Background
Methods
Population and sampling procedures
Data Collection
Laboratory Investigation
Analysis
Ethics
Results
Participation and distribution
1995 | 1999 | 2003 | ||
---|---|---|---|---|
Listed
| 5847 | 6235 | 6791 | |
Absent
| 927 (15.9%) | 1763 (28.3%) | 1346 (19.8%) | |
De facto
eligible (found)
| 4920 | 4472 | 5445 | |
Refused interview
| 108 (2.2%) | 53 (1.2%) | 185 (3.4%) | |
Interviewed
| 4812 (97.8%) | 4419 (98.4) | 5260 (96.6%) | |
Saliva test
| Accepted | 4499 (93.5%) | 4021 (91%) | 4913 (93.4%) |
Refused | 281(5.8%) | 397 (9%) | 347 (6.6% | |
Lost | 32 (0.7%) | -- | -- | |
Damaged/Mislabelled | 162 | 264 | 162 | |
Sample (Interviewed & tested, Less damaged/mislabelled) § | 4337 (88.2%) | 3757 (84%) | 4751 (87.3%) | |
Final sample age 15–59 years
| 3158 | 3731 | 4751 | |
Response (%) (Listed-[absent+refusals]/listed*100) | 77.4% | 64.5% | 72.3% |
Age-specific HIV infection trends
Sex | Age group (years) | Age-specific Prevalence, % (total number of respondents, n) | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Rural | Urban | ||||||||||
1995 | 1999 | 2003 | χ2 for trend (P value) | Age-adjusted ORψ for 2003 (Ref., 1995) | 1995 | 1999 | 2003 | χ2 for trend (P value) | Age-adjusted ORψ for 2003 (Ref., 1995) | ||
Males | 15–19 | 5.5 (73) | 5.4(129) | 2.1(146) | 0.161 | 4.5(266) | 6.3(224) | 2.2(314) | 0.144 | ||
20–24 | 5.8(103) | 9.4(139) | 4.3(163) | 0.468 | 10.7(168) | 8.6(208) | 4.2(309) |
0.006
| |||
25–29 | 20.9(67) | 13.2(114) | 12.2(147) | 0.127 | 33.3(114) | 22.0(109) | 13.1(160) |
0.001**
| |||
30–39 | 31.9(91) | 23.1(169) | 20.8(235) |
0.048
| 40.0(150) | 39.2(120) | 35.4(181) | 0.378 | |||
40–49 | 12.3(65) | 12.9(101) | 22.9(131) |
0.036
| 41.5(106) | 40.2(82) | 33.3(78) | 0.276 | |||
50–59 | 14.6(48) | 9.3(92) | 17.9(89) | 0.416 | 26.5(34) | 13.5(37) | 25.8(66) | 0.847 | |||
15–24 | |||||||||||
Crude | 5.7(176) | 7.5(268) | 3.2(309) | 0.143 | 0.56(0.25–1.26) | 6.9(434) | 7.4(432) | 3.2(623) |
0.005
|
0.40(0.25–0.66)
| |
Adjusted† | 5.6 | 7.2 | 3.1 | 0.141 | 7.5 | 7.4 | 3.2 |
0.001
| |||
F:M ratio | 2.8 | 1.46 | 2.06 | 3.12 | 2.47 | 3.87 | |||||
Urban:Rural ratio | 1.34 | 1.03 | 1.03 | ----- | ----- | ----- | |||||
15–49 | |||||||||||
Crude | 15.3(399) | 13.3(652) | 13.0(822) | 0.314 | 0.80(0.55–1.18) | 21.4(804) | 18.3(743) | 12.6(1042) |
0.000**
|
0.58(0.38–0.87)
| |
Adjusted† | 15.4 | 12.8 | 11.6 | 0.072 | 24.8 | 18.3 | 16.9 |
0.000
| |||
F:M ratio | 1.12 | 1.10 | 1.15 | 1.23 | 1.49 | 1.35 | |||||
Urban:Rural ratio | 1.61 | 1.43 | 1.46 | ----- | ----- | ----- | |||||
Females | 15–19 | 8.2(122) | 5.9(217) | 3.1(223) |
0.039
| 12.3(391) | 9.5(336) | 7.7(431) |
0.026
| ||
20–24 | 24.6(114) | 15.9(163) | 10.3(233) |
0.001
| 35.4(311) | 27.9(305) | 17.6(409) |
0.000**
| |||
25–29 | 17.7(79) | 20.6(160) | 18.2(187) | 0.929 | 48.7(199) | 41.2(221) | 31.1(286) |
0.000**
| |||
30–39 | 19.8(111) | 18.4(233) | 23.8%(256) | 0.249 | 34.5(310) | 39.3(244) | 39.6(273) | 0.202 | |||
40–49 | 17.8(73) | 11.7(120) | 14.7(156) | 0.140 | 26.0(100) | 22.3(112) | 22.9(148) | 0.614 | |||
50–59 | 15.4(52) | 6.9(110) | 5.3(94) |
0.043
| 0(11) | 25.0(12) | 13.9(36) | 0.444 | |||
15–24 | |||||||||||
Crude | 16.1(236) | 10.3(380) | 6.8(456) |
0.000**
|
0.36(0.19–0.67)
| 22.5(702) | 18.3(641) | 12.5(840) |
0.000**
|
0.43(0.33–0.57)
| |
Adjusted† | 15.7 | 10.5 | 6.4 |
0.000**
| 23.4 | 18.3 | 12.4 |
0.000**
| |||
Urban:Rural ratio | 1.49 | 1.74 | 1.94 | ------ | ------ | ------ | |||||
15–49 | |||||||||||
Crude | 17.4(499) | 14.4(893) | 14.1(1055) | 0.118 | 0.76(0.47–1.23) | 29.6(1311) | 27.0(1218) | 21.7(1547) |
0.000**
|
0.68(0.57–0.81)
| |
Adjusted† | 17.3 | 14.1 | 13.4 | 0.056 | 30.6 | 27.3 | 22.8 |
0.000**
| |||
Urban:Rural ratio | 1.78 | 1.94 | 1.70 |
HIV infection trends by other socio-demographic characteristics
Level of education
Males | Females | |||||||
---|---|---|---|---|---|---|---|---|
Adjusted Odds Ratio(95%CI): reference time, 1995 |
§MH χ2 for Linear trend, 1995–2003: | Adjusted Odds Ratio(95%CI): reference time, 1995 |
§MH χ2 for Linear trend, 1995–2003: | |||||
1999 | 2003 | P value | 1999 | 2003 | P value | |||
R
|
Education (~age)‡ | |||||||
0–7 years | 2.05(0.63–6.61) | 0.69(0.17–2.80) | 0.495 | 0.66(0.34–1.26) |
0.43(0.19–0.93)
| 0.084 | ||
U
| 8–9 years | 0.84(0.34–2.04) | 0.40(0.09–1.78) | 0.670 | 0.86(0.38–1.93) | 0.25(0.05–1.26) |
0.002
| |
≥10 years | 1.26(0.11–13.8) |
0.16(0.11–0.25)
| 0.113 | 0.29(0.08–11.1) | 0.10(0.01–7.34) |
0.004
| ||
R
|
Marital status
| Single | 1.57(0.57–4.36) | 0.58(0.21–1.64) | 0.383 | 1.45(0.29–7.24) | 0.36(0.04–2.98) |
0.028
|
Married | 0.79(0.22–2.88) | 0.14(0.02–1.30) | 0.187 |
0.42(0.23–0.76)
|
0.29(0.13–0.68)
|
0.001*
| ||
A
|
Employed
| Yes | 0.75(0.36–1.59) | 0.38(0.13–1.09) | 0.194 | 1.59(0.15–17.2) | 0.43(0.04–5.01) | 0.215 |
No | 2.30(0.77–6.90) | 0.44(0.13–1.56) | 0.338 | 0.65(0.37–1.13) |
0.33(0.14–0.78)
|
0.001*
| ||
Travels
| Never | 1.79(0.65–4.92) | 0.68(0.31–1.48) | 0.496 | 0.56(0.9–1.58) |
0.35(0.13–0.97)
| 0.089 | |
L
| Sometimes | 1.06(0.41–2.77) |
0.18(0.05–0.60)
| 0.259 | 0.62(0.27–1.45) |
0.27(0.11–0.68)
|
0.001*
| |
Often | 1.21(0.49–2.99) | 0.44(0.15–1.33) | 0.396 | 0.47(0.16–1.39) | 0.21(0.01–4.91) | 0.113 | ||
Duration lived
| <1 year | #* | 0.32(0.01–22.1) | 0.649 | 0.33(0.08–1.39) | 0.41(0.08–2.14) | 0.087 | |
(In current residence) | 1–5 yrs | 1.77(0.53–5.92) | 0.65(0.12–3.41) | 0.565 | 0.85(0.39–1.88) |
0.34(0.12–0.97)
| 0.058 | |
≥6 yrs | 1.92(0.43–8.56) | 0.28(0.03–2.31) | 0.184 | 0.51(0.15–1.72) |
0.23(0.08–0.69)
|
0.003
| ||
Migration
| Village | 1.12(0.42–2.99) | 1.07(0.30–3.79) | 0.711 |
0.44(0.21–0.90)
|
0.18(0.06–0.55)
|
0.002
| |
(origin 5 years) | Town | 0.59(0.03–9.98) |
0.01(0.00–0.13)
| 0.456 | 1.46(0.32–6.52) | 0.75(0.20–2.77) | 0.494 | |
Given birth
| Yes | -- | -- |
0.65(0.39–1.08)
|
0.42(19–0.89)
|
0.005
| ||
(ever): age, 15–24 | No | -- | -- |
0.45(0.21–0.96)
|
0.09(0.02–0.51)
|
0.001
| ||
U
|
Education (~age)‡ | |||||||
0–7 years |
6.69(2.47–18.1)
| 1.45(0.22–9.40) | 0.634 | 0.65(0.39–1.07) | 0.79(0.43–1.43) | 0.674 | ||
R
| 8–9 years | 0.42(0.06–2.78) | 0.57(0.22–1.49) | 0.885 | 1.20(0.66–2.18) | 0.59(0.33–1.07) | 0.110 | |
≥10 years | 0.94(0.45–1.95) |
0.29(0.14–0.60)
|
0.001*
| 0.79(0.34–1.79) |
0.38(0.19–0.79)
|
0.001*
| ||
B
|
Marital status
| Single | 1.29(0.66–2.53) |
0.56(0.32–0.95)
|
0.011
| 1.09(0.68–1.74) |
0.57(0.36–0.88)
|
0.002
|
Married | 1.03(0.69–1.55) | 0.70(0.46–1.06) | 0.306 |
0.49(0.30–0.80)
|
0.38(0.25–0.58)
|
0.003
| ||
A
|
Employed
| Yes | 1.89(0.35–10.2) | 0.98(0.25–3.93) | 0.454 | 1.02(0.39–2.66) |
0.41(0.19–0.86)
| 0.232 |
No | 1.07(0.51–2.23) |
0.41(0.23–0.73)
|
0.003
| 0.86(0.56–1.32) |
0.53(0.34–0.83)
|
0.001*
| ||
N
|
Travels
| Never | 1.12(0.48–2.60) | 0.79(0.34–1.87) | 0.208 | 0.96(0.66–1.40) |
0.58(0.39–0.85)
|
0.025
|
Sometimes | 1.45(0.34–6.19) |
0.16(0.04–0.71)
|
0.003
| 0.86(0.51–1.45) |
0.46(0.26–0.81)
|
0.001*
| ||
Often | 0.86(0.13–5.63) | 0.99(0.19–5.21) | 0.983 | 0.38(0.02–9.51) | 0.32(0.06–1.84) |
0.001*
| ||
Duration lived
| <1 year | 4.67(0.93–23.2) | 0.51(0.16–1.62) | 0.571 | 0.87(0.44–1.74) | 0.66(0.33–1.35) | 0.638 | |
(In current residence) | 1–5 yrs | 0.63(0.23–1.72) |
0.33(0.16–0.69)
|
0.034
|
0.68(0.48–0.96)
|
0.42(0.26–0.67)
|
0.001*
| |
≥6 yrs | 1.60(0.22–11.5) | 1.38(0.23–8.26) | 0.353 | 1.26(0.46–3.40) | 0.47(0.15–1.45) |
0.001*
| ||
Migration
| Village | 1.49(0.37–6.12) | 0.46(0.07–2.98) | 0.902 | 1.19(0.32–4.45) | 1.09(0.24–4.99) | 0.865 | |
(origin 5 years) | Town | 1.08(0.31–3.74) |
0.38(0.18–0.79)
| 0.068 | 0.71(0.48–1.08) |
0.47(0.30–0.74)
|
0.001*
| |
Given birth
| Yes | -- | -- |
0.65(0.51–0.86)
|
0.47(0.30–0.74)
|
0.002
| ||
(ever): age, 15–24 | No | -- | -- | 0.96(0.67–1.38) |
0.65(0.41–0.98)
| 0.129 |
Males | Females | |||||||
---|---|---|---|---|---|---|---|---|
Adjusted Odds Ratio(95%CI): reference time, 1995 |
§MH χ2 for Linear trend, 1995–2003: | Adjusted Odds Ratio(95%CI): reference time, 1995 |
§MH χ2 for Linear trend, 1995–2003: | |||||
1999 | 2003 | P value | 1999 | 2003 | P value | |||
R
|
Education (~age)‡ | |||||||
0–7 years | 0.93(0.62–1.34) | 0.72(0.47–1.09) | 0.227 | 1.07(0.57–2.01) | 1.03(0.62–1.72) | 0.838 | ||
U
| 8–9 years | 0.74(0.29–1.88) | 0.84(0.28–2.46) | 0.731 | 0.52(0.24–1.13) | 0.50(0.22–1.14) | 0.104 | |
≥10 years |
0.38(0.15–0.98)
|
0.44(0.22–0.87)
| 0.223 |
0.33(0.17–0.65)
|
0.29(0.08–0.96)
|
0.043
| ||
R
|
Marital status
| Single | 1.48(0.76–2.86) | 0.50(0.22–1.12) | 0.188 | 0.74(0.23–2.4) | 0.31(0.06–1.49) |
0.021
|
Married | 0.66(0.38–1.15) |
0.63(0.42–0.96)
| 0.096 | 0.91(0.53–1.57) | 0.82(0.49–1.37) | 0.112 | ||
A
|
Employed
| Yes | 0.66(0.42–1.03 | 0.76(0.48–1.21 | 0.914 | 0.81(0.21–3.15) | 0.73(0.22–2.42) | 0.479 |
No | 1.03(0.57–1.84) |
0.55(0.34–0.89)
|
0.026
| 0.82(0.48–1.38) | 0.78(0.47–1.31) |
0.055
| ||
Travels
| Never | 0.99(0.52–1.91) | 1.36(0.86–2.16) | 0.180 | 0.93(0.54–1.60 | 1.09(0.70–1.71) | 0.644 | |
L
| Sometimes |
0.66(0.44–0.98)
|
0.43(0.27–0.70)
|
0.019
| 0.76(0.33–1.71) | 0.59(0.31–1.10) |
0.024
| |
Often | 0.76(0.21–2.75) | 0.62(0.19–1.94) | 0.563 | 0.92(0.23–3.67) | 0.44(0.07–2.89) |
0.051
| ||
Duration lived
| <1 year |
0.25(.10–0.63)
| 0.63(0.22–1.81 | 0.733 |
0.57(0.33–0.99)
| 0.79(0.35–1.82) | 0.199 | |
(In current residence) | 1–5 yrs | 0.74(0.36–1.52) | 0.57(0.26–1.28) | 0.069 | 1.79(0.88–3.62) | 1.41(0.74–2.69) | 0.234 | |
≥6 yrs | 1.24(0.76–2.03) | 0.95(0.60–1.51) | 0.937 |
0.45(0.23–0.89)
|
0.48(0.26–0.88)
|
0.011
| ||
Migration
| Village | 0.72(0.43–1.22) | 0.99(0.51–1.94) | 0.922 | 1.12(0.58–2.16) | 1.04(0.55–1.97) | 0.840 | |
(origin 5 years) | Town |
0.48(0.22–0.98)
|
0.30(0.13–0.72)
|
0.041
| 1.75(0.99–3.01) | 1.31(0.75–2.32) | 0.586 | |
Given birth
| Yes | -- | -- | 0.75(0.42–1.34) | 0.58(0.30–1.11) |
0.019
| ||
(ever): age, 15–29 | No | -- | -- | 0.56(0.23–1.33) |
0.27(0.07–0.99)
|
0.012
| ||
U
|
Education (~age)‡ | |||||||
0–7 years | 1.66(0.80–3.42) | 1.34(0.72–2.49) | 0.398 | 0.83(0.59–1.16) | 1.11(0.71–1.76) | 0.498 | ||
R
| 8–9 years | 0.42(0.14–1.26) | 0.52(0.26–1.06) | 0.305 | 1.10(0.76–1.61) | 0.66(0.39–1.08) | 0.179 | |
≥10 years | 1.03(0.72–1.49) |
0.55(0.40–0.74)
|
0.001*
| 0.91(0.61–1.34) |
0.53(0.39–0.72)
|
0.001*
| ||
B
|
Marital status
| Single | 0.95(0.62–1.46) |
0.51(0.33–0.79)
|
0.001*
| 1.05(0.69–1.58) |
0.49(0.35–0.69)
|
0.001*
|
Married | 1.04(0.72–1.52) |
0.71(0.47–0.98)
|
0.035
| 0.92(0.74–1.14) |
0.73(0.57–0.94)
|
0.002
| ||
A
|
Employed
| Yes | 0.97(0.69–1.36) |
0.64(0.44–0.95)
|
0.001
| 0.98(0.67–1.41) |
0.69(0.51–0.95)
|
0.018
|
No | 0.99(0.60–1.64) |
0.52(0.37–0.74)
|
0.001*
| 0.93(0.76–1.15) |
0.63(0.47–0.85)
|
0.001*
| ||
N
|
Travels
| Never | 0.81(0.57–1.16) | 0.57(0.32–1.02) |
0.001
| 0.88(0.70–1.11) |
0.64(0.49–0.83)
|
0.003
|
Sometimes | 1.14(0.86–1.49) |
0.52(0.34–0.81)
|
0.001*
| 1.06(0.84–1.35) |
0.71(0.52–0.97)
|
0.008
| ||
Often | 1.11(0.55–2.21) | 0.80(0.38–1.70) | 0.189 | 0.77(0.23–2.59) |
0.44(0.23–0.82)
|
0.002
| ||
Duration lived
| <1 year | 1.62(0.83–3.19) |
0.47(0.28–0.76)
|
0.052
| 0.83(0.54–1.27) |
0.66(0.45–0.97)
| 0.196 | |
(In current residence) | 1–5 yrs | 0.85(0.54–1.35) | 0.71(0.47–1.09) |
0.007
| 0.83(0.59–1.16) |
0.56(0.40–0.79)
|
0.001*
| |
≥6 yrs | 0.90(0.56–1.46) |
0.53(0.29–0.99)
|
0.001*
| 1.31(0.95–1.81) | 0.86(0.57–1.33) | 0.129 | ||
Migration
| Village | 1.01(0.39–2.59) | 0.39(0.09–1.54) | 0.314 | 0.98(0.42–2.32) | 0.93(0.42–2.09) | 0.651 | |
(origin 5 years) | Town | 1.03(0.63–1.68) |
0.69(0.49–0.96)
|
0.001
| 0.83(0.64–1.06) |
0.58(0.45–0.74)
|
0.001*
| |
Given birth
| Yes | -- | -- |
0.73(0.63–0.35)
|
0.51(0.38–0.67)
|
0.001*
| ||
(ever): age, 15–29 | No | -- | -- | 0.87(0.64–1.19) |
0.52(0.35–0.75)
|
0.042
|
Marital status
Employment
Mobility factors
Sex | Residence | Year | HIV prevalence (n) | Age-adjusted Odds Ratio (OR)ψ for likelihood of HIV infection in 1999 and 2003 (Reference, 1995) | χ2 for linear trend (P value) |
---|---|---|---|---|---|
Males | Rural | 1995 | 19.1(94) | 1.00 | 0.255 |
1999 | 12.6(87) | 0.59(0.26–1.33) | |||
2003 | 16.3(104) | 0.72(0.34–1.54) | |||
Urban | 1995 | 23.0(226) | 1.00 |
0.036
| |
1999 | 23.4(107) | 0.98(0.56–1.75) | |||
2003 | 14.7(197) |
0.52(0.31–0.88)
| |||
Females | Rural | 1995 | 20.0(65) | 1.00 | 0.289 |
1999 | 15.9(107) | 0.74(0.33–1.66) | |||
2003 | 16.4(128) | 0.77(0.35–1.67) | |||
Urban | 1995 | 35.0(314) | 1.00 |
0.009
| |
1999 | 28.1(139) | 0.75(0.48–1.18) | |||
2003 | 25.0(252) |
0.63(0.43–0.92)
|
Fertility
Parallel behaviour changes in higher educated young people
Factor | Education | 1995 | 1999 | 2003 | |||
---|---|---|---|---|---|---|---|
Prevalence [%(n)] | Adjusted Odds Ratio(95%CI) | Prevalence [%(n)] | Adjusted Odds Ratio(95%CI) | Prevalence [%(n)] | Adjusted Odds Ratio(95%CI) | ||
Condom use during the last casual sex
| 0–7 years | 25.5 (286) | 1 | 26.2(126) | 1 | 42.9(119) | 1 |
8–10 years | 27.4 (402) | 0.98(0.69–1.43) | 51.2 (201) | 2.82(1.73–4.60) | 53.8 (184) | 1.54 (0.96–2.46) | |
≥11 years | 42.7(218) | 1.40(0.94–2.10) | 68.9 (270) | 5.62(3.44–9.20) | 67.3 (437) |
2.96(1.93–4.52)
| |
Proportion having ≥2 sexual partners, last 12 months
| 0–7 years | 16.2 (376) | 1 | 11.0 (145) | 1 | 20.8 (144) | 1 |
8–9 years | 16.2 (469) | 0.76(0.51–1.13) | 18.4 (228) | 1.48(0.78–2.82) | 16.7 (204) | 0.63(0.35–1.12) | |
≥11 years | 15.6 (270) | 0.49(0.30–0.79) | 17.2 (285) | 1.06(0.55–2.82) | 11.5 (442) |
0.33(0.19–0.56)
|