Discussion
Influenza viruses are generally known to infect the respiratory system and cause primary viral pneumonia. This patient presented during the winter with symptoms of fever, cough, sore throat, and diarrhea, along with hemoptysis and significant shortness of breath that required intubation.
Other possibilities include pulmonary hemorrhage with acute pulmonary embolism, pulmonary tuberculosis, and aspiration pneumonia with acute myocardial infarction. Pulmonary embolism with hemorrhage was excluded by the chest CT scan. Pulmonary tuberculosis was considered, given the right lower lobe consolidation; however, the patient had no risk factors for tuberculosis, such as recent travel or a history of incarceration, and no weight loss or night sweats. In addition, the acute onset of symptoms and the negative acid-fast bacilli smears militate against the diagnosis of tuberculosis. Aspiration pneumonia with acute myocardial infarction was excluded, as she had no risk factors for aspiration, such as loss of consciousness or altered mental status. An acute ischemic event was ruled out, given that her transthoracic echocardiogram showed no wall motion abnormality and her ECG revealed diffuse ST segment elevation with atrial fibrillation. These findings are not consistent with acute myocardial infarction.
Her respiratory viral panel PCR assay was positive for influenza A H3 subtype. A sputum culture with Gram staining was positive for methicillin-resistant Staphylococcus aureus, and a blood culture was positive for S aureus.
Because this patient has uncontrolled diabetes and COPD, she is at risk for complications from influenza. The following features of her illness fit the diagnostic criteria for influenza-associated myopericarditis[1]:
Positive clinical features, such as chest pain, shortness of breath, and tachyarrhythmia
An ECG showing diffuse ST segment elevation
An elevated cardiac enzyme (troponin I) level
A transthoracic echocardiogram showing a reduced ejection fraction with left ventricular wall thickness and pericardial effusion
A positive influenza A polymerase chain reaction test in the respiratory specimen
Influenza viruses are commonly known to cause secondary bacterial pneumonia,[2] but they may be associated with syndromes that affect other organ systems, such as the cardiovascular, central nervous system, renal, musculoskeletal, ocular, hematologic, hepatic, and endocrine systems.[3] Viral infections of the respiratory tract facilitate bacterial adherence by disrupting the epithelial lining; decrease mucociliary activity; and increase immunosuppression, which affects both innate and acquired immune responses, resulting in bacterial overgrowth.[2]
Streptococcus pneumoniae and S aureus are two common pathogens involved in secondary bacterial pneumonia following influenza virus infection.[2] In a retrospective and prospective cohort study conducted in 35 adult intensive care units among 683 critically ill patients with confirmed or probable 2009 influenza A (H1N1), Rice and colleagues[4] identified 207 patients with bacterial co-infection. Among these patients, cultures were positive for S aureus in 54 patients (26%) and for S pneumoniae in 19 (9.2%). Increased mortality was observed among those with S aureus co-infection.
Medscape © 2020 WebMD, LLC
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: Avnish Sandhu, Pranatharthi Chandrasekar. Dyspnea, Fever, Hemoptysis, and Diabetes in a Tobacco User - Medscape - Dec 02, 2020.
Comments