目標：為回應聯邦疾病監測及應變單位（Federal Disease Surveillance and Response Unit） 所報導位於巴基斯坦伊斯蘭瑪巴德I-9/4區的急性水樣腹瀉（acute watery diarrhea, AWD）個案， 巴基斯坦國家衛生研究院（National Institute of Health）派出調查團，前往確認該地疫情、找出風險因素、提出疫情控制建議。方法：採用描述性研究方法，在2018年7月27日至8月20日期間探討潛在病因以及該疾病的傳播途徑。本研究透過逐戶調查搭配已建立的AWD個案定義，積極尋找個案，研究期間中一共調查了508戶，確認了46個AWD個案。結果：研究結果顯示，存儲在不安全飲用容器中的地下水（OR 0.1916, CI 0.0633-0.5798, p < 0.0034）及公共水龍頭提供的飲用水（OR 6.6182, CI 5.2384-25.3678, p < 0.0027）是最有可能導致此次疫情爆發的原因。雖然大部分的個案（n = 30, 65.2%）都知道水質不好，但他們仍然選擇持續飲用，且所有個案家中都有封閉式排水的廁所設備（100%），此因素可能引爆疾病傳染。最常見的徵兆和症狀為腹瀉、腹絞痛、嘔吐、發燒等，此地區居民有良好的經濟地位以及教育程度。結論：此地區AWD疫情爆發的狀況顯示出，公共區域的供水隨時都有可能受到污染，進而造成疫情爆發。

Objectives: In response to the reports of presence of acute watery diarrhea (AWD) in sector I-9/4 of Islamabad, Pakistan, the Federal Disease Surveillance and Response Unit of the National Institute of Health (NIH) Islamabad appointed an outbreak investigation team to confirm the outbreak, identify risk factors and formulate recommendations for control. Methods: A descriptive study was conducted from July 27 to August 20, 2018 to investigate the potential causation of illness and modes of transmission in the outbreak. Active case finding started through a house-to-house case search and the establishment of a case definition. A total of 46 cases of AWD were identified by surveying 508 homes during the study period. Results: The study results revealed that ground bore water (OR 0.1916, CI 0.0633-0.5798, p < 0.0034) and public supply water (OR 6.6182, CI 5.2384-25.3678, p < 0.0027) stored in unsafe utensils for drinking are probable causes of this outbreak. Despite most of these people (n = 30, 65.2%) being aware of the poor quality of the water, they still consuming it. All cases had closed drained toilet facilities at their homes which may have resulted in triggering of the infection. Commonly witnessed signs/symptoms included loss of motion, abdominal cramps, vomiting and fever. People living in this sector belong to an excellentsocio-economic class. Conclusions: The outbreak of AWD in this area revealed that the public water supply may become contaminated at any instance resulting in an outbreak.