Top 5 Infectious Disease News Stories Week of December 14-20

While Hospital-Acquired C difficile Cases Have Decreased, Community-Acquired Cases Have

In an interview with Joseph Zackular, PhD, he discussed the decline in hospital-onset C difficile infections, attributed to better infection control, and the promising future of an mRNA-based vaccine currently in pre-clinical trials. This vaccine, showing potential even at low doses, aims to address C difficile’s complexity. Zackular emphasized the importance of targeting high-risk groups for vaccination, particularly those in healthcare settings, long-term care facilities, or those with comorbidities or on antibiotics. He noted that while predicting C difficile infection risk is more feasible than with viral infections like COVID-19, ongoing epidemiological studies are necessary to refine the target population for this vaccine.

The Slow-Moving Antimicrobial Resistance Train is Picking-up Morbidity and Mortality Steam

Antimicrobial resistance (AMR) is a growing issue that threatens patients with bacterial infections, fueled in part by public misunderstanding and misuse of antibiotics. While many people are aware of the risks associated with overusing antibiotics—such as the need for stronger treatments and the spread of more dangerous infections—a significant disconnect remains in understanding personal responsibility. A Kaiser Family Foundation poll found that while 67% of respondents recognized the consequences of antibiotic misuse, nearly half admitted to not following prescribed antibiotic regimens, contributing to resistance. Furthermore, many believe the responsibility for combating AMR falls on drug companies and healthcare providers rather than individuals.

Peer-Assisted Telemedicine Enables More People With Hepatitis C to Get into the Continuum of Care

A recent study demonstrated that involving peers with lived experience of illicit drug use significantly improved hepatitis C (HCV) diagnosis, treatment initiation, and cure rates among people who use drugs (PWUD) in rural areas. The study, conducted in seven rural Oregon counties with high rates of opioid use and HCV, compared two approaches: peer-assisted telemedicine (TeleHCV) and enhanced usual care (EUC). Results showed that 85% of participants in the TeleHCV group initiated treatment, compared to just 13% in the EUC group, and 63% achieved a cure, compared to 16% in EUC. The success of TeleHCV highlights the effectiveness of peer support and telemedicine in overcoming barriers to healthcare access in rural communities, particularly for conditions like HCV that are linked to injection drug use.

CACTUS Study Compares Ceftolozane-Tazobactam vs. Ceftazidime-Avibactam for MDR Pseudomonas

The CACTUS Study compared the effectiveness of ceftolozane-tazobactam (CT) and ceftazidime-avibactam (CZA) in treating multidrug-resistant Pseudomonas aeruginosa infections. The study found similar clinical outcomes for both drugs, with 62% of CT-treated patients and 55% of CZA-treated patients achieving clinical success, and 30-day mortality rates of 20% for CT and 19% for CZA. In an interview, Jason M. Pogue, PharmD, BCPS, BCIDP, discussed the study's background, design, and the reasons behind choosing these two drugs. He explained that CT and CZA are both recommended in clinical guidelines due to their superiority over older, more toxic treatments. The study aimed to address limitations of prior smaller studies by focusing on pneumonia and bloodstream infections, where treatment differences could have significant effects. Using a matched-pair design, the study minimized bias, and found that while CT patients were more likely to receive prolonged infusions, there were no significant differences between the two drugs regarding microbiologic failures or resistance development. Pogue also highlighted the potential pharmacokinetic and pharmacodynamic advantages of CT.

Gilead Submits FDA New Drug Application for Lenacapavir for HIV Prevention

During its two Phase 3 clinical trials, Gilead's twice-yearly lenacapavir injection demonstrated high efficacy in preventing HIV infection. In the PURPOSE 1 trial, lenacapavir showed 100% efficacy in preventing HIV in cisgender women, with zero infections observed in the treatment group. The PURPOSE 2 trial, which included a broader, geographically diverse population, showed 99.9% efficacy with only two infections in the lenacapavir group, a 96% reduction in HIV infections compared to background HIV incidence (bHIV). Lenacapavir was superior to both bHIV and the standard once-daily oral PrEP (Truvada), prompting the independent Data Monitoring Committee to stop the blinded phase of both trials due to the compelling results. Both lenacapavir and Truvada were well-tolerated, with no significant safety concerns. Gilead has now submitted a New Drug Application (NDA) for lenacapavir for HIV pre-exposure prophylaxis (PrEP) and is working on expanding access globally, especially in areas of high need.