một số trường hợp trẻ em đã trình bày mà không có bất kỳ triệu chứng hô hấp nhưng nặng đường tiêu hóa (GI) hoặc các triệu chứng thần kinh. Một yếu tố lịch sử quan trọng của hầu như tất cả các trường hợp tiếp xúc gần đây để các loài chim hoang dã hoặc trong nước. Một chỉ số có sự nghi ngờ cao là cần thiết để xem xét chẩn đoán. | 352 John V. Williams Table 2. Clinical features of H5N1 avian influenza in children Reference 36 42 41 43 Number of patients 7 7 9 Male 57 43 56 Previously healthy 71 100 87 Fever 100 100 100 Cough 43 100 90 Rhinorrhea 71 - 35 Dyspnea - 100 69 GI symptoms 29 57 25 Pneumonia 29 100 100 Ventilated 29 86 100 Mortality 29 86 90 Not reported. a number of pediatric cases have presented without any respiratory symptoms but with severe gastrointestinal GI or neurological symptoms. A key historical element of virtually all cases is a recent exposure to domestic or wild birds. A high index of suspicion is necessary to consider the diagnosis. In most cases the onset of symptoms occurs within 1 week of the bird exposure. The median duration of symptoms prior to hospitalization was 4 days range 0-18 days . Prominent laboratory findings include leukopenia especially lymphopenia thrombocytopenia and elevated liver transaminases Tab. 3 . Most pediatric patients do not manifest hemoconcentration this finding and the prominent respiratory symptoms help distinguish the illness from dengue virus infection in dengue-endemic areas. Renal failure hyperglycemia and hemophagocytosis have been noted in some patients. Most have abnormal chest radiographs at presentation. Many patients develop complications such as respiratory failure requiring assisted ventilation ARDS shock and multiorgan system dysfunction. Severe infections have typically progressed rapidly with a median duration of symptoms prior to death of 9 days range 2-31 days . The proximate cause of death is usually respiratory failure. The overall mortality in the cumulative human H5N1 cases reported to date is 59 Tab. 1 . However the highest mortality rates occurred in patients age 10-19 73 n 49 20-29 65 n 45 30-39 61 n 33 and 40-49 years 45 n 11 . Very high mortality rates were also observed in children 5 years 43 n 21 and 5-9 years 41 n 32 . The lowest rates were in the patients older than 50 18 n 11 45 . This distribution .
