Guévart E, Van Hecke C, Noeske J, Sollé J, Bita Fouda A, Manga B
Délégation Provinciale de la Santé publique du Littoral, BP 1329 Douala, Cameroun.
Med Trop (Mars). 2008 Oct;68(5):507-13.
Well disinfection is generally recommended as an emergency response measure during cholera outbreaks. However few studies have been carried out to document chlorination techniques, prove the efficacy of chlorination, or determine how often disinfection should be performed. The purpose of this study was to test a handmade device for continuous chlorination, to measure the initial concentration of free residual chlorine, and monitor chlorine concentration to determine when renewal is necessary. Eighteen wells in 2 neighbors of Douala, Cameroon, i.e., 9 wells/neighborhood, were tested. Testing included daily measurement of water volume, pH, and residual chlorine for a period of two weeks after installing the handmade device composed of river sand and hypochlorite in a pre-perforated plastic bag that was renewed after disappearance of free residual chlorine. The maximum concentration of residual chlorine was reached after 1 day in 31 out of 36 chlorinations or 2 days in 5 out of 36. On day 4 the chlorine level was less than 0.2 mg/l in half of the wells. The chlorine concentration was higher in family than community wells. Notwithstanding feasibility and acceptability issues, the device allowed chlorination at effective nontoxic levels for 3 days. These findings open the possibility of developing devices allowing longer diffusion at lower cost for use within the framework of integrated cholera epidemic control programs.
在霍乱暴发期间，通常建议对水井进行消毒作为应急响应措施。然而，很少有研究记录氯化技术、证明氯化效果或确定消毒的频率。本研究的目的是测试一种用于连续氯化的手工制作装置，测量游离余氯的初始浓度，并监测氯浓度以确定何时需要更换。对喀麦隆杜阿拉两个社区的18口水井进行了测试，即每个社区9口水井。测试包括在安装由河沙和次氯酸盐组成的手工制作装置后，连续两周每天测量水量、pH值和余氯，该装置放置在预先打孔的塑料袋中，当游离余氯消失后进行更换。在36次氯化中，有31次在1天后达到余氯最高浓度，5次在2天后达到。在第4天，一半的水井中氯水平低于0.2毫克/升。家庭水井中的氯浓度高于社区水井。尽管存在可行性和可接受性问题，但该装置能以有效的无毒水平进行3天氯化。这些发现为开发能够以更低成本实现更长时间扩散的装置提供了可能性，以便在霍乱疫情综合防控计划框架内使用。
