全世界每年约有1,500万5岁以下儿童死亡(即每2秒钟1个),其中发展中国家占97%。但在这些死亡病例中占高比例的急性呼吸道感染并未得到广泛重视。据WHO 估计,每年有400万～500万儿童(占死亡儿童的25～33%)死于急性呼吸道感染;联合国国际儿童基金会(UNICEF)估计,每年死于肺炎的儿童达300万以上。这些估计数字均远高于WHO 收到的例行报告,例行报告大多低估了死于肺炎的儿童人数,因为递交报告的一些国家较为富裕,而呼吸 Every year, about 15 million children under the age of 5 die (ie, every 2 seconds) worldwide, of which about 97% are developing countries. However, acute respiratory infections, which account for a high proportion of these deaths, have not gained much attention. WHO estimates that between 4 and 5 million children (25-33% of all deaths) die of acute respiratory infections every year, and UNICEF estimates more than 3 million children die each year from pneumonia. These estimates are much higher than the routine reports received by WHO, most of the routine reports underestimated the number of children died of pneumonia, because some of the countries that submitted the report were richer, while breathing