a disease is considered as rare disease if
Rare disease In the United States, the Rare Diseases Act of 2002 defines rare disease strictly according to prevalence, specifically "any disease or condition that affects fewer than 200,000 people in the United States",[3] or about 1 in 1,500 people. This definition is essentially the same as that of the Orphan Drug Act of 1983, a federal law that was written to encourage research into rare diseases and possible cures.
Sexually transmitted infection AIDS is among the leading causes of death in present-day Sub-Saharan Africa.[96] HIV/AIDS is transmitted primarily via unprotected sexual intercourse. More than 1.1 million persons are living with HIV/AIDS in the United States,[97] and it disproportionately impacts African Americans.[98] Hepatitis B is also considered a sexually transmitted disease because it can be spread through sexual contact.[99] The highest rates are found in Asia and Africa and lower rates are in the Americas and Europe.[100] Approximately two billion people worldwide have been infected with the hepatitis B virus.[101]