October 13, 2009 Vol. 58, No. 21

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OREGON PUBLIC HEALTHOGY DIVISION PUBLICATION • DEPARTMENT OF THE PUBLIC OF HEALTH HUMAN DIVISION SERVICES ORECON DEPATMENT OF HUMAN SERVICES ALGAE BLOOMS: AN EMERGING PUBLIC HEALTH CONCERN

arine algal blooms are in- 6 days and resolved without medical OREGON’S HARMFUL ALGAE creasing in frequency and att ention. The individual had no pre- BLOOM SURVEILLANCE PROGRAM Mseverity around the world, existing health conditions. The bloom These are two of the 18 human and and freshwater blooms are predicted underway was Anabaena, a species animal suspect illness reports att ribut- to worsen with warmer temperatures of cyanobacteria known to produce able to exposure to toxic freshwater brought by climate disruption and anatoxin-a, a neurotoxin that can algae that have been received by the increases in nutrient pollution.1 While produce symptoms similar to those Public Health Division’s Harmful most species of algae are not harmful, experienced by this case. Algae Bloom Surveillance program in a few dozen are capable of produc- CASE REPORT 2 2009. Also of note this year, the Harm- ing potent toxins. As algal blooms A 42-year old man swam in a Doug- ful Algae Bloom Surveillance program increase, so does the likelihood that las County reservoir shortly before it recorded the fi rst confi rmed dog death public health and private physicians was posted for a cyanobacteria bloom. in Oregon due to anatoxin-a exposure, will see increased cases of illness at- By nightfall he experienced GI symp- produced by cyanobacteria. The report tributable to algal toxins. toms, including nausea, vomiting, follows numerous anecdotal accounts diarrhea, and abdominal pain that of dog deaths that have been received CASE REPORT 1 lasted several days. The symptoms over the years. In time, these dog A 38-year old man swam for 45 are consistent with microcystin, a deaths may become regarded as senti- minutes in a Lane County reservoir hepatoxin associated with Anabaena. nel events, portending future human while an active cyanobacteria bloom Unfortunately, no clinical specimens health impact. was in progress. Within an hour he ex- or environmental samples were taken ALGAL TOXINS AND HEALTH perienced onset of itching, and within that enabled confi rmation of microcys- EFFECTS 24 hours became lightheaded with a tin poisoning. “pins and needles” tingling in his up- Exposure to high concentrations of per extremities. Symptoms lasted 5 to algal toxins can cause rapid onset of acute symptoms in otherwise healthy Toxins produced by algal species found in the Pacific Northwest*

Toxin Source Vector Acute Symptoms Diagnosis Anatoxin-a Contaminated Cyanobacteria Progression of muscle fasciculations, decreased History of swimming in bloom fresh water movement, abdominal breathing, cyanosis, waters; head immersion or accidental convulsions, death (animals). swallowing of water. Algal cells in feces; toxin in blood (other tissues and body fl uids at autopsy such as liver and vitrious fl uid). Ciguatoxins Warm marine Many fi sh Hypotension, bradycardia, blurred vision, Consumption of tropical and water species: eel, dyspnea, paresthesias of the extremities and subtropical fi sh and neurologic grouper, circumoral region, diarrhea, nausea, vomiting, symptoms with or without GI mackerel, abdominal pain, arthralgias and myalgias. symptoms. snapper Domoic Acid Marine water Shellfi sh: crab, Headache, short-term memory loss, hemiparesis, Consumption of shellfi sh and GI (Amnesic clams, scallops, visual abnormalities, ophthalmoplegia, seizures, symptoms and neurologic symptoms. Shellfi sh mussels, oysters myoclonus, confusion, lethargy, agitation, Poisoning) coma, mutism, arefl exia,hypotension, peripheral vasodilation, pulmonary edema, nausea, vomiting, abdominal cramps, diarrhea, anorexia. Microcystins Contaminated Cyanobacteria Hepatotoxicity, elevated gamma glutamyl Evidence of hepatic dysfunction fresh water transpeptidase, vomiting, diarrhea, abdominal and history of cyanobacterial bloom pain, malaise, rash. exposure. Saxitoxins Marine water Shellfi sh: clams, Nystagmus, iridoplegia, jaw and facial muscle Consumption of shellfi sh or pufferfi sh (Paralytic cockles, mussels, incoordination, tachycardia, T wave changes, and rapid onset of neurological Shellfi sh oysters, whelk; or numbness, ataxia, headache, dizziness. symptoms with or without GI Poisoning) pufferfi sh symptoms.

*CDC case defi nitions for algal toxin-related disease; adapted from Harmful Algal Blooms, Centers for Disease Control and Prevention (reference 2). The CD Sum mary (ISSN 0744-7035) is published biweekly, free of CD SUM MA RY charge, by the Oregon Dept. of Human Services, Offi ce of Com muni ca ble PERIODICALS Disease and Epidemiology, 800 NE Oregon St., Portland, OR 97232 October 13, 2009 POSTAGE Periodicals postage paid at Portland, Oregon. Postmaster—send address changes to: Vol. 58, No. 21 PAID CD Sum mary, 800 NE Oregon St., Suite 730, Portland, OR 97232 Portland, Oregon

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people (Table, verso). If the patient ate is not known, mostly because symp- so there may be additional blooms shellfi sh, swam in or ingested water toms are oft en mild and self-limited for which we have no record. aff ected by an active algal bloom, toxic and people do not seek medical care. While acute exposures and poisoning should be considered as a Others who suff er more serious illness recreational water illnesses is the diagnosis. The only treatment for these may be misdiagnosed because of lack major focus of the Harmful Algae illnesses is supportive care. of awareness of the presence of cyano- Bloom Surveillance program, we In Oregon, marine algal blooms are toxins in Oregon waters. Additionally, are also investigating public health typically associated with a “red tide.” the patient’s symptoms are usually concerns regarding chronic health Dinofl agellate blooms can produce non-specifi c. The lack of specifi city in eff ects from potential impacts to saxitoxin, which may cause Paralytic symptoms results in common dif- drinking water. A future goal is Shellfi sh Poisoning. Diatom blooms ferential diagnoses such as pesticide to identify and prioritize water can produce domoic acid, which may poisoning, cholinesterase inhibitor systems that may require preven- cause Amnesic Shellfi sh Poisoning.3 poisoning, microbial food poisonings tive action. During a red tide, the public is warned and food allergies. If a patient presents with com- not to eat shellfi sh from aff ected If a patient presents in your offi ce parable symptoms, accompanied waters. If they experience neurological with acute symptoms, a history of by contact with water where there symptoms, such as tingling or numb- how the illness came about will help has been an algae bloom, alert ness in the hands and lips or diffi culty with diagnosis. A key question to ask the Local County Health Depart- breathing aft er consuming seafood, is whether the person has either been ment of the suspected illness, they are advised to seek immediate recreating in or drinking water that is and the Public Health Division at medical att ention. Paralytic Shellfi sh described as scummy or discolored, or 877-290-6767 so we can take a com- Poisoning and Amnesic Shellfi sh for which a health advisory has been plete history, including environ- Poisoning are serious illnesses that issued.** mental conditions and exposure are legally reportable to public health ALGAE AND THE FUTURE: information. authorities. A GROWING CONCERN We appreciate the assistance of Less well known to the general Cyanobacteria blooms appear to be readers in helping us character- public, and physicians, are the health increasing in frequency and duration ize this growing problem. To dive eff ects from exposures to freshwater in Oregon, and are becoming more further into harmful algae blooms cyanobacteria. Freshwater cyanobacte- widespread across the state. This year via the Web, visit us at www.oregon. ria are capable of producing a variety the Public Health Division (PHD) gov/DHS/ph/hab/. of toxins, including those classifi ed as posted 20 advisories for cyanobacteria Disease reporting information hepatotoxins, neurotoxins and skin in fresh water bodies across the state, can be found at. www.oregon.gov/ irritants. Microcystin, a hepatotoxin, breaking the 2008 record of 14 adviso- DHS/ph/acd/reporting/disrpt.shtml. and anatoxin-a, a neurotoxin, are the ries. It is also worth mentioning that REFERENCES

most common toxins associated with not all waters are actively monitored, 1. Paerl, Hans W and Huisman, Jef. Blooms freshwater algae blooms in Oregon. like it hot. Science 2008; 320: 57–58.

Common to all freshwater blooms are ** When algae blooms capable of 2. Harmful Algal Blooms, Centers for Disease Control and Prevention, National Center for lipopolysaccharides, which can lead to producing toxins are detected in Oregon Environmental Health (www.cdc.gov/hab/ skin irritation. fresh waters, the Public Health Division default.htm) (accessed October 2009). DIAGOSING CYANOBACTERIA issues advisories that recommend 3. Van Dolah, Frances M. Marine algal toxins: ILLNESS avoidance of aff ected water through Origins, health effects, and their increased contact, ingestion or inhalation of occurrence. Environmental Health Perspec- The true incidence of illness due to tives 2000; 108 Supplement 1. fresh water cyanobacteria exposure droplets.