HIV Epidemics in the South Asia
Region – Strategic Considerations
James Blanchard, MD, MPH, PhD
University of Manitoba
Issues
• Analyzing the heterogeneity of HIV epidemics:
– Strategic implications at the macro, meso and micro
levels
– Understanding epidemic potential and epidemic phase
• Rural HIV epidemics:
– Strategic considerations for a response
• What we don’t know, but must
Heterogeneity – Strategic Implications
• Macro Level – Differences between countries
– Overall design of the national plans
– Relative emphasis on targeted, focused and broad-based
prevention strategies
– Geographic concentration vs. dispersion
• Meso Level – Differences between states/provinces
– Flexibility vs. standardization of implementation plans
– Decentralized capacity and decision-making
• Micro Level – Differences between/within districts
– Requirement for fine-grained information at the local level
– Flexibility/elasticity of intervention programs
– Capacity building requirements of local implementers
Defining and Assessing Heterogeneity –
Analytic Framework
Apparent (observed) epidemic (i.e. HIV prevalence)
reflects two constructs:
1. Epidemic potential (trajectory)
–
–
How an uninterrupted epidemic will evolve
Determined by factors influencing the transmission dynamics:
sexual structure, IDU networks, transmissibility (e.g.
circumcision)
2. Epidemic phase
–
–
Extent to which the epidemic has spread in various high risk
networks and sub-populations
Depends on both time and connectivity to other epidemics
(geography, mobility)
“Truncated” Epidemic
Truncated Epidemic
High risk network
(distal)
Bridge
Population
Local
Partners
“Local Concentrated” Epidemic
Local Concentrated Epidemic
High risk network
(distal)
Bridge
Population
High risk network
(local)
Local
Partners
“Generalizing” Epidemic
Generalizing Epidemic
High risk network
(distal)
Bridge
Population
High risk network
(local)
Local
Partners
Epidemic Potential and Phase Country Level Assessments
Pakistan
• Epidemic Potential
– “Local Concentrated” epidemics in several of the larger cities;
information is lacking elsewhere
– Intersection between IDU and female sex work and MSM can
accelerate the transmission in several cities
– “Truncated” epidemics are likely in many of the rural areas due
to substantial male migration to large cities within the country,
and externally
– “Generalizing” epidemics are unlikely, though little is known
about the sexual structure.
• Epidemic Phase
– Epidemic is emerging rapidly in some high risk sub-populations,
especially in IDU and MSM networks in larger cities
– It appears that FSW networks are still at an early epidemic
phase
India
• Epidemic Potential
– Many “Local Concentrated” epidemics, most involving female sex
work networks. IDU is important in the northeast. Insufficient
information on MSM-related transmission dynamics.
– “Generalizing” epidemic potential exists in some pockets.
However, widespread generalizing epidemics are unlikely.
– “Truncated” epidemics are likely in many of the rural areas due
to substantial male migration to large cities within the country,
and externally.
– Paucity of information on sexual structure in much of N. India.
• Epidemic Phase
– “Local Concentrated” epidemics are advanced in many areas of
S. India and the northeast.
– Epidemics might be at an earlier phase in N. India, but
information is insufficient.
Nepal
• Epidemic Potential
– “Local Concentrated” epidemics in a number of areas, most
involving female sex work networks. FSW migration to Mumbai is
likely an important epidemic amplifier. IDU is also likely an
important component in some areas.
– “Generalizing” epidemic potential does not appear to be
substantial, though more information about population sexual
structure is required.
– “Truncated” epidemics are likely in areas with a substantial
population of out-migrating men.
• Epidemic Phase
– “Local Concentrated” epidemics are advanced some areas, with
acceleration related to FSW migration to Mumbai.
Bangladesh
• Epidemic Potential
– Substantial “Local Concentrated” epidemics in a number of
areas, most involving female sex work networks. IDU is also
likely an important component in some areas.
– Intersection between IDU and female sex work will accelerate
local epidemics in some locations
– “Generalizing” epidemic potential does not appear to be
substantial, though more information about population sexual
structure is required.
– “Truncated” epidemics are likely in areas with a substantial
population of out-migrating men.
• Epidemic Phase
– “Local Concentrated” epidemics still appear to be relatively early
in sex work networks.
– Expansion is observed in some IDU networks
Sri Lanka
• Epidemic Potential
– Potential for “Local Concentrated” epidemics in some areas,
particularly in relation to IDU, and FSW in some areas.
– “Generalizing” epidemic is unlikely.
– Limited “truncated” epidemics could occur in areas with a
substantial population of out-migrating men, but this will depend
largely on expansion of epidemics in high risk networks at
migration destination locations.
• Epidemic Phase
– Still appears to be at an early epidemic phase.
Implications for a Prevention Strategy –
“Scale up Focused Prevention”
• Saturate major urban centres in all countries
• In India… identify and saturate the large number
of small and medium size “spread” networks
fuelling local concentrated epidemics:
– Restricting targeted intervention coverage to large
clusters of high risk groups will result in low coverage
overall.
• Ensure that all risk networks are covered in
intervention areas… FSWs, clients, IDUs, MSMs.
Scaling up at Macro and Micro Levels –
“Geography and Networks”
District
Hot Spot
HS
Hot
Spot
Hot
Spot
HS
Coverage – critical transmission “hot spots”
“MACRO”
Coverage – critical sexual networks
“MICRO”
Example – Coverage of Karnataka “Sankalp” Project
under BMGF’s Avahan Program (18 months)
MACRO – “Geography”
35000
32,386
29,466
30000
Number of FSWs
• 16 districts
• All 138 towns
& cities
mapped
• FSW programs
in 117/138
towns
• Est. 96% of
urban FSWs in
“covered”
towns
MICRO – “Networks”
25000
22,812
20000
17,086
15000
10000
5000
0
Est. FSWs
Contacted
Regular
Contact
Visited
Clinic
Rural HIV Epidemics in India – A
Study in Heterogeneity
Rural Epidemics in India –
Some Strategic Issues
• To what extent do rural epidemics exist?
– “Do we need a rural strategy”?
• What drives rural epidemics?
– “Can we control rural epidemics through urban
interventions?”
– “What should be the focus of rural prevention
programs?”
• How much variability is there in rural epidemics?
– “Can we prioritize intervention locations?”
India HIV Prevalence Estimates - 2004
2,000,000
1,803,000
1,800,000
HIV Prevalence
1,600,000
1,400,000
1,329,000
1,200,000
1,000,000
1,204,000
798,000
800,000
600,000
400,000
200,000
0
Males
Source: NACO 2004
Females
Urban
Rural
HIV Prevalence (%) in Antenatal Sentinel
Surveillance Sites – Karnataka Districts, 2002-2004
HIV prevalence: Rural > Urban in 15/27 districts
Size of FSW Population in Urban Centres
and Villages of Karnataka Districts
16
FSWs per 1000 Adults
14
12
10
8
Mean: 6.6
6
Mean: 5.5
4
2
0
Urban
Rural
Case Study: Bagalkot District
• Population: 1.65 million
• 6 Talukas (sub-district
administrative units)
• Mix of irrigated and droughtprone areas
• Mainly agricultural
(sugarcane), with some
mining
• 71% live in rural areas
• 65% of workers are
agricultural cultivators or
labourers (38%)
• Recently completed large
dam project
• Literacy rate: 49% (37%
among females)
HIV prevalence by sex and residence –
Bagalkot District, 2003
4
HIV prevalence (%)
3.5
3
3.6
3.3
2.9
2.5
2.4
2.5
2
1.5
1
0.5
0
Total
Male
Female
Rural
Urban
HIV Prevalence by Taluka and Location
7%
HIV Prevalence
6%
5%
6.0%
Urban
Rural
Total
4.9%
4%
3.7%
3.3%
3%
2.7%
2%
1%
1.0%
1.4%
2.9%
1.2%
0%
Taluka A
Taluka B
Taluka C
Distribution of Female Sex Workers –
3 Talukas of Bagalkot District
90%
84%
<5 FSWs
5-9 FSWs
10-19 FSWs
20+ FSWs
Percent of Villages
80%
70%
60%
51%
47%
50%
40%
26% 27%
30%
21%
20%
10%
4% 5%
6%
0%
Taluka A
4.2 FSW/1000
0%
25%
4%
Taluka B
Taluka C
10.4 FSW/1000
12.6 FSW/1000
Males with commercial and non-marital
partners – Bagalkot Talukas, 2004
45%
Percent of Men
40%
35%
30%
42.3%
Ever visited FSW
Ever other non-marital
partner
26.0%
28.0%
25%
18.0%
20%
15%
11.4%
13.2%
10%
5%
0%
Taluka A
Taluka B
Taluka C
Variations in FSW client volume –
Bagalkot Talukas
Clients per week
<5
5-9 10+
70%
63%
Percent of FSWs
60%
50%
40%
44%
39%
39%
32%
30%
20%
22%
22%
24%
15%
10%
0%
Taluka A
Taluka B
Taluka C
Summary of 3 Talukas – Sexual Structure
and HIV Prevalence
Characteristic
Taluka A
Taluka B
Taluka C
94
66
81
Total # FSWs (per 1000)
295 (3.0)
1,993 (14.5)
1,269 (11.8)
Rural FSWs/1000 adults
4.2
10.4
12.6
Villages with 10+ FSWs
11%
53%
46%
Rural men, ever visited
FSW
11.4%
13.2%
18.0%
Sex workers with 10+
clients per week
39%
63%
44%
Rural men, ever nonmarital partner
26.0%
28.0%
42.3%
HIV prevalence – overall
1.2%
2.9%
4.9%
HIV prevalence – rural
1.4%
3.3%
6.0%
Number of villages
Observations on Sexual Structure –
3 Bagalkot Talukas
• Taluka A – HIV prevalence 1.2% (1.4% rural) :
–
–
–
–
Lower sex worker population and client volume
Least males reporting commercial or non-marital sex partners
Less affluent, more drought-prone
Furthest away from state boundary (Maharashtra)
• Taluka B – HIV prevalence 2.9% (3.3% rural)
– Highest sex worker population overall, but intermediate in rural areas. Highest
client volumes.
– Intermediate males reporting commercial or non-marital sex partners
– Relatively affluent (irrigated, sugar cane)
– Closest to state boundary (Maharashtra) – tradition as vibrant sex work
destination for clients.
• Taluka C – HIV prevalence 4.9% (6.0% rural)
–
–
–
–
Intermediate sex worker population overall, highest in rural areas.
Highest males reporting commercial or non-marital partners.
Affluent (irrigated, sugar cane)
Intermediate distance from state boundary.
3 Talukas - Hypothesis
• Rural HIV transmission dynamics are largely
dependent on local sex work volume:
– Taluka C – sex work volume is relatively high, and
appears to cater mostly to local clients
– Taluka B – sex work volume is highest, but a higher
proportion of the sex involves “external” clients
– Taluka A – low volume of sex work and fewer sex
clients
Program Implications – Rural Strategy
• HIV prevention for rural areas needs to be applied
“locally” to interrupt local high risk sexual networks
• High variability in the sexual structure, including sex
work volume, indicates the need for “focused”
prevention in rural areas
• Some rural areas with high sex work volume involve
sex clients from a large catchment area, and therefore
require high priority for prevention programs
• Non-commercial sexual networks are probably
important in some locations, requiring a broader
prevention program
What We Need to Know
• Distribution and size of high risk sexual and IDU
networks, especially outside of major urban
centres (including rural areas)
• Presence and characteristics of non-commercial
sexual networks that could amplify or
“generalize” HIV epidemics
• Current epidemic “phase” – sub-population
distribution of HIV (high risk, bridge, general)
• How to efficiently identify local “high risk” zones
in rural areas