Recreational water contact as a risk factor for Cryptosporidium exposure among persons with HIV/AIDS in Baltimore, Maryland

The purpose of this dissertation is to provide evidence of recreational water contact as a specific route of microbial exposure to Cryptosporidium for persons with HIV/AIDS for whom Cryptosporidium is an important opportunistic agent. The objectives of this research were to (1) Characterize patterns of recreational water activity in HIV/AIDS patients; (2) Sample and test recreational waters used by HIV/AIDS patients, as well as wild-caught blue crabs caught from Baltimore waters to identify them as reservoirs of Cryptosporidium; and (3) Evaluate risks of self-reported recreational water activity with gastrointestinal illness (chronic and/or intermittent diarrhea and associated symptoms), relative to the U.S. EPA acceptable levels of risks for waterborne pathogens.;For Objective 1, a detailed cross-sectional study of an outpatient HIV/AIDS clinic population was undertaken. Objective 2 was accomplished by identification of the most frequently used recreational water sites identified from the questionnaire in Objective 1, and assessment of monthly collected water samples for the presence of Cryptosporidium oocysts. Objective 3 was achieved by analyzing the questionnaire data from Objective 1 for recent self-reported gastrointestinal diarrhea and self-reported recreational water activity, and other risk factors.;Results of my research: (1) Provide the first documentation that persons with HIV/AIDS in the Baltimore region are actively engaged in recreational water activities. Patients also reported consuming wild-caught fish and crabs from these waters; (2) Found viable Cryptosporidium oocysts on surface washes of blue crabs caught in local waters in Baltimore at the Middle Branch Park of the Patapsco River, and in local waters frequently used by the HIV/AIDS population for recreational water activities, and (3) Found no association between self-reported gastrointestinal illness (i.e., chronic and/or intermittent diarrhea and associated symptoms) and self-reported recreational water activity.;In conclusion, this research provides evidence to support the hypothesis that persons with HIV/AIDS are exposed to Cryptosporidium from recreational water activities in local water bodies within the Baltimore watersheds of the Chesapeake Bay. HIV/AIDS patients at risk for severe cryptosporidiosis should avoid recreational water contact, and patients reporting chronic and/or intermittent diarrhea should be further queried regarding potential exposures to enteric parasites such as Cryptosporidium.