GU PAK/63/2007 FJ BAG/AFG/L1494/2009 HQ MAY/11/2009 HQ PAK/1/2008 FJ PAK/29/2008 GU CAM/1/2008 HQ VIT/124/2010 VIT/169/2010 VIT/17/2005 HQ VIT/7/2002 HQ UKG/3802/2001 DQ164982*** SKR/1/2002 DQ VIT/3/2005 HQ SEA CAM TUR/2/2001 DQ Ankara/TUR/377/10/02 DQ TUR/4/2005 FJ TUR/2/2000 DQ PAK/18/2002 DQ IRN/20/2004 DQ Mersin/TUR/13/01/04 DQ IND/53/73_AF O1 Manisa iso87 AY Vaccine Virus representative India/R2/75 AF CAM/3/98 AJ Phylogeny Reconstruction Statistical Method Maximum Likelihood Test of Phylogeny Bootstrap method (500 replicates) Substitutions Type Nucleotide Model/Method General Time Reversible model Rates among Sites Gamma distributed with Invariant sites (G+I) No of Discrete Gamma Categories - 5 ML Heuristic Method Nearest-Neighbor-Interchange (NNI) Initial Tree for ML Make initial tree automatically No. of Seqs : 33 No. of Sites : 623 *** - reference strain

9 O/ISB/255/12 O/FSD/266/12 O/JGH/6/12 O/KHI/41/11 Serotype O Vaccine Matching against O1 Manisa BT neut. r1-value BT neut. r1-value BT neut. r1-value BT neut. r1-value * All values given in log 10 Conclusion: r1-values are above 0.3 suggesting the vaccine is protective against the serotype O viruses tested.

10 Vaccine Evaluation Serotype A FMDV PAK/CHK/11/2012* PAK/KCH/15/2012* PUN/PAK/L1354/2009_HQ PAK/76/2009_GU SIN/PAK/L694/2009_HQ SAR/AFG/L1435/2009_HQ IRN/5/2008_FJ TUR/1/2008_FJ IRN/1/2005_EF208769*** vaccine virus representative PAK/1/2006_FJ PAK/ICT/2/2008* PAK/ICT/1/2008 PAK/ICT/3/2008 PAK/KCH/5/2009* PAK/KCH/6/2009 PAK/KCH/7/2009 AFG/131/2004_EF IRN/41/2003_FJ PUN/PAK/L1364/2009_HQ IRN/22/99_EF208772*** IRN/2/87_EF208770*** A22 Iraq64 iso86_aj251474*** vaccine virus representative IRN/1/96_EF208771*** IRN/5/2003_FJ Phylogeny Reconstruction Statistical Method Maximum Likelihood Test of Phylogeny Bootstrap method (500 rep) Substitutions Type Nucleotide Model/Method General Time Reversible model Rates among Sites Gamma distributed with Invariant sites (G+I) No of Discrete Gamma Categories - 5 ML Heuristic Method Nearest-Neighbor-Interchange (NNI) Initial Tree for ML Make initial tree automatically No. of Seqs : 24 No. of Sites : 623 *** Ref Strains * used for vaccine matching

11 A/ICT/2/2008 A/KCH/5/2009 A/CHK/11/2012 A/KCH/15/12 Serotype A Vaccine Matching against A-IRN05 and A22 IRQ BT neut. r1 A22 R1 IRN BT neut. r1 A22 r1 IRN BT neut BT neut F 1F < < < < <1.2 Conclusion: * All values given in log 10 VN titers above 1.6 observed for isolates VN titers below 1.2 for 2012 isolates, suggesting that the vaccine is not a good match to these strains.

12 VIETNAM MOLECULAR EPIDEMIOLOGY, SURVEILLANCE AND PREDICTIVE TOOLS FOR FMD CONTROL IN VIETNAM F, S 6/1/2010-9/30/2012 Collaborators: Dr. Jonathan Arzt Dr. Helena Ferreira Dr. Thanh Long Ngo, DAH, HCMC Dr. Ho Huu Dung, DAH, Hanoi Dr. Carla Huston, Mississippi State University

13 Objectives 1- Molecular epidemiology of FMDV in local livestock including cattle, buffaloes and pigs 2- To better understand the transmission mechanism of persistently infected to susceptible livestock in natural setting 3- Enhance strategies for identification of persistently infected animals using new technology

14 Design Objective 1 Acute Clinical Samples Samples collected during outbreak Pigs, buffalo and cattle Northern and Southern Vietnam Objective 2 Longitudinal Field Study HCMC region tranmsission cells (9 farms) Hanoi-SonLa region carrier cattle and buffalo (field necropsy) Objective 3 Persistent buffalo studies Field necropsies Molecular characterization (tissue level, cytokine mrna, protein expression)

15 Objective 1. Phylogenetics of novel strains of FMDV Multiple lineages in multiple species no species specific lineages Novel strains (bold) found in this study

16 Objective 2. Ecology of FMDV carriers Two Provinces identified with history of FMD outbreaks in cattle, buffalo SonLa (north) Jan 2011 LongAn (south) Feb Established study sites: Targeted surveillance study Buffalo necropsy study / cattle transmission study

17 Targeted surveillance study Risk of being FMDV infected and/or FMDV carrier: Buffalo - highest risk of being FMDV-infected, intermediate carrier risk Dairy cattle lower risk of being FMDV-infected (OR=0.2), lowest carrier risk (OR=0.2) Beef cattle - lowest risk of being FMDV-infected (OR=0.4), highest carrier risk (OR=4.9) Carrier infected : 3ABC+ and Probang +; Ever inf.: 3ABC+; Never inf. : 3ABC neg

18 Objective 3. Transmission Study From Carrier Cattle to Sentinel Cattle Study site in southern Vietnam no clinical activity >1yr Individual small premises - pastures, surrounding premises vaccinated bi-annually 9 farms 2 donor carrier buffalo or cattle (NSP +, Probang +) housed in direct contact with 2 naïve cattle (NSP -, Probang -) Direct contact - one year study serum and probang every 2-3 months Probang samples from naïve cattle all tested NEGATIVE for FMDV by rrt-pcr, VI Serum from naïve animals all tested for negative NSP -

19 Preliminary Results All donors shed virus intermittently throughout the exposure time None of the naïve cattle developed antibodies (NSP) Naïve cattle remained probang negative until the end of the study Multiple viral sequences were obtained from persistent animals

20 Thank you! SUPPORT: 20