The Fish Vet's Blog

From: Evan Sergeant <evan>
Date: Tue, Dec 20, 2011 at 7:17 AM
Subject: FRDC workshop on epidemiology and disease outbreak investigation

Dear all,

Just a reminder that the above workshop will be held at Attwood Motel and Convention Centre at Attwood, near Melbourne Airport on 13-15 March 2012. More details are attached or available from our website http://training.ausvet.com.au/index.php?n=Main.Welcome.

Thank you to all those who have already registered. If you are thinking of coming and haven’t registered please get your registration form in promptly

evan

EpiDiseaseOutbreakInvest WorkshopMar12.pdf
FRDC outbreak investigation registration form.pdf

http://midnightwatcher.wordpress.com/2011/12/18/australia-sea-of-dead-fish-at-buffalo-creek-blamed-on-too-much-rain/#comment-5456

On 19/12/2011, at 6:40, noreply> wrote:

AquaticHealth.net Disease News Update >> Dermo spreading through Texas [ProMed]

Link to source content: http://floridaindependent.com/60885/algae-outbreak-shuts-down-texas-oyster-industry.

Your input is important: Please verify and add any relevant commentary to this report. Also, is the information in the report summarised somewhere in the Wiki?

Report Content:

RED TIDE, SHELLFISH – USA (02): (TEXAS) OYSTER

**********************************************

A ProMED-mail post

ProMED-mail is a program of the

International Society for Infectious Diseases

Date: Wed 14 Dec 2011

Source: The Florida Independent, USA Today report [edited]

A widespread toxic algae outbreak has shut down oyster season across the Texas coast and caused health problems for many nearby residents.

Fueled by Texas’ ongoing drought, the algae — known as _Karenia brevis_ — [one of the causative agents for red tide. – Mod.TG] thrive in warm, salty water and have spread through the bays and islands along Texas’ 350-mile coast [560 km], says Meridith Byrd, a marine biologist for the Texas Parks and Wildlife Department. The algae could cause nausea, vomiting, and diarrhea in humans and are harmful to fish but not fatal to people, she says.

State health officials took the rare step of closing the entire coast for oyster harvesting — all 17 586 acres [7117 ha] of oyster beds — before the season opened 1 Nov 2011. The state has shut down the entire coast before, most recently in 2000, according to state health officials. But the size of the current bloom coupled with the state’s ongoing drought and lack of rain could make it one of the biggest and most destructive in history, Byrd says. The bloom so far has killed

4.5 million fish, she says.

In Florida, algae blooms have caused health problems for residents and, in towns that rely on water to fuel their business, have hurt the bottom line.

The Texas bloom appears different from those in Florida and is likely caused by red tide that, due to the drought, is creeping ever-closer to oyster beds near the shore.

A parasite known as “dermo”, which has fast been spreading through Texas coastal waters, is also becoming a major threat to the industry.

And it isn’t just the shellfish industry that’s hurting. One hardware store owner told USA Today that the closures are costing his business at least USD 4000 a month. Restaurants, fueling stations, and fishing equipment suppliers have also been negatively impacted.

The Texas bloom is only the latest in a string of events negatively affecting the state’s USD 30 million oyster industry. In 2005, Hurricane Katrina devastated the Gulf Coast area, and remains t he costliest natural disaster the country has ever seen. Last year’s [2010] gulf oil spill only made matters worse — especially for the fishing industry, which is still grappling with consumer’s concerns over the safety of Gulf of Mexico seafood.

[Byline: Virginia Chamlee]

Antibiotic resistance might be caused by aquaculture

November 22, 2011 Boston, MA –

Researchers from Tufts University School of Medicine agree on the controversial, non-therapeutic use of antibiotics in food animals and fish farming as a cause of antibiotic resistance. They report that the evidence shows a need for stricter regulation of the practice. “The US lags behind its European counterparts in establishing a ban on the use of antibiotics for growth promotion. For years it was believed that giving low-dose antibiotics via feed to promote growth in cows, swine, chickens and the use of antibiotics in fish farming had no negative consequences. Today, there is overwhelming evidence that non-therapeutic use of antibiotics contributes to antibiotic resistance, even if we do not understand all the mechanisms in the genetic transmission chain,” said Levy, MD, professor of molecular biology and microbiology and director of the Centre for Adaptation Genetics and Drug Resistance at Tufts. Antibiotics have been used for the last 70 years to fight bacterial infections such as streptococcus, meningitis, tuberculosis and urinary tract infections. The misuse and overuse of antibiotics have played a part in antibiotic resistance. Today, antibiotics are less effective when used to save lives. Levy and co-author Bonnie Marshall summarize their findings after reviewing numerous studies:• According to estimates, antibiotics are eight times more likely to be used for non-therapeutic purposes than for treating a sick animal.• Current practices set the stage for the rapid spread of antibiotic-resistant bacteria.• The long-term administration of antibiotics in animal feed creates an optimal environment for antibiotic resistance genes to multiply.• Treated animals become “factories” for the production and distribution of antibiotic-resistant bacteria such as Salmonella and Methicillin-resistant Staphylococcus aureus (MRSA).• Even if farmers turn to antibiotics that are not commonly used to treat people, these drugs – given over long periods of time – can also promote resistance.• Several studies demonstrated that antibiotic-resistant bacteria can easily spread from animals to people in close contact with animals, such as veterinarians, slaughterhouse workers, farmers, and the families of farmers.• As much as 90 per cent of antibiotics given to livestock are excreted into the environment. Resistance spreads directly by contact and indirectly through the food chain, water, air, and manured and sludge-fertilized soils.• The broad use of antibiotics in fish food in farm fishing, particularly overseas, leads to leaching where it can be washed to other sites, exposing wild fish to trace amounts of antibiotics.• The consequences of antibiotic resistance are great. According to the Centres for Disease Control and Prevention, antibiotic-resistant infections cause longer and more expensive hospital stays and greater risk of death.• Bans on the use of non-therapeutic antibiotics are effective in diminishing antibiotic resistance. Bans in European countries have seen less antibiotic resistance. It is common sense to avoid overcrowding food animals to improve hygiene and reduce the practice of routinely giving antibiotics to promote growth. “While the use of non-therapeutic antibiotics remains contentious, the evidence is strong enough to merit precaution. Antibiotics save lives. When infections become resistant to primary antibiotics, and alternative antibiotics must be used, health care costs increase. As more infections become more resistant to more antibiotics, we run the risk of losing more of our arsenal of antibiotics, resulting in needless deaths. It’s important to consider what we stand to gain versus what we stand to lose,” concludes Levy.

Source: http://tinyurl.com/7385dn5  [See http://tinyurl.com/7gn7xdu for Bonnie M. Marshall, BM & SB Levy (2011). Food Animals and Antimicrobials: Impacts on Human Health. Clin. Microbiol. Rev., 24:718-733.  ADS-Mod.]

From: “Dr. David Scarfe” <DScarfe>
Date: 16 December 2011 8:53:08 AWST
Subject: AquaVetMed: US Senate Hearing – Environmental Risks of Genetically Engineered Fish

Check out an article my colleague just published!

Journal of Fish Diseases
Volume 35, Number 1 (January 2012)
	The pathology of ‘scale drop syndrome’ in Asian seabass, Lates calcariferBloch, a first description
	Authors:	S Gibson-Kueh 1, D Chee 2, J Chen 2, Y H Wang 2, S Tay 2, L N Leong 3, M L Ng 4, J B Jones 5, P K Nicholls 1, H W Ferguson 6
	Author Affiliations:	1: School of Veterinary and Biomedical Sciences, Murdoch University, Western Australia, Australia  2: Animal & Plant Health Laboratories, AgriFood & Veterinary Authority of Singapore, Singapore  3: Electron Microscopy Unit, Faculty of Medicine, National University of Singapore, Singapore  4: Department of Microbiology, Faculty of Medicine, National University of Singapore, Singapore  5: Fish Health Laboratory, Department of Fisheries, Western Australia, Australia  6: Marine Medicine Program, School of Veterinary Medicine, St George’s University, Grenada, West Indies
	Source:	Journal of Fish Diseases, Volume 35, Number 1 (January 2012)
	Page Numbers:	19 – 27
	Available Full Text:	Full Text: Subscription Required to view full text Format: PDF Size: unknown Location: Publisher’s Site Authentication: EBSCOhost EJS
	Abstract:	This is the first pathological description of ‘scale drop syndrome’ (SDS) in Asian seabass, Lates calcariferBloch. Cumulative mortality was estimated at 40–50%. The vasculitis in all major organs including the skin and associated tissue necrosis was distinctive. The dermis overlying scale beds was often necrotic and associated with scale loss. Necrosis of splenic ellipsoids, renal glomeruli and choroid reteglands of eye were further hallmarks of a disease with systemic vascular involvement. The brain was not spared vascular damage, and the resulting multifocal encephalomalacia probably accounts for the spiral swimming behaviour in some affected fish. Other lesions included accentuated hepatic lobulation and gastric gland necrosis. Nuclear chromatin margination and karyolysis in hepatocytes, renal tubular epithelium and gastric and intestinal epithelium suggest specific targeting of cells. Basophilic cytoplasmic inclusions were present in spleen, kidney, liver, heart and choroid rete,but they were not prominent. Using transmission electron microscopy, two morphological forms of virions were observed: single- and double-enveloped hexagonal virions. Based on size and morphology, these virions resemble iridovirus or herpesvirus. The cause of SDS is unknown, but the pathological changes, especially the vasculitis, suggest an infectious aetiology, possibly viral.
	Citation:	S Gibson-Kueh, D Chee, J Chen, Y H Wang, S Tay, L N Leong, M L Ng, J B Jones, P K Nicholls, H W Ferguson . The pathology of ‘scale drop syndrome’ in Asian seabass, Lates calcariferBloch, a first description. Journal of Fish Diseases, Volume 35, Number 1 (January 2012), pp. 19-27, <http://ejournals.ebsco.com/direct.asp?ArticleID=4212A4D57163E64A7546&gt;
	URL:	http://ejournals.ebsco.com/direct.asp?ArticleID=4212A4D57163E64A7546