Table 1

Characteristics of included studies

Income	Country	Data collected	Outcome	Recruitment site	Location	Definition	Migrants	Non-migrants	Age (all)	Primary aim	Reference
High	UK	2008–2009	HIV STI* behavioural	Specialist sexual health services, flats, saunas, social networks	Flats, saunas	Exchanged sex for drugs, good or money in last 4 weeks	163	105	26 (IQR: 22–35)	Yes	33
	Spain	2000	HIV	HIV/STI clinic	No information	No information	1797	331	29.2	Yes	30
	Spain	1989–1991	HIV	Collaborating centre and snowball sample	Brothels, bar, street	Self-identified sex work for money at least once in last year	404	663	29.8 (14–74)	No	32
	Spain	2000–2001	HIV	STI clinics	No information	No information	2607	523	29.2 (SD=7.6)	No	29
	Italy	1988–1994	HIV	HIV testing clinic	No information	Professional defined as non-IDU	136	593	No information	Yes	35
	Italy	1991–1995	HIV	STI and infectious disease clinic	No information	Professional defined as non-IDU, but includes IDUs	176	223	Median=37 (21–55)	No	34
	Portugal	2000–2001	HIV	Clinic and street	Street	No information	54	42	No info	No	31
	The Netherlands	1991	HIV	STI clinics brothels, hotels	Indoor	Received money or goods in exchange for sex at least once in past 6 months	129	72	29 (SD=7)	No	36
	Australia	1991–1993	HIV STI† Behavioural	Specialist sexual health clinic for sex workers	No information	No information	123	91	Migrant=25.3 Non-migrant=25.5	Yes	37
	Australia	1990–2005	Behavioural	Sexual health care centre and primary health care centre for sex workers	Parlour, private arrangement, escorts, workers	Self-identification and assessment by staff	148	141	16–25 years migrant=46% non-migrant=50%	Yes	23
	Hong Kong	2004–5	Behavioural	Specialist sexual health clinic	Street and indoor	No information	75	170	35.8 (SD=6.04)	No	43
	Hong Kong	2005–2007	Behavioural STI‡	Specialist sexual health clinic	Street and indoor	No information	406	97	26–30 years 11%	Yes	42
Upper-middle	Argentina	2000–2002	HIV/STI§ Behavioural	Work	Street, bar and cabaret	UNAIDS definition	169	456	18–24 yrs Mig=18.4% Non=24.3%	Yes	47
	Argentina, Bolivia, Ecuador, Uruguay	1999–2002	HIV, STI¶ Behavioural	Work	No information	UNAIDS definition	185	1660	No data	Yes	46
	Mexico	1998	HIV, STI**	Bars	No information	Identified by bar managers and health authorities	363	121	25.5	Yes	48
	Mexico	2004–2005	HIV STI††	Municipal and community health clinics, via street outreach, and by referrals from other FSWs	Street, clubs, bars	Sex work and unprotected vaginal sex with client once in last 2 months	370	101	60% (18–34)	Yes	24
	Turkey	1993	Syphilis markers‡‡	STI clinic	No information	Registered sex workers and women arrested for not being registered	96	88	No data	Unclear	28
Lower-middle	Cameroon	1995–1996	HIV	Outreach workers in community referred women to three clinics (family planning clinic, STI and community clinic)	Bars, home	Having at least four different sex partners per month	1453	808	25.5	No	26
	China	2004	Any STI§§ Behavioural	Work	Indoors	Self-identified	151	264	23.5 (SD=5.1)	Yes	38
	China	1998–1999	HIV	Hospital and via outreach to working locations	Bars, hotels, hair dressing salons, beauty parlours	No information	135	831	25 (SD=5)	No	40
	Thailand	1992	HIV	STI clinic and work places	Indoors	Brothels (direct workers) bars, massage parlours, karaoke clubs (indirect)	51	672	48% (383) <20 years	No	41
	Thailand	1991–1994	HIV	STI clinic and work places	Indoors	No information	37	463	23.6 (mean)	No	39
	Kenya	1985	HIV	STI clinic	Missing	No information	399	19	29.2 (SD=6.5)	No	27
Low	Ethiopia	1998	HIV	STI clinic set up for research	Individual, shared rooms, bars, street	Known to health staff as being sex workers	290	82	57% <24 years	No	44
	Mali	1995	HIV	Work	Street	No info	94	82	28.8 (15–50)	No	45
	Benin	1993, 1995, 1999	HIV STI¶¶ Behavioural	Specialist STI clinic for sex workers	No information	No information	461	130	28.4	No	25

The UNAIDS definition of a female sex worker is a woman who receives money or goods in exchange for sexual services, either regularly or occasionally, and who may or may not consciously define those activities as income generating.
*Antibodies to T. pallidum, chlamydia and/or Gonorrhoea.
†Chlamydia, pelvic inflammatory disease, clinical genital herpes, chronic hepatitis B virus and syphilis (all stages).
‡Syphilis, gonorrhoea and chlamydia.
§Syphilis, and hepatitis B and C.
¶Treponema pallidum, gonorrhoea, chlamydia, herpes simplex virus 2 and hepatitis B.
**Treponema pallidum, gonorrhoea, chlamydia, herpes simplex virus 2 and hepatitis B.
††Chlamydia, gonorrhoea, HIV, syphilis or any STI.
‡‡Includes past infection, early latent, late latent syphilis.
§§Gonorrhoea, chlamydia, trichomoniasis, syphilis and genital warts.
¶¶Syphilis, gonorrhoea and chlamydia.
EIA, enzyme immunoassay; FSW, female sex worker(s); IDU, injecting drug user; STI, sexually transmitted infections; UNAIDS, Joint United Nations Programme on HIV/AIDS.