Spatial Epidemiology Challenges Spatial Epidemiology Challenges d A hi t l thd A hi t l thand Achievements along the and Achievements along the

Mexico/USMexico/US borderborderMexico/US Mexico/US borderborder

AAGAAG NIH S iNIH S iAAGAAG‐‐NIH SymposiumNIH SymposiumJuly 27July 27‐‐28, 201228, 2012

Kimberly C. Brouwer, Ph.D.Associate Professor In ResidenceDivision of Global Public HealthDepartment of MedicineUniversity of California, San Diego, U.S.A.kbrouwer@ucsd.edu

Using GIS to Study IDU Risk Environments in TijuanaNIDA t K01DA020364 PI B 2005 2010NIDA grant K01DA020364, PI Brouwer  2005‐2010

Proyecto El Cuete Epi. of HIV and BBVs among IDUs in Tijuana

R01DA019829, PI Strathdee

Evolving HIV/STI risk environments of FSWs on the Mexico/U.S.  (Mapa de Salud)

NIDA G R01DA028692 PI B 2010 2015

Molecular Epi. of HIV‐1 In the California‐Mexico Border Region

NIDA Grant R01DA028692, PI Brouwer 2010‐2015

Molecular Epi. of HIV 1 In the California Mexico Border Region NIAID Grant K23AI093163, PI Mehta  2010‐2015

A Mixed‐Method Study of Injection Drug Use Settings Among FSW i TijFSWs in Tijuana

NIDA Grant K01DA032443, PI Davidson  2012‐2017

HIV and Substance Abuse Epidemiology among IDUs: Structural p gy gand Network Risk Factors

NIDA Grant K01DA033879, PI Rudolph (pending) 2012‐2017

HIV prevalence in the Americas

2 42.5

2.63.3

3.8

GuyanaBelize

Tinidad and TobagoBahamas

Haiti

0 91.1

1.51.51.5

1.92.4

El SalvadorDomincan Republic

JamaicaHondurasBarbadosSuriname

y a

0 60.60.6

0.70.90.90.9

PColombia

ArgentinaVenezuela

PanamaGuatemalaEl Salvador

0.30.4

0.50.5

0.60.6

CanadaParaguayUruguay

BrazilUnited States

Peru

0 10.2

0.30.30.30.3

CubaNicaragua

MexicoEcuador

Costa RicaChile

0.10.1

0 0.5 1 1.5 2 2.5 3 3.5 4

BoliviaCuba

Adult (15-49 years) prevalence (%)ADAPTED FROM: Report on the Global AIDS Epidemic, UNAIDS, 2006

Major opium producers and trafficking routestrafficking routes

Source: 2006 World Drug Report of the UNODC and U.S. Central Intelligence Agency, “Major Narco Trafficking Routes and Crop Areas” GPO item 751981AI (R00350) 1-00.

(Rachlis, Brouwer et al, 2007)

Tijuana has one of the Tijuana has one of the fastest growing IDU fastest growing IDU populations in Mexico, with populations in Mexico, with ~21,000 drug users, and ~21,000 drug users, and ~10 000 IDUs~10 000 IDUs10,000 IDUs10,000 IDUs

HIV Risk Environments

Photos by O. Loza

Questions to ExploreQuestions to ExploreDoes pharmacy density affect syringe sharing by

IDUs? Is sex work outside of the Zona Roja associated with

f t t d l t h lthmore frequent arrests and less access to health services?

I th di t b t d ’ id dIs the distance between a drug user’s residence and the Mexico/U.S. border associated with type of drug used or disease risk?drug used or disease risk?

Where best to provide health services?Are more dispersed social networks at higher risk forAre more dispersed social networks at higher risk for

HIV/STIs than concentrated ones?

Methodological ChallengesMethodological Challenges

1) Mapping

2)   Mobility

3) M i li ti3) Marginalization

Photo by O. Loza

Challenge: Mapping

Challenges in Mapping along M i /U S B dMexico/U.S. Border

• Obtaining detailed shapefiles• No regular system of addresses/street namesg y• Inconsistencies in naming census

tracts/neighborhoods• Transient/mobile population• Security concerns

R idl i i i• Rapidly growing cities

Participatory Mapping

Google StreetmapsGoogle Streetmaps

Moving Beyond ResidenceMoving Beyond Residence

Clustering of HIV-positive participants at baseline by activity location (n=47)at baseline by activity location (n=47)

Activity Z-Score P-valueLi 4 447 0 000Live -4.447 0.000Buy Drugs -2.113 0.035Inject Drugs -6 173 0 000Inject Drugs 6.173 0.000Work -1.535 0.125*Average Nearest Neighborg g

Brouwer et al, Annals Amer Assoc Geog, 2012

Challenge: Mobility

Holmes et al, J. virology, 2011

Photo: O. Loza

Median distance between injection site and residence was 3.5 km (IQR 1.9-5.8)

Brouwer et al, Sub Use Misuse, 2012

Individual Life History Maps

Victoria Ojeda, 2010

Specific Trajectory Maps

Challenge: Marginalization

Marginalization ChallengesMarginalization Challenges

R hi th t t i k• Reaching those most at-risk– Not visible in most traditional datasets

• No denominator information

• Unequal number surveyed per neighborhood• Unequal number surveyed per neighborhood

Recruitment Trees & Syphilis StatusRecruitment Trees & Syphilis Status

Syph. - Male Syph. + Male Syph. - Female Syph. + Female Unknown Status

Clustering of Injection and HIV

(Brouwer et al, Annals Amer Assoc Geog 2012)

PrevemoPrevemovihvihl Sitesl SitesPrevemoPrevemovihvihl Sitesl Sites

HIV Hot and Cold spots of Injection Sites

Directional trends (light blue) suggested a very concentrated epidemic until July‐Dec. 2008, when HIV cases spread to the southeast

(Brouwer et al, Annals Amer Assoc Geog 2012)

spread to the southeast 

Collaborators & Data Sources

University of California San Diego

Hospital General de

Tijuana

Programa COMPAÑEROS

Patronato Pro-Comusida Tijuana A.C.