Threat from drug-resistant cholera

Cholera outbreaks kill hundreds every year

Strains of cholera resistant to some of the key antibiotics used to treat it have been found by Indian researchers.

They suggest that overuse of certain drugs be curbed to avoid giving the bacterium even more staying power.

A recent outbreak of severe, dehydrating, diarrhoea in West Bengal has already been linked with the emergence of strains resistant to furazolidone, antibiotics commonly used to treat cholera in children.

The latest study, published in the Journal of the Indian Medical Association, is further evidence that the dangerous illness is becoming harder to treat.

A team from the National Institute of Cholera and Enteric Diseases in Calcutta analysed samples taken from 23 adults taken ill during an outbreak in West Bengal in 1997.

They found that the bacteria isolated from the samples were all resistant to five commonly-used antibiotics, and seven samples showed some resistance to another key drug.

One, furazolidone, is particularly worrying because it is the first choice drug for children, who cannot tolerate more powerful antibiotics such as tetracycline.

Bacteria gain resistance against antibiotics when the course of drugs does not kill eradicate all the bacteria in the body.

Bacteria thrive

Those which survive are likely to be those with slightly more resistance naturally, so an incomplete antibiotic cure will kill off weaker bacteria, leaving stronger ones to thrive.

The more those bacteria encounter the same antibiotic, the more likely it is that powerful strains will emerge.

The problem is compounded if patients do not complete the full week or two week course of drugs, because, even if they feel better, it is unlikely that all the bacteria in their bodies will have been killed, and they can still pass these onto other people.

Fortunately, there are still a number of antibiotics which are effective against Cholera.

The disease has been a particular concern for health authorities in India following widespread flooding in some districts over recent weeks.

Cholera is passed from person to person by poor sanitation conditions.

It causes severe diarrhoea and vomiting, which can quickly lead to dangerous levels of dehydration, particularly in younger children, babies and the elderly.

In addition to antibiotics, doctors use intensive rehydration.