He has less bottomland to fish 

 than his grandfather did, but 

 oysterman David Oglesby is still 

 on the water. 



But if someone eats a tainted oys- 

 ter that's raw or partially cooked, he 

 may get sick. 



Typhoid fever is rare these days, 

 but other symptoms can occur. 



If you've ever eaten an oyster that's 

 sent you running to the bathroom, 

 you know. 



Nausea, vomiting and diarrhea can 

 strike within hours of eating con- 

 taminated shellfish. Or in a few 

 cases, stomach or intestinal illnesses 

 can occur. 



Bob Benton, head of the state's 

 Shellfish Sanitation Program, says he 

 gets reports of about four or five 

 cases a year. Most of the outbreaks 

 can be traced to oysters taken from il- 

 legally fished waters or from 

 imports. 



To guard against bootleg opera- 

 tions, the Division of Marine 

 Fisheries polices North Carolina's 

 shellfish areas. The state follows U.S. 

 Public Health Service and Federal 

 Drug Administration standards to 

 provide additional protection. 



Benton and his crew routinely 

 check waters and shellfish meats, in- 

 spect wastewater treatment plants 

 and certify and inspect processors. 



As for the past 64 years, the 

 agents' main job is to check the 

 water for harmful bacteria from fecal 

 wastes. Waters close to oystermen 

 when test totals show more than 14 

 organisms per 100 milliliters of 

 water. 



Oglesby can verify that. 



Resting in his skiff on a cold 

 December morning, the fisherman 

 points up river to an area that's been 

 closed for more than four years. 



That was some of his private shell- 

 fish beds they closed. Now he fishes 

 mostly on public bottomland. 



The FDA and Public Health Ser- 

 vice established the current stan- 

 dards in the 1970s, Sobsey says. The 

 original measures set up in the 1920s 

 were 70 fecal coliform bacteria per 

 100 milliliters of water. 



' 'These standards have been useful 



Photo by Nancy Davis 



in protecting the public from typical 

 bacterial diseases such as typhoid 

 fever,' ' Sobsey says. 



But in the 1950s, scientists 

 discovered that oysters and other 

 bivalves could also pick up human 

 viruses such as hepatitis. The virus- 

 es, as well as diarrhea and stomach 

 diseases, could be transmitted to 

 people. 



Since then, there has been a lot of 

 research trying to find out if the cur- 

 rent standards for testing can also 

 detect viruses, Sobsey says. 



So far the answer is "no." 



"We need to look for a better indi- 

 cator of shellfish viruses," Sobsey 

 says. "We still don't have convenient 

 ways to detect all viruses.' ' 



With his research, the Sea Grant 

 scientist hopes to find a new testing 

 standard acceptable by the FDA. 



Keeping bad oysters off the market 

 is one way to stop diseases from 

 spreading. 



Nature provides another way. 



Remarkably, oysters can purge 

 themselves of contaminants if placed 

 in clean water. Over time, the clean 

 water flushes out harmful bacteria 

 and viruses. 



North Carolina fishermen some- 



times transfer polluted oysters to 

 clean estuarine waters, under super- 

 vision, then harvest the shellfish 

 when the cleaning process is done. 



Federal law requires relayed oysters 

 to stay in clean water at least two 

 weeks. But Sobsey found that it may 

 take longer to rid oysters of viruses. 

 In his tests, it took one month to pur- 

 ify relayed oysters of all bacteria and 

 viruses. 



Commercial cleaning, or depura- 

 tion, shows similar results. 



Sobsey 's lab tests simulating de- 

 puration revealed most viruses 

 moved out rapidly. But one virus — 

 Hepatitis A — persisted. Now he 

 recommends commercial depuration 

 periods also be extended. 



In spite of his job, Sobsey still eats 

 raw oysters. 



The chances of infection are ex- 

 tremely rare, he says. And, he points 

 out, all bacteria and viruses can be 

 transmitted by other routes besides 

 shellfish. Swimming in contami- 

 nated water, eating foods prepared by 

 someone without proper hygiene, 

 and mixing sick children in day-care 

 centers can produce the same 

 results. 



