Table 2

Behavioural and sociodemographic associations with incident herpes simplex virus-2 (HSV-2) or syphilis infection in men (n=4136)

HSV-2Syphilis
Variable% Seroconversions
(N)*
 Univariate associations
IRR (95% CI)
Combined multivariate model adjusted IRR (95% CI)Percentage
positive (N)
 Univariate
associations
IRR (95% CI)
Combined
multivariate model
adjusted IRR (95% CI)
Overall:10.81 (3923)1.80 (4052)
Sociodemographics
Age at baseline (years)
 15–193.66 (737)1.001.000.53 (753)1.001.00
 20–245.65 (672)1.56 (0.95 to 2.55)1.34 (0.79 to 2.28)0.58 (687)1.09 (0.27 to 4.38)0.55 (0.14 to 2.14)
 25–299.05 (652)2.53 (1.61 to 4.00)2.07 (1.18 to 3.65)1.06 (662)1.99 (0.58 to 6.81)0.82 (0.23 to 2.96)
 30–3413.23 (514)3.79 (2.43 to 5.92)2.78 (1.58 to 4.88)1.69 (533)3.19 (0.98 to 10.37)1.19 (0.34 to 4.12)
 35–3913.60 (522)3.91 (2.51 to 6.08)2.82 (1.60 to 4.96)3.11 (546)5.94 (2.00 to 17.65)2.20 (0.68 to 7.07)
 40–4416.42 (402)4.79 (3.06 to 7.49)3.37 (1.90 to 5.95)3.86 (414)7.40 (2.47 to 22.14)2.78 (0.86 to 9.01)
 45–4922.41 (424)6.77 (4.42 to 10.37)4.79 (2.75 to 8.33)3.50 (457)6.70 (2.24 to 20.04)2.47 (0.74 to 8.29)
Place of residence
 Urban8.85 (1728)1.001.001.37 (1821)1.00
 Rural12.35 (2195)1.42 (1.17 to 1.73)1.30 (0.90 to 1.78)2.15 (2231)1.57 (0.97 to 2.55)
Standard of living index
 0–1612.51 (983)1.002.00 (1000)1.001.00
 17–229.90 (1040)0.78 (0.60 to 1.02)2.50 (1082)1.25 (0.70 to 2.23)1.31 (0.73 to 2.35)
 23–2910.95 (1023)0.87 (0.68 to 1.13)1.78 (1069)0.89 (0.48 to 1.67)0.96 (0.50 to 1.82)
 30–549.81 (877)0.78 (0.59 to 1.02)0.78 (901)0.39 (0.16 to 0.92)0.44 (0.18 to 1.07)
Education 
 None14.31 (1027)1.001.003.04 (1054)1.00
 Class 1–1010.75 (2149)0.74 (0.60 to 0.90)0.93 (0.75 to 1.15)1.48 (2227)0.48 (0.30 to 0.79)
 Class 11–125.25 (305)0.35 (0.21 to 0.58)0.57 (0.34 to 0.97)0.94 (319)0.31 (0.90 to 1.00)
 Technical school/college6.80 (441)0.46 (0.31 to 0.68)0.71 (0.47 to 1.07)1.11 (451)0.36 (0.14 to 0.93)
Occupation
 Other10.48 (3656)1.001.001.64 (3779)1.001.00
Transport related15.36 (267)1.49 (1.08 to 2.06)1.27 (0.90 to 1.78)4.03 (273)2.47 (1.30 to 4.69)2.01 (1.04 to 3.89)
Caste
 Forward caste10.03 (1376)1.001.001.54 (1426)1.00
 Backward caste11.05 (977)1.11 (0.86 to 1.42)1.15 (0.89 to 1.49)2.20 (999)1.43 (0.79 to 2.58)
 Scheduled caste13.36 (846)1.34 (1.05 to 1.72)1.57 (1.08 to 2.28)1.83 (875)1.18 (0.62 to 2.24)
 Scheduled tribe9.70 (133)0.97 (0.55 to 1.71)1.01 (0.56 to 1.80)2.19 (137)1.43 (0.43 to 4.78)
 Not applicable8.81 (590)0.87 (0.63 to 1.20)2.10 (1.10 to 4.01)1.63 (615)1.05 (0.50 to 2.22)
Religion† 
 Hindu11.03 (2503)1.001.001.82 (2580)1.00
 Muslim7.89 (596)0.70 (0.52 to 0.96)0.44 (0.22 to 0.84)1.60 (626)0.88 (0.44 to 1.73)
 Christian12.30 (821)1.12 (0.89 to 1.40)0.82 (0.57 to 1.17)1.90 (83)1.04 (0.59 to 1.83)
 Other0 (3)0 (3)
Marital status
 Never3.66 (1065)1.000.46 (1085)1.00
 Currently13.45 (2802)3.87 (2.79 to 5.38)2.30 (2908)5.05 (2.04 to 12.54)
 Previously14.29 (56)4.13 (1.93 to 8.82)1.69 (59)3.71 (0.43 to 31.8)
Health behaviours
Circumcision‡ 
 No11.30 (3229)1.001.84 (3320)1.00
 Yes8.72 (654)0.76 (0.58 to 1.01)1.74 (691)0.95 (0.51 to 1.76)
Alcohol history
 Never8.56 (2092)1.001.001.11 (2156)1.00
 Currently12.76 (1552)1.52 (1.24 to 1.86)1.03 (0.83 to 1.29)2.62 (1603)2.37 (1.44 to 3.91)
 Previously16.97 (277)2.08 (1.51 to 2.86)1.35 (0.97 to 1.88)2.41 (291)2.18 (0.94 to 5.04)
Sexual behaviour
Lifetime female sex partners
 03.67 (817)1.001.000.24 (833)1.001.00
 18.82 (1089)2.46 (1.63 to 3.71)0.96 (0.57 to 1.60)0.71 (1122)2.97 (0.63 to 14.00)1.70 (0.31 to 9.20)
 >114.94 (1975)4.32 (2.97 to 6.29)1.38 (0.83 to 2.31)3.07 (2054)12.97 (3.17 to 53.02)5.97 (1.30 to 27.32)
HSV-2/syphilis-positive spouse§
 No9.97 (3782)1.001.001.69 (4029)1.001.00
 Yes33.33 (141)3.80 (2.82 to 5.12)2.59 (1.89 to 3.55)21.74 (23)14.54 (5.90 to 35.82)6.78 (2.52 to 18.21)
  • *Seroconversion from negative to positive over study duration.

  • †For religion ‘other’ category excluded from regressions because of sample size.

  • ‡Circumcision excluded from final model because of collinearity with Muslim religion.

  • §HSV-2 positive spouse included in HSV-2 model and syphilis-positive spouse included in syphilis model.

  • HSV-2, herpes simplex virus-2; IRR, incident rate ratio; N, total number of people (positive and negative) in category.