Trends in Herpes Simples Virus Type 2 infection in the United States — Data from NHANES Centers for Disease Control and Prevention (CDC) Emory University Atlanta, USA
NHANES —A Unique Data Source NHANES—National Health And Nutrition Examination Survey A series of nationally representative surveys of non-institutionalized US population conducted by National Center for Health Statistics, CDC Survey staff travel across the nation to conduct interviews and health examinations
Statistical Methods Age-adjustment –US Census as the standard population Weights –Accounting for oversampling and non- response SUDAAN software –Accounting for multi-stage sampling design
Laboratory Methods HSV-2 serology (IgG antibodies) Type-specific immunodot assay –Glycoprotein of gG2 as antigen The same assay and the same laboratory were used over time
Tracking HSV-2 Trends Using Data from NHANES NHANES II: NHANES III: NHANES NHANES (data to be released in May 2004)
NHANES Surveys NHANES II ( ) NHANES III ( ) ( )NHANES1999-’00 Examination rate 71%*76%78% Sample size , Age range >=12 yrs yrs *Response rate. Remaining sera for all non-whites and a random sample of % of the whites in each age group were tested.
Changes in HSV-2 Seroprevalence between NHANES II and NHANES III Overall, 30% increase The relative increases similar in men (27%) and women (32%) Relative increases were largest in adolescents.. Relative increase larger in whites (30%) than blacks (9%)
Changes in HSV-2 Seroprevalence between NHANES II and NHANES III Fleming DT et al. N Engl J Med 1997; 337:
Changes in HSV-2 Seroprevalence between NHANES III and NHANES’99-00
Variables NHANES III ( ) % (95% CI) % (95% CI)NHANES % (95% CI) Percentagechange Total Age (yrs) (19.4, 23.3) 5.8 (4.4, 7.5 ) 17.2 (14.9, 19.8) 27.8 (24.6, 31.4) 26.3 (23.0, 30.1) 17.6 (15.4, 20.0) 1.5 (0.9, 2.7) 8.9 (7.2, 11.1) 25.4 (21.6, 29.9) 26.4 (21.4, 32.5) -17%†-74%‡-48%‡-9%-0% CI, confidence interval. † p<0.05; ‡ p<0.001
Changes between NHANES III and NHANES’99-00 in year-olds Variables NHANES III ( ) N = 4537 % (95% CI) % (95% CI)NHANES N = 2232 % (95% CI) Percentagechange Sex Males Males Females FemalesRace/ethnicity NH whites NH whites NH blacks NH blacks Mex Americans Mex Americans 9.8 (7.5, 12.9) 16.6 (14.9, 18.6) 11.1 (9.0, 13.9) 24.9 (21.9, 28.2) 11.7 (9.7, 14.1) 4.0 (2.7, 5.9) 8.5 (6.4, 11.2) 3.3 (1.9, 5.4) 21.9 (16.8, 28.5) 6.2 (3.6, 10.8) -59%‡-49%‡-70%†-12%-47%† CI, confidence interval. † p<0.05; ‡ p<0.001
HSV-2 Seroprevalence in NHANES By Age Group
Conclusions From the NHANES, HSV-2 seroprevalence increased and then decreased between Largest changes occurred in adolescents and in whites –Cohort effect
Discussion No sexual behavior data in NHANES II Limited sexual behavior data in NHANES III and NHANES ’99-00 –The number of lifetime sexual partners –Changes in wordings
Teenage Pregnancy Rate in the US, Rate per 1,000 women aged 15-19
Discussion (cont) Youth Risk Behavior Surveys ( )* Ever had sex Ever had sex Had four or more partners Had four or more partners Used condoms Used condoms Decreased sexual activity accounted for about 25% of the decline in teenage pregnancy between 1988 and 1995 *CDC. MMWR 2002; 51: