One Health Harmful Algal Bloom-related Illness Surveillance

Cyanobacteria and marine algae are ubiquitous in the earth's freshwaters and oceans. Under the right circumstances, these organisms can proliferate, causing harmful algal blooms (HABs) which may produce toxins that threaten human and animal health as well as local and regional ecology. Animals may play in, swim in, or drink from ponds and lakes that have extensive blooms, even if the water bodies smell or look unpleasant to people; the first warning that a toxin-producing HAB exists may come from the death of a pet dog or livestock. People may also play in waters that contain HABs if they are not aware of the potential hazard. Despite reports of human health effects and cases of animal poisonings from HABs or HAB produced toxins, the clinical course and public health effects of these adverse health events have not been well-characterized in the U.S.