adj.传染性的，(疾病)接触传染的，患接触性传染病

Laughter and happiness can be contagious.
笑声和快乐能感染他人。
There's nothing more contagious than laughter.
笑声是最具感染性的了。
Keep him out of school until he's not contagious anymore.
如果我感染了怎么办？
The flu is highly contagious, and it spreads quickly in crowded places.
流感非常传染性强，它在拥挤的地方迅速传播。
Her laughter was so contagious that soon the whole room was filled with joy.
她的笑声极具感染力，很快整个房间都充满了欢乐。
The measles virus is extremely contagious, and children who haven't been vaccinated are at risk.
麻疹病毒极其传染，未接种疫苗的儿童处于风险之中。
His optimism is contagious, and it's hard not to feel uplifted when you're around him.
他的乐观情绪具有传染性，当你和他在一起时，很难不感到振奋。
The disease is contagious during its early stages, making it crucial to identify and isolate infected individuals promptly.
疾病在早期阶段具有传染性，因此必须迅速识别并隔离感染者。
Gossip can be as contagious as a cold, spreading through a workplace or school in no time.
流言蜚语像感冒一样具有传染性，很快就会在工作场所或学校中传播开来。
The excitement around the new project was contagious, inspiring everyone to work harder and more collaboratively.
对新项目兴奋的情绪具有传染性，激发了每个人更加努力和协作地工作。
The happiness of the newlyweds was contagious, and their love filled the air at their wedding celebration.
新婚夫妇的幸福具有感染力，他们的爱在婚礼庆典上弥漫着。
The fear of the unknown can be contagious, causing panic among people who don't have all the facts.
对未知的恐惧可以传染，导致不了解所有事实的人产生恐慌。
Once you catch the travel bug, it's contagious – you'll find yourself constantly planning your next adventure.
一旦你染上了旅行瘾，它就会传染——你会发现自己总是在计划下一次冒险。