Zero or negligible risks of HIV, HBV or HCV transmission by biting or spitting

Simon Collins, HIV i-Base

Two related posters presented results from literature searches on the risk of transmission of HIV or viral hepatitis from biting or spitting. These reviews were prompted by recent parliamentary debates on a proposed parliamentary bill that sought to increase penalties for assaults on staff.

The HIV review concluded “there is no risk of transmitting HIV through spitting and only a negligible risk from biting” and that this would be zero too if someone is on ART. Policy to protect emergency workers should be made with this evidence in mind, and balanced with respecting the rights and dignity of people living with HIV.

The hepatitis review concluded “although transmission of HBV and HCV via spitting or biting is biologically plausible, the virulence and risk of this is not established. Only a small number of transmissions of HBV and HCV from spitting or bite injuries have been reported and that the overall risk appears to be very low.”


  1. Cresswell F et al. A systematic review of risk of HIV transmission through biting or spitting: implications for policy. 4th Joint BHIVA/BASHH Conference, 17–20 April 2018, Edinburgh. Poster abstract P66. HIV Medicine, 19 (Suppl. 2), s21–s152.
  2. Pintilie H and Brooks G. What is the likelihood of acquiring hepatitis B virus (HBV) or hepatitis C virus (HCV) through biting or spitting? A review of the published literature with particular reference to the emergency services. 4th Joint BHIVA/BASHH Conference, 17–20 April 2018, Edinburgh. Poster abstract P140. HIV Medicine, 19 (Suppl. 2), s21–s152.

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