Implementacija programa za veterinarsku biosigurnost u akvakulturi u skladu sa međunarodnim standardima i nacionalnom regulativom

Progresivno povećanje rizika od izbijanja, kao i sve veći uticaj zaraznih bolesti na proizvodnju u akvakulturi širom sveta je u poslednjih 10 godina pokrenulo rasprave velikog broja učesnika na mnogobrojnim konferencijama, simpozijumima i radionicama o tome kakve procedure treba ugraditi u biosigurnosne planove i programe. Ključni zadatak se sastojao u određivanju koji bi proceduralni elementi bili u saglasnosti sa međunarodnim standardima, npr. procesima i procedurama opisanim u Kodu i Priručniku OIE (Svetske Organizacije za Životinjsko Zdravlje) kao i u nacionalnim propisima. U pokušaju da se nađe ravnoteža između regulatornih zahteva i praktičnih pristupa koji bi bili korisni i upotrebljivi za sve zainteresovane strane (od proizvođača do državnih organa) identifikovani su sledeći prioriteti: Svaki biosigurnosni program treba da bude a) praktičan i ekonomičan; b) fokusiran na infektivne i zarazne bolesti; c) uključuje procedure preventive, kontole i eradikacije bolesti u tačno određenim epizootiološkim jedinicama d) baziran na naučno potvrđenim i opravdanim veterinarskim procedurama; e) ugradi međunarodno priznate standarde iz OIE Koda i Priručnika; i, f) zasnovan na javno-privatnom partnerstvu i saradnji između proizvođača, veterinara i paraveterinarskih službi, i državnih organa. Sa fokusom na gore navedene prioritetne principe, Međunarodni Konzorcijum za Veterinarsku Biosigurnost u Akvakulturi (IAVBC) je testirao procedure iz Slike 1, sa učesnicima nekoliko konferencija i radionica u više zemalja (Norveška, Južna Afrika, Čile, itd.), u pokušaju da se definiše sveobuhvatni pristup razvoja, primene, provere i sertifikacije efektivnih programa biosigurnosti u akvakulturi. Osnova za biosigurnosni program je pravilno definisanje epizootiološke jedinice (Epi-jedinica), geografski određene populacije životinja na kojoj su primenljivi svi koraci i/ili procesi predviđeni u biosigurnosnom planu. Epi-jedinica može na primer biti jedan ribnjak, ili više ribnjaka u jednom odeljku (OIE “kompartmentu”) koji se nalaze na različitim lokacijama ali pod jedinstvenom upravom; ali može takođe biti i zona (region u okviru države), ili čak cela država. Svaka Epi-jedinica je donekle odvojena od ostalih populacija, na taj način olakšavajući kontrolu nad širenjem zaraze, međutim unutar Epi-jedinice širenje zaraznih bolesti među populacijom se odvija relativno lako. Sledeći princip od velike važnosti je da sve procedure primenjlive na odabranu Epi-jedinicu moraju biti osmišljene unapred i dobro dokumentovane. Ovaj princip zahteva a priori evaluaciju Epi-jedinice zajedno sa napisanim biosigurnosnim planom koji opisuje sve korake i procedure koje će biti uvedene na Epi-jedinici (ribnjaku), kao i dokumentaciju o svim procedurama koje su već primenjene (npr. zapisnici o primenjenim biosigurnosnim merama). Uz periodične terenske evaluacije biosigurnosnih aktivnosti i pregleda ribljih populacija u okviru Epi-jedinice, napisani planovi i dokumentacija o primenjenim procedurama postaju fokus za audite i sertifikacije. Takođe je važno napomenuti da je biosigurnosni plan specifičan za individualnu Epi-jedinicu.Upotrebljivost i opravdanost predloženih biosigurnosnh koraka i procedura se zasniva na sledećim formalnim procesima: analiza rizika i hazarda (identifikacija i prioritizacija hazarda, procena rizika, upravljanje i ublažavanje rizika, i komunikacija rizika); analiza i korekcija kritičnih kontrolnih tačaka (uključujući procenu i planove za korekciju aktivnosti u toku kojih zarazna bolest može ući ili izaći iz Epi-jedinice); epidemiološka analiza (uključujući neophodnu dijagnostiku, praćenje epizootiološke situacije na terenu, i utvrđivanje epizotiološkog statusa zaraznih bolesti u Epi-jedinici); priprema za slučaj nesreće (priprema protokola o hitnoj kontroli i eradikaciji bolesti u slučaju izbijanja zaraze); kao i formalne procedure pregleda/audita i sertifikacije Epi-jedinice u cilju dobijanja statusa “slobodno od bolesti” koji može pomoći prilikom npr izvoza ribe u EU. Plan ove prezentacije je da predstavi i ukratko opiše važnost svake procedure, kao i načine na koji se one mogu uklopiti u jedinstven biosigurnosni program (Slika 1.). Ovaj pregled će biti od naročite koristi privatnim ili državnim veterinarima, kao i državnim službenicima odgovornim za pomoć proizvođačima koji razvijaju biosigurnosne programe na pojedinačnim ribnjacima ili većim Epi-jedinicama kao što su kompletna ribarska gazdinstva.Facing progressively increasing risks and impacts of disease on aquaculture productions in all countries, over more than a decade at numerous conferences, symposia and workshops, a large number of individuals have discussed and debated what procedure that should be incorporated into biosecurity programs. A key feature has been determining which procedures will meet International Standards (i.e. processes and procedures in OIE Codes and Manuals) and National regulations. In balancing these requirements with practical approaches that aquaculture producers can implement, and are effective and useful for all stakeholders around the world (from producers to governmental regulators), the following were recognized as priorities for all biosecurity programs: a) Be practical and economic; b) Focus only on infectious and contagious diseases; c) Include procedures that address disease prevention, control and eradication in definable epidemiological units; d) Be based on well established, sound scientific justifiable veterinary procedures; e) Incorporate internationally accepted standards in the OIE Code and Manual; and, f) Involve public-private partnerships and collaboration between producers, aquatic veterinarians and paraveterinary professionals, and governmental regulators. In focusing on these principles, the International Aquatic Veterinary Biosecurity Consortium (IAVBC) has tested the procedures in Figure 1, with stakeholders at several conferences and workshops in Norway, South Africa, Chile, and elsewhere, that involve an integrated approach for developing, implementing, auditing and certifying effective aquaculture biosecurity program. At the core of a biosecurity program is defining an epidemiologic unit (EpiUnit), a well-defined geographical population of animals, on which all biosecurity steps or processes will be implemented. An EpiUnit might be an establishment (farm), a compartment (different locations that are all managed as an integrated operation, usually under one ownership), a zone (typically a region of a country), or a whole country. To some degree, each EpiUnit population is separated from other populations, allowing control over the spread of disease. However, within the EpiUnit, infectious and contagious diseases transmission between individuals is relatively easy. A second important principle is that all procedures implemented for a selected EpiUnit must be thought out ahead of time, and well documented. This requires both an a priori evaluation of the EpiUnit, and a written biosecurity plan that addresses all steps and processes to be implemented in the EpiUnit, and documentation of all procedures that are implemented over time (i.e. a biosecurity implementation record). Along with periodic onsite evaluation of operations and animals on the EpiUnit, the written plan and the documentation of implemented procedures become the focus for auditing and certification. Every biosecurity plan will be specific for an individual EpiUnit. To be effective and justifiable the processes and procedures need to involve several formal processes, including: hazard and risk analysis (hazard identification and prioritization, risk assessment/evaluation, risk management/mitigation and risk communication); analysis and remediation of critical control points (including evaluation and mitigation plans for correcting practices where disease could enter or leave the epidemiological unit); epidemiological principles (including necessary diagnostics, surveillance, monitoring and determining the status or freedom of diseases in the epidemiological unit); emergency preparedness (contingency protocols for disease control and eradication); and, auditing of procedures and records, and certification (providing assurance of disease freedom and useful as compliance incentives). This presentation will outline and provide an overview of the importance of each procedure, and how these can be implemented and integrated (Figure 1). This outline will be useful for other veterinarians or government officials to assist producers in developing effective and efficient biosecurity programs in aquaculture operations and larger EpiUnits

Titanium dioxide nanoparticles enhance mortality of fish exposed to bacterial pathogens

Nano-TiO2 is immunotoxic to fish and reduces the bactericidal function of fish neutrophils. Here, fathead minnows (Pimephales promelas) were exposed to low and high environmentally relevant concentration of nano-TiO2 (2 ng g−1 and 10 μg g−1 body weight, respectively), and were challenged with common fish bacterial pathogens, Aeromonas hydrophila or Edwardsiella ictaluri. Pre-exposure to nano-TiO2 significantly increased fish mortality during bacterial challenge. Nano-TiO2 concentrated in the kidney and spleen. Phagocytosis assay demonstrated that nano-TiO2 has the ability to diminish neutrophil phagocytosis of A. hydrophila. Fish injected with TiO2 nanoparticles displayed significant histopathology when compared to control fish. The interplay between nanoparticle exposure, immune system, histopathology, and infectious disease pathogenesis in any animal model has not been described before. By modulating fish immune responses and interfering with resistance to bacterial pathogens, manufactured nano-TiO2 has the potential to affect fish survival in a disease outbreak

Epidemiology of Noble Pen Shell (Pinna nobilis L. 1758) Mass Mortality Events in Adriatic Sea Is Characterised with Rapid Spreading and Acute Disease Progression

From May to October 2019, multiple mass mortality events (MMEs) of Pinna nobilis were observed along Croatian coastline starting from the south-east and rapidly progressing in north-western direction. Time dynamics of the MMEs closely followed general speed and direction patterns of surface sea-currents, advancing approximately 350 km in less than 3 months. Surveillance, clinical evaluation, and sample collection were performed on multiple sites with various degrees of mortality rates. Moribund P. nobilis individuals were collected and subjected to pathological, molecular, and microscopical investigation. Affected animals were positive for Mycobacterium in 70% of the individuals, and Haplosporidium pinnae was present in 58% of the cases. Observed pathological lesions were most severe where concurrent presence of both pathogens was confirmed (in 45.8% of moribund individuals). Moderate to strong lesions were observed in animals positive for Mycobacterium only (25% of cases), and lesions were absent or minor to moderate when only H. pinnae was confirmed (16% of cases). Considering the rapid and severe spread of the MMEs, the areas less exposed to major sea currents appeared to be at lower risk of pathogen transmission. Surveillance activities along the Croatian coastline identified several P. nobilis populations in such “lower risk” areas without apparent mortality or clinical symptoms. Such areas are of particular interest as source of potentially healthy individuals to support active recovery actions

Titanium dioxide nanoparticles enhance mortality of fish exposed to bacterial pathogens

Nano-TiO2 is immunotoxic to fish and reduces the bactericidal function of fish neutrophils. Here, fathead minnows (Pimephales promelas) were exposed to low and high environmentally relevant concentration of nano-TiO2 (2 ng g−1 and 10 μg g−1 body weight, respectively), and were challenged with common fish bacterial pathogens, Aeromonas hydrophila or Edwardsiella ictaluri. Pre-exposure to nano-TiO2 significantly increased fish mortality during bacterial challenge. Nano-TiO2 concentrated in the kidney and spleen. Phagocytosis assay demonstrated that nano-TiO2 has the ability to diminish neutrophil phagocytosis of A. hydrophila. Fish injected with TiO2 nanoparticles displayed significant histopathology when compared to control fish. The interplay between nanoparticle exposure, immune system, histopathology, and infectious disease pathogenesis in any animal model has not been described before. By modulating fish immune responses and interfering with resistance to bacterial pathogens, manufactured nano-TiO2 has the potential to affect fish survival in a disease outbreak.This article is published as Jovanović, Boris, Elizabeth M. Whitley, Kayoko Kimura, Adam Crumpton, and Dušan Palić. "Titanium dioxide nanoparticles enhance mortality of fish exposed to bacterial pathogens." Environmental pollution 203 (2015): 153-164. doi: 10.1016/j.envpol.2015.04.003. </p