Infectious Disease Alert Updates
July 1, 2020 6 minutes read
By Carol A. Kemper, MD, FACP
Clinical Associate Professor of Medicine, Stanford University, Division of Infectious Diseases, Santa Clara Valley Medical Center
Dr. Kemper reports no financial relationships relevant to this field of study.
Let’s Not Shake on This
SOURCE: Pinto-Herrera NC, Jones LD, Ha W, et al. Transfer of methicillin-resistant Staphylococcus aureus by fist bump versus handshake. Infect Control Hosp Epidemiol 2020 May 27;1-3. [Online ahead of print].
Not only am I missing the smiles and facial greetings of recognition as I walk down the corridors of the hospital but, in the COVID era, the basic handshake also has been “masked.” The origin of the handshake is thought to extend back to the 5th century B.C. in Greece to show you had laid down your weapons as a gesture of peace. As the National Post once wrote, “The handshake is one of the highest forms of symbolic currency with the power to unite, divide, seal deals, and broker peace. … It is also a ‘universal norm of reciprocity’ and its rejection sends a powerful message.” Not to mention the “laying on of hands” that usually conveys healing and reassurance. And yet, face-to-face with a new patient and her husband in “reality clinic” (vs. virtual clinic), I realized that, not only could they not see half of my face, nor I theirs, but was I supposed to shake their hands? Apparently not. Later in the morning, one elderly couple was wearing gloves — do you shake gloved hands? My usual currencies of communication with patients had been mucked with.
I have never really thought about a handshake as a hazard, although we touch patients all the time, and hands are a leading source of transmission of micro-organisms in the hospital. My hand was now perceived as a threat.
These authors examined the risk of transmission of methicillin-resistant Staphylococcus aureus (MRSA) with a standard handshake, with and without 2 mL of alcohol hand sanitizer, as well as the exchange of bacteria from a “fist bump” and something called a “cruise tap” (when the first knuckle of each hand is tapped). The fist bump has been proposed as a way to extend a hand in greeting while minimizing skin-to-skin contact.
A convenience sample of 50 patients with known MRSA colonization was selected — and the recipient wore a sterile glove, which was then directly imprinted onto BBL CHROMagar with cefoxitin. Remarkably, a similar frequency of MRSA transfer was observed with the traditional handshake and the fist bump (22% vs. 16%, respectively). However, the risk of transfer was less frequent with the cruise tap (8%). Transfer of MRSA to a gloved hand was significantly reduced by the preemptive use of hand sanitizer (6%).
The 50 patients included 20 residents of long-term care facilities (49%); 31 (62%) had limited mobility, and 25 (50%) had parenteral catheters or indwelling urinary catheters. Only three (6%) reported regular use of hand sanitizer.
The Tricky Business of Treating Early Cocci
SOURCE: Galgiani JN, Blari JE, Ampel NM, Thompson GR. Treatment for early, uncomplicated coccidioidomycosis: What is success? Clin Infect Dis 2020;70:2008-2012.
No one disputes the need for treatment of coccidioidomycosis with more severe manifestations of infection (such as progressive necrotizing pulmonary infection or evidence of lymphatic or hematologic spread). Most clinicians offer antifungal therapy to people with early pulmonary infection and compromised cellular immunity, even before more severe manifestations occur. But throughout my career in infectious disease, there still are no good data on the treatment of newly diagnosed symptomatic pulmonary infection in immune competent people.
It is well-recognized that, before the availability of the azoles, a good number of such infections would resolve on their own, without specific antifungal therapy. But since the introduction of the azoles, experts remain divided on the risks and benefits of treatment for early symptomatic pulmonary cocci infection. Some experts advocate that the benefits of fluconazole therapy outweigh the risks, and all such patients should receive treatment, if only to prevent subsequent complications in a few. Others advocate for an individualized approach, based on features of more severe infection. And others argue that early initiation of treatment in otherwise healthy people may blunt the immune system response to infection, and perhaps even increase the risk for later complications.
Certainly, as one stuck in the middle of these arguments, it often is difficult to decide on the duration of treatment in patients with more troubling and persistent symptoms, and the occurrence of late-onset dissemination in some raises questions. Current Infectious Diseases Society of America guidelines recommend (at most) three to six months of fluconazole 400 mg daily, and treatment can be successfully stopped in those whose pulmonary process has resolved, with no evidence of dissemination.
This helpful article from Dr. Galgiani, a renowned expert on cocci infection, provides some guidance to clinicians struggling with treatment decisions in patients with early symptomatic cocci infection. It is important to distinguish (confidently) between signs and symptoms of ongoing fungal replication and progressive infection vs. common side effects observed in many patients and manifestations of a host immunologic response.
Evidence of ongoing fungal replication or dissemination, which warrants continued treatment, includes progression of pulmonary lesions and cavitation, cutaneous ulceration, subcutaneous abscess formation, lytic bone involvement, active joint infection as manifested by joint effusion and synovitis, and abnormal cerebrospinal fluid (CSF) parameters consistent with meningitis. Histopathologic evidence of continued inflammation, neutrophilic infiltrate, and/or eosinophils and tissue destruction should be taken as evidence of active infection. Beyond these more obvious severe manifestations of infection, Dr. Galgiani adds that extension of azole therapy > 6 months may be considered in other, more unusual circumstances, such as more extensive infiltrate, a pulmonary lesion adjacent to a major blood vessel, new-onset hemoptysis near the end of treatment, or possibly for a frail, elderly patient who is slow to respond to treatment.
In contrast, manifestations of immunologic response, likely secondary to immune complex deposition, such as arthralgias and other rheumatologic signs (e.g., erythema nodosum, elevation in sedimentation rate) commonly occur during the course of infection. Although they may be severe, and even disabling, they are not markers of worsening infection and do not warrant an extension of therapy. The peak onset of arthralgias is ~20 weeks after initial infection. They typically involve the lower extremities, or occasionally the wrists, in a symmetric fashion, but do not lead to synovitis or joint destruction. Similarly, persistent fatigue, malaise, and headache (without evidence of abnormal CSF) are observed commonly in cocci infections, and are not to be attributed to worsening infection.
Finally, to make matters even more confusing, while quantitative complement fixation antibodies can help to guide therapy, rising titers can be observed in a subset of patients either during successful therapy or months or years later, and by themselves do not necessarily mean the patient is failing therapy or relapsing. Similarly, many patients continue to have detectable titers at the completion of successful therapy, so waiting for an undetectable titer, or even a stable serofast one, is not a requirement for stopping treatment.
On-Site Rapid Detection of Bacteriuria
SOURCE: Michael I, Kim D, Gulenko O, et al. A fidget spinner for the point-of-care diagnosis of urinary tract infection. Nat Biomed Eng 2020 May 18. doi: 10.1038/s41551-020-0557-2. [Online ahead of print].
These authors engineered a diagnostic fidget spinner for the rapid detection of bacteriuria in a small 1 mL sample of undiluted urine, which can be used on site and does not require electricity. This clever device is basically a hand-held centrifuge, which concentrates pathogens by > 100-fold with only 12 manual spins of the device. The team incorporated a colorimetric assay, with gradual changes in an orange coloration, to allow for semi-quantitative assessment of bacterial load (1,000 to > 100,000 colony forming units per mL).
The spinner assessment of bacterial load was validated in 39 patients with clinical symptoms of urinary tract infection, and was compared with culturing (which generally takes two to three days for final results). The authors also demonstrated the same colorimetric technique could be used for a down-and-dirty bacterial susceptibility assessment. By adding ciprofloxacin or cefazolin to the sample, if the bacterial colony counts diminished, they inferred that the bacteria present were susceptible.
Let’s Not Shake on This; The Tricky Business of Treating Early Cocci; On-Site Rapid Detection of Bacteriuria
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