Careful What You Catch

Update: Chronic Wasting Disease was recently found in a white-tailed deer in Issaquena County, directly north of Vicksburg and across the river from East Carroll and Madison parishes. 

The Louisiana Department of Wildlife and Fisheries encourages landowners in East Carroll, Madison and Tensas parishes to to curtail supplemental feeding of deer as a means to limit concentration and spread of the disease. Visit Louisiana Wildlife and Fisheries for more information.

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Hunters in Louisiana will want to begin taking care with any deer they kill, especially if they plan to take home a freezer full of tasty venison for winter meals. Chronic wasting disease (CWD), a fatal disease affecting deer and their relatives, has ravaged certain captive and wild populations in Texas and Arkansas. Though it has not yet been reported in Louisiana, the disease has spread unrelentingly throughout much of the United States and Canada, and Louisiana Wildlife and Fisheries has set restrictions on the bringing of deer carcasses into the state—and has cautioned hunters to avoid eating certain parts of their kills.

Animals infected with CWD don’t show symptoms until relatively late in the disease process but will then present with drooling, apparent confusion and strange behavior, weakness, uneven gait, weight loss, and, invariably, death. CWD is part of a group of diseases called transmissible spongiform encephalopathies (TSE), which punch fatal holes in the structure of the brain (hence “spongiform”). Humans can fall prey to these: kuru, the “laughing sickness,” tore through a New Guinea tribe due to their ritual cannibalism practices; the famous mad cow disease, formally “variant Creutzfeldt-Jakob disease,” is another. There have been no confirmed cases of CWD affecting a human being, but with very real human deaths recorded from mad cow and scrapie, a form that affects sheep, it can’t be said with certainty that we’re immune.

Most scientists believe that TSEs like chronic wasting disease are caused by prions, misfolded proteins that can be passed between animals or persons and “teach” proteins in the brain to take on different shapes that prevent them from functioning correctly, but one LSU scientist isn’t convinced. Dr. Frank O. Bastian, a neuropathologist, sees prions merely as the symptom, a result of infection with a particular and strange bacterium in the Spiroplasma genus, which he’s successfully isolated from diseased tissue. (Other Spiroplasma species cause the wonderfully named but crop-devastating Stubborn Citrus Disease and Corn Stunt Disease.) Small even by bacterial standards, Spiroplasma species lack the cell wall most similar organisms have, and may instead protect themselves in a sticky biofilm broadly similar to dental plaque. After initial difficulties getting the odd little bacterium to grow in culture, he switched to a low-oxygen medium and watched colonies flourish. Now, other laboratories are working to replicate the result and contribute to the research Bastian has begun.

The next step for the research will be to develop a test for Spiroplasma infection, followed eventually, it is hoped, by a vaccine. In the meantime, hunters (and we indoorsmen who prefer our game delivered) are advised not to eat likely infective parts of deer, such as the spleen, tonsils, or anything containing significant nerve tissue, in areas with a known or suspected presence of CWD—for what it’s worth, Bastian avoids venison entirely. (Both prions and Spiroplasma are heat-resistant, so simply cooking isn’t enough.) The next few years may hold big news, good and bad, for Louisiana deer populations and the hunters, nature lovers, and meat-eaters they share the state with—stay tuned.  

Learn more about Dr. Bastian's latest research into Chronic Wasting Disease here.