Potential links between irrigation water quality and microbiological quality of food in subsistence farming in KwaZulu-Natal, South Africa

To lead a healthy lifestyle, it is essential to have a diet that includes fresh and minimally processed fruit and vegetables. A large proportion of the South African population exhibits suppressed immune systems, largely due to the HIV/AIDS epidemic. It is therefore imperative that minimally processed foods are not contaminated with potentially pathogenic microorganisms. As a result of local fresh water scarcity, many farmers resort to using surface water for irrigation. Due to a large number of informal settlements located near river systems lacking adequate sanitation, South Africa’s rivers are prone to microbial pollution. A selected river in KwaZulu-Natal (South Africa), as well as fresh vegetables irrigated with this water, were therefore analysed to verify whether a transfer of potential pathogens onto produce might take place. The river selected was the Baynespruit, which is used to irrigate a local market garden. Microbiological analysis (for example detection of faecal coliforms) of river water and fresh produce was conducted using standard procedures. Both irrigation water and fresh produce samples showed the presence of faecal coliforms and E. coli with the microbial load of river water typically several times higher than the values recommended by WHO guidelines for safe use of wastewater. This demonstrates that the transfer of river bound microorganisms via irrigation water to fresh produce can take place and might therefore lead to fresh produce contamination at unacceptable levels.