Title |
Paralytic shellfish poisonings resulting from an algal bloom in Nicaragua
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Published in |
BMC Research Notes, March 2015
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DOI | 10.1186/s13104-015-1012-4 |
Pubmed ID | |
Authors |
Luis Callejas, Ana Cristian Melendez Darce, Juan Jose Amador, Laura Conklin, Nicholas Gaffga, Helen Schurz Rogers, Stacey DeGrasse, Sherwood Hall, Marie Earley, Joanne Mei, Carol Rubin, Sylvain Aldighieri, Lorraine C Backer, Eduardo Azziz-Baumgartner |
Abstract |
During an October 2005 algal bloom (i.e., a rapid increase or accumulation in the population of algae) off the coast of Nicaragua, 45 people developed symptoms of paralytic shellfish poisoning (PSP) and one person died. PSP in humans is caused by ingestion of saxitoxin, which is a neurotoxin often associated with shellfish contaminated by algal blooms. To explore the relationship between the algal bloom and human illnesses, we performed a case-control study of residents living in a coastal island. We administered a standardized clinical questionnaire, sampled locally harvested seafood and algae, and obtained urine samples for saxitoxin testing from symptomatic and asymptomatic persons. PSP case-patients were defined as island residents who developed at least one neurological symptom during the November 4-16 intoxication period. Seafood and algal samples were analyzed for saxitoxins using the receptor-binding assay and high-performance liquid chromatography. Two urine samples were analyzed for saxitoxins using a newly developed immunoassay. Three shellfish and two algal samples tested positive for saxitoxins. Ten (9%) of 107 participants developed neurological symptoms during the specified time period and five required hospitalization. While 6 (67%) of 9 possible case-patients and 21 (21%) of 98 controls had eaten fish (p=0.008), all case-patients and 17 (17%) of controls had eaten clams (P<0.0001). The saxitoxin concentration in the urine of a hospitalized case-patient was 21 ng saxitoxin/g creatinine compared to 0.16 ng saxitoxin/g creatinine in the single control patient's urine. These findings suggest that a bloom of saxitoxin-producing algae resulted in saxitoxin accumulation in local clams and was responsible for the PSP intoxication. |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
Unknown | 47 | 100% |
Demographic breakdown
Readers by professional status | Count | As % |
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Researcher | 10 | 21% |
Student > Master | 10 | 21% |
Student > Ph. D. Student | 5 | 11% |
Other | 3 | 6% |
Student > Bachelor | 3 | 6% |
Other | 5 | 11% |
Unknown | 11 | 23% |
Readers by discipline | Count | As % |
---|---|---|
Agricultural and Biological Sciences | 8 | 17% |
Environmental Science | 6 | 13% |
Medicine and Dentistry | 5 | 11% |
Biochemistry, Genetics and Molecular Biology | 4 | 9% |
Chemistry | 3 | 6% |
Other | 7 | 15% |
Unknown | 14 | 30% |