Facts about mycobacteriosis

[CharlieTuna]

I have been reading up on this, pretty gross stuff. I wanted to know why, as opposed to just seeing pics of it. It can turn up in lots of places, and can actually require a trip to the hospital if you get in inside your bloodstream. be careful, fellas.




"Malnutrition makes the population vulnerable to mycobacteriosis, a disease that causes loss of scales, skin ulcers, severe weight loss and lesions. Officials estimate that sixty to seventy-five percent of the striped bass in Chesapeake Bay are infected.

Fish Handler’s Disease

Last week Artie Peltier of Erickson’s Bait & Tackle of Warwick related a story about a customer that caught a bacterial infection, he thinks from a striped bass when he was cut handling the fish. Artie related that he and customers are seeing more ulcers and lesions on fish. His claim has merit as the striped bass plague mentioned above moves up the east coast from the Chesapeake. Some anglers have caught “fish-handler's disease”. It is totally treatable and a common ailment of those working in a marine environment, salt or freshwater.

According to the Virginia Institute of Marine Science (they have spent a lot of time studying Chesapeake Bay striped bass and mycobacteriosis) primary symptoms of the infection in humans includes infections of the skin and soft tissues. Infections typically become evident as reddish raised nodules on the hands, elbows, knees, and feet. In many instances the joints may also become swollen. The good news is that there is no evidence that humans can contact mycobacteriosis by consumption of cooked fish that is infected. However, because the infection can be transmitted when handling infected fish, any fish that exhibits external signs of infection should be released or disposed of."

[cowherder]

You find some pretty nasty info if you start searching, Charlie, thanks for the eye-opening thread. :upck:

http://www.wm.edu/news/stories/2008/vimsshowsbacterialdiseasecankilstripedbass-002.php




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VIMS study shows bacterial disease can kill striped bass

by Dave Malmquist | October 27, 2008

A study led by researchers at the Virginia Institute of Marine Science, College of William and Mary, is the first to demonstrate that striped bass in Chesapeake Bay are succumbing to mycobacteriosis. This chronic bacterial disease, first detected in Bay stripers in 1997, now infects more than half of all striped bass in Bay waters.

The study, which appears in the October 2008 issue of Ecological Applications, was authored by VIMS researchers David Gauthier, Rob Latour, Chris Bonzek, Jim Gartland, and Wolfgang Vogelbein, as well as Erin Burge of Coastal Carolina University and Dennis Heisey of the U.S. Geological Survey's National Wildlife Center.

Observation of mortality among wild fish is typically limited to acute fish-kill events of schooling species such as menhaden, when large numbers of dead fish float to the surface or wash up on shore.

Detection of mortality from chronic infections is much more difficult, as fish are likely to die by ones or twos through time across a wide area. "Due to the chronic nature of mycobacteriosis in striped bass, the mortality is cryptic," says lead researcher Gauthier. "That makes it difficult to measure."

Knowing whether mycobacteriosis ultimately kills Bay stripers is of concern to fisheries managers and anglers all along the Eastern seaboard. Striped bass are one of the region's most economically and ecologically important finfish, and Chesapeake Bay is the main breeding and nursery ground for this species on the Atlantic coast.

Evidence that mycobacteriois might be killing Bay stripers comes from recent fishery stock assessments, which show an increase in natural, non-fishing mortality among striped bass in Maryland waters since 1999. However, these studies do not differentiate between death due to disease and death due to other factors such as predation or old age.

To test whether mycobacteriosis has contributed to the observed increase in natural mortality, the researchers fed data from a three-year field survey of mycobacteriosis in Chesapeake Bay striped bass into a state-of-the-art demographic model developed by co-author Heisey.

The team conducted the survey work between 2003-2005 in collaboration with the Chesapeake Bay Multispecies Monitoring and Assessment Program (ChesMMAP), an ongoing VIMS study of fish demographics and food-web interactions in the Bay.

"That's what sets our study apart," says Vogelbein, a fish pathologist at VIMS. "We were able to provide our model with field data showing the prevalence of infection in different age classes through time."

For each of the 1,420 striped bass sampled, the researchers determined the fish's age, sex, and whether it was diseased with mycobacteriosis. They then fed these data into their model. Their findings show that:

—A fish infected with mycobacteriosis is only about 70% as likely to survive another year as a non-infected fish.
—Older females are more likely than males to succumb to mycobacteriosis, perhaps due to the energetic demands of spawning and migration.
—Disease-related mortality increases through the summer, possibly due to stress from warm temperatures and low oxygen levels in Chesapeake Bay.
The authors caution that the results of their model rest on several assumptions. One is that an infected fish will remain diseased throughout its life. A second is that the risk of death from mycobacteriosis is independent of age. They write that these assumptions "are reasonable given the current understanding of mycobacterial pathobiology in fishes, but require testing, especially in the context of wild populations. "
"We think our work will inspire tests of these assumptions," says Gauthier, "and thus help develop more sophisticated models of disease dynamics based on directed field studies and experiments."

[7deadlyplugs]

yummy :upck:

[voyager35]

There is a thread about catch and release here where this should be addressed as well. The incidents of mycobacteriosis are random and depend on many factors. However handling fish too aggressively with your hands or rubbing their slime coat off on the sand indirectly contributes to the spread of this disease by making the fish more susceptible to contract it.

[dogfish]

I think that picture is an extreme case. I have gotten bass with sores on them, but never as bad as that. I think it has something to do with the water being colder up here. I don't know the numbers, but Chesapeake bay has to be at least 10degrees warmer on a year-round average basis.

[ledhead36]

http://stripersandanglers.com/Forum/attachment.php?attachmentid=7409&thumb=1&d=1249517006 (http://stripersandanglers.com/Forum/attachment.php?attachmentid=7409&d=1249517006)

I would never eat a bass that looked like that, let alone touch it. The worst I have ever seen was one that had a few sores. That bass looks like it led a miserable life. Like having acid poured on your body.

[strikezone31]

What is mycobacteriosis?

Mycobacteriosis is a generic term that describes diseases caused by a group of bacteria (simple single-celled organisms) known as mycobacteria. Mycobacteria are widespread in the natural world, particularly in aquatic environments. A small fraction of mycobacterial species cause disease in animals and humans.
A newly described species of mycobacteria, Mycobacterium shottsii, is the type most commonly associated with the current outbreak of mycobacteriosis among striped bass in Chesapeake Bay. M. shottsii was first identified by VIMS scientists in 2001, and is present in 76% of infected bass. Some infected striped bass from the Bay are also known to harbor multiple mycobacterial species. Other mycobacteria recovered from Bay bass include M. peregrinum, M. marinum, and isolates resembling M. scrofulaceum, M. szulgai, M. interjectum, and M. simiae.
The human health significance of M. shottsii is not yet known (see below (http://web.vims.edu/myco/FAQ.html?svr=www#Handling)). Concern is warranted because M. shottsii is closely related to M. marinum, a species responsible for mycobacterial infections of skin and soft tissue in humans (http://web.vims.edu/myco/FAQ.html?svr=www#Human). M. marinum is also considered the primary cause of mycobacteriosis in fish in aquarium, aquaculture, and natural settings. Other more distantly related species of mycobacteria include M. tuberculosis (the cause of pulmonary tuberculosis) and M. leprae (the cause of leprosy).
Although M. shottsii is in the same genus as M. tuberculosis, mycobacteriosis in humans is not the same disease as tuberculosis. Contagious mycobacteria that cause serious disease in humans include M. tuberculosis (the cause of pulmonary tuberculosis) and M. leprae (the cause of leprosy). "Environmental" mycobacteria such as M. shottsii, M. marinum, and other species are collectively termed "non-tubercular" mycobacteria to distinguish them from the species that cause tuberculosis. [top] (http://web.vims.edu/myco/FAQ.html?svr=www#Top)
What are the symptoms of mycobacteriosis in striped bass?


Mycobacteriosis of Chesapeake Bay striped bass is predominantly a visceral disease, infecting organs such as the spleen and kidneys. Internal signs of the disease typically include small grayish white nodules called granulomas (javascript:GranulomaWindow()) in these organs. A small percentage of the infected fish also exhibit unsightly shallow, rough-surfaced, reddened, or darkly pigmented skin ulcers (javascript:UlcerWindow()). Loss of scales is common in these ulcers. Infected fish sometimes exhibit significant weight loss. These disease symptoms are mainly observed in the summer and fall. Fish exhibiting the unsightly skin ulcers are of greatest concern to anglers. [top] (http://web.vims.edu/myco/FAQ.html?svr=www#Top)
Can I contract mycobacteriosis by handling striped bass?


There is a slight potential for human infection from handling striped bass infected with M. shottsii and other mycobacteria. Concern is warranted because M. shottsii is closely related to M. marinum, a species known to pass from infected fish to humans via handling. However, M. shottsii prefers growth at cooler temperatures than M. marinum. It seldom grows in laboratory cultures at 30°C (86°F), suggesting that it may not produce infections in humans.

Anglers should thus:

return any fish with skin lesions (javascript:UlcerWindow()) to the water
wear gloves when handling striped bass
take particular care if they have a cut, scrape, or abrasion on their hands or arms, and wash thoroughly with soap and water after coming into contact with fish or open water.
Individuals whose immune systems are weakened or compromised because of disease or immune suppression therapy should be especially careful to avoid wounds or abrasions.


Human infection by M. marinum following exposure to the marine environment probably requires a portal of entry and is often linked with trauma such as puncture wounds from handling marine animals such as fish, turtles, shellfish, crustaceans. M. marinum infections in humans are known by names such as "fish-handler's disease," "aquarium disease," and "swimming-pool disease." [top] (http://web.vims.edu/myco/FAQ.html?svr=www#Top)
Can I contract mycobacteriosis by eating striped bass?


There is no evidence that humans can contract mycobacteriosis by consumption of cooked fish infected by M. marinum or M. shottsii. However, because of the risk of infection via handling (see above (http://web.vims.edu/myco/FAQ.html?svr=www#Handling)), any striped bass that exhibit external signs of mycobacteriosis (unsightly skin ulcers (javascript:UlcerWindow())) should be released or disposed of. Do not keep or eat a fish that you would not buy in a fish market.
Any fish that are consumed should be cooked thoroughly. M. shottsii, one of the bacteria responsible for causing mycobacteriosis in striped bass, prefers to grow at temperatures below about 30°C (86°F), and is killed after heating to temperatures greater than 75°C (~170°F) for 20 minutes. [top] (http://web.vims.edu/myco/FAQ.html?svr=www#Top)
What are the symptoms of mycobacteriosis in humans?


It is not yet known whether Mycobacterium shottsii (the dominant species isolated in the current outbreak of striped bass mycobacteriosis in Chesapeake Bay) can infect humans. Concern is warranted because M. shottsii is closely related to M. marinum, a species known to cause disease in both humans and fish.
Primary symptoms of human infection by M. marinum include infections of the skin and soft tissues. Infection most typically becomes evident as reddish raised nodules (javascript:MedlineWindow()) on the hands, elbows, knees, and feet. In many instances the joints may become swollen.

M. shottsii and M. marinum have very different growth rates. M. marinum grows well at 30-33°C (86-91°F), but not at the normal human body core temperature of 37°C (98.6°F). This helps explain why M. marinum tends to infect the extremities, which are cooler than the body core. M. shottsii prefers a cooler temperature (23°C or 73°F) and grows very slowly or not at all at 30¡C under laboratory conditions.

http://web.vims.edu/myco/FAQ.html?svr=www#Handling

[storminsteve]

Fish handlers disease. An interesting article
http://www.drjball.com/article6.html (http://www.drjball.com/article6.html)

[wish4fish]

nasty **** only got fish like that a few times put them back rite away!

[cowherder]

Have been reading about a lot of these fish turning up. Did a search and found this thread.

[porgy75]

yuck!

[hookset]

Good thread thanks for sharing.