Image credit: Umanoide Unsplash

A new study published in the Annals of Family Medicine shows that even when patients have a negative chest radiography (CR) for community-acquired pneumonia (CAP), a majority of these patients were given antibiotics by their clinicians. Antibiotics were prescribed in 79 of 115 patients with a negative CR. ¹

“Despite the absence of radiologic confirmation, most practitioners initiated antibiotics in the case of clinical suspicion of CAP,” the authors wrote.¹

This was a prospective cross-sectional study that was performed with general practitioners in France from November 2017 to December 2019. The study included 259 adult patients with suspected CAP after CR were included. CR results were categorized as CAP positive or CAP negative.¹

In terms of other findings, 55.6% of patients (144 out of 259) had a positive CR, and of these patients, they were found to be more clinically severe than those with negative CR, and with longer-lasting symptoms. Patients with positive chest X-ray results had higher body temperature, faster heart rate, faster breathing rate, more difficulty breathing, and more frequent unilateral chest pain than patients with negative X-ray results, and their symptoms lasted for a longer time. And in the positive CR group, antibiotics were initiated for 142/143 (99.3% [95% CI, 97.9%-100.0%]).¹

[Check out our respiratory infections section.]

Typically, guidelines for diagnosing include blood work and a positive CR to confirm inflammation and the presence of the respiratory infection.² This study demonstrates the differences in treatment guidelines and actual practice.

The investigators surmise there are some situations in clinical practice where treatment may be best even in the absence of clinical evidence of a positive CR. They write that 1 consideration may be the absence of opacity on the x-ray to be from radiologic delay. Still this did not prove to be the case in the overall results.

“The time to symptom onset before inclusion and CR was not statistically different between CR+ and CR− patients (4.0 days [IQR 2.0-8.0 days] vs 4.0 days [IQR 2.0-7.0 days]; P = .280),” the authors write.¹

In addition, the authors developed other potential theories for treatment with antibiotics when patients exhibit a negative CR. Other treatment considerations included a low sensitivity of CR to diagnose pneumonia, premature closure bias, differing opinions between the treating clinician and the radiologist on the x-ray results, lack of ready access to CR, and some clinicians may have obtained a secondary diagnosis that required antibiotics.¹

“The effect of a negative CR on the antibiotic initiation decision appears to be low. This raises questions regarding the role of CR in the management strategy for CAP and justifies clarification of the guidelines as to what should be done in case of clinical suspicion of CAP without radiologic confirmation,” the authors wrote.¹

References

1.Pinot J, Gilberg S, Laouénan C, et al. Relation Between Chest Radiography Results and Antibiotic Initiation in Community-Acquired Pneumonia Management by General Practitioners. Ann Fam Med. 2024;22(6):509-517. doi:10.1370/afm.3179
2.Regunath H, Oba Y. Community-Acquired Pneumonia. [Updated 2024 Jan 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430749

Image explaining how H5N1 can be transmitted from cow to human.

Image credit: CDC

California health officials issued a warning after a second batch of raw milk from Raw Farms tested positive for H5N1, prompting a recall and new health alerts. In addition, two dairy workers in California have tested positive for the virus, raising the state’s total human cases to 31 for 2024. The national total of human cases is now at 55.¹

The California Department of Public Health (CDPH) originally issued the alert on November 27, following the detection of the virus in milk produced by Raw Farms, based in Fresno County. While no human illnesses have been linked to the contaminated milk, investigations are ongoing, and health authorities are tracking affected products at retail outlets.²

The affected batch of raw milk was discovered through testing at the Santa Clara Public Health Laboratory, leading to a voluntary recall of products by Raw Farms. Health authorities are also monitoring other affected retail locations, including Sprouts Farmers Market stores. Authorities are also tracking retail outlets that sold the contaminated milk, with 49 locations identified, including Sprouts Farmers Market stores. Consumers who have purchased the recalled milk are urged to return it to the retailer.¹
The H5N1 virus has spread to additional dairy herds and poultry farms in the US Since November 27, California has reported 14 new outbreaks, raising the state’s total to 475, with 689 affected dairy herds across 15 states. Poultry farms in California, Minnesota, North Dakota, South Dakota, Utah, and Tennessee have also been impacted.¹
Symptoms of bird flu in humans can include fever, cough, sore throat, diarrhea, muscle aches, fatigue, difficulty breathing, and pneumonia, with severe cases potentially leading to death. The virus spreads primarily through contact with infected animals or their bodily fluids, including feces, feathers, and saliva. People can become infected by inhaling contaminated dust or droplets, touching contaminated surfaces, or consuming raw (unpasteurized) milk from infected cows.³

To reduce the risk of infection, workers should use personal protective equipment (PPE) such as goggles, NIOSH-approved respirators, gloves, coveralls, and boots when handling animals that could be infected with H5N1. Workers are also advised to wash their hands thoroughly after handling animals, animal waste, or raw dairy products.¹

To protect workers at high risk, the California Department of Public Health has distributed protective gear and provided 5,000 seasonal flu vaccines to dairy farm workers to reduce the potential for co-infection with seasonal flu. California health officials recommend wearing dedicated work clothing and footwear, changing after work, and showering to reduce the chance of spreading the virus.³

As the situation evolves, California health officials are urging the public to stay informed about potential risks related to bird flu. For the latest updates and guidance, individuals can contact their local public health department or visit the CDPH website. While outbreaks continue, health officials emphasize that the risk to the public remains low. There have been no cases of person-to-person transmission, and no illnesses have been linked to the contaminated raw milk. Health authorities reassure consumers that pasteurized milk is safe, as the pasteurization process effectively eliminates the virus.¹

References

1. Current Bird Flu Situation. CDPH. Updated December 2, 2024. Accessed December 3, 2024. https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/Bird-Flu.aspx

2. California Acts to Protect Public Health: ​CDPH Warns Against Drinking Single Lot of Raw Milk Following Bird Flu Detection; Secures Voluntary Recall. CDPH. November 27, 2024. Accessed December 3, 2024. https://www.cdph.ca.gov/Programs/OPA/Pages/NR24-039.aspx

3. Current H5N1 Bird Flu Situation in Dairy Cows. CDC. December 2, 2024. Accessed December 3, 2024. https://www.cdc.gov/bird-flu/situation-summary/mammals.html

Jacinda Abdul-Mutakabbir, PharmD, MPH, AAHIVP, assistant professor of Clinical Pharmacy, University of California San Diego, was working with her research partner, Karen Tan, PhamD, BCIDP, assistant professor, Pharmacy Practice School of Pharmacy, Loma Linda University, and they discovered disparities in how antimicrobials were being prescribed across different racial and ethnic groups. Their study of disparities and social determinants expanded and developed into a framework around these findings.

“For us, it really became clear that there were not only racial and ethnic disparities, but disparities in terms of social vulnerability, disparities in terms of sexuality, and gender. And it really pushed us to think about how can we to address these things?” recalled Abdul-Mutakabbir. “And we really developed, like, our own set of steps, you know, for walking through how it is that we wanted to engage in the research. And we developed the [Equity in Antimicrobial Stewardship Efforts] (EASE) framework.

The framework is aimed at shining a light on inequities as it equates to antimicrobial prescribing practices and strategies to reduce them. She was part of a team that published a paper earlier this year that detailed the framework comprehensively in Antimicrobial Stewardship & Healthcare Epidemiology.

Jasmine Marcelin, MD, FACP, FIDSA, associate professor, Department of Internal Medicine, associate medical director, Antimicrobial Stewardship Program, became involved in the project early on and stressed the importance of collecting data as a starting point.

Contagion: What do you want to see in terms of patients responding to treatment—timeframe, cultures, follow-ups?

Jones: When assessing clinical response, one of the first things I look at is the white blood cell count—whether it’s decreasing. If the patient was febrile initially, are they now afebrile, and have they remained afebrile for more than 24 hours? We aim to get repeat cultures within 24 to 48 hours once they’re on appropriate therapy, and ideally, we want to see blood cultures clear within three days. Some guidelines allow up to seven days, but we prefer to see an earlier response, especially in critically ill patients. A major consideration is source control. While it’s not always possible, it’s essential for effective treatment. We need to determine where the infection originated and if source control interventions can be applied.

Contagion: In the recent literature, the DOTS study, which looked at dalbavancin as an option for treatment of S aureus that demonstrated promising results. Can you talk about the potential benefits for this therapy?

Jones: It’s still in peer review right now, but we’re hoping for publication by the end of the year. I saw some initial data presented earlier in the year at the Estimate conference, as well as more recently at ID Week in October 2024. Although we’re still waiting on the final publication, the preliminary data looks promising.

Currently, dalbavancin has just one indication: acute bacterial skin and skin structure infections, like cellulitis or abscesses. However, its clinical utility is likely highest for off-label uses, such as in cases of bacteremia, endocarditis, and osteomyelitis. This study assessed the desirability of outcomes ranking (DOOR) and included a day-70 secondary outcome, which is a familiar benchmark. It compared dalbavancin against the standard of care, with around 100 patients in each arm, specifically focusing on Staph aureus bacteremia and including some patients with right-sided endocarditis.

Although we’re awaiting peer review, the study showed that dalbavancin was non-inferior to standard care in terms of clinical efficacy, with comparable rates of adverse events between groups. This suggests that dalbavancin could be a viable treatment option, potentially encouraging more clinicians to consider it. For many—including myself—this study validates current off-label practices, as around one-third of my dalbavancin use is off-label, mostly for osteomyelitis, and we’ve seen a rise in its use for Staph aureus bacteremia and endocarditis. Additionally, the study could help standardize dosing, as there is currently some variability in dosing for off-label indications.

The conversation was edited for grammar and clarity.