If health care professionals are to effectively stop antibiotic resistance, then fungal diagnostic capabilities must be improved. The two are inextricably linked, according to a recent article by Denning et al (Emerg Infect Dis 2017;23:177-183).
“Antimicrobial resistance [AMR], a major public health concern, largely arises from excess use of antibiotic and antifungal drugs. Lack of routine diagnostic testing for fungal diseases exacerbates the problem of antimicrobial drug empiricism, both antibiotic and antifungal,” the researchers wrote.
“If … we’re treating blindly for fungal infections that we don’t know are present with antibiotics, then we may inadvertently be creating greater antibiotic resistance,” said David Perlin, PhD, the executive director and a professor at Public Health Research Institute Rutgers-New Jersey Medical School, in New Brunswick; the director of the Rutgers Regional Biocontainment Laboratory; and a fellow of the New York Academy of Sciences.
The authors described four clinical scenarios in which failure to conduct routine diagnostic testing for fungal diseases could exacerbate the development of AMR.
Fungal sepsis involving Candida species, for example, is not routinely diagnosed in hospitals, resulting in patients being erroneously placed on broad-spectrum antibiotic drugs. The widespread implementation of rapid nonculture diagnostics for Candida species would be extremely beneficial to prescribing practices, particularly to hospitalized patients with poor organ function and multiple concurrent conditions that require multiple medications.
The authors also examined the misdiagnosis of smear-negative pulmonary tuberculosis (TB). In 2013, the World Health Organization received reports of more than 2.7 million smear-negative TB cases. A common unrecognized issue for patients with smear-negative TB is chronic pulmonary aspergillosis (CPA), which has symptoms similar to TB. To remedy this, Aspergillus antibody testing should become more easily accessible and be incorporated into TB control programs. Further, the possibility of CPA should be emphasized as a post-TB sequela, they suggested.
The third scenario is the misdiagnosis of fungal asthma as chronic obstructive pulmonary disease. Approximately 3% to 8% of 200 million asthma sufferers have fungal asthma, which could be diagnosed with simple skin and blood tests. Fungal asthma responds to antifungal agents, they said.
The last scenario is the over- and undertreatment of Pneumocystis carinnipneumonia (PCP) in HIV-positive patients. While approximately 400,000 patients with PCP go undiagnosed, more than 2 million receive unnecessary PCP therapy. A solution to this would be to use Pneumocystis polymerase chain reaction to test all respiratory samples in laboratories attending to large immunocompromised populations.
“Invasive fungal infections are often opportunistic and arise as a result of other underlying conditions, such as HIV/AIDS and cancer,” Dr. Perlin said. Countries in regions with scarce resources “do not have funds to purchase the diagnostic kits and/or equipment or medical infrastructure and training to implement widespread diagnostics.” Regarding training, “most physicians are trained to think first, viral and bacterial, and then when the patient is nonresponsive, fungal.”
Dr. Perlin noted there is a global need for comprehensive training about fungal infection management, including understanding the nature of fungal infections, who is at risk, and how to diagnose and treat different infections.
He said the topic needs to be a public policy initiative integrating the dialogue on fungal infections to any discussion of AMR. At the hospital level, stewardship programs on antimicrobial agents must include the integration of modern fungal diagnostics.
“Hats off to the authors of this article for addressing four ‘real-world fungal stewardship’ scenarios that contribute to the overuse and inappropriate use of antimicrobial agents,” said Debra A. Goff, PharmD, a clinical associate professor of the College of Pharmacy at the Ohio State University Medical Center, in Columbus, who was asked to comment on the study.
“I agree with the authors that it’s time to also focus on the importance of fungal stewardship.” Promoting the diagnosis of fungal infections would be beneficial to reducing deaths and illness from fungal disease and inappropriate antibacterial drug usage, and increasing stewardship programs, added Dr. Goff, who serves on the editorial advisory board of Infectious Disease Special Edition.
Antimicrobial resistance has become a major public health concern due to poorly diagnosing fungal diseases and consequently overprescribing antibiotics. Fungal infections often go undiagnosed, resulting in 1.5 million annual deaths. In the United States alone, antibiotic-resistant infections cause approximately 23,000 deaths per year and increase health care–associated costs by approximately $20 to $25 billion, according to the researchers.