Importance of Asking about Travel and Healthcare ExposuresTimely reporting of healthcare-associated cases ensures that steps can be taken to protect these highly susceptible populations. Show
The majority of recognized Legionnaires’ disease outbreaks are associated with travel (hotels, resorts, cruise ships) or healthcare settings (hospitals, long-term care facilities).2 Approximately 10–15% of all reported cases of Legionnaires’ disease occur in people who have traveled during their exposure period. Outbreaks among travelers can be difficult to detect because of
Therefore, collecting and reporting information about overnight travel is important. See “Reporting” below for information about reporting cases, including travel information. See Healthcare Investigation Resources for more information about healthcare exposures. Preferred Diagnostic TestsCultureIsolation of Legionella on media that supports growth of Legionella (i.e., Buffered Charcoal Yeast Extract [BCYE] agar) is confirmatory and an important method for diagnosis. Isolation of Legionella can come from lower respiratory secretions, lung tissue, pleural fluid, or a normally sterile site. Culturing specimens can detect Legionella species and serogroups that the urinary antigen test does not.
Comparing clinical and environmental isolates using serologic and molecular techniques can help identify the source in Legionnaires’ disease outbreak investigations. Because Legionella commonly occurs in the environment, clinical isolates can help interpret the findings of an environmental investigation. Note that laboratories sometimes reject lower respiratory specimens during a work-up for pneumonia based on specimen quality (e.g., due to lack of white blood cells in the sample, contamination with other bacteria). However, laboratories should not reject lower respiratory specimens for these reasons when working-up Legionnaires’ disease because Legionella can often be recovered.
Urinary Antigen TestThe most commonly used laboratory test for diagnosis of Legionnaires’ disease is the urinary antigen test (UAT), which detects a molecule of the Legionella bacterium in urine. If the patient has pneumonia and the test is positive, then you should consider the patient to have Legionnaires’ disease. The test can remain positive for a few weeks after infection, even with antibiotic treatment. The UAT detects the most common cause of Legionnaires’ disease, L. pneumophila serogroup 1. However, all species and serogroups of Legionella are potentially pathogenic, so a patient with a negative urinary antigen result could have Legionnaires’ disease caused by other Legionella species or serogroups, which is why using culture and UAT in combination is recommended. Sensitivity and Specificity of Diagnostic TestsSensitivity varies depending on the quality and timing of clinical specimen collection, as well as technical skill of the laboratory worker performing the test. The table below provides general ranges for the sensitivity and specificity of each diagnostic test.
1 Cross reactions with other species and serogroups have been documented. Advantages and Disadvantages for Each Diagnostic TestOther Advantages and Disadvantages for Each Diagnostic Test table
1 Cross reactions with other species and serogroups have been documented. TreatmentIf your patient has Legionnaires’ disease, please see the most recent IDSA-ATS guidelines for treatment of community-acquired pneumonia and the most recent IDSA-ATS guidelines for treatment of hospital-acquired pneumonia. Note that first line treatment, however, does not always include Legionella-directed antibiotics (e.g., macrolides and respiratory fluoroquinolones). While it is preferred that you obtain diagnostic testing before antibiotic administration, antibiotic treatment should not be delayed to facilitate this process. If your patient has Pontiac fever, antibiotic treatment should not be prescribed. It is a self-limited illness that does not benefit from antibiotic treatment. Patients usually recover within 1 week. PreventionMinimizing Legionella growth in complex building water systems and devices is key to preventing infection. Timely identification and reporting of legionellosis cases are also important because this allows public health officials to act quickly. This way they can identify and stop potential clusters and outbreaks by linking new cases to previously reported ones. ReportingReport cases and outbreaks of Legionnaires’ disease to your local, state, or territorial health department. Refer to your state or territorial health department website to find more information about how to contact your state, territorial, or local health department. Which of the following is considered to be the first stage of acceptance of dying for the terminally ill patient?Which of the following is considered to be the first stage of acceptance of dying for a terminally ill patient? denial and isolation, followed by anger, bargaining, depression, preparatory depression and then acceptance.
What type of question should you ask the patient to begin a patient history?When questioning patients to obtain an accurate patient history: Start with open-ended questions and then follow up with more direct inquiries. It would be inappropriate to: Ask the patient leading questions regarding his or her symptoms.
When a radiographer is obtaining a patient history both subjective and objective data should be obtained An example of subjective data is?ARRT Registry Review. What are the sacred seven of medical histories?The “Sacred Seven”.
They are (1) location, (2) quality, (3) quantity, (4) timing, (5) environment, (6) influencing factors, and (7) associated manifestations (Bickley & Szilagyi, 2012).
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