Algal bloom-associated disease outbreaks among users of freshwater lakes--United States, 2009-2010.

Harmful algal blooms (HABs) are excessive accumulations of microscopic photosynthesizing aquatic organisms (phytoplankton) that produce biotoxins or otherwise adversely affect humans, animals, and ecosystems. HABs occur sporadically and often produce a visible algal scum on the water. This report summarizes human health data and water sampling results voluntarily reported to CDC's Waterborne Disease and Outbreak Surveillance System (WBDOSS) via the National Outbreak Reporting System (NORS) and the Harmful Algal Bloom-Related Illness Surveillance System (HABISS)* for the years 2009-2010. For 2009-2010, 11 waterborne disease outbreaks associated with algal blooms were reported; these HABs all occurred in freshwater lakes. The outbreaks occurred in three states and affected at least 61 persons. Health effects included dermatologic, gastrointestinal, respiratory, and neurologic signs and symptoms. These 11 HAB-associated outbreaks represented 46% of the 24 outbreaks associated with untreated recreational water reported for 2009-2010, and 79% of the 14 freshwater HAB-associated outbreaks that have been reported to CDC since 1978. Clinicians should be aware of the potential for HAB-associated illness among patients with a history of exposure to freshwater.

Fish intake guidelines: incorporating n-3 fatty acid intake and contaminant exposure in the Korean and Japanese communities.

BACKGROUND: Fish consumption advisories are developed to prevent overexposure to various contaminants. Recently, discussion has centered on the need to consider the benefits of fish consumption alongside possible risks when providing guidance. OBJECTIVE: As part of the Arsenic Mercury Intake Biometric Study involving the Japanese and Korean communities living in Washington State, we obtained fish and nutrient intake data. Japanese and Korean women of childbearing age (n = 214) participated in this longitudinal study. We used these data, along with hair-mercury data to determine the need for both the nutritional benefits and concern about contaminants to be included when providing guidance. DESIGN: We examined the intake of 2 n-3 long-chain fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), found in fish and associated with a variety of beneficial health effects. Intakes of these lipids were used as surrogates to characterize the beneficial effect from fish consumption, and the intake of mercury was used to establish the risk from consumption. RESULTS: These 2 populations provided an ideal basis from which to examine this issue because their fish consumption rates were identical and higher than national rates, but their mercury intakes vary substantially because of different consumption behaviors. Results indicate that basing fish consumption guidelines on contaminant concentrations alone can have the unintended consequence of causing a portion of the population to have inadequate intake of required nutrients. CONCLUSION: Public health goals may be better served if nutritional elements and contaminant concerns are quantitatively incorporated into fish consumption guidelines.