Surveillance for harmful algal bloom events and associated human and animal illnesses—One Health Harmful Algal Bloom System, United States, 2016—2018

Harmful algal bloom (HAB) events can result from the rapid growth, or bloom, of photosynthesizing organisms in natural waterbodies. HAB events can be exacerbated by nutrient pollution and a warming climate (1) and can negatively impact the health of humans, animals, and the environment and damage local economies (2,3). U.S. HAB events of public health concern are centered on a subset of phytoplankton: diatoms, dinoflagellates, and cyanobacteria (also called blue-green algae). CDC launched the One Health Harmful Algal Bloom System (OHHABS) in 2016 to inform efforts to prevent human and animal illnesses associated with HAB events. For 2016–2018, 18 states reported 421 HAB events, 389 cases of human illnesses, and at least 413 cases of animal illnesses. Most HAB events occurred during May–October (413; 98%) and in freshwater bodies (377; 90%). Human and animal exposures primarily occurred during June–September and May–September, respectively. Gastrointestinal or generalized signs or symptoms were the most frequently reported (i.e., >40% of human cases and >50% of animal cases); however, multiple other signs and symptoms were reported. A multidisciplinary approach to surveillance provides data about HAB events, exposures, and health effects that are critical to prevention of HAB-associated illnesses.

Impact/Purpose

Harmful algal blooms in fresh and marine waters are associated with human and animal illnesses. This report is the first surveillance summary of reports from the new One Health and Harmful Algal Blooms surveillance system from the National Outbreak Reporting System at the Centers for Disease Control and Prevention. By further defining illnesses associated with blooms, this work advances the understanding of the public health and ecologic burden associated with algal blooms.

Citation

Roberts, V., M. Vigar, L. Backer, G. Veytsel, E. Hilborn, E. Hamelin, K. Vanden Esschert, J. Cope, M. Hlavsa, AND J. Yoder. Surveillance for harmful algal bloom events and associated human and animal illnesses—One Health Harmful Algal Bloom System, United States, 2016—2018. U.S. Department of Health and Human Services, Washington, DC, 69(50):1889-1894, (2020). [DOI: 10.15585/MMWR.MM6950a2]

DOI: Surveillance for harmful algal bloom events and associated human and animal illnesses—One Health Harmful Algal Bloom System, United States, 2016—2018