A case of pulmonary abscess in which Haemophilus parainfluenzae and Streptococcus intermedius were isolated by percutaneous needle aspiration]

Some microbes, including the Bacteroides species, Staphylococcus aureus and Streptococcus milleri groups, can cause pulmonary abscess. Haemophilus parainfluenzae is usually categorized as one of the normal flora which colonizes in the ears and the nasopharynx, and it has been long considered that H. parainfluenzae has little pathogenicity in the lower respiratory tract and lung parenchymal. In this report, we present a case of pulmonary abscess caused by both H. parainfluenzae and Streptococcus intermedius. The patient was a 75-year-old man who had had total esophageo-gastrectomy because of esophageal cancer. He presented with purulent sputum, and chest X-ray film showed a dense consolidation in the right upper lung field. CT-guided transcutaneous fine needle aspiration was performed as a diagnostic procedure. Since both H. parainfluenzae and S. intermedius had been isolated from the lesion, pulmonary abscess caused by these two pathogens was diagnosed. The patient was treated with panipenem/betamipron, and his symptoms and pulmonary infiltrates on the chest X-ray film improved thereafter. So far, very few cases have been reported in which H. parainfluenzae caused lower respiratory tract infection. Although S. intermedius is known as one of the pathogens of pulmonary abscess, it is possible that H. parainfluenzae could also be pathogenic in infectious diseases of the lung.