There are occasional cases of dengue fever in Brunei, and there are no other serious infectious diseases such as pertussis, tetanus, poliomyelitis, etc. Brunei has a relatively complete medical security system. The government provides free medical care to its citizens, including free medical treatment abroad, but not to the foreigners. Common drugs can be purchased in the clinic with the prescription issued by the doctor. There are no regulations to force foreigners to buy medical insurance in Brunei.