Today was a slow day. A research about fecal contamination (whoooo) in the sunny, 65 degree weather sort of day. It was also a bit of a frustrating day. Although I spent a lot of time researching, I didn’t actually find much information that was pertinent to what I was looking for. There was a lot of information about chlorination of water, but much less on the effectiveness of chlorinating storage vessels to prevent re-contamination. There was a lot of information about how fecal contamination got onto hands, but much less on whether the contamination transferred to water by touching the cups.

I’ll include my bullet-pointed list of notes at the end of this. Meanwhile, I’ll go ahead and highlight my key findings:

• Cups are definitely a source of contamination and should be cleaned (whether treated water or chlorinated water is more effective than untreated water has yet to be tested)
• Filling half a container with chlorine solution and shaking for 1 minute reduced re-contamination by 85%; rinsing removed residual chlorine and increased chance of re-contamination
• The passive chlorination system (below) was introduced in one of the papers. I figure that we may be able to adapt it for our system.
• If chlorine is used, the common standard is 200 ppm of available chlorine when cleaning equipment

I also started on my survey for the community members. Here is the link, I plan to edit it tomorrow or Wednesday with some members of Cantaro Azul.

Between starting this post and now, I’ve devoured two bags of “natural” popcorn — and the food coma is starting to hit. I’ll see y’all on the flip side!

-Horatia

Literature Review

Drinking Cup as a High Potential Recontamination Risk[i]

• 11% of these households used a glass container, 44% used plastic cups, 24% used metal cups
• Although 96% of households washed their drinking cups, only 48% washed them daily.
• A total of 347 water vessels were tested, ~⅔ of these cups were contaminated with coil.
• At home water treatment reduced the median concentration of coil to 0 CFU [IQR: 0-1], or colony forming units.
• However, only 36% of treated water inside the drinking vessels were free of coli, the water contained a median concentration of 8 CFU [IQR 0-500].
• One cause of recontamination may be due to biofilm on the inner surface of the container, which can be removed by frequent cleaning.

Fecal Contamination of Drinking Water within Peri-Urban Households[ii]

• E. coli grew in 36% of cups filled with uncontaminated, boiled water
• Wet cups were at a higher risk of recontamination than dry cups. Cup storage in dry containers also lower recontamination risk.
• All of the households claimed to wash their cups; however, only 82% washed their cups in clean, rather than used, water. Detergent was used when cleaning by 97% of households.
• The researchers also found that 91% of household residents’ hands tested positive for fecal contamination.

The effect of container-biofilm on the microbiological quality of water used from plastic household containers[iii]

• Biofilms form when bacteria adhere to surfaces in aqueous environments and excrete slimy, glue-like substances
• Found contaminant build up on the PVC container walls contained microogranisms and could therefore be considered container-biofilm
• This contributed substantially to the deterioration of water

Impact of Jerry Can Disinfection in a Camp Environment (N. Uganda)[iv]

• Three methods of cleaning jerry cans reduced recontamination by 85%, but one not better than the other (half fill and shake for 1 minute, fully fill and sit for 1 minute, and fully fill and sit for 5 minutes)
• Did not prevent recontamination at the household in 46% of jerry cans because cans were rinsed in between and lacked chlorine residual
• Note that only 13 jerry cans tested total

Guidelines for Use of Chlorine Bleach as a Sanitizer in Food Processing Operations[v]

• Solutions used for sanitizing equipment shall not exceed 200 ppm available chlorine (~1 TB bleach per gallon water)
• If higher solutions are used then the surface must be rinsed

Microbiological Evaluation of the Efficacy of Soapy Water to Clean Hands[vi]

• Soapy water preformed just as well as a bar of soap in reducing thermotolerant coliforms
• Soapy water lasts 8-10 days by latrine and 14-15 days by the kitchen. Bars of soap last around 13 days
• Bar of soap in Bangladesh is $0.35 whereas soapy water is $.09 with an additional $.09 the first month
• They only required 15 seconds to remove indicator organisms

The Effects of Interventions on HWMS and hand contamination[vii]

• Respondents who received household test results alongside normal information were equally or less likely than the information cohort (received strategies used to reduce water and sanitation illnesses) to have actual reductions of E. coli on hands

Field Effectiveness and Adoptive Chlorination System[viii]

• 60% adoption of chlorinated water in passive systems; did not require further promotional visits in order to work
• Note that the chlorine device tended to clog because of the build up of solid precipitate
• It also didn’t deliver the most reliable results

[i] Rufener, S., Mäusezahl, D., Mosler, H., & Weingartner, R. (2010). Quality of Drinking-water at Source and Point-of-consumption – Drinking Cup As a High Potential Recontamination Risk: A Field Study in Bolivia.

[ii] Oswald, W. E., Lescano, A. G., Bern, C., Calderon, M. M., Cabrera, L., & Gilman, R. H. (2007). Fecal Contamination of Drinking Water within Peri-Urban Households, Lima, Peru. The American Society of Tropical Medicine and Hygiene, 77(4), 699-704. Retrieved February 6, 2017.

[iii] Jagals, P., Jagals, C., & Bokako, T. C. (2003). The effect of container-biofilm on the microbiological quality of water used from plastic household containers. Journal of Water and Health,1(3), 101-108.

[iv] Steele, A., Clarke, B., & Watkins, O. (2008). Impact of jerry can disinfection in a camp environment – experiences in an IDP camp in Northern Uganda. Journal of Water and Health,06(4), 559. doi:10.2166/wh.2008.072

[v] Guidelines for use of chlorine bleach as a sanitizer in food processing operations. (2017, April 01). Retrieved May 08, 2017, from http://www.worldcat.org/title/guidelines-for-use-of-chlorine-bleach-as-a-sanitizer-in-food-processing-operations/oclc/671957576

[vi] Amin, N., Pickering, A. J., Ram, P. K., Unicomb, L., Najnin, N., Homaira, N., . . . Luby, S. P. (2014). Microbiological Evaluation of the Efficacy of Soapy Water to Clean Hands: A Randomized, Non-Inferiority Field Trial. American Journal of Tropical Medicine and Hygiene,91(2), 415-423. doi:10.4269/ajtmh.13-0475

[vii] Davis, J., Pickering, A. J., Rogers, K., Mamuya, S., & Boehm, A. B. (2011). The Effects of Informational Interventions on Household Water Management, Hygiene Behaviors, Stored Drinking Water Quality, and Hand Contamination in Peri-Urban Tanzania. American Journal of Tropical Medicine and Hygiene,84(2), 184-191. doi:10.4269/ajtmh.2011.10-0126

[viii] Pickering, A. J., Crider, Y., Amin, N., Bauza, V., Unicomb, L., Davis, J., & Luby, S. P. (2015). Differences in Field Effectiveness and Adoption between a Novel Automated Chlorination System and Household Manual Chlorination of Drinking Water in Dhaka, Bangladesh: A Randomized Controlled Trial. Plos One,10(3). doi:10.1371/journal.pone.0118397