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Cryptosporidium exposure associated with crabbing within urban Baltimore watersheds. Cynthia McOliver, MPH Johns Hopkins University Bloomberg School of Public Health 2007. Introduction : Recreational Water Activities.
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Cryptosporidium exposure associated with crabbing within urban Baltimore watersheds Cynthia McOliver, MPH Johns Hopkins University Bloomberg School of Public Health 2007
Introduction: Recreational Water Activities • Recreational water activities are important to people and communities all across the United States • Fishing/angling, crabbing, boating, swimming and related activities • In our area, the Chesapeake Bay and its tributaries support both recreational activities and subsistence activities • Baltimore waters such as the Baltimore Harbor, Patapsco, Jones Falls and Gunpowder are popular sites Photo credits: Top: http://www.nps.gov/cbpo/planyourvisit/outdooractivities.htm; Middle: Personal photo; Bottom: US Fish and Wildlife Service Eufaula National Wildlife Refuge in Alabama
Baltimore, MD: Urban setting for fishing and crabbing • Our waters are receiving pathogens (bacteria, viruses, parasites eg Cryptosporidium) from many sources: • Point source: • Human waste water treatment effluents • Nonpoint sources: • Combined and sanitary sewer overflows • Storm/rain event runoff • Animals/pets • Some of these pathogens cause human sickness such as gastroenteritis from foodborne/waterborne exposure • Photo credit: top, leaking sewage main, • http://www.ci.baltimore.md.us/government//minority/images/MBEoutreachWWP.pdf; • Bottom: Immunofluorescently stained Cryptosporidium oocysts, H.D.A Lindquist, U.S. EPA
Studies: Part 1 • Question: Are persons with HIV/AIDS at risk of exposure to Cryptosporidium from recreational water contact? • Questions regarding type/frequency/location of water contact, residence, age, ethnicity, consumption of local catch, GI symptoms, handwashing etc • Premise: Persons with HIV/AIDS and other immunosuppressions are likely to develop severe/chronic illness from infections from Cryptosporidium (Colford et al., 1996 Am J Epidemiol. 1996 Nov 1;144(9):807-16; Chen et al., N Engl J Med. 2002 May 30;346(22):1723-31) • Recreational waters in Baltimore area, caught fish and handwashes from anglers have been found to be positive with Cryptosporidium (Roberts et al., J Toxicol Environ Health A. 2007 Sep;70(18):1568-76; Sunderland et al., Water Res. 2007 Aug;41(15):3483-9)
Studies: Part 2 • Question: Is Cryptosporidium detectable from crabs (hard, soft), water samples, and handwashes? Experiment 1: Commercial Chesapeake soft crabs Experiment 2: Middle Branch Park-Patapsco River blue crabs
Conclusions • Recreational water contact and a high level of consuming self-caught or wild caught fish and crabs from local waters occurs in persons with HIV/AIDS in Baltimore. • Blue crabs were shown to be contaminated with low levels of Cryptosporidium. • Recreational water activities and handling of crabs are possibly a source of exposure to Cryptosporidium for persons with HIV/AIDS in our area. • Sustaining the safety of our local waterways, food organisms and protecting human health requires cooperation between regulators, WWTP, local and state government, citizens, and watershed and other environmental organizations
Acknowledgements • The JHSPH Center for a Livable Future (Funding) • Advisors: Dr. Ellen Silbergeld, Thaddeus Graczyk, a • Dr. Richard Moore, Director; the patients and staff of the JHMI Moore Clinic, East Baltimore • Leena Tamang, Field sampling & Lab analysis • Carol Resnick (IRB help, survey design) • Preety Gadhoke (survey design) • Sean Evans, Hanna Blum, Marisa Caliri (survey administration and entry) • Ruth Quinn & Ellen Wells (survey beta testers) • Volunteers: Renee, Mark, Ellen, Priscilla & friend