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Avian Influenza in Indonesia: A veterinary problem

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Avian Influenza in Indonesia: A veterinary problem Powered By Docstoc
					Dr Tri Satya Putri Naipospos MPhil PhD
              TOPICS

H5N1 virus in Asia and Indonesia

Improve control of avian influenza in the
country
H5N1 Virus in Asia and
     Indonesia
           Multiple sublineages of
             H5N1 virus in Asia
1.   VTM (Vietnam, Thailand and Malaysia)
2.   GD (Guangdong)
3.   HN (Hunan)
4.   YN (Yunan)
5.   IDN (Indonesia)
Chen H, Smith GJ, Li KS, Wang J, Fan XH, Rayner JM, Vijaykrishna D,
Zhang JX, Zhang LJ, Guo CT, Cheung CL, Xu KM, Duan L, Huang K, Qin K,
Leung YH, Wu WL, Lu HR, Chen Y, Xia NS, Naipospos TSP, Yuen KY,
Hassan SS, Bahri S, Nguyen TD, Webster RG, Peiris JS, Guan Y.
Establishment of multiple sublineages of H5N1 influenza virus in Asia:
implications for pandemic control.
Proc Natl Acad Sci U S A. 2006 Feb 21;103(8):2845-50
     Spread through movement of
     poultry and poultry products
• The establishment of regional virus
  sublineages suggests that H5N1 virus is
  perpetuated in poultry largely through the
  movement of poultry and poultry products
  rather than by continued reintroduction of
  viruses by migrating birds.
• Phylogenetic analysis suggests that the VTM
  sublineage is derived from southern China, but
  systematic surveillance data from this period
  are lacking.
            “Influenza epicenter”
                 hypothesis
• Viruses isolated from some provinces of southern China
  (Guangdong, Guangxi, and Hunan; in the sublineages
  Mixed) are more diverse, containing genotypes Z, V, W,
  and G.
• The precursors of these H5N1 viruses, Gs/GD/1/96, was
  originally detected in southern China in 1996 and because
  H5N1 viruses in this region have the greatest genetic
  diversity, southern China is the most likely source of the
  emergent and reemergent HPAI H5N1 influenza viruses.
• This finding supports the „„influenza epicenter‟‟ hypothesis,
  which argues that southern China is the epicenter from
  which influenza pandemics emerge.
     The spread of H5N1 virus
• H5N1 virus has persisted in its birthplace,
  southern China, for almost 10 yr and has been
  repeatedly introduced into neighboring (e.g.,
  Vietnam) and distant (e.g., Indonesia) regions,
  establishing „„colonies‟‟ of H5N1 virus
  throughout Asia that directly exacerbate the
  pandemic threat.
• The best approach to avert the threat is to
  control H5N1 virus infection at its source,
  domestic poultry.
      Control Effort in Asia
• Experience in Hong Kong, Japan, and South
  Korea has shown that early detection and
  large-scale culling of infected poultry,
  combined with other measures, is effective in
  controlling this HPAI H5N1 influenza.
• Control measures in China, Indonesia,
  Thailand, and Vietnam have been less
  effective, allowing the establishment of virus
  endemicity and repeated interspecies
  transmission to humans.
         Genetic characterization of
               H5N1 viruses
• All 41 viruses isolated in Indonesia (2003-2005) from
  geographically distant sites cluster together, which
  suggests a common introduction.
• Phylogenetic analysis of the viruses isolated within
  each of these countries revealed the emergence of
  groups of H5N1 viruses based on geographical
  regions within Indonesia and Vietnam.
  Smith GJ, Naipospos TSP, Nguyen TD, de Jong MD, Vijaykrishna D,
  Usman TB, Hassan SS, Nguyen TV, Dao TV, Bui NA, Leung YH, Cheung
  CL, Rayner JM, Zhang JX, Zhang LJ, Poon LL, Li KS, Nguyen VC, Hien TT,
  Farrar J, Webster RG, Chen H, Peiris JS, Guan Y.
  Evolution and adaptation of H5N1 influenza virus in avian and human hosts
  in Indonesia and Vietnam.Virology May 17 (2006)
Phylogenetic relationship of the HA gene
of influenza A viruses isolated in Indonesia



                     • Blue text indicates
                       viruses isolated
                       from Java;
                     • Purple text
                       indicates viruses
                       isolated from
                       Sumatra and
                       Bangka Island;
                     • Green text
                       indicates viruses
                       isolated from Bali,
                       Flores, Sulawesi
                       and West Timor.
        Indonesian sublineage,
        three groups of viruses
• Group A includes viruses from central and
  eastern Indonesia with isolates from Java,
  southern Sulawesi and West Timor.
• Group B also contains viruses from central and
  eastern Indonesia but with isolates from Java,
  Bali, Flores Island and West Timor.
• Group C viruses are from central and western
  Indonesia being found throughout Java and
  Sumatra and also in Bangka Island.
     Groups identified in the
phylogenetic analysis are marked
  onto the regions of Indonesia
      Spread of viruses across
          the archipelago
• This virus then probably spread across the
  Indonesian archipelago, possibly along routes of
  trade of poultry and poultry products, and has now
  evolved into regionally based groups within the
  sublineage.
• While Sumatra and West Java share viruses from
  one such group (i.e., group C), all three groups (A,
  B and C) are found in central and eastern Java.
• Java is the hub of the poultry industry in Indonesia
  with approximately 35% of all poultry production
  being in East Java and approximately a further
  25% in other parts of Java.
    Endemicity in Indonesia
• Results of the present study demonstrate that
  H5N1 genotype Z viruses have been endemic
  in poultry populations of Indonesia since 2003.
• Phylogenetic analysis showed that all H5N1
  viruses, tested in this study, from Indonesia
  was derived from a single introduction, likely to
  have come from domestic poultry in southern
  China (Li et al., 2004; WHO, 2005a; Chen et
  al., 2006).
Improve control of avian
 influenza in the country
      Are the nine control measures
            are still effective?
• The nine control strategies is determined at the
  time where there is no human cases yet (early
  January 2004), more emphazised was given to
  vaccination and improving biosecurity.
• All parties realized that nine control strategies
  are still relevant, but there are serious
  problems in implementing its, particularly with
  regards to culling, vaccination sector 3 and 4,
  as well as control movement of poultry and
  poultry products
          Is the vaccination program
       succeeded in decreasing the rate
             of disease in poultry ?
• Vaccination program implemented quite well in
  sector 1, 2 and part of sector 3, which is reducing
  intensity of the disease significantly
• While in part of sector 3 and most of sector 4,
  vaccination program was unsuccessful, due to
  several factors:
  –   Low coverage of poultry population
  –   No „booster‟
  –   Field operational is difficult and time consuming
  –   Low operational cost (no incentive)
  –   Provision of vaccine delayed and insufficient
      Eco-epidemiology aspect
         of the H5N1 virus
• H5N1 virus is still circulating in the poultry
  husbandry environment and has opportunities to
  spread through various media (fertilizer/manure,
  pen, flies, water, and sewage)
• H5N1 virus enter and live in asymptomatic duck
  as a reservoir
• H5N1 virus enter other intermediate hosts such
  as pig, cat, and other mammalians
   Control disease at source
    has to be a high priority

  Elimination of the virus at source is
           critically important

   Veterinary issues should receive a
higher priority in the effort of combating
      the avian influenza outbreak
      Stop rapidly and effectively
       transmission chain from
           poultry to human
• The only effective way to eliminate the virus is
  through culling sick and in-contact chicken by
  actively applying the principle of 3 E (early
  detection, early reporting and early response).
• Within the next six months, implement
  depopulation program by doing more
  preemptive culling systematically and
  continuously to reduce the poultry population,
  particularly sector 4.
        Networking with private
               sectors
• Develop a networking of field personnel who are
  capable to implement the principle of 3 E by
  optimizing various parties of non governmental
  sectors such as:
   – Technical based: private veterinarians in the
     poultry industry, poultry veterinarians
     association, and veterinary paramedics.
   – Community-based: IRC volunteers, community
     animal health workers who are trained in
     applying culling procedure and vaccination.
    What have to be prepared by
         the government?
• Legislative backup and enforcement
• Term and clear definition of “pre-emptive
  culling‟ or „stamping out” in new area
• SOPs (outbreak, diagnosis, etc)
• Compensation cost
• Good quality vaccine
• Grass root surveillance
• Public awareness
                  Conclusions
1. Government has a strong “political will” to reduce
   number of poultry as the only source of infection for
   human by actively and intensively implement measures
   as follows :
    1.1. A combination of preemptive culling and ring
         vaccination in infected areas whenever clinical
         cases erupted in all sectors within the next six
         months with a proper compensation scheme.
    1.2. Public awareness program using socio-cultural
         approach :
         a. How is the best approach to cull/stamp out
         b. Hygienic practices in live bird and wet market
          c. Restructuring poultry sectors plan.
                       Conclusions
2. Government has to conduct more research in various
   fields to deal with the following unanswered questions:
   2.1. Has the avian virus mutate or reassort?
   2.2. Has the virus been transmitted to pigs, the
        hypothetical intermediate host?
   2.3. Is there a role of wild migrating aquatic birds in the
        spread of H5N1 virus?
   2.4. What is the role of life birds and wet markets in the
        spread of H5N1 virus?
   2.5. What is the role of cats?
Thank you for your
    attention

				
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posted:7/3/2010
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