Shoemaker R C
McCready Outpatient Services Center, Pocomoke City, Maryland 21851, USA.
Environ Health Perspect. 2001 Oct;109 Suppl 5(Suppl 5):791-6. doi: 10.1289/ehp.01109s5791.
Evidence suggests that the estuarine dinoflagellates, Pfiesteria piscicida Steidinger & Burkholder and P. shumwayae Glasgow & Burkholder, members of the toxic Pfiesteria complex (TPC), may release one or more toxins that kill fish and adversely affect human health. In the current study we investigated the potential for undiagnosed cases of possible estuary-associated syndrome (PEAS), as termed by the Centers for Disease Control and Prevention (CDC), in a population that had residential and/or recreational exposure to TPC-affected estuaries, but that did not have direct contact with fish kills or lesioned fish. Age-adjusted visual contrast sensitivity (VCS) was significantly lower and the presence of PEAS-associated symptoms was much higher in the estuary cohort (n = 77) than in combined-control cohorts (n = 87), one without exposure to bodies of water (n = 53) and one with exposure to marine waters (n = 34). In the estuary cohort, 37 individuals met the CDC case definition for PEAS and had significantly lower VCS than non-PEAS cases. The VCS improved and symptoms abated after 2 weeks of treatment with cholestyramine. Cholestyramine, the original drug approved for treatment of hypercholesterolemia, has previously been reported to enhance the elimination rates of a variety of toxins, presumably by interruption of enterohepatic recirculation through toxin entrapment in its polymeric structure and/or anion-exchange process. Control studies showed that repeated VCS testing alone did not improve VCS scores and that cholestyramine treatment did not affect VCS in patients with elevated cholesterol levels. These results suggested that a) susceptible individuals may acquire PEAS through residential and/or recreational contact with TPC-affected estuaries in the absence of an active fish kill; b) VCS is a useful indicator in PEAS diagnosis and treatment monitoring; and c) PEAS can be effectively treated with cholestyramine. Because the study did not use population sampling techniques, the results do not indicate PEAS prevalence. Furthermore, definitive diagnosis of PEAS and association with TPC toxin(s) must await identification of, and a serologic test for, the putative TPC toxin(s).
有证据表明，河口甲藻，即有毒费氏藻复合体（TPC）的成员派氏费氏藻（Pfiesteria piscicida Steidinger & Burkholder）和舒氏费氏藻（P. shumwayae Glasgow & Burkholder），可能释放一种或多种毒素，这些毒素会杀死鱼类并对人类健康产生不利影响。在本研究中，我们调查了在一个有居住和/或娱乐性接触受TPC影响河口但未直接接触鱼类死亡或患病鱼类的人群中，未确诊的可能与河口相关综合征（PEAS，由美国疾病控制与预防中心（CDC）命名）病例的可能性。经年龄调整的视觉对比敏感度（VCS）在河口队列（n = 77）中显著低于联合对照队列（n = 87），联合对照队列包括一个未接触水体的队列（n = 53）和一个接触海水的队列（n = 34），且河口队列中PEAS相关症状的出现率更高。在河口队列中，37名个体符合CDC对PEAS的病例定义，其VCS显著低于非PEAS病例。用消胆胺治疗2周后，VCS有所改善，症状减轻。消胆胺是最初被批准用于治疗高胆固醇血症的药物，此前有报道称它可提高多种毒素的清除率，推测是通过其聚合结构中的毒素截留和/或阴离子交换过程中断肠肝循环来实现的。对照研究表明，仅重复进行VCS测试并不能提高VCS分数，且消胆胺治疗对胆固醇水平升高的患者的VCS没有影响。这些结果表明：a）易感个体可能在没有活跃的鱼类死亡的情况下，通过居住和/或娱乐性接触受TPC影响的河口而患上PEAS；b）VCS是PEAS诊断和治疗监测中的一个有用指标；c）消胆胺可有效治疗PEAS。由于该研究未使用人群抽样技术，结果并未表明PEAS的患病率。此外，PEAS的明确诊断以及与TPC毒素的关联必须等待对假定的TPC毒素进行鉴定并开展血清学检测。
