HOUSEHOLDERS WHO use water from private wells have been strongly advised by the Health Protection Surveillance Centre (HPSC) to ensure their wells are properly maintained following an increase in cases of E.coli infection.
To date this year there have been 139 cases of verotoxigenic E.coli (VTEC) reported across the State compared to about 70-90 cases for the same period in previous years.
In 62 of the 139 cases those who became infected were under five years of age and in 11 cases those who became infected suffered complications. However, all patients have since recovered or are recovering.
Some 98 of the 139 cases reported were found to be E.coli 0157, 33 were E.coli 026 and eight were other E.coli organisms.
Dr Darina O'Flanagan, director of the HPSC, said 30 per cent of the 139 cases occurred in households using private wells.
"In general only 10 per cent of households have private wells, so there is an over-representation of people in households that have private wells among those who became ill," she explained.
"The issue that causes concern is in recent months we have been informed by colleagues in HSE South of 13 cases of VTEC and in all but two of the cases they were getting water from private wells. One was a family cluster with four cases and the well was found to be contaminated with E.coli 0157," she said. The HPSC, she added, was also aware of a case of VTEC in the southeast where the person who contracted the infection was found to have been drinking water from a well contaminated with E.coli 0157.
However, she stressed not all cases in private well households will have been caused by water consumption. People with wells tend to be farming families and could be at risk of picking up the infection from direct contact with animals and not washing their hands afterwards. The bug is carried in faeces.
VTEC can cause severe diarrhoea and abdominal cramps. Usually there is little or no fever, and patients recover within five to 10 days.
However, some people, particularly children under five and the elderly, are at risk of a complication called haemolytic uraemic syndrome (HUS), in which the red blood cells are destroyed and the kidneys fail.
This complication occurred in 11 of the 139 cases this year.
Dr O'Flanagan said there was evidence the increase in VTEC cases may be linked to rainfall this summer. "This summer's heavy rainfall has caused very high water table levels, excessive run off and flooding which increases the chances of drinking water being contaminated.
"After periods of heavy rainfall well users may need to consider boiling water for consumption or taking other appropriate measures. This is particularly important if vulnerable people such as children, the elderly or immunocompromised persons are drinking the water, especially if the water colour changes or it smells or tastes differently."