婴幼儿肺炎：多见肺炎链球菌感染，较重的肺炎（如有肺大疱或胸腔积液）多为金黄色葡萄球菌、A组链球菌、流感嗜血杆菌或其他革兰阴性杆菌感染所致。
B-dis I-dis I-dis I-dis I-dis O O O B-mic I-mic I-mic I-mic I-mic O O O O O O B-dis I-dis O O O B-sym I-sym I-sym O B-sym I-sym I-sym I-sym O O O B-mic I-mic I-mic I-mic I-mic I-mic I-mic O B-mic I-mic I-mic I-mic I-mic O B-mic I-mic I-mic I-mic I-mic I-mic O O O B-mic I-mic I-mic I-mic I-mic I-mic O O O O O