黄热病 A型肝炎

A型肝炎是一种由肝炎病毒（HAV）引发的肝脏疾病。任何人都有可能患病。一岁或以上的人群可通过注射疫苗而长期预防HAV病毒感染。

A型肝炎如何传播？

A型肝炎可通过人与人的直接接触、摄取受污染的水、冰、从污水中收获的贝类、水果，蔬菜或其他在收获时或之后处理过程中遭污染的生食食物而传播。

许多与旅行有关的A型肝炎病例都发生在前往发展中国家旅行的旅客中。虽然A型肝炎在发达国家的发病率要小得多，但是仍可能爆发社区内大范围的感染。感染风险随着旅行时间的长度而升高。那些生活在农村地区、在穷乡僻壤徒步旅行、或经常在卫生条件差的地方饮食的人士患病率最高。

目前，社会上还没有治疗A型肝炎的具体方案。由于A型肝炎是旅行期间最常见的可通过疫苗预防的传染病之一，因此，我们强烈建议公众接受该疫苗接种。

Laboratory diagnostic tests are not perfect and are not 100% accurate

We do not have a test for every disease or virus but most of those pathogens that are of public health importance or have long term implications on your health can be tested
No one single test can be used with absolute certainty to diagnose a disease. Often, we depend on a combination of tests to make a diagnosis
Sometimes, we have to resort to trial treatment or empiric treatment if investigative tests are inconclusive. If the patient makes a therapeutic response and feels better, we have achieved our goal
In PUO, we are looking for treatable causes and to rule out sinister causes eg. malignancies so that we do not miss opportunities for early treatment or intervention