In addition, mucosal lymphoid cells in the oral epithelia and tonsils, as well as the salivary glands, appear to be a target of HIV infection
and a possible reservoir of infectious HIV
. In this regard, oral tissues can be infected in vivo and in vitro, and can support viral replication. Oral trauma, ulcers, drug use, smoking, co-infection with oral herpes, sexually transmitted bacterial diseases (e.g., oral gonorrhea) or periodontal disease might increase oral HIV transmission.