Microbiological Evaluation of 5 L- and 20 L-Transparent Polypropylene Buckets for Solar Water Disinfection (SODIS).

BACKGROUND: Solar water disinfection (SODIS) is an appropriate technology for household treatment of drinking water in low-to-middle-income communities, as it is effective, low cost and easy to use. Nevertheless, uptake is low due partially to the burden of using small volume polyethylene terephthalate bottles (1.5-2 L). A major challenge is to develop a low-cost transparent container for disinfecting larger volumes of water. (2) Methods: This study examines the capability of transparent polypropylene (PP) buckets of 5 L- and 20 L- volume as SODIS containers using three waterborne pathogen indicators: Escherichia coli, MS2-phage and Cryptosporidium parvum. (3) Results: Similar inactivation kinetics were observed under natural sunlight for the inactivation of all three organisms in well water using 5 L- and 20 L-buckets compared to 1.5 L-polyethylene-terephthalate (PET) bottles. The PP materials were exposed to natural and accelerated solar ageing (ISO-16474). UV transmission of the 20 L-buckets remained stable and with physical integrity even after the longest ageing periods (9 months or 900 h of natural or artificial solar UV exposure, respectively). The 5 L-buckets were physically degraded and lost significant UV-transmission, due to the thinner wall compared to the 20 L-bucket. (4) Conclusion: This work demonstrates that the 20 L SODIS bucket technology produces excellent bacterial, viral and protozoan inactivation and is obtained using a simple transparent polypropylene bucket fabricated locally at very low cost ($2.90 USD per unit). The increased bucket volume of 20 L allows for a ten-fold increase in treatment batch volume and can thus more easily provide for the drinking water requirements of most households. The use of buckets in households across low to middle income countries is an already accepted practice.

Community Knowledge Variation; Bed-Net Coverage and the Role of a District Healthcare System; and their Implications for Malaria Control in Southern Malawi

This paper presents data on the pattern of knowledge of caregivers; bed-net coverage and the role of a rural district healthcare system; and their implications for malaria transmission; treatment; prevention and control in Chikhwawa; southern Malawi; using multi-level logistic regression modelling with Bayesian estimation. The majority of caregivers could identify the main symptoms of malaria; that the mosquito was the vector; and that insecticide-treated nets (ITN) could be used to cover beds as an effective preventative measure; although cost was a prohibitive factor. Use of bed nets displayed significant variation between communities. Groups that were more knowledgeable on malaria prevention and symptoms included young mothers; people who had attended school; wealthy individuals; those residing closest to government hospitals and health posts; and communities that had access to a health surveillance assistant (HSA). HSAs should be trained on malaria intervention programmes; and tasked with the responsibility of working with village health committees to develop community-based malaria intervention programmes. These programmes should include appropriate and affordable household improvement methods; identification of high-risk groups; distribution of ITNs and the incorporation of larval control measures; to reduce exposure to the vector and parasite. This would reduce the transmission and prevalence of malaria at community level