The 2018 Centers for Disease Control and Prevention report shows about 28.9 million adults had sinus infections. This infection is also known as sinusitis, and many wonder if it is contagious. In this article, you will find answers to your question and many more helpful information. Whether or Not Sinus Infections Are Contagious Sinus infections themselves are not contagious. They are usually caused by viruses, bacteria, or fungi already present in the body. However ...