title: Population and dyadic-based seroincidence of herpes simplex virus-2 and syphilis in southern India.
abstract: OBJECTIVE
  Herpes simplex virus-2 (HSV-2) and syphilis are associated with increased risk of HIV, highlighting the importance of understanding their transmission dynamics. In India, most studies of HSV-2 and syphilis incidence are in high-risk populations and may not accurately reflect infectious activity. In this study, we aim to define HSV-2/syphilis incidence and risk factors in a population sample.
  
  
  METHODS
  We conducted a longitudinal population-based survey in Andhra Pradesh, India, in two rounds: 2004-2005 and 2010-2011. Sociodemographic and behavioural data were collected, and dried blood spots tested for HSV-2 and Treponema pallidum IgG. After calculating sexually transmitted infection (STI) incidence, associated factors were assessed using modified Poisson regression and within-couple transmission rates modelled using seroconcordance/discordance data.
  
  
  RESULTS
  12,617 adults participated at baseline with 8494 at follow-up. Incidence of HSV-2 and syphilis per 1000 person-years was 25.6 (95% CI 24.1 to 27.2) and 3.00 (95% CI 2.52 to 3.54). Incidence of HSV-2 was higher in women vs. men (31.1 vs. 20.2) and in rural vs urban residents (31.1 vs 19.0) (p<0.05 for both). STI seroincidence increased in a step-wise fashion with age and was associated with spousal seropositivity for both sexes (incidence rate ratio (IRR) 2.59 to 6.78). Within couples the rate of transmission per 1000 couple-years from men to women vs. women to men was higher for HSV-2 (193.3 vs. 119.0) compared with syphilis (27.6 vs. 198.8), p<0.05 for both.
  
  
  CONCLUSIONS
  HSV-2 has higher incidence among subpopulations such as women, rural residents and older-aged individuals, suggesting a need for more generalised STI prevention approaches among populations traditionally considered low risk.
authors.affiliation: Pritzker School of Medicine, University of Chicago Chicago, Illinois, USA.
authors.forename: Chad H
authors.identifier: http://orcid.org/0000-0002-4376-5754
authors.initials: CH
authors.lastname: Hochberg
authors.affiliation: Department of Medicine and Chicago Center for HIV Elimination, University of Chicago, Chicago, Illinois, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Schneider
authors.affiliation: Public Health Foundation of India, New Delhi, India.
authors.forename: Rakhi
authors.initials: R
authors.lastname: Dandona
authors.affiliation: Department of Microbiology, Nizam's Institute of Medical Sciences, Hyderabad, India.
authors.forename: Vemu
authors.initials: V
authors.lastname: Lakshmi
authors.affiliation: Public Health Foundation of India, New Delhi, India.
authors.forename: G Anil
authors.initials: GA
authors.lastname: Kumar
authors.affiliation: Department of Microbiology, Nizam's Institute of Medical Sciences, Hyderabad, India.
authors.forename: Talasila
authors.initials: T
authors.lastname: Sudha
authors.affiliation: Public Health Foundation of India, New Delhi, India.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Akbar
authors.affiliation: Public Health Foundation of India, New Delhi, India.
authors.forename: G Md Mushtaq
authors.initials: GM
authors.lastname: Ahmed
authors.affiliation: Public Health Foundation of India, New Delhi, India.
authors.forename: Sri P
authors.initials: SP
authors.lastname: Ramgopal
authors.affiliation: Department of Engineering, Northwestern University, Chicago, Illinois, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Armbruster
authors.affiliation: Département de médecine sociale et préventive, URESP, Centre de recherche du CHU de Québec, Université Laval, Québec, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Alary
authors.affiliation: Public Health Foundation of India, New Delhi, India Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington, USA.
authors.forename: Lalit
authors.initials: L
authors.lastname: Dandona
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control; D006558:Herpes Genitalis / Q000097:blood / Q000453:epidemiology*; D018258:Herpesvirus 2, Human / Q000302:isolation & purification*; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012725:Sexual Behavior; D013587:Syphilis / Q000097:blood / Q000453:epidemiology*; D014210:Treponema pallidum / Q000302:isolation & purification*
keywords: EPIDEMIOLOGY (GENERAL); HIV; HSV; INDIA; SYPHILIS