Case
A previously healthy 37-year-old man presented with a five-day history
of high fever, dry cough, nasal discharge, headache, and back pain.
There were no chest auscultation findings and respiratory failure;
however, chest X-ray showed bilateral extensive shadow and computed
tomography (CT) revealed multilobar bronchopneumonia (Figures 1, 2).
Blood examination showed an elevated white blood cell count of 10,100/μL
and a C-reactive protein level of 7.04 mg/dL. Azithromycin was
empirically initiated on the assumption of Mycoplasma pneumoniae(MP) pneumonia, and all findings resolved in only three days (Figure 1).
Multiplex polymerase chain reaction (mPCR) of the sputum was negative
for MP but positive for human metapneumovirus (hMPV). Sputum culture,
Pneumococcal and Legionella urinary antigen, and MP antibody pairs were
negative.
CT imaging findings of hMPV pneumonia are multilobar bronchiolitis
consisting of bronchial wall thickening and centrilobular nodules, often
with hilar-predominant consolidation, which then resembles
bronchopneumonia of MP. The presence of reticular opacities on CT may
suggest MP pneumonia1,2. Additionally, since the
clinical presentation of the two are similar, a certain number of cases
of hMPV pneumonia may be misdiagnosed. The use of mPCR could make the
diagnosis of community-acquired pneumonia more
accurate1, and reduce the inappropriate use of
antimicrobials.