Additionally, it causes bacterial pneumonia, especially in adults with a compromised immune system. It has been identified as an important cause in bronchopulmonary infection, causing infection through pulmonary aspiration in the upper pulmonary tract. catarrhalis has recently been gaining attention as an emerging human pathogen. catarrhalis appears to occur around 2 years of age, with a striking difference in colonization rates between children and adults (very high to very low). catarrhalis is associated with bronchopneumonia, as well as exacerbations of existing chronic obstructive pulmonary disease. Elderly patients and long-term heavy smokers with chronic obstructive pulmonary disease should be aware that M. These bacteria are known to cause otitis media, bronchitis, sinusitis, and laryngitis. catarrhalis CCUG 353 type strain was deposited and published in DNA Data Bank of Japan, European Nucleotide Archive, and GenBank in 2016 under the accession number LWAH00000000. Catarrhalis is derived from catarrh, from the Greek meaning "to flow down" ( cata- implies down -rrh implies flow), describing the profuse discharge from eyes and nose typically associated with severe inflammation in colds. Moraxella is named after Victor Morax, a Swiss ophthalmologist who first described this genus of bacteria. Nevertheless, some in the medical field continue to call these bacteria Branhamella catarrhalis. As a consequence, the name Moraxella catarrhalis is currently preferred for these bacteria. However, results from DNA hybridization studies and 16S rRNA sequence comparisons were used to justify inclusion of the species M. The rationale for this was that other members of the genus Moraxella are rod-shaped and rarely caused infections in humans. catarrhalis was previously placed in a separate genus named Branhamella. Other primates, such as macaques, might become infected by this bacterium. catarrhalis is a human pathogen with an affinity for the human upper respiratory tract. Legionella pneumonia complicated by rhabdomyolysis. Risk factors for sporadic community-acquired Legionnaires' disease. Arch Intern Med 1994 154:2417.ĭen Boer JW, Nijhof J, Friesema I. Risk factors for morbidity and mortality. In: Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, 8, Bennet JE, Dolin R and Blaser MJ (Eds), Elsevier, Pennsylvania 2015. (Accessed on February 19, 2021.)Įdelstein PH and Roy CR. In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA. Treatment and prevention of Legionella infection. Clinical manifestations and diagnosis of Legionella infection. Per UpToDate, all patients with moderate to severe CAP or patients with CAP who require hospitalization should be tested ! TLDR - Though less common than COVID, don’t forget about Legionella as a possible cause of your patient’s CAP. Complications - rhabdomyolysis & renal failure ( watch for rising creatinine, hematuria, muscle aches/pain ).Treatment - azithromycin or levofloxacin.Diagnosis - rapid urine antigen test - typically results in 1 hour or less, has a 99% specificity, and should remain positive for weeks after symptom onset!.Risk Factors - smoking, age ( most patients are >50 y/o ), immunosuppression, chronic cardiopulmonary or renal disease, exposure to contaminated manmade water reservoir(s) ( ie showers, hot tubs, pools, etc ).Patients can get community acquired or nosocomial (hospital acquired) infections.Transmission - via inhalation aerosols from contaminated water or soil.CXR - patchy unilobar infiltrates, which can progress to consolidations.Labs - hyponatremia, elevated transaminases.The patient may also be bradycardic or have a normal pulse rate, despite having a high fever & hypoxia!.Clinical Presentation - fever (as high as 105F), fatigue, cough, shortness of breath, +/- GI symptoms (nausea, vomiting, diarrhea), +/- neurologic symptoms (confusion, AMS).Remember, Legionella can cause 2 ( technically 3 ) syndromes…ġ) Legionnaires' disease - a pneumonia caused by Legionella speciesĢ) Pontiac fever - an acute, self-limited febrile illness typically acquired during outbreaks ( no respiratory symptoms )ģ) Extrapulmonary legionellosis (very rare - cellulitis, endocarditis, peritonitis, etc) Remember that ‘SS Cysteine’ drawing from Sketchy Micro? I’ll give you a hint, it involves sailors having similar symptoms. Rapid influenza A & B tests are also negative.Ĭould it still be COVID? Absolutely. You stabilize the patient and a few hours later, the COVID PCR comes back negative. It’s 2021… so naturally, the ‘COVID alarms’ start sounding in our heads. A patient comes into the ED with a high fever, shortness of breath, mild headache, diarrhea, and general malaise.