Reported by:
Shira Doron, MD, Assistant Professor, Division of Infectious Diseases, Associate Hospital Epidemiologist, Antimicrobial Management, Tufts Medical Center,
Boston, MA
Kirthana Beaulac, PharmD, Clinical Pharmacy Specialist- Infectious Diseases and Antimicrobial Stewardship, Tufts Medical Center, Boston, MA
Patient Background:
JP is a 29 year-old female presenting to the Emergency Department with dyspnea, myalgia, and rhinorrhea. Her symptoms began approximately 1 day ago and are continuous, steadily getting worse. She is having significant nasal discharge but minimal cough. Her 4 year-old son has experienced rhinorrhea as well over the past 3 days, but is not as ill as she is. She has no significant past medical history, and takes no routine medications. She reports receiving the flu vaccine when her child first fell ill, 3 days ago. She was a smoker but quit when she became pregnant 4 years ago. Ten point review of systems was negative except for fever, lethargy, nasal discharge, shortness of breath, and muscle soreness.
| Tmax | 101.0oF, 38.3oC |
| Heart Rate | 105 bpm |
| Respiratory Rate | 22 bpm |
| Blood Pressure | 120/76 |
| Oxygen Saturation | 89% on room air, 100% on 2L nasal cannula |
Vitals| Na: 138 |
Creatinine: 1.0 |
| K: 3.6 |
WBC: 14.2 |
| Cl: 105 |
Hgb: 12.2 |
| Bicarb: 26 |
Hct: 38.4 |
| BUN: 24 |
Platelets: 356 |
Labs| General |
Well nourished, uncomfortable young woman |
| HEENT | Pupils equally round and reactive to light and accommodation, copious nasal discharge |
| Neck | Supple |
| Resp |
Wheezes, no crackles; diminished breath sounds at bases |
| Card | Regular rate and rhythm, no murmurs, rubs, or gallops |
| Abd | Soft, non-tender, normal bowel sounds |
| Ext | No edema, but tender upon palpation |
| Skin | Warm and diaphoretic |
| Neuro | Normal |
Physical Exam| Radiology |
Chest X-ray showed patchy diffuse bilateral infiltrates suggestive of pneumonia. |
Radiology| Blood Culture |
Negative <24 hrs |
| Sputum Culture |
Gram Stain: 1+ squamous epithelial cells, 3+ segmented neutrophils, no organisms Culture: No growth <24 hours |
| Rapid Flu Swab |
Positive: influenza A |
| Viral Culture |
Cancelled |
MicroDiagnosis:
JP was diagnosed with influenza. The patient was admitted to the hospital for respiratory support and started on the antiviral Tamiflu (oseltamivir). She was not started on antibiotics for bacterial pneumonia, as the patient did not demonstrate typical symptoms of bacterial pneumonia (a notable lack of cough). Also, she had a reasonable alternative explanation for her symptoms and clinical findings. She was discharged after 1.5 days of hospitalization as her ability to oxygenate improved. She completed a 5-day course of oseltamivir at home and returned to usual health within two weeks.
The diagnosis of influenza has been problematic to our healthcare system for quite some time. The gold standard for flu testing has been viral culture; however, this process can have a 3-10 day turnaround. A shell vial culture can reduce the time to results down to 48 hours, with similar accuracy to viral cultures.1 However, even if received only 48 hours after presentation, a shell vial culture for flu is of limited value to practicing clinicians, since the mainstay of treatment, oseltamivir, works best only when initiated within 48h of symptom development.2 Likewise, because the course of treatment with oseltamivir is 5 days, if a patient was empirically initiated on oseltamivir at the time shell vial culture was sent, they would have completed half their antiviral course by the time the diagnosis was confirmed or refuted. Therefore, rapid flu testing provides significant advantages over traditional diagnostics.
