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Crane Survey Select Results from Recent Surveys Kampala, 2012/3 Men Who Have Sex With Men (MSM) Female Sex workers (FSW) Drug users Kampala, December 2013. Crane Survey. Standing survey platform, Wandegeya PEPFAR funded Collaborative activity
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Crane SurveySelect Results from Recent SurveysKampala, 2012/3Men Who Have Sex With Men (MSM) Female Sex workers (FSW) Drug usersKampala, December 2013
Crane Survey • Standing survey platform, Wandegeya • PEPFAR funded • Collaborative activity • Makerere University / School of Public Health • Ministry of Health • CDC
Key population HIV surveillance: Three pillars • Surveys • How affected are they? • Population size estimates • How many are they? • Mapping • Where are they?
Bio-behavioral surveys How affected are they?
Bio-behavioral survey design • Sampling: Respondent-driven sampling • Participants refer others to survey • Facilitates population estimates: Survey findings apply to all key population members, not just those who participated • Anonymous (no names)
Bio-behavioral survey design (2) • Data collection: audio-computer-assisted self interviews, facilitates more candid answers • Blood draw • HIV antibodies • CD4 cell count (disease stage) • Viral load: Number of viruses (“copies”) in blood • HIV results returned, HIV-positives referred
2012/3 Crane surveys • Female sex workers (FSW): 15+ years, sold sex to men in last 6 months • Men who have sex with men (MSM): 18+ years, had anal sex with another man in last 6 months • Drug users (DUS): 18+ years, habitual consumer of drugs in last 6 months (by nose, mouth, or injection) • All: residing in greater Kampala
Number of survey participants • FSW: 1,490 • MSM: 595 • DUS: 1,170
HIV prevalence estimates (preliminary) • FSW*: 33% (Kampala general women: 9.5%) • MSM: 13% (Kampala general men: 4.1%) • DUS: 17% (Kampala general pop: 7.1%) • *) Note: Median duration of sex work at time of survey participation: 2 years
Select MSM characteristics CD4 cell count Viral load Average: 37,000 copies / ml 50% between: 8,000–120,000 Suppressed (<1000): ~11%* • Average: 406 • 50% between: 300–520 • CD4<350: ~27%* *) Small numbers – unstable estimates Syphilis prevalence: 3% Ever tested for HIV: 70% HIV prevalence: 13% Self-reported on ART: 14% (among HIV-pos)
Select FSW characteristics CD4 cell count Viral load Average: 3,500 copies / ml 50% between: 100–38,000 Suppressed (<1000): 37% • Average: 443 cells / ul • 50% between 300–600 • CD4<350: 32% (of these, 86% not on ART) Syphilis prevalence: 6% HIV prevalence: 33% Self-reported on ART 18% (among HIV-pos)
High rates of gender-based violence (GBV) among Kampala FSW • 49% ever experienced rape • Rape defined as the use of force or threat to use force • Of those who have ever been raped, on average report having been raped twice in last 6 months (50% range: 1-3) • 82% exposed to some form of GBV in last 6 months • Defined as: physical abuse, verbal abuse, forced sex acts, paid less or not paid at all after sex act • 52% experienced three or more GBV events in last 6 months
Conclusion - FSW • Very high HIV prevalence among FSW: 33% • 3x that of Kampala women in general • One in three HIV-pos FSW with CD4 <350 • Short average duration of sex work at time of survey participation suggests: • high turn-over • high HIV incidence • warrants frequent outreach services
Conclusion – MSM, drug users • MSM: HIV prevalence 13% • triple that of Kampala men in general • low self-reported ART uptake • high average viral load (high forward transmission potential) • small proportion with suppressed viral load • Drug users: HIV prevalence 17% • more than double that of general population in Kampala
Population size estimates How many are there?
Objective • To estimate the population sizes of • Female sex workers (FSW) • Men who have sex with men (MSM) in Kampala, Uganda
Method to estimate population size: Capture/recapture Universe: (e.g., all sex workers in Kampala) N Sex workers captured twice (“Match”) M Sex workers captured, e.g., with key chains (Sample 1) C1 Sex workers recaptured, e.g., by survey (Sample 2) C2 N=C1*C2 /M
Capture 1 – tagging key pop members with a small gift • Ordered several hundred tailor-made key chains • Not available commercially • Distributed by community members • 540 key chains among FSW • 400 key chains among MSM
Capture 2 - survey • Respondent-driven sampling survey (RDS) • Start: after key chain distribution • Asked every participant if s/he can • show key chain or • identify key chain (received but doesn’t have) • Had to choose correct key chain out of 6 similar key chains • “Match” defined as survey participant who showor identified correct key chain
Population size estimates – Match: presenting or identifying correct key chain • FSW: 13,200 (95% CI: 10,200 – 16,200) • MSM: 7,900 (95% CI: 4,400 – 11,300) • Kampala 15-59 population: ~800,000 (49% male)* + • Proportion FSW: 3.3% (2.5% - 4.0%) • Proportion MSM: 2.0% (1.1% - 2.9%) *): Source: UBOS: 1.73M in 2012, assumed proportion <15 yrs: 49%, assumed sex distribution: 50%. http://www.ubos.org/onlinefiles/uploads/ubos/pdf%20documents/abstracts/2012%20Statistical%20Abstract.pdf +) : Note: Age bands not identical to MSM survey eligibility age criteria
Conclusion – FSW and MSM size estimates for Kampala • Conservative estimate: • MSM: 8,000 (95% CI: 4,000 - 11,000) • FSW: 13,000 (95% CI: 10,000 - 16,000) • Note: FSW highly mobile, both • Occupationally (in and out migration of sex work) • Geographically (change in sex work location)
Linking size estimation and mapping Where are they?
Crane survey – virtual, electronic mapping of key populations • Respondents: • Interview location: • Software: • Mapping results: Survey participants (MSM, FSW) Survey office Google Earth (offline) Geo-social locations, i.e., where - FSW respondents meet clients - MSM socialize Note: mapping of (transient) individual geo-social locations, not primarily venues / buildings
Geo-social locations of sex workers - Makindye “About 200 sex workers hang out at G8 club,…, especially on the weekends.” (Venue names changed by investigators)
Using GIS software to identify and characterize clusters of sex workers Color: population size (darker ~ larger) Size: geographic extent of cluster
Projecting Kampala’s FSW population size estimate (13,000) to the relative sizes of mapped clusters
George Lubwama, EnosSande (SPH / Makerere University) Rachel Kwezi, Sam Sendagala, Michael Ediau (CDC Uganda) Steven Borders (GIS Corps) Wolfgang Hladik, Drew Baughman, Jim Tobias (CDC Atlanta) Thank you
Using GIS software to characterize clusters of sex workersColor: population size (darker ~ larger)Size: geographic size of cluster
“Mapping and Size Estimation of the Key Affected Populations in Kampala Capital City Authority”, 2013 • Method: Census (?) • FSW: 2,148 (95% CI: 1,611-2,685) • MSM: 253 (95% CI: 169-338) • Note: Crane MSM Survey 2012/3, sample size: 595 Commissioned work by D Muhangi and J Kiwanukafor: Alliance of Mayors and Municipal leaders on HIV/AIDS in Africa
Modes of Transmission study • UNAIDS commissioned report, 2009 • Country-wide estimates • FSW (last 12 months): 32,652 • MSM: 3,976
Future size estimation activity: Network scale-up • Population size estimation through general population based survey • Nation-wide • Sample size ~5,000 adults • Size estimates for MSM, MSW, FSW, PWID, ‘mobile men with money’ • Strata: Kampala, urban, rural • Start early 2014
Past population size estimates lack quality data sources: Modes of Transmission study (2009) National size estimates • FSW : Sex for money in last 12 months: • Number: 32,652 (projected % value from abroad) • Proportion: 0.3% • MSM: (No operational definition) • Number: 4,000 (“MSM study expert guess x 2”) • Proportion: <0.1%
Assumptions • Closed population • Everyone has equal, non-zero sampling probability • Capture and recapture constitute independent samples (no correlation) • Matches are accurate In practice, hard to meet all assumptions
Summary *Approximately 20 UMOs distributed “late”, i.e., during RDS sampling period (excluded from analysis) ** presented UMO *** did not present, but did identify correct UMO
Population size estimates - Match: presenting correct key chain • FSW: 26,000 (95% CI: 18,000 – 35,000) • MSM: 28,000 (95% CI: 4,000 – 53,000) *): Source: UBOS: 1.73M in 2012, assumed proportion <15 yrs: 49%, assumed sex distribution: 50%. http://www.ubos.org/onlinefiles/uploads/ubos/pdf%20documents/abstracts/2012%20Statistical%20Abstract.pdf