Faecal-oral paradigm: part 5 - Good summary paper

When researching my mini-series of blogs on the faecal-oral paradigm I found this paper provides a nice context for the arguments outlined in part 3. 

The study by Tumwine et al., (2002)  revisits the work of the original Drawers of Water study, surveying 1015 households in 33 sites across Uganda, Tanzania and Kenya. Results showed that 1/3 of households which relied on an unprotected surface source as the main source of water reported at least one case of diarrhea in the week before the survey with the type of surface source important too. The use of streams and rivers had lower incidence than using springs, reservoirs and ponds. Water vendors also appear to be much safer sources of water than communal piped connections. The type of sanitation facility also appeared important. For instance, out of piped households, 14% with a pit latrine had at least one incidence of diarrhea, where as for piped households with a flush toilet households this was lower at 7.4%. The piped vs unpiped disparity was also apparent with unpiped households without sanitation displaying much higher prevalence at 66%, whereas those with pit latrines reduced prevalence to 20%.

Examples of unsafe vs improved sources of drinking water.
The use of unpiped surface water was found to be significant in increasing
 diarrhoeal prevalence. Source: UCL lectures: Credit: Richard Taylor.

In addition to these observational results, the study also performed multiple regression analysis, with particularly interesting results. The chance of a diarrhea case was higher for unpiped households. However, rather surprisingly, the results showed that the use of unimproved toilet facilities, and or observed faces near the toilet was not significantly correlated with diarrhea. Furthermore, the type of sanitation facility was not important but ownership of any form of toilet or pit latrine was. This supports earlier findings which have argued for the particular importance of improving satiation, but suggests the type of sanitation facility should be of lesser concern. As suggested above, the use of surface water as a primary source was significant in in creasing diarrhoeal prevalence. Furthermore, supporting the arguments of Esrey et al. (1991) in part 3 of this mini-series,  the use of water for household cleaning can prevent disease prevalence, with each increase in litres per capita per day reducing the odds of diarrhoeal prevalence by 0.96.

Therefore, according to Tumwine et al., the biggest determinants in preventing faecal-oral transmission appear to relate to:

1. Water source
2. Amount of water used for personal and household hygiene
3. Ownership of a latrine or sanitation facility - type is less important

The next mini-series of blogs will focus on the varying pathways for enforcing these factors to prevent faecal-oral transmission.