Role of Antibiograms in Infectious Disease Epidemiology
One of the most critical tools available to hospital epidemiologists and healthcare practitioners is the antibiogram. By definition, an antibiogram is an assemblage of epidemiology data, which is presented in a table format (Carlsen et al., 2019). It summarizes the percentage of pathogenic organisms that are receptive to various antimicrobial agents. In other words, an antibiogram is a report that depicts the susceptibility of particular strains of pathogens to a variety of antibiotics.
Conventionally, clinicians use antibiograms to test whether a specific antibiotic may be effective when paired against a certain bacteria isolate. Such susceptibility tests are conducted in a medical laboratory. If an antibiotic is found to work against certain bacteria, clinicians label it as “S.” Contrariwise, if they find out that an antibiotic cannot work against a particular bacterium, they label the antibiotic as “R” to denote resistance.
Markedly, antibiograms are created by generating laboratory profiles using aggregate data from a particular hospital or healthcare system. Clinicians summarize the data periodically and present it, showing the percentages of tested organisms and their susceptibility to a certain microbial drug. For every pathogenic organism that undergoes susceptibility testing, medical clinicians record the trend of susceptibility and resistance in laboratory information systems (Carlsen et al., 2019). It is prudent to note that only results for routinely tested microbial drugs are deemed clinically useful.
Microbiology laboratory technologists are tasked with the responsibility of compiling antibiograms. In some instances, the task may require a collaborative effort involving a laboratory, pharmacy, clinicians, and infection preventionists. Producing a series of antibiograms helps to track changes in resistance patterns over a certain duration. Subsequently, the track record can be used to guide the development of therapeutic interventions at both the national and local levels of the health sector.
Conventionally, antibiotics work differently; while some antibiotics require the use of one antibiotic, others need a completely varied antibiotic. On the underscore, some pathogens that used to be susceptible to a particular antibiotic develop a gradual resistance to it. This limits the number of drugs that can be used to destroy such a pathogen. Antibiograms come in handy to prevent the growth of multidrug-resistant organisms. They are profoundly useful in detecting and monitoring trends in antimicrobial resistance. When trends in resistance are identified, clinicians use antibiograms to suppress the growth of resistant pathogens (Carlsen et al., 2019). In essence, antibiograms are profoundly useful in both epidemiology and clinical practice.
On the flip side, the use of antibiograms has some limitations. Despite being used to improve empirical antibiotic prescribing, antibiograms are not quite effective in some hospital setups. For instance, pathologists who create antibiograms do not include the minimum inhibitory concentrations (MICs) (Carlsen et al., 2019). Consequently, some of the subtle trends that appear below the resistant threshold are not reflected. Additionally, the data postulated in antibiograms does not take into account patient factors such as past antimicrobial use and history of infection.
One of the most perceptible controversies regarding the use of antibiograms involved the Centers for Disease Control (CDC). In March 2002, CDC started a campaign aimed at preventing antimicrobial resistance in healthcare facilities. To achieve this objective, the organization leveraged a 12-step program. Intriguingly, half of the steps in the program were implicit in using microbial wisely, however, the program was not quite successful. Arguably, the reason why CDC’s program failed is that clinicians, who are the front liners in the creation and use of antibiograms, had little knowledge regarding the matter (Carlsen et al., 2019). Apparently, many pharmacy and medical clinicians do not study antibiograms in detail during their clinical portion of educational training. Consequently, it becomes difficult for them to create and use antibiograms in preventing the growth of multi-resistant pathogens.
In conclusion, antibiograms play significant roles in infectious disease epidemiology. For instance, clinical specialists use antibiograms to test whether a certain antibiotic may be effective when paired against a certain bacteria isolate. They also help nurses to summarize the data periodically and display it, showing the percentages of tested organisms and their susceptibility to a specific microbial drug. However, the antibiograms have drawbacks in that the data postulated in them does not take into account patient factors such as past antimicrobial use and the infection history.
Carlsen, S., Krall, S. P., Xu, K. T., Tomanec, A., Farias, D., & Richman, P. (2019). Sensitivity of urinary pathogens for patients discharged from the emergency department compared with the hospital antibiogram. BMC Emergency Medicine, 19(1), 1-4.