hiv burden in india lalit dandona professor/chair, international public health school of public...
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HIV Burden in India
Lalit DandonaProfessor/Chair, International Public Health
School of Public Health &George Institute for International Health
The University of Sydney
26 July 2007
Population / Public Health
• Disease / health distributionEpidemiology, biostatistics
• Society-health interactionsSocial, behavioural, environmental
sciences
• Population health interventionsHealth systems, health policy
Major tracks
HIV Studies in IndiaHIV Studies in India• Population-based assessment of HIV distribution and risk factors
• Risk behaviour of men who have sex with men and female sex workers
• Impact of HIV interventions, including economic analysis
To inform policies & programs
Background of HIV Burden in India
• UNAIDS estimated in 2006 that India had
the highest number of persons with
HIV (5.7 million), but with a 3-fold
plausibility range
• HIV estimates in India calculated by NACO
based predominantly on public sector
sentinel surveillance data
• No systematic comparison of this method
with population-based data
Population category
Sentinel surveillance based calculations by NACO*
2005 population(15-49 years)
HIV rate Number with HIV
Urban men 6,131,043‡ 0.0240 147,145
Urban women 5,881,092‡ 0.0200 117,622
Rural men 14,464,583‡ 0.0240 347,150
Rural women 14,178,474‡ 0.0200 283,569
Urban men with STI 391,343§ 0.2280 89,226
Urban women with STI 340,978§ 0.1900 64,786
Rural men with STI 972,539§ 0.2280 221,739
Rural women with STI 870,077§ 0.1900 165,315
Woman sex workers 117,635¶ 0.1280 15,057
Men who have sex with men 5,082# 0.0645 328
Total 43,352,845 0.0335 1,451,937
HIV Burden in Andhra Pradesh 2005: NACO
Population-based HIV Study in Guntur District (4.5 million pop)
Stratified random cluster sample to represent rural and urban populationsOf the 13,838 sampled persons 15-49 years of age, 12,617 (91.2%) participated
Rigorous quality control of field and laboratory procedures
Dandona L et al. BMC Medicine 2006; 4: 31
Data Collection
• September 2004 – September 2005
• Relevant ethics approvals
• Informed consent, interview, blood sample as dried blood spots (DBS)
• Demographic data, standard of living index (SLI), risk factors and health services
use history
Laboratory Analysis
• HIV antibody: Murex, Tridot HIV p24 antigen: Murex, Vidas HIV nucleic acid: Amplicor PCR
• Established laboratory procedures usedFortes et al. J Clin Microbiol 1989; 27: 1380-81Behets et al. J Clin Microbiol 1992; 30: 1179-82Panteleeff et al. J Clin Microbiol 1999; 37: 350-53Roth et al. Lancet 1999; 353: 359-63Quinn et al. AIDS 2000; 14: 2751-57
• Quality assurance procedures
Sampled men(3376)
Sampled women(3414)
Gave blood sample and
interview(3135, 92.9%)
Gave interview only
(62, 1.8%)
Gave blood sample only
(4, 0.1%)
Rural sampled(6790)
Did not participate
(175, 5.2%)
Gave blood sample and
interview(3177, 93.1%)
Gave interview only
(77, 2.3%)
Gave blood sample only
(1, 0.0%)
Sampled men(3475)
Sampled women(3573)
Gave blood sample and
interview(3096, 89.1%)
Gave interview only
(107, 3.1%)
Gave blood sample only
(0)
Urban sampled(7048)
Did not participate
(272, 7.8%)
Gave blood sample and
interview(3204, 89.7%)
Gave interview only
(138, 3.9%)
Gave blood sample only
(0)
Did not participate
(231, 6.5%)
Did not participate
(159, 4.7%)
Participation Profile of Sample
High Risk Groups in SampleSample Participation (%) (%)
Men visited woman sex workerEver 18.7Last 6 months 2.7
Identified woman sex workers 0.14
Men who had sex with men 2.1
Men who sold sex to men 0.26
Transport-related job – men 7.0 91.3
Unskilled labourers 31.6 92.1
Other regularly mobile jobs 7.2 92.8
Participation rates similar across age groups and marital status
HIV-1(N = 221)
HIV-2(N = 14)
HIV-1 & HIV-2(N = 3)
Retested by fourth-generation ELISA (Vidas)
Negative(N = 2)
PCR (Amplicor)
Negative (N = 2)
Third-generation rapid test(Tridot)
Positive(N = 238)
PCR (Amplicor) for HIV nucleic acid in high-risk cases (N = 585)
Negative(N = 584)
Negative(N = 12,375)
10% for quality assurance withfourth-generation ELISA (Murex) and PCR (Amplicor) (N = 1,238)
Negative with ELISA & PCR
(N = 1,238)
Positive(N = 0)
Third-generation ELISA for HIV antibody (Murex)
Positive(N = 238)
Negative(N = 4)
Positive(N = 242)
Fourth-generation ELISA for HIV antibody/antigen (Murex)
(N =12,617)
Initially false positive
Positive(N = 1)
Positive(N = 2)
p24 antigen test (Vidas)
Positive(N = 2)
Confirmed positive with
PCR (Amplicor)
Results of HIV Testing
Men Women Total
ParticipantsHIV
positive
Adjusted HIV
preva-lence
%
95% confidenceinterval; design effect
ParticipantsHIV
positive
Adjusted HIV
preva-lence
%
95% confidenceinterval;
designeffect
Adjusted HIV
preva-lence
%
95% confidenceinterval;
designeffect
Rural 3139 54 1.570.86-2.28;
2.363178 50 1.71
1.18-2.24; 1.43
1.641.10-2.18;
2.86
Western region (Durgi)
733 6 0.81 763 7 0.97 0.890.06-1.72;
3.02
Central region 1527 38 2.58 1543 26 1.79 2.191.41-2.97;
2.30
(Mupalla) 757 21 2.73 776 15 2.03 2.391.19-3.59;
2.47
(Narsaraopet)
770 17 2.43 767 11 1.54 1.990.92-3.06;
2.36
Eastern region (Kollur)
879 10 1.23 872 17 1.94 1.580.45-2.71;
3.75
Urban 3096 76 2.111.50-2.72;
1.373204 61 1.67
1.22-2.12; 1.04
1.891.39-2.39;
2.13
Guntur 2358 61 2.45 2443 44 1.63 2.041.44-2.64;
2.29
Narsaraopet 738 15 1.91 761 17 1.83 1.870.95-2.79;
1.84
Total 6235 130 1.741.27-2.21;
1.806382 111 1.70
1.36-2.04; 1.21
1.721.35-2.09;
2.44
Age (years)
Men Women
ParticipantsHIV positive
(%)Participants
HIV positive (%)
15-19 1175 3 (0.26) 1159 10 (0.86)
20-24 1086 16 (1.47) 1162 25 (2.15)
25-29 972 18 (1.85) 1027 26 (2.53)
30-34 833 33 (3.96) 886 19 (2.14)
35-39 842 35 (4.16) 864 17 (1.97)
40-44 628 15 (2.39) 757 8 (1.06)
45-49 699 10 (1.43) 527 6 (1.14)
Total 6235 130 (2.09) 6382 111 (1.74)
Age Distribution of HIV
Guntur ANC vs. Population-based HIV Prevalence
• 2005 sentinel surveillanceHIV 3% (12/400)
• September 2004 – September 2005Among 10,504 women receiving PMTCT
(96.9% of new ANC registrations)
HIV 2.95% (95% CI 2.63-3.27%)
• Population-based HIV ratesAll 1.72% (95% CI 1.35-2.09%)
Men 1.74% (95% CI 1.27-2.21%)
Women 1.70% (95% CI 1.36-2.04%)
HIV & Standard of Living Index
• Entire sampleUp to 50th percentile of SLI: 2.58% Above 50th percentile of SLI: 1.20%
• HIV ratio for lowest-highest SLI quartilesUrban: 3.47Rural: 2.37
• SLI gradient relatively lower for rural men
Population-based sample
SLI quartiles (score range)
I (up to 16)
II (17-22)
III (23-29)
IV (30+)
Antenatal care services utilized Total (%)Number
(%)Number
(%)Number
(%)Number
(%)
Public sector hospitals* 152 (21.1) 68 (44.7) 46 (30.3) 28 (18.4) 10 (6.6)
Other options 570 (78.9) 144 (25.3) 140 (24.6) 159 (27.9) 127 (22.3)
Private health facility 512 (70.9) 112 (21.9) 121 (23.6) 153 (29.9) 126 (24.6)
Other public sector facilities 14 (1.9) 6 (42.9) 4 (28.6) 4 (28.6) 0
Check-up at home 8 (1.1) 7 (87.5) 1 (12.5) 0 0
No check-up 36 (5.0) 19 (52.8) 14 (38.9) 2 (5.6) 1 (2.8)
Data not available 55 15 (27.3) 24 (43.6) 11 (20) 5 (9.1)
Total 777 227 (29.2) 210 (27.0) 198 (25.5) 142 (18.3)
Population-based sample
SLI halves(score range)
Lower(up to 22)
Upper(23 or more)
Type of health services utilized NumberHIV positive
(%)Number
HIV positive (%)
Antenatal care by women
Public sector hospitals* 114 5 (4.39) 38 1 (2.63)
Other 284 3 (1.06) 286 3 (1.05)
Total 398 8 (2.01) 324 4 (1.23)
General health services by men
Public sector 325 18 (5.54) 165 4 (2.42)
Other 2831 70 (2.47) 2909 38 (1.31)
Total 3156 88 (2.79) 3074 42 (1.37)
General health services by women
Public sector 516 19 (3.68) 246 4 (1.63)
Other 2792 60 (2.15) 2827 28 (0.99)
Total 3308 79 (2.39) 3073 32 (1.04)
Private to Public Sector Referral
Public sector antenatal clinic attendees
Guntur city Narsaraopet town
Rural Number
(%)
Urban Number
(%)
Total Number
(%)
Rural Number
(%)
Urban Number
(%)
Total Number
(%)
Total 235 (100) 252 (100) 487 (100) 311 (100) 91 (100) 402 (100)
Visited private health facility previously for this pregnancy
95 (40.4) 83 (32.9) 178 (36.6) 112 (36.0) 28 (30.8) 140 (34.8)
Referred by private facility to public sector hospital for this pregnancy
37 (15.7) 16 (6.3) 53 (10.9) 63 (20.3) 8 (8.8) 71 (17.7)
Includes referrals due to HIV positive result and suspected HIV
Population category
Sentinel surveillance method Population-based study method
2005 population
(15-49 years)
HIV prevalence
Number with HIV
2005 population
(15-49 years)
HIV prevalence
Number with HIV
Urban men 370,005‡ 0.0360 13,320 373,926** 0.0210 7,852
Urban women 366,235‡ 0.0300 10,987 378,557†† 0.0162 6,133
Rural men 848,207‡ 0.0360 30,535 873,893‡‡ 0.0157 13,720
Rural women 828,055‡ 0.0300 24,842 880,365§§ 0.0170 14,966
Urban men with STI 23,526§ 0.2280 5,364
Urban women with STI 21,234§ 0.1900 4,034
Rural men with STI 56,821§ 0.2280 12,955
Rural women with STI 50,815§ 0.1900 9,655
Woman sex workers 7,003¶ 0.1320 924 9,420¶¶ 0.1320 1,243
Men who have sex with men 300# 0.0645 19
Prisoners – men 800## 0.1050 84
Hostel residents – men 5,000*** 0.0420 210
Hostel residents – women 5,000*** 0.0324 162
Under-sampled urban men 14,297††† 0.0420 600
Under-sampled rural men 30,943††† 0.0314 972
Total 2,572,201 0.0438 112,635 2,572,201 0.0179 45,942
HIV Burden in Guntur District
Did We Under-estimate HIV?
• Sampling and calculationsNo known bias in sampling method for population
Under-represented high risk groups added
Participation rate of other high risk groups not low
• Laboratory methodsEstablished storage and analysis methods used
Quality assurance procedures utilized
No obvious reason for under-estimation in our methods
HIV Over-estimation with Official Method
• STI clinic component added extra HIV to estimate
70% extra
• Profile of public ANC usersReferral of HIV positive and suspects46% extraHigher representation of lower SLI28% extra
Population-based HIV Studies in IndiaLocation Data
collection year(s)
Sampling approach Participation rate
Sample size
Number of HIV positive persons
Population HIV prevalence as % (95% confidence interval)*
Power of sample size to detect difference from antenatal HIV prevalence at 95% confidence level†
Comments
Tamil Nadu: 3 districts
1998 90 rural & urban clusters selected using probability proportional to size; selected households from each cluster invited for medical camp; first 25 adults 15-45 years old from each cluster who came to camp included in study
82.5% for selected households; not mentioned for eligible individuals
1,981 34 Age & gender adjusted:1.80 (0.89-2.71)
17% to detect 20% difference from 1% antenatal HIV prevalence
Selection bias likely due to medical camp sampling approach, making interpretation difficult
Grossly under-powered for reliable comparison with antenatal HIV prevalence
Tamil Nadu: 1 rural sub-district, 1 urban town
1999-2000 120 rural & urban clusters selected using probability proportional to size; 15-40 years old persons from randomly selected households included in study
90.9% of 3-40 years old; not mentioned for eligible 15-40 years old individuals
2,870 29 Crude:1.01 (0.44-1.58)
21% to detect 20% difference from 1% antenatal HIV prevalence
Grossly under-powered for reliable comparison with antenatal HIV prevalence
Karnataka: 1 district
2003 10 villages and 20 urban blocks selected with cluster sampling using probability proportional to size; 15-49 years old persons included in study; further details not published
59.8% of 6700 eligible 15-49 years old individuals
4,008 118 Crude:2.94 (2.12-3.76)
50% to detect 20% difference from 2.6% antenatal HIV prevalence
Poor participation rate makes interpretation difficult
Under-powered for reliable comparison with antenatal HIV prevalence
Andhra Pradesh: 1 district [This study]
2004-2005 5 sub-districts selected to represent strata in district, from which 66 rural & urban clusters selected randomly; 15-49 years old persons from randomly selected households included in study
91.2% of 13838 eligible 15-49 years old individuals
12,617 241 Age, gender & rural-urban adjusted:1.72 (1.35-2.09)
93% to detect 20% difference from 3% antenatal HIV prevalence
Adequately powered for reliable comparison with antenatal HIV prevalence
Can These Findings be Generalized?
• STI clinic component in HIV estimationNot used elsewhere in the world for HIV
estimation from sentinel surveillance
• Referral of HIV positive and suspectsA widespread phenomenon in India
• Higher representation of lower SLIData from nationwide RCH survey
States2005 pop (millions)
Sample of women
who provided
data regarding antenatal
care
% who received antenatal
care
Percent who
received antenatal
care at public sector
hospital†
Percent who
received ante-natal
care at other public sector
facilities
SLI of women who used
public sector hospital for
antenatal care
SLI of women who used any public sector
facility for antenatal care
2005 HIV estimate 15-49 years¶ (1000s)
% in lower SLI half
% in upper SLI half
% in lower SLI half
% in upper SLI half
Andhra Pradesh 80.0 5,476 95.1 23.9 9.0 62.4 37.6 64.1 35.9 1,452
Karnataka 56.0 7,543 90.5 24.7 13.4 61.0 39.0 65.3 34.7 640
Maharashtra 104.2 9,284 94.0 14.8 29.5 43.5 56.5 63.0 37.0 1,232
Tamil Nadu 65.2 7,480 99.3 29.7 26.2 70.4 29.6 74.5 25.5 366
Nationwide RCH Survey 2002-2004
State
2005 pop
15-49 years
millions
2005 median
ANC sentinel surveill-ance HIV
prev(%)
NACO 2005 HIV estimate
15-49 years
millions
Plausible estimate (low) Plausible estimate (high)
Change needed in ANC HIV rate to
estimate population prevalence
(% of ANC HIV prev)
Corr-ection factor
for ANC HIV prev
2005 HIV estimate
15-49 years
millions
Change needed in ANC HIV rate to
estimate population prevalence
(% of ANC HIV prev)
Corr-ection factor
for ANC HIV prev
2005 HIV estimate
15-49 years
millionsRefer-
rals SLI
Under-repres-ented high-risk
groupsRefer-
rals SLI
Under-repres-ented high-risk
groups
Andhra Pradesh 42.7 2.00 1.45 -33 -9 +5 0.63 0.54 -20 -5 +10 0.85 0.73
Karnataka 30.0 1.25 0.64 -33 -8 +8 0.67 0.25 -20 -4 +16 0.92 0.35
Maharashtra 55.0 1.25 1.23 -33 +5 +12 0.84 0.58 -20 +3 +24 1.07 0.73
Tamil Nadu 36.3 0.50 0.37 -33 -14 +20 0.73 0.13 -20 -8 +40 1.12 0.20
Total 3.69 1.50 2.01
Conservative Extrapolations to Estimate HIV Burden
Indicative Estimates for India
HIV estimate for India may be
3-3.5 million or lower instead of the
official estimate of 5.2 million 15-49 year
old adults or 5.7 million total
Dandona L et al. BMC Public Health 2006; 6: 308
Recommendations
• Drop STI clinic component in the HIV estimation
method used in India
• Plan strategic and scientifically sound
population-based HIV studies every 3-4 years in
India to provide correction factors for
ANC/PMTCT HIV rates to estimate burden
• Rethink HIV surveillance strategy for India
Recent National DHS Survey in India
• Sample of 103,000 men and women, 82% of
eligible persons, tested for HIV
• 0.3% of adults had HIV in population-based
sample; 0.4% after adjusting for under-
represented high-risk groups
• In early July 2007, based on calculations by NACO
& UNAIDS, the Health Minister announced HIV
burden for India as 2.5 million (2-3.1 million)
New Lower HIV Burden in India
• Resource need for treatment less than projected
• This freeing-up of resources could make relatively
more resources available for prevention
• Focus of HIV prevention efforts
• More scientific basis needed for dynamics of HIV
spread and impact of HIV interventions in India
Implications
Prevention vs. Treatment
Basic sciences 49.6%
Clinical sciences 47.1%
Public health 3.3%
Original Health Research OutputIndia 2002
Dandona L et al. BMC Public Health 2004; 4: 55
Health Research Output
Impact factor Impact factorper million pop per billion GDP-PPP
India 5.6 2.0
Australia 991 39
Aus–Ind Ratio 175 20
India versus Australia - 2002
Dandona L et al. BMC Public Health 2004; 4: 55