在1989年至1990年的两年期间，16个州报告了26起来自饮用水的水传播疾病暴发。这些暴发导致约4288人患病。蓝氏贾第鞭毛虫被认为是12起疫情中的7起的病原体，其中一起是病原体。贾第虫病的暴发都与摄入未经过滤的地表水或受地表水影响的地下水有关。一场有四人死亡的疫情归因于大肠杆菌O157:H7，这是所有疫情调查中唯一涉及的细菌病原体。缓解性、复发性腹泻的暴发与蓝藻样体有关，蓝藻在引起腹泻疾病中的作用正在研究中。两起由甲型肝炎引起的疫情和一起由诺沃克类药物引起的疫情与使用井水有关。国家对水传播疾病暴发的监测已经进行了20年，这仍然是描述水传播疾病流行病学特征的有用手段。 包括24个参考文献、表格和图表。

For the two-year period 1989-90, 16 states reported 26 outbreaks of waterborne disease from water intended for drinking. These outbreaks resulted in illness in an estimated 4,288 people. Giardia lamblia was implicated as the etiologic agent for seven of the twelve outbreaks in which an agent was identified. The outbreaks of giardiasis were all associated with ingestion of unfiltered surface water or groundwater influenced by a surface water. An outbreak with four deaths was attributed to Escherichia coli O157:H7, the only bacterial pathogen implicated in any of the outbreak investigations. An outbreak of remitting, relapsing diarrhea was associated with cyanobacteria (blue-green algae)-like bodies, whose role in causing diarrheal illness is being studied. Two outbreaks caused by hepatitis A and one caused by a Norwalk-like agent were associated with use of well water. National surveillance of outbreaks of waterborne disease, which has been conducted for two decades, continues to be a useful means for characterizing the epidemiology of waterborne diseases. Includes 24 references, tables, figures.