Carcinogenic pathogens found in slum groundwater

Researchers from the IHE Delft Institute for Water Education as well as their colleagues from local universities in Uganda and Tanzania have found traces of 25 harmful viruses in surface waters in the slums of Kampala and Arusha.

Some of the 25 families of DNA viruses pose health risks to residents.

The study, whose findings were presented to the Assembly of the European Geoscience Union (UGU) on Monday in Vienna, revealed that most of the groundwater of the two slums – Bwaise in Kampala, Unga Limited and Sombetini in Arusha – contained traces of herpes virus, poxvirus and the most important and the papillomavirus.

The latter may be one of the causes of different types of cancer in the region.

"To our knowledge, these viruses have never been detected in groundwater on such a large scale, perhaps because there has never been a thorough badysis," said Dr. Jan Willem Foppen, the one of the leading researchers who is a hydrologist. The institute is based in the Netherlands.

Cancer is one of the leading killer diseases in the East African region, causing nearly 100,000 deaths a year.

According to the latest report of the International Agency for Research on Cancer (IARC), 32,617 new cases of cancer were reported in Uganda last year, of which 21,829 were fatal.

During the same period, Kenya recorded 47,887 new cases of cancer and 32,987 died. The trend was similar in Tanzania, where 42,060 new cases were recorded and 28,610 deaths.

Scientists have therefore feared that the widespread use of groundwater in slums for cooking, cleaning and bathing could aggravate the health situation of the inhabitants of the region.

In this two-year study, scientists badyzed water samples from a variety of sources, including surface water (rivers, sewers), springs, dug wells, and water sources. piezometers (groundwater of specific depth) in the three countries.

"We have discovered 25 families of different DNA viruses, 14 of which belong to aerial hosts including frogs, mice, rats, cows, horses, monkeys and humans," said Foppen.

Of the human pathogens present in water samples, herpes virus and poxviruses can cause various types of skin infections, while papilloma virus can cause incurable diseases such as cervical cancer, laryngeal cancer and oral cancer.

According to Foppen, "this could only be part of the iceberg," he said. "With the method we applied, we did not find all the viruses, rather we found the most abundant ones." The next step, said the scientists, is to elucidate the infectivity of viral particles.

"Let's do something about sanitation, improve drinking water sources and identify (new) routes with local communities for more sustainability," he said.