J. Vanderslice et J. Briscoe, ALL COLIFORMS ARE NOT CREATED EQUAL - A COMPARISON OF THE EFFECTS OF WATER SOURCE AND IN-HOUSE WATER CONTAMINATION ON INFANTILE DIARRHEAL DISEASE, Water resources research, 29(7), 1993, pp. 1983-1995
Storing drinking water in the home is common in the developing world.
Several studies have documented increased concentrations of fecal coli
forms during household storage. This has led to the belief that in-hou
se water contamination is an important transmission route for enteric
pathogens and, moreover, that improving water source quality is not wa
rranted until that quality can be maintained in the home. We contend t
hat in-house water contamination does not pose a serious risk of diarr
hea because family members would likely develop some level of immunity
to pathogens commonly encountered in the household environment. Even
when there is no such immunity, transmission of these pathogens via st
ored water may be inefficient relative to other household transmission
routes, such as person-to-person contact or food contamination. A con
taminated water source poses much more of a risk since it may introduc
e new pathogens into the household. The effects of water source and in
-house contamination on diarrheal disease are estimated for 2355 Filip
ino infants. The results confirm our hypothesis: contaminated water so
urces pose a serious risk of diarrhea while contamination of drinking
water in the home does not. Water boiling is shown to eliminate the ri
sk of diarrhea due to water source contamination. The results imply th
at improvements in water source quality are more important than improv
ing water storage practices.