The growth of microbiological organisms and pathogenic contamination are linked to problems of water contamination with nutrients or human excreta. Water borne diseases such as diarrhoea, cholera, typhoid, gastro-entertitis and hepatitis are the primary cause of disease and poor health in the SADC region (SADC 2009). Micro-organisms enter rivers via untreated human waste and partially-treated sewage and can cause various diseases amongst downstream users. Potential costs to society include:
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Increasing burden on healthcare facilities;
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Loss of income to families;
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Cost of funerals;
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Loss of production in the economy; and
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Adverse media attention and its effect on overseas tourism.
 Giardia is a common protozoal parasite that can cause diarrhea in people. Source: Weese 2008 ( click to enlarge ) |
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A site specific survey relating to water and health issues in the lower Kunene River basin raised potential problems with:
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Diarrhoea;
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Bilharzia;
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Malaria; as well as
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Colds and respiratory tract infections.
Cholera is also a major concern, particularly along the Lower Kunene. In the first four months of 2008 for example, a record 2 168 cases had been reported. Cholera is spread by the direct contamination of drinking water or food with the faeces of an infected person. However, in the site specific study carried out in the Lower Kunene in 2009 the majority of interviewed women did not understand any relationship between water and illnesses (ERM 2009).
Of greater major concern for the local people is the turbidity of the river water following heavy rains. High turbidity is commonly associated with stomach ache and other diseases.
In water sources subjected to significant levels of faecal pollution, some correlation can be expected between turbidity and faecal indicators or pathogens. The strength of this correlation is variable and while some approximations can be made, its value in decision making will be site-specific (Allen et al. 2008).
