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Paralytic shellfish poisonings resulting from an algal bloom in Nicaragua.

Callejas L, Darce AC, Amador JJ, Conklin L, Gaffga N, Schurz Rogers H, DeGrasse S, Hall S, Earley M, Mei J, Rubin C, Aldighieri S, Backer LC, Azziz-Baumgartner E - BMC Res Notes (2015)

Bottom Line: PSP in humans is caused by ingestion of saxitoxin, which is a neurotoxin often associated with shellfish contaminated by algal blooms.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.

View Article: PubMed Central - PubMed

Affiliation: Field Epidemiology Training Program, Managua, Nicaragua, USA. lcallejas@asamblea.gob.ni.

ABSTRACT

Background: 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.

Findings: 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.

Conclusions: These findings suggest that a bloom of saxitoxin-producing algae resulted in saxitoxin accumulation in local clams and was responsible for the PSP intoxication.

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Related in: MedlinePlus

Anadara tuberculosa(concha negra) implicated in Isla Madera paralytic shellfish poisoning in Nicaragua, November, 2005.
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Fig3: Anadara tuberculosa(concha negra) implicated in Isla Madera paralytic shellfish poisoning in Nicaragua, November, 2005.

Mentions: During November 4–16, 45 possible PSP cases were reported from El Playón, Corinto, El Realejo, Chichigalpa, Chinandega, and El Viejo, Nicaragua, including one case with severe respiratory distress and one death. The most affected area was a small island off the coast of Corinto called Maderas Negras Island (Figure 2) where 10% of the population became ill after eating shellfish harvested in local bays (Figure 3). Samples of shellfish obtained from nearby areas were analyzed in Managua, Nicaragua, for the presence of neurotoxins using the mouse bioassay [8] and tested strongly positive for a toxicant. All 15 mice died after an intraperitoneal injection of 1 ml of an acid extraction from the implicated shellfish samples, with survival time ranging from 1–15 minutes.Figure 2


Paralytic shellfish poisonings resulting from an algal bloom in Nicaragua.

Callejas L, Darce AC, Amador JJ, Conklin L, Gaffga N, Schurz Rogers H, DeGrasse S, Hall S, Earley M, Mei J, Rubin C, Aldighieri S, Backer LC, Azziz-Baumgartner E - BMC Res Notes (2015)

Anadara tuberculosa(concha negra) implicated in Isla Madera paralytic shellfish poisoning in Nicaragua, November, 2005.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4359551&req=5

Fig3: Anadara tuberculosa(concha negra) implicated in Isla Madera paralytic shellfish poisoning in Nicaragua, November, 2005.
Mentions: During November 4–16, 45 possible PSP cases were reported from El Playón, Corinto, El Realejo, Chichigalpa, Chinandega, and El Viejo, Nicaragua, including one case with severe respiratory distress and one death. The most affected area was a small island off the coast of Corinto called Maderas Negras Island (Figure 2) where 10% of the population became ill after eating shellfish harvested in local bays (Figure 3). Samples of shellfish obtained from nearby areas were analyzed in Managua, Nicaragua, for the presence of neurotoxins using the mouse bioassay [8] and tested strongly positive for a toxicant. All 15 mice died after an intraperitoneal injection of 1 ml of an acid extraction from the implicated shellfish samples, with survival time ranging from 1–15 minutes.Figure 2

Bottom Line: PSP in humans is caused by ingestion of saxitoxin, which is a neurotoxin often associated with shellfish contaminated by algal blooms.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.

View Article: PubMed Central - PubMed

Affiliation: Field Epidemiology Training Program, Managua, Nicaragua, USA. lcallejas@asamblea.gob.ni.

ABSTRACT

Background: 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.

Findings: 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.

Conclusions: These findings suggest that a bloom of saxitoxin-producing algae resulted in saxitoxin accumulation in local clams and was responsible for the PSP intoxication.

Show MeSH
Related in: MedlinePlus