New multidrug-resistant enterobacteria spreads from India, Pakistan to United Kingdom

**Kumarasamy KK. Lancet Infect Dis. 2010; DOI:10.1016/S1473-3099(10)70143-2.**

Enterobacteriaceae species that express the New Delhi metallo-beta-lactamase 1 (NDM-1) resistance factor have the potential to rapidly spread resistance worldwide, according to recently published study data.

The discovery of NDM-1 in a Swedish patient with Klebsiella pneumoniae and Escherichia coli who returned home after spending time in a New Delhi hospital prompted researchers from Cardiff University in Wales and several other institutions to investigate the prevalence of NDM-1 throughout India and Pakistan. The resistant species also spread to the United Kingdom, resulting from what researchers said was medical travel between these three countries.

“Many people choose to undergo surgical procedures in countries such as India, China and South Korea to avoid long waiting times and to save money,” Johann D.D. Pitout, MD, of the University of Calgary, wrote in an accompanying editorial. “This so-called medical tourism to India might grow by 30% each year over the next 5 years. Medical tourism has some risks, including ethical and legal issues as well as the quality of postoperative care.”

The researchers analyzed isolates from Chennai and Haryana in India and from patients who were referred to the United Kingdom’s Antibiotic Resistance Monitoring and Reference Laboratory between 2003 and 2009. Other samples came from areas around Bangladesh and Pakistan.

Seventy-five cases of E. coli, 60 of Klebsiella and six other Enterobacteriaceae resistant to carbapenems surfaced in Chennai during 2009, according to the researchers. Of the 141 carbapenem-resistant Enterobacteriaceae, 44 were NDM-1 positive.

Forty-seven carbapenem-resistant isolates were noted in Haryana, and 13% were positive for NDM-1. All were K. pneumoniae, the researchers said.

“The worldwide spread of multi-resistant NDM-producing Enterobacteriaceae will have serious implications for the empirical treatment of hospital-associated and community-associated infections,” Pitout wrote. “To make matters worse, there are very few antibiotics in development with activity against Gram-negative bacteria. Of particular concern is that NDM enzymes are present in E. coli; the most common cause of community-associated urinary tract infections.”

In the United Kingdom, NDM-1 first appeared in 2008 and by 2009 was the leading carbapenemase-producing Enterobacteriaceae. This change in prevalence prompted a National Resistance Alert 3 notice from the government’s Department of Health.

The researchers drew data from 25 laboratories in England and one each in Scotland and Northern Ireland. All specimens came from 29 patients, 17 of whom reported travel to India or Pakistan within the past year — 14 of whom were hospitalized for cosmetic or transplant procedures.

“It is disturbing in context, to read calls in the popular press for U.K. patients to opt for corrective surgery in India with the aim of saving the NHS money,” the researchers wrote. “As our data show, such a proposal might ultimately cost the NHS substantially more than short-term saving and we would strongly advise against such proposals.”

Results indicate that K. pneumoniae isolates from Haryana were clonal, although those producing NDM-1 from the United Kingdom and Chennai were clonally diverse.

Data also show that most of the isolates from Chennai and Haryana were from community-acquired infections. The researchers called this information “disturbing” because it suggests that NDM-1 is pervasive in these areas.

Pitout said that further international studies should be conducted so the medical community can gain more insight into this serious public health threat. He also recommended that patients who have undergone medical procedures in India be screened for multiresistant bacteria before receiving medical care in their home countries.

“If this emerging public health threat is ignored, sooner or later the medical community could be confronted with carbapenem-resistant Enterobacteriaceae that cause common infections, resulting in treatment failures with substantial increases in health-care costs,” Pitout wrote. “The consequences will be serious if family doctors have to treat infections caused by multiresistant bacteria on a daily basis.” — by Melissa Foster