The Bugs Aren't on Vacation: What Pharmacists Need to Know About the Evolving Infectious Disease Landscape

The pathogens driving infectious disease outbreaks and resistant infections do not observe holidays, geography, or guideline publication cycles. That was the central premise of a packed session delivered by Callan Bleick, PharmD, MSc, assistant professor at the University of Rhode Island College of Pharmacy and director of the Infectious Disease Research Program at the VA in Providence, at the 2026 American Pharmacists Association Annual Meeting and Exposition.¹

In a 1-hour overview of emerging threats, updated treatment guidelines, and the evolving role of pharmacy professionals in infectious disease response, Bleick challenged attendees to approach their everyday work with a more intentional public health lens—and gave them the science to back it up.¹

"The key takeaway is that things are getting a lot more complicated, and it's not going to slow down," Bleick told the audience. "Bugs are adapting. They're not taking a break. We're going to be dealing with a lot more resistance, more emerging infections, and fewer straightforward treatment options."¹

Antimicrobial Resistance: A Shifting Landscape

Bleick opened with antimicrobial resistance (AMR), calling it one of the most significant and rapidly evolving threats in infectious disease practice today. She described a clinical and public health landscape in which the pipeline of new antibiotics is slowing even as multidrug-resistant organisms like methicillin-resistant Staphylococcus aureus (MRSA) and carbapenem-resistant Enterobacterales (CRE) continue to evolve, and where increasingly limited therapeutic options are raising the stakes of every prescribing decision.¹

One case study she highlighted, which has been circulating widely in the infectious disease community, concerns a dramatic shift in carbapenemase epidemiology in the US. Historically, Klebsiella pneumoniae carbapenemase (KPC) has been the predominant carbapenemase among CRE in the US since the 1990s. But a 2025 CDC analysis published in Annals of Internal Medicine found that NDM-producing CRE (NDM-CRE) increased by more than 460% between 2019 and 2023—and by 2024, NDM had surpassed KPC as the most frequently reported carbapenemase in surveillance networks, including New York City's health department reporting system.^2,3

The clinical significance of this shift is considerable: NDM-producing organisms are resistant to most available antibiotics, including novel β-lactam/β-lactamase inhibitor combinations such as ceftazidime-avibactam that remain active against KPC-producing CRE. This means that the treatment of NDM-CRE requires different, and often more limited, therapeutic options. For pharmacists, Bleick framed this shift as a call to stay attuned to local antibiogram data and resistance pattern trends, increase clarification and verification interactions around antibiotic therapy, and counsel patients more thoroughly on the importance of completing antibiotic courses.^1,2

"Here are some possible downstream consequences," Bleick said. "Increased prescriptions being driven by treatment failure. More clarification calls. A greater need to assess appropriate therapeutic options. And managing expectations when antibiotics don’t work, while navigating cost considerations for our patients.”¹

Vaccine-Preventable Disease Resurgence

The second major threat Bleick addressed was the resurgence of vaccine-preventable diseases, a trend she characterized as both deeply frustrating and entirely avoidable. Using measles as a case study, she pointed to the compounding consequences of declining vaccination rates fueled by growing antivaccine sentiment. Measles was declared eliminated in the US in 2000, but 2025 saw 2285 confirmed cases, the highest annual total in more than 3 decades, across 49 outbreaks. By the time of the session, the CDC had already confirmed 1575 measles cases in 2026 across 32 jurisdictions, putting the country on pace to surpass the prior year's record. Nearly all cases—approximately 93%—have been in individuals who were unvaccinated or whose vaccination status was unknown.⁴

"Although we know that measles was declared eliminated in 2000, more outbreaks are occurring," Bleick said. "This just highlights how important vaccine-preventable diseases are, and how we are on the front lines as pharmacy professionals to potentially eliminate and prevent this from happening as best we can."¹

She urged pharmacists not to accept a vaccine refusal as a terminal end point, but instead to build confidence within their pharmacy teams to engage patients with empathy, evidence, and resources. Bleick noted that patients are more likely to reconsider hesitancy when health care providers they trust make strong, confident recommendations. "When we feel confident as pharmacists and pharmacy technicians to address our patients, they trust us a lot more," she said.¹

Globalization, Climate, and Zoonotic Spillover

Bleick also addressed 2 drivers of infectious disease emergence that often receive less attention in pharmacy education but are increasingly shaping the clinical landscape: globalization and climate change. Pathogens now travel as rapidly as their human hosts, she explained, meaning that resistance patterns or outbreak organisms that originate overseas can quickly appear in domestic clinics and pharmacies. She encouraged pharmacists to routinely ask patients about recent international travel, particularly when evaluating a new antibiotic prescription, as a simple question that can meaningfully inform the likelihood of drug-resistant pathogen exposure.¹

Rising temperatures, she added, are promoting bacterial growth, altering animal behavior, and disrupting gut microbiomes in livestock, creating expanded reservoirs for resistant bacteria. Combined with increasing human-animal interaction through agriculture and urbanization, these dynamics are accelerating zoonotic spillover, as already evidenced by ongoing H5N1 transmissions linked to animal reservoirs and the persistent threat of novel pandemic-potential pathogens.^1,5

Guideline Updates: UTIs and Tuberculosis

Bleick dedicated a substantial portion of the session to reviewing high-impact clinical guideline updates with direct relevance to pharmacy practice.

The first was the 2025 Infectious Diseases Society of America (IDSA) guideline on the management and treatment of complicated urinary tract infections (cUTIs). It is the first IDSA guideline to address cUTIs in both men and women, and the first major update to the topic since 2010. A key change in the new guidelines is a revised classification framework for complicated vs uncomplicated UTIs, now defined based on whether infection has extended beyond the bladder (complicated) or remains confined to it (uncomplicated)—a shift away from the prior reliance on broad anatomical risk factors, designed to better reflect clinical reality and prevent overtreatment.⁶

The updated guidelines also introduce a structured 4-step framework for empiric antibiotic selection that incorporates illness severity, risk for resistance, patient-specific factors, and local antibiogram data. Critically for stewardship efforts, the new recommendations support shorter antibiotic courses—5 to 7 days of a fluoroquinolone or 7 days of a nonfluoroquinolone for clinically improving cUTI—replacing prior 10- to 14-day standards. A clear stepwise approach to IV-to-oral switching is also included: patients who are clinically improving, able to tolerate oral medication, and for whom an effective oral option exists should be transitioned promptly, reducing hospital stays, costs, and adverse event risk.⁶

"As soon as patients are clinically improving, stable, and able to take oral medications with a good oral option available, we should feel comfortable transitioning," Bleick said. "We don't need to keep our patients on antibiotics any longer than necessary."¹

She also reviewed updates to tuberculosis management, highlighting the shift from traditional 6-month isoniazid-rifampin regimens toward newer, shorter 4-month regimens incorporating rifapentine—a change driven by the TB-PRACTECAL (NCT02589782) and ZeNix (NCT03086486) trial data that demonstrated improved tolerability and comparable efficacy with the longer half-life of rifapentine over rifampin. For drug-resistant TB, she noted the adoption of BPaL (bedaquiline, pretomanid, linezolid) as a preferred all-oral regimen for pre–XDR-TB, with the BPaLM regimen (adding moxifloxacin) available for fluoroquinolone-susceptible disease.^1,7,8

The Pharmacist as Infectious Disease Sentinel

Bleick closed by articulating a vision of the pharmacist as an active, front-line participant in infectious disease surveillance, prevention, and response; not simply a medication dispenser. She cited data showing that community pharmacists encounter an average of 11 to 30 patients presenting with minor ailments daily, making the pharmacy one of the most accessible health care touchpoints in the US health system. That volume, she argued, gives pharmacists an early-warning advantage: the ability to detect upticks in antibiotic prescriptions for influenza, patterns of treatment failure, or unusual infection clusters before they are identified through formal surveillance channels.^1,9,10

"It's not about adding more work. It's about recognizing that we're on the front line of surveillance and helping our patients, whether we realize it or not," she said. Bleick also pointed to the expanding role of test-to-treat programs, such as pharmacist-administered rapid antigen tests for influenza, COVID-19, and streptococcal pharyngitis, as both a stewardship tool and a natural extension of pharmacy scope that varies by state but is increasingly available to practice.^1,10

She concluded with a charge that cut across all the session's themes: "Stewardship doesn't just happen in hospitals. It starts with us, at the pharmacy, in the everyday decisions and questions we ask and make. We're not just dispensing medications—we're identifying patterns, catching errors, educating patients, staying informed. We are on the front line of infectious disease."¹

REFERENCES

1. Bleick C. Totally buggin': infectious disease update. Presented at: American Pharmacists Association Annual Meeting & Exposition; March 28, 2026; Los Angeles, CA.

2. Rankin DA, Stahl A, Sabour S, et al. Changes in carbapenemase-producing carbapenem-resistant Enterobacterales, 2019 to 2023. Ann Intern Med. 2025;178(12):1818-1821. doi:10.7326/ANNALS-25-00516

3. Devinney K, Burton N, Alroy KA, et al. Notes from the field: increase in New Delhi metallo-β-lactamase–producing carbapenem-resistant Enterobacterales — New York City, 2019-2024. MMWR Morb Mortal Wkly Rep. 2025;74(23):401-403. doi:10.15585/mmwr.mm7423a2

4. Centers for Disease Control and Prevention. Measles cases and outbreaks. Updated March 27, 2026. Accessed March 28, 2026. https://www.cdc.gov/measles/data-research/index.html

5. Valletti D. Clinical and public health implications of recent H5N1 poultry outbreaks. Pharmacy Times. October 7, 2025. Accessed April 1, 2026. https://www.pharmacytimes.com/view/clinical-and-public-health-implications-of-recent-h5n1-poultry-outbreaks

6. Trautner BW, Cortés-Penfield NW, Gupta K, et al. Clinical practice guideline by Infectious Diseases Society of America (IDSA): 2025 guideline on management and treatment of complicated urinary tract infections. Clin Infect Dis. Published online December 20, 2025. doi:10.1093/cid/ciaf460

7. Nyang’wa BT, Berry C, Kazounis E, et al. A 24-week, all-oral regimen for rifampin-resistant tuberculosis. N Engl J Med. 2022;387(25):2331-2343. doi:10.1056/NEJMoa2117166

8. Conradie F, Bagdasaryan TR, Borisov S, et al. Bedaquiline-pretomanid-linezolid regimens for drug-resistant tuberculosis. N Engl J Med. 2022;387(9):810-823. doi:10.1056/NEJMoa2119430

9. Amare SN, Yee KC, Leung M, et al. Impact of pharmacist-led interventions on COVID-19, herpes zoster, influenza, pneumococcal, and respiratory syncytial virus vaccines uptake in people aged 60 years and older: Systematic review and meta-analysis. Res Social Adm Pharm. 2025;21(11):857-871. doi:10.1016/j.sapharm.2025.06.110

10. Klepser DG, Klepser ME, Smith JK, et al. Utilization of influenza and streptococcal pharyngitis point-of-care testing in the community pharmacy practice setting. Res Social Adm Pharm. 2018;14(4):356-359. doi:10.1016/j.sapharm.2017.04.012