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Spraying with chlorine for cholera response – effective or not?


Do you have any technical papers which demonstrate the efficacy of spraying with chlorine to control cholera outbreaks? It is standard practice but we don't have evidence to prove that it actually works.



6 Answers


My one comment (as a non-physician) would be that cholera is water bourne so not sure how spraying (surfaces?) with chlorine is going to have much of an impact on control. But I am no expert at all.



I am presently running a program in Sulaymaniyah (North Iraq) to control a cholera epidemic there. The program is funded by IOM and is in coordination with the local Health Authority. It is based in 20 team going around proceeding to chlorination of water of superficial ground water wells, the contamination of which has caused the epidemic. This is the seventh epidemic I am involved with. Both as a physician and as a health manager. That made clear, I never heard of chlorine spraying to control cholera. I am always willing to learn. I am a member of the East Africa Association of Surgeons, the motto of which is "Ex Africa Semper Aliquid Novum" What is this chlorine spraying? Which chemical form of chlorine? Spraying where or what?



I have witnessed cholera rather than being involved in responding. All the literature talks of using chlorine solutions of various strengths for sterilizing equipment, working areas/surfaces, hands, bodies, waste etc.. The inquiry seems to imply spraying in a more general sense – which I have never heard of and it sounds expensive and inefficient.



I have never heard of spraying to control cholera. Spraying what exactly? Chlorine is an effective disinfectant, solutions of which can be used to decontaminate surfaces such as walls, floors, hands and utensils to prevent transmission of the disease by contact with these surfaces; such solutions are commonly used as part of the hygiene protocols in cholera treatment centres. Chlorine can also be used to disinfect water supplies where free residual chlorine in the water will provide continued protection from further contamination. These are the only common uses of chlorine that I am aware of. John Cod.


Spraying chlorine generally would not make much sense - however perhaps it is an organochlorine (i.e. a pesticide) that is being sprayed?

Although organochlorine have fallen somewhat into disfavour because of their persistence in the environment, they can be effective against flies - which one would be keen to control in a cholera outbreak.

John Cos.


Hi, normal practice would be to focus on surfaces known to be contaminated, using 0.2% chlorine solution for walls, floors, beds, shoes etc. that may have been shat or vomited on and 0.5% solution for contact with skin. I can't cite the evidence, but chlorine at these concentrations is an extremely effective disinfectant and it would certainly reduce the numbers of vibrios drastically.

General spraying as a preventive measure would not be advised, as John Cosgrave points out.

John A.