Health officials say he tested positive after he traveled abroad and became ill upon returning to the United States. However, health officials know they need to identify who this patient has been in contact with and get them quarantined. According to the U.S. Department of Health and Human Services, isolation and quarantine are public health practices used to stop or limit the spread of disease. Isolation and quarantine are used to protect the public by preventing exposure to infected persons or to persons who may be infected. Mosquito-borne illnesses are usually different from coronavirus, according to the health department.