Question

Antibiotic-resistance genes, as well as other virulence factor genes, are easily passed between bacterial cells through horizontal gene transfer. Conduct additional research on New Delhi metallo-beta-lactamase 1 strains of bacteria, and explain why medical tourism poses a serious threat to the spread of this organism.

Answer 1

ANS : Medical Tourism is where people who live in one country travel to another country to receive medical, dental and surgical care while at the same time receiving equal to or greater care than they would have in their own country, and are traveling for medical care because of affordability, better access to care or a higher level of quality of care. “Domestic Medical Tourism” is where people who live in one country travel to another city, region or state to receive medical, dental and surgical care while at the same time receiving equal to or greater care than they would have in their own home city, and are traveling for medical care because of affordability, better access to care or a higher level of quality of care.

New Delhi metallo-beta-lactamase 1 (NDM-1)^[1] is an enzyme that makes bacteria resistant to a broad range of beta-lactam antibiotics. These include the antibiotics of the carbapenem family, which are a mainstay for the treatment of antibiotic-resistant bacterial infections. The gene for NDM-1 is one member of a large gene family that encodes beta-lactamase enzymes called carbapenemases. Bacteria that produce carbapenemases are often referred to in the news media as "superbugs" because infections caused by them are difficult to treat. Such bacteria are usually susceptible only to polymyxins and tigecycline.

Medical tourism-travel by healthcare patients to a foreign location for medical treatment-is a growing industry. Healthcare is nationally regulated in every country, and difficulties arise where legal remedies and standards vary between a medical tourist's resident and destination county. Antibiotic-resistant bacteria, which are typically limited to healthcare settings and close community quarters, have predictable risk factors. These predictable risk factors generally reduce concern regarding healthcare-associated strains in the medical community because hospitals can set admission and contact policies to reduce the spread of health care associated strains. As medical tourism increases, however, the spread of healthcare-associated antibiotic-resistant bacteria infections is also likely to increase because patients are more likely to be exposed to hospitals and healthcare settings in different countries. Patients may thus spread their infections to facilities around the world. One recently discovered antibiotic-resistant strain of bacteria has shown evidence of fast international spread due to connections with medical tourism.

In 2010, a study in The Lancet medical journal reported the emergence of a new antibiotic-resistant bacteria strain called NDM-1." This strain of antibiotic resistance is particularly dangerous because it is resistant even to treatments reserved as last resorts, making the strain difficult to combat." The Lancet study linked the emergence of NDM-1 to both the over- and under-use of antibiotics. The WHO has endorsed The Lancet results by issuing a press release acknowledging the necessity of measures to prevent the spread of NDM-1. The subsequent spread of NDM-1 to other countries highlights the changes brought by medical tourism to the spread of antibiotic-resistant bacteria. After release of The Lancet study, the US CDC announced that three cases of NDM-1 had been found in the country, "all from patients who received recent medical care in India, a country where people often travel in search of affordable healthcare." These three cases were the first reports of NDM-1 cases in the US. Because the new antibiotic resistance was discovered during routine testing at the CDC, it is likely that NDM-1 was not in the US prior to these three cases. A scientist at the European Center for Disease Prevention and Control (ECDC) announced that seventy-seven cases of NDM-1 had been reported in thirteen countries between 2008 and 2010. The ECDC reported that "among 55 cases with recorded travel history, 31 had previously traveled or been admitted to a hospital in India or Pakistan and five had been hospitalised in the Balkan region." The ECDC concluded that NDM-1 has been spreading across Europe and is linked to both a history of healthcare abroad and nosocomial (or healthcare-setting acquired) transmission." The ECDC expressed particular concern regarding transmission across national borders: Carbapenemase-producing strains [NDM-1 bacteria] have been the cause of country-wide epidemics of healthcare-associated infections in Greece, Israel, the United States (US), several Latin American countries and China, and of local outbreaks in Poland and Italy. These epidemic strains have been shown to spread when carried by patients who are transferred between hospitals. Such introductions into healthcare systems across country borders have led to international epidemics by secondary local or regional transmission. There is heightened concern regarding international transmission in light of the fact that recent medical care appeared to be a significant factor, not just medical care in another country at any prior point in time. "Most patients with recent travel had been hospitalized in a foreign country during the 30 days prior. Hence medical tourism poses a serious threat to the spread of this organism.