However, the risks associated with cholera are not limited to poorly serviced areas, and any settlement where there is faecal contamination of water resources is a risk.
Cholera risks and levels of services
Communities with no sanitation services are forced into bush toiletting – often along the banks of rivers. These communities often rely on these same rivers for their drinking and washing water. The cholera bacterium therefore spreads by people drinking contaminated water.
In settlements with waterborne sanitation systems, human waste is usually safely removed from the settlement for treatment elsewhere. These communities also tend to have ready access to treated and safe water supplies. Cholera risks are therefore lower in these areas. But, when these services fail the risks of transmitting the cholera bacterium can be very high.
When waterborne sanitation systems fail wastewater flows untreated into nearby rivers, or often flows between the houses themselves. The cholera risks associated with this are:-
- These settlements may lie upstream of communities still using untreated water from rivers.
- Children may play in the polluted effluent and ingest the bacterium.
- Baptisms often occur in rivers near these settlements.
- As faecal waste is mobilised in water, it readily flows down to rivers.
- Population densities are often higher in these areas increasing the chances of infection.
- In some cases communities no longer use the services provided.
- Solid waste problems in these areas increase the risk of insects (like flies) transmitting the disease.
What are the underlying causes of pollution in settlements with higher levels of services?
Pollution in settlements with higher levels of services normally occurs due to the physical failure of the sewer systems. This may be due to the capacity being exceeded where population densities are too high for the services. In many settlements there are often frequent sewer blockages or pump station failures. However, these physical causes are often underlain by Institutional or Social causes.
Institutional causes arise where the service provider does not have the capacity to operate and maintain the services effectively. Social causes arise where the community does not use the services properly. In most cases pollution in settlements is due to a combination of these two causes.
