Two-case cluster of rapidly progressive influenza B and Staphylococcus aureus pneumonia with one death.

OBJECTIVES

To report a cluster of two epidemiologically linked construction workers with fulminant necrotizing pneumonia associated with co-infection by Panton-Valentine leukocidin (PVL)-positive methicillin-susceptible Staphylococcus aureus (MSSA) and influenza B virus.

METHODS

Clinical characteristics, imaging findings, and microbiological results were retrospectively reviewed. Metagenomic next-generation sequencing (mNGS) was performed on sputum and bronchoalveolar lavage fluid after conventional diagnostic tests failed to identify the causative pathogens.

RESULTS

Following shared occupational exposure, both patients developed severe pneumonia. One patient experienced rapid progression and died. For the second patient, mNGS successfully identified co-infection with PVL-positive sequence type 22 MSSA and influenza B virus, prompting a timely shift to targeted antimicrobial therapy that led to survival after prolonged intensive care.

CONCLUSION

This report demonstrates the extreme virulence of PVL-positive MSSA-influenza co-infection, highlights the diagnostic value of mNGS in severe treatment-refractory pneumonia, and emphasizes the need for effective respiratory protection in high-risk occupational environments.