Risk of transmission following HIV exposure

Table 1: Exposure and transmission risk/exposure

Type of exposure with known HIV+ source Estimated risk of HIV transmission/exposure
Receptive anal intercourse (RAI) 1/120
Use of contaminated injecting equipment 1/150
Occupational needlestick injury 1/333
Receptive vaginal intercourse 1/10002
Insertive anal or vaginal intercourse 1/10002
Receptive fellatio with or without ejaculation Not measurable3
Insertive fellatio Not measurable
Cunnilingus Not measurable
Bites etc. Not measurable
Other trauma Not measurable
Non-occupational exposure of intact mucous membrane4 and skin Not measurable
Community needle-stick injury Not measurable

Table source: 2013 National guidelines for post-exposure prophylaxis after non-occupational and occupational exposure to HIV (external site).


1 These estimates are based on prospective studies, not cross-sectional data or figures derived from modelling.
2 This estimate has been rounded down from 1/909 to 1/1000.
3 Although there have been case reports of transmission, the risk associated with the exposures below is so low that it is not measurable.
4 Conjunctival, oral or nasal mucosa.