Superbug NDM-1: 2010 results confirmed by others

Published in The Hindu on April 14, 2011

If the first paper on NDM-1 superbug published last year created an uproar in India, the second paper published on April 7 created a storm. From denying to finally agreeing to investigate the presence of drug-resistant NDM-1 bacteria in hospitals and drinking water, the government appears to be taking some steps.

Mark Toleman of Cardiff University, U.K., one of the co-authors of the paper, discussed with R. Prasad through email how serious the NDM-1 issue is, how his Indian co-authors had faced threats from the government, and about the naming of the superbug after New Delhi.

Do you think two tap water samples testing positive can serve as representative of a city’s drinking water supply?

The time taken between collection and analysis and our knowledge of DNA degrading enzymes in the water suggests that the 2 out of 50 samples is a very conservative figure. Again, just one month ago, 18 per cent of the drinking water was contaminated by sewage.

My guess based on this is that the real figure is much higher. Of course, if the water is cleaned up before the new study begins the figure may be less than this. For this reason it is very important to work out carriage rates of NDM-1 by doing screening of faecal samples or anal swabs both in the community and in the hospital.

This will give a baseline of carriage and can be used to assess if future interventions are effective and whether some geographic regions have higher incidence than others etc.

Will drinking water studied immediately after collection show up more NDM-1 positive results?

I think that you will get higher results than we did given the transport and time between collection and detection. I would be surprised if you do not.

What do you think is the route of transmission of the superbugs to tap water?

From reading the newspapers, it is obvious that the drinking water is often contaminated with sewage material. An article just last month stated 18 per cent of water in New Delhi was contaminated. This most likely is the number one source of NDM-1 i.e. faecal contamination. This is a very serious matter and certainly is a direct cause of deaths especially of vulnerable and precious individuals, example those under five years of age. In 2002, ‘Clean drinking water’ was declared by the United Nations to be a human right. A country that is able to send rockets into space and develop nuclear technology surely must be able to provide clean drinking water.

The government has now constituted a committee to study patients in a few hospitals in New Delhi and check for the prevalence of NDM-1, and if found, to test the drinking water in the surrounding areas. Do you think this approach is correct?

A really positive step. We applaud the Indian government — my thoughts are about knowing the prevalence of carriage.

This can be done by [taking] faecal samples or anal swabs and looking for carbapenem resistant bacteria and testing by NDM-1 PCR and probing. My reservation is, given our prior history with the Indian government, what about transparency?

Denial appears to be the first response and the second is to blame someone else. I notice that just one month ago 18 per cent of water supplies in New Delhi were found to be contaminated with faecal material in accordance with our results. Yet I read about government ministers proclaiming that the water is safe to drink.

Are there any other ways to study its spread?

I think it would be correct to look wherever there is human contact which is more or less what we did. Given that a lot of sewage is just dumped in the Yamuna River and this is then used to irrigate crops, it would be good to look at all water sources.

Why did you not opt to take samples directly from the sewerage system?

[It] probably [has] to do with ease.

Why did you take the help of a journalist and not a scientist to collect the samples?

Simply because your government “encouraged” Indian scientists not to help and the opportunity arose.

Unlike your earlier work published last year, no Indian authors are part of the study published on April 7, 2011. What is the reason?

To coin Tim’s [Tim Walsh, the lead author of the paper] words: “When your Indian colleagues, who have also become your friends, are the subject of a vicious witch-hunt and threatened with their livelihoods and even jail we thought it would be prudent to do this study alone.

The treatment of our Indian co-authors from the last study was disgraceful and highly unprofessional.”

You were quoted as saying to a news agency recently that the government is threatening scientists in the wake of last year’s findings. Your comments.

As mentioned earlier, it is very difficult for me to understand this mentality. A caring government would do everything in its power to uncover sources of harm and infection to its people. There are several cases where your government only does what is right, just and fair when they come under the media spotlight.

The Indian media had not reported Indian co-authors facing any witch hunting/threats by the Indian government. What is the source of your information?

The source of my information is e-mails directly from individuals being threatened. Furthermore when other scientists change from being “delighted” in a collaboration to asking you not to contact them again. This suggests that they have been got at.

Despite the terrible experience that your Indian co-authors (of 2010 paper) faced, you still had Mohd Shahid from India writing the Comment piece published along with your current paper. Your comments.

I cannot comment here as I have had no personal contact and did not know about the comment piece until publication.

Do you ever think you would get Indian scientists to be a part of your team in any studies on NDM-1 in the foreseeable future?

I know there are people who would gladly collaborate with us tomorrow if they could do so without fear of reprisals.

Unlike your current paper (published in April 2011) which has stuck to the normal format of a scientific paper, the discussion part of your paper published last year read like an editorial. Don’t you think such observations are best made by authors writing the ‘Comment’ piece or Editorial?

The discussion part of the paper is supposed to reflect ideas and opinions based on the results.

At the time of writing we knew little about medical tourism but an article in the Independent newspaper suggested that the National Health Service pays to send patients to India for surgery.

We felt that we had a moral obligation to forewarn of the possible dangers of being exposed to NDM-1 positive bacteria and the associated costs of treatment and cleanup when they returned to the UK. Since we have a nationally funded health care [system] it is difficult to understand how this statement could be motivated by financial incentives as we were accused of.

Do you think the government was trying to deflect attention from the main issue by saying that there was some ulterior motive for targeting India?

Of course they are. Most people cover things up they know are wrong. But it is only by exposing our problems and bringing them into the light are any of our deficiencies addressed.

What do you have to say about the recent comment by government officials that your study is not scientific?

This is what was said of the last study which basically has now been verified by over 80 further papers and by many groups around the globe. The wonderful thing about science is that it is repeatable — in fact this is what science is.

Of course if you want credibility it would be good to have an independent observer. I wonder if your government has thought of that.

What did these papers published after yours report?

These papers are mostly identifying NDM-1 in their own countries by several different groups. Many of these have direct links to either hospitalisation in India, Pakistan or Bangladesh or a recent visit.

Do you agree that not all gram-negative bacteria resistant to carbapenem are named after the place where they are found? So don’t you think there was a case to name the superbug without making a reference to New Delhi?

I consider that this naming system is a good one and has brought to light a very serious issue that may well have been “swept under the carpet” without the reaction to the name. That said, this was not by design but just simply by force of circumstance.

Even if it has brought out some desired results from the government, there was no compulsion to name them after the location. They could have been named following other naming protocols, as well. Your comments.

Naming does not necessarily mean that it emerged at that exact spot. Of course, it is possible that it first emerged in Bangladesh or Pakistan or anywhere else in the world and was brought to India. I think this unlikely myself, given that the earliest isolates that we know of are actually from New Delhi. No one else in the world seems to get upset about a name as mentioned before and many bacteria are named after places.

Many pathogens are named after the people who discovered them like Escherichia and Yersinia etc.

It is also interesting that the travel advisories to India recommend that individuals are first vaccinated against Japanese encephalitis — this does smack a bit of double standards. Has anyone asked the Japanese what they think of this? I doubt it and I also doubt that they care.

Why did the Editor of The Lancet admit that it was a mistake to name the superbug after New Delhi if the journal was indeed not responsible for naming it in the first place?

I don’t know. The papers were not published in The Lancet but in a sister journal Lancet Infectious Diseases that Dr Richard Horton is not an editor of.

My guess is that he was put on the spot and was not aware of all the details of prior publication in AAC and didn’t want to cause offence as indeed we do not.