| Clinical
Features |
A range of syndromes, including
acute dehydrating diarrhea (cholera), prolonged febrile illness
with abdominal symptoms (typhoid fever), acute bloody diarrhea
(dysentery), and chronic diarrhea (Brainerd diarrhea). |
| Etiologic
Agent |
Common agents include Vibrio
cholerae, Campylobacter, Salmonella, Shigella,
and the diarrheogenic Escherichia coli. |
| Incidence |
Each year, an estimated 4 billion
episodes of diarrhea result in an estimated 2 million deaths,
mostly among children. Waterborne bacterial infections may
account for as many as half of these episodes and deaths.
|
| Sequelae |
Many deaths among infants and young
children are due to dehydration, malnutrition, or other complications
of waterborne bacterial infections. |
| Transmission |
Contaminated surface water sources
and large poorly functioning municipal water distribution
systems contribute to transmission of waterborne bacterial
diseases. Chlorination and safe water handling can eliminate
the risk of waterborne bacterial diseases. |
| Risk
Groups |
Over 2 billion persons living in
poverty in the developing world are at high risk. Certain
U.S. groups (residents of periurban "colonias" and remote
rural areas with poor water treatment and delivery systems)
are also at risk. |
| Surveillance |
Sporadic cases are under-reported.
CDC surveillance may detect a small proportion of outbreaks
in the United States; outbreaks abroad are often missed. |
| Trends |
Despite global efforts during the
water and sanitation decade, improvements in water and sanitation
infrastructure have barely kept pace with population increases
and migrations in the developing world. |
| Challenges |
Centralized water treatment and
distribution systems are expensive and take years to complete.
To provide the under-served with potable water in the short
term requires innovative practical solutions such as point-of-use
disinfection and safe water storage vessels. |
| Opportunities |
Electrolytic generators that produce
sodium hypochlorite from salt water are now affordable and
available for use in the developing world. Villages that produce
and use sodium hypochlorite and that store treated water in
vessels to protect it from recontamination have had nearly
50% reductions in diarrheal disease incidence for pennies
per family. This strategy has been successfully field tested
in households in Bolivia, Zambia, Kenya, and Pakistan, in
oral rehydration clinics in Guinea-Bissau, and among street
vendors in Guatemala. |
|
December 2003
|
