A 17-year-old immunocompetent male visited our emergency department with a high fever, cough for four days previous, and abdominal pain, vomiting, and diarrhea (5-6 times per day) for two days previous to admission. He also complained of a sore throat, purulent sputum, and rhinorrhea, as well as a headache and dizziness at admission. He had a history of meningitis at the age of seven, and his 12-year-old brother had also complained of an upper respiratory infection for the previous three days. He was a senior in high school, and as an athlete (Taekwondo), he had been staying in an athlete's village for the previous two months with other student athletes training for an upcoming competition. He denied a history of smoking or alcohol.
His initial vital signs included blood pressure of 141/56 mmHg, heart rate of 114 beats/min, respiration rate of 22 breaths/minute, and a temperature of 40.7  C. On physical examination, bilateral tonsillar hypertrophy with pharyngeal injection was identified. Coarse crackles were auscultated in the left lung field, and tenderness was revealed in left lower quadrant of the abdomen. There was no evidence of nuchal rigidity or impaired neurologic signs. Laboratory exams showed a normal total white blood cell (WBC) count (5.01 x 109/L) with increased neutrophil proportion (84.0%) and decreased lymphocyte proportion (9.4%). Hemoglobin was within the normal range (14.0 g/dL), but mild thrombocytopenia was revealed (126 x 109/L). Hypochloremia (96 mEq/L) and hyponatremia (133 mEq/L) were observed with elevated C-reactive protein (CRP, 8.65 mg/dL; reference range: 0-0.3 mg/dL) and procalcitonin (0.88 ng/mL; reference range: 0-0.05 ng/mL). His community-acquired Pneumonia Severity Index (PSI) and CURB-65 scores were 31 and 1, respectively. An initial chest X-ray and computed tomography (CT) confirmed dense consolidation and centrilobular nodules in the left upper and lower lungs (Fig. 1-A, Fig. 2-A, B). An abdomen X-ray and CT showed diffuse bowel wall swelling, mucosal enhancement of the rectosigmoid colon, and mild hepatosplenomegaly (Fig. 2-C, D).
The patient underwent blood, urine, and sputum Gram stain/culture tests and began empirical antibiotic treatment with a third-generation cephalosporin and a macrolide under an initial diagnosis of community-acquired pneumonia combined with severe extrapulmonary symptoms. On the third hospital day, the patient still showed a high fever and complained of a cough, vomiting, and diarrhea. His chest radiography showed infiltration and rapid progression in the left upper and lower lung fields and a newly developed consolidation in the right upper lung field (Fig. 1-B). Although his total WBC counts were still in the normal range (4.43 x 109/L), neutrophilia (84.7%), lymphopenia (9.5%), and thrombocytopenia (121 x 109/L) were sustained, and his CRP increased from 8.65 to 10.90 mg/dL. Multiplex real-time reverse transcription polymerase chain reaction (RT-PCR) for respiratory viruses in his initial sputum specimen was positive for adenovirus, whereas other microbiological tests, including mycoplasma antibody-PCR, acid-fast bacilli, fungus, and mycobacterium tuberculosis-PCR, were all negative. After observing the overall clinical findings, we diagnosed him with combined pneumonia and gastroenteritis caused by systemic adenovirus infection and administered Cidofovir (5 mg/kg per week) with probenecid for a progressive clinical course.
His fever subsided after 24 h of Cidofovir administration, and his other clinical symptoms also improved rapidly (Fig. 3); however, his radiologic and laboratory findings, including CRP (13.05 mg/dL) and platelet (139 x 109/L) levels, did not improve until hospital day five. On hospital day nine, he complained of only a mild cough and showed significant improvement in the chest X-ray (Fig. 1-C) and normalization of laboratory markers such as CRP (1.0 mg/dL), platelets (478 x 109/L), neutrophil (55.9%), and lymphocyte (29.5%) fraction (55.9%). In addition, abnormal renal function was not identified in follow-up laboratory tests after Cidofovir. He was discharged at hospital day 10, and an outpatient visit was scheduled to monitor further complications. After discharge, we confirmed that adenovirus was cultured in his sputum sample from the initial visit. The patient showed complete improvement of residual pneumonic consolidation in follow-up chest X-rays taken two weeks after discharge (Fig. 1-D).