Interstitial Lesions in Both Lungs Finally Diagnosed as a Rare Coinfection of Influenza A Virus and Pneumocystis Jiroveci.

BACKGROUND

Influenza is an acute respiratory infection caused by influenza viruses, with influenza A virus (IAV) being the most common and most likely to progress to critically ill cases leading to death. Pneumocystis jiroveci is an opportunistic lung-causing fungus that occurs most often in immunocompromised individuals and can cause Pneumocystis jiroveci pneumonia (PJP). It is rare for both diseases to occur in the same patient.

METHODS

Appropriate laboratory tests, chest computed tomography (CT), bronchoalveolar lavage fluid, second-generation macro gene sequencing, and pathogenetic tests to clarify the diagnosis.

RESULTS

G test and LDH were high, and chest CT showed rapidly progressive interstitial pneumonia, which was confirmed by bronchoalveolar lavage fluid and macrogenomic second-generation sequencing (mNGS) to be a mixed infection of H. influenzae type A virus and Pneumocystis jiroveci.

CONCLUSIONS

In rapidly progressive interstitial pneumonia, bronchoalveolar lavage and mNGS should be done early to clarify the presence of infection with specific pathogenic organisms.