Deadly Diarrheal Disease Triggered by Use of Wastewater on Crops in Developing Countries

Researchers from Australia have identified another source responsible for the spread of a deadly virus called rotavirus, which is one of the major causes of diarrheal diseases.

The report documented in the journal Risk Analysis, found that wastewater used to irrigate vegetable crops may significantly contribute to the risk of rotavirus.  Several developing countries use wastewater for irrigation purposes.

The study led by Dr Andrew Hamilton from the Melbourne School of Land and Environment, mainly concentrated on region around Beijing. He identified that the children consuming vegetables grown with wastewater have higher risk of diarrhoea.

Diarrheal disease is one of the leading causes of preventable death especially among children below five years in developing countries. In such countries 99 percent of deaths occur mainly due to the diarrheal disease out of which 90 percent of them are children under five years.

"This research shows that the use of wastewater in irrigation is a global critical health issue for the Asia Pacific region and beyond. There can be lots of microorganisms that cause disease in wastewater. They can be transferred from infected people, travel through the sewerage system, and then be eaten from the vegetables. This is a dangerous cycle," said Dr. Hamilton in a news release.

During the study investigation, the researcher noticed that few vegetables contributed to greater health risks when compared to others. The greatest health risk was posed by Choy Sum, Chinese flowering cabbage. The least risk was caused by Bok Choy, a variety of Chinese leaf vegetables. The reason for the variation in the health risk they posed is mainly due to the shape of the leaf. The total amount of wastewater and contaminants retained in the leaf is based on its shape.

When compared to the rest of the world, China uses a lot of wastewater irrigation. Most of it is used to grown vegetables. Based on this finding, the researcher recommends that China develops its own guidelines for wastewater use.

The researcher also highlighted the Asian and other developing countries where similar situation exists, where the risk posed by diarrheal disease is highest.

"Vaccination programs for rotavirus are being rolled out globally, but at this stage, they are far from reaching all children in developing countries.

"When vaccinations cannot be relied upon to stop the spread of rotavirus and other diarrheal diseases, research like this is very important to identify other contributing causes," explained Dr Hamilton.