"Suberbug" bugs India

Coming back to the blog after a long time.

The issue today is the “Superbug”. Indian print and visual media is full of reports about NDM-1, translated as New Delhi metallo-beta-lactamase-1. No, NDM-1 is not the “superbug”. It is the name given to a gene that causes multiple drug (antibiotic) resistance to bacteria that carry this gene.

The Lancet Infectious Diseases, a British journal, published an article titled “Emergence of a new antibiotic resistance mechanism in India, Pakistan, and the UK: a molecular, biological, and epidemiological study” on August 11, 2010. This article reports results from a study in which the authors “investigated the prevalence of NDM-1 in mutidrug-resistant Enterobacteriaceae in India, Pakistan, and the UK”. They found widespread prevalence of NDM-1 in India and Pakistan. Some, but not all, of the UK cases were linked to travel and hospitalization in India.

Here is a link to the paper.

If you want to read it, you have to register at the Lancet site. This is surprising since the work was partially funded by the Wellcome Trust, which has a stated Open Access policy.

“The potential of NDM-1 to be a worldwide public health problem is great, and co-ordinated international surveillance is needed”. This is the final interpretation of this scientific study. There is nothing wrong about that.

So what is the brouhaha all about?

It is the last paragraph of the paper, which reads as follows.

“Several of the UK source patients had undergone elective, including cosmetic, surgery while visiting India or Pakistan. India also provides cosmetic surgery for other Europeans and Americans, and blaNDM-1 will likely spread worldwide. It is disturbing, in context, to read calls in the popular press for UK patients to opt for corrective surgery in India with the aim of saving the NHS money. As our data show, such a proposal might ultimately cost the NHS substantially more than the short-term saving and we would strongly advise against such proposals. The potential for wider international spread of producers and for NDM-1-encoding plasmids to become endemic worldwide, are clear and frightening”.

This is an unusually tough conclusion, not fully supported by results shown in the Lancet Infectious Disease paper. The authors say, and I quote “We could not prove statistically significant strain relatedness between the Indian and UK isolates”.

Naturally, the growing medical tourism industry in India has felt threatened. And the response from the Indian media and its political class has been along expected lines. It is a classic case of paying no attention to the message, but trying to shoot the messenger.

India’s Minister for Health and Family Welfare and his deputy have gone on record to debunk the findings as being overblown and underwritten by multi-national drug companies (see Report).

If we buy that, should we not consider the possibility that the Indian press and politicians are reacting so at the behest of our medical tourism industry?

Objections have also been raised on equating the drug-resistance gene with India’s capital, New Delhi. So how did this name – NDM-1, come about?

This gene was discovered by one of the authors of the Lancet study, Timothy Walsh from Cardiff University, UK. His group obtained this gene from a Swedish national of Indian origin who underwent surgery in New Delhi and acquired a urinary tract infection due to an antibiotic-resistant form of the bacterium Klebsiela pneumoniae. The discovery was described in a paper titled “Characterization of a New Metallo-b-Lactamase Gene, blaNDM-1, and a Novel Erythromycin Esterase Gene Carried on a Unique Genetic Structure in Klebsiella pneumoniae Sequence Type 14 from India”, published in the December 2009 issue of the journal Antimicrobial Agents and Chemotherapy. This article is open access, so I can post it. Click here for the paper.

The Lancet Infectious Diseases research was a natural follow up to investigate how widely prevalent this gene might be in enteric bacteria in the Indian sub-continent. And, as expected, they found it to be widely prevalent in India and Pakistan.

Some might consider associating the city (New Delhi) with the bug/gene (NDM-1) to be offensive. But it is not unusual in scientific research to name a pathogenic organism after the place of its possible occurrence or discovery. Names like Chandipura (named after a village in Maharashtra), Kyasanur Forest (in Karnataka), Rift Valley Fever (an area in Kenya) are commonly found names in the virus world.  

While every Western tourist to this city is familiar with “Delhi Belly”, the Lancet report is too much to digest for the Indian establishment. Instead of crying foul, it would do everyone a lot of good if we focused on the huge problem of antibiotic resistance facing the country. Rampant and unchecked over-the-counter sale of antibiotics is causing high levels of drug resistance. And since bacteria (and other pathogens) can travel fast (without visas of course) in this jet age, it does not take very long for pathogens with newly acquired properties (genes) to go around the globe. The 2009 swine-origin influenza (first called Mexican flu, despite protests by Mexico) is an excellent recent example of this.

The priorities of our Health Ministry seem to be all wrong. Instead of shooting down the Lancet Infectious Disease report, they should be addressing the overuse of antibiotics in India.

For a different point of view, see the blog of a respected Indian microbiologist.