Apr 07, 2011
The NDM-1 gene bearing bacteria is no longer a hospital-born infection as a team of UK scientists find new species in the Indian capital's tap water and seepage. The researchers warn the water bugs with cholera and dysentery causing strains will spread with the monsoon rains.
It is the first time the bacteria, found in the drinking water supply of New Delhi, has been located in the wider environment outside a hospital.
The bacteria includes species which cause cholera and dysentery.
The full findings are published in The Lancet Infectious Diseases.
Cardiff scientists were the first to identify the NDM-1 gene which makes bacteria resistant to a large range of antibiotics.
Their research was extended when it was discovered that while most patients with the bacteria had recently been hospitalised in India, some cases had occurred without recent hospital treatment.
This then prompted the team to test the wider environment in New Delhi.
Samples were taken from public water taps and waste seepage, such as water pools in the streets.
Resistant bacteria was found in 4% of the water supplies, and in 30% of the water pools.
Researchers then identified 11 new species of bacteria carrying the NDM-1 gene, including strains which cause cholera and dysentery.
Antibiotics are used to reduce excretion of bacteria in cholera patients, and to reduce the duration and severity of dysentery.
Study leader, Prof Tim Walsh, from Cardiff University's School of Medicine, called the results "extremely worrying".
"We found resistant bacteria in public water used for drinking, washing and food preparation and also in pools and rivulets in heavily-populated areas where children play," he said.
"The spread of resistance to cholera and to a potential-untreatable strain of dysentery is also a cause for extreme concern," he added.
Researchers say a recent United Nations report showed 650 million Indian citizens do not have access to a flush toilet and even more probably have no clean water.
The New Delhi sewage system is also reported to be unable to cater for the city's population.
The research team also said it believes that temperatures and monsoon flooding make New Delhi ideal for the spread of NDM-1.
"This is an urgent matter of public health," said Prof Walsh.
"We need similar environmental studies in cities throughout India, Pakistan and Bangladesh to establish how widespread resistant bacteria are.
"If we are to maintain our ability to treat severe infection in vulnerable patients, this action is vital," he added.
The team has offered to help the World Health Organisation (WHO) and the Asian health authorities with the action that needs to be taken.
"The environmental spread of bacteria is also an international issue," Prof Walsh said.
"We have discovered patients in the UK and Europe carrying NDM-1 who did not visit hospitals while in India," he added.