Antimicrobial resistance: Q&A with Dr Ling Moi Lin and Dr Andrea Kwa
Dr Ling Moi Lin, Director of Infection Prevention & Control and Dr Andrea Kwa, pharmacy clinician scientist at Singapore General Hospital (SGH) speak to Roshini Claire Anthony about the current antimicrobial resistance situation and the potential repercussions if it is not controlled.
Why is antimicrobial resistance a pertinent issue?
Kwa: Antimicrobial resistance is a big problem globally considering the dwindling pipeline of new antibiotics. Antimicrobial resistance is a bigger problem in developing countries where antibiotics are easily available with or without prescription. We should remain vigilant and recognize that antimicrobial resistance is a potential problem or threat that is associated with international travel.
What are the potential complications of antimicrobial resistance?
Kwa: Looking back at the pre-antibiotic era, infections from simple operations and procedures were potentially life-threatening. The complication of antimicrobial resistance is the generation of pan-drug resistant bacteria (or bacteria that are resistant to all available antibiotics). If the incidence of pan-drug resistant bacteria continues to increase, it could become the main causative pathogen of any infection even from a simple operation.
Ling: It means that therapeutic options could be limited when the patient has an infection. In terms of resource management in the hospital, it impacts the utilization of isolation facilities.
According to the World Health Organization (WHO), even procedures such as Caesarean sections, chemotherapy, organ transplantation, and diabetes management could become high-risk due to antimicrobial resistance. Could you explain the reasons for these specific situations?
Ling: Any patient is at risk of acquiring multidrug-resistant organisms (MDRO) if infection prevention and control measures are inadequate. However, there are some patients who are at a higher risk of acquiring MDRO (eg, patients in the intensive care unit, on dialysis or chemotherapy, or on immune-suppressants). This increased risk could also be related to their more frequent exposure to healthcare facilities.
Kwa: Examples of diseases that are now less successfully treated due to antimicrobial resistance are diabetic foot and surgical site infections.
The WHO has published a global priority list of antibiotic-resistant bacteria. Which of these is of particular concern in Singapore, and the Southeast Asian region?
Ling: Carbapenem-resistant Enterobacteriaceae
and methicillin-resistant Staphylococcus aureus (MRSA) are of top concern. However, we need to be vigilant against the other types of antibiotic-resistant bacteria mentioned in the global priority list, even though incidence rates of such bacteria are still relatively low in Singapore. We may start seeing high incidences of such bacteria, if we do not control antibiotic use when prescribing, at the community level, and in agriculture.
How would this affect conditions such as tuberculosis and malaria?
Ling: If antimicrobial drugs for treating tuberculosis and malaria are inappropriately used, the causative bacteria and parasite may develop resistance to the drugs. It is important to note that tuberculosis is endemic in Singapore. Based on the WHO’s classification, Singapore is a country of “moderate” tuberculosis burden/endemicity instead of “low” which is defined as <20 cases per 100,000 population. In 2015, the incidence of tuberculosis in Singapore was 36.1 per 100,000 among Singapore residents (citizens and PRs) and long-staying foreigners. [https://www.moh.gov.sg/content/dam/moh_web/Publications/Reports/2016/HIV-AIDS%20STIs%20Tuberculosis%20Leprosy.pdf]
To prevent the development of resistance against antimicrobial drugs for treating tuberculosis, correct doses of these drugs have to be given for an adequate period to cure the infection and reduce the risk of developing drug resistance. Directly Observed Therapy (DOT) reduces the risk of relapse and development of drug resistance, and is advocated by the WHO as the standard of care for all infectious tuberculosis cases. [https://www.moh.gov.sg/content/moh_web/home/diseases_and_conditions/t/tuberculosis.html] In Singapore, outpatient DOT is carried out at all polyclinics nationwide and at the Tuberculosis Control Unit.
Kwa: In addition, there are not many options available for the treatment of tuberculosis. Some antibiotics used in tuberculosis are also used to treat other bacterial infections. If such antibiotics are overprescribed at the community level, the bacteria that cause tuberculosis can develop resistance against such antibiotics.
How does antimicrobial resistance affect diseases caused by viruses, parasites etc?
Ling: Currently, the major concern is with bacteria. Similar impact may be seen for antivirals and drugs used to treat parasitic infections if they are used inappropriately.
What is the role of the primary care physician (GP) in reducing antimicrobial resistance?
Ling: They play the important role of using antimicrobials appropriately as part of global efforts to prevent the development of resistance.
Kwa: GPs’ roles include:
· Prescribing antibiotics judiciously and cautiously, and not for prophylaxis or “just in case”
· Exercising good clinical judgement when assessing patients and actively utilizing rapid diagnostic kits in the clinic where available to assess for viral infections (viral infections are the main reason for fever at primary care)
· Advocating pneumococcal and flu vaccination to decrease clinic visits due to fever
· Educating patients
How does antimicrobial resistance affect healthcare cost?
Ling: A local study reported that the median excess hospitalization cost associated with MRSA infections in two Singapore hospitals is more than USD13,000, the majority of which is borne by the government under the financing structure of Singapore’s healthcare system. Another local study reported that the excess hospitalization cost attributed to an infection caused by multidrug resistant Gram-negative bacteria amounted to SGD8,638.58 per episode. [J Hosp Infect 2011;78:36-40; Ann Acad Med Singapore 2012;41:189-193]
The factors in which antimicrobial resistance impacts healthcare costs include:
· Extended length of stay and higher hospitalization costs
· Cost of interventions used (eg, cohorting and isolation, use of personal protective equipment)
The above excludes costs associated with outbreak management, if any.
A note on MRSA:
Is MRSA a significant issue in Singapore? What can be done to address this?
Ling: MRSA is one of the MDRO of concern in Singapore. To prevent the spread of MRSA, patients are screened for MRSA as they are admitted. Contact precautions are then applied for patients identified with MRSA, including isolation or cohorting of the patients, and the use of gowns and gloves as personal protective equipment.