Prevalence, incidence and correlates of HSV-2 infection in an HIV incidence adolescent and adult cohort study in western Kenya

PLoS One. 2017 Jun 6;12(6):e0178907. doi: 10.1371/journal.pone.0178907. eCollection 2017.


Background: Herpes simplex virus type 2 (HSV-2) infections are associated with increased risk of HIV transmission. We determined HSV-2 prevalence, incidence and associated risk factors, incidence among persons with indeterminate results, and prevalence of HSV-2/HIV co-infection among young adults (18-34 years) and adolescents (16-17 years) enrolled in an HIV incidence cohort study in western Kenya.

Methods: Participants (n = 1106; 846 adults) were screened and those HIV-1 negative were enrolled and followed-up quarterly for one year. HSV-2 was assessed using the Kalon enzyme immunoassay. HSV-2 incidence was calculated separately among HSV-2 seronegative participants and those indeterminate at baseline. Logistic regression was used to estimate the odds of HSV-2 infection and Poisson regression was used to assess HSV-2 incidence and associated factors.

Results: Overall, HSV-2 prevalence was 26.6% [95% confidence interval (CI): 23.9-29.4] and was higher in adults (31.5% [95% CI: 28.3-34.9]) than adolescents (10.7% [95% CI: 7.1-15.3]). Factors associated with prevalent HSV-2 included female gender, increasing age, HIV infection, history of sexually transmitted infection, low level of education, multiple sexual partners, and being married, divorced, separated or widowed. Overall HSV-2 incidence was 4.0 per 100 person-years (/100PY) 95% CI: 2.7-6.1 and was higher in adults (4.5/100PY) and females (5.1/100PY). In multivariable analysis only marital status was associated with HSV-2 incidence. Among 45 participants with indeterminate HSV-2 results at baseline, 22 seroconverted, resulting in an incidence rate of 53.2 /100PY [95% CI: 35.1-80.9]. Inclusion of indeterminate results almost doubled the overall incidence rate to 7.8 /100 PY [95% CI: 5.9-10.5]. Prevalence of HIV/HSV-2 co-infection was higher in female adults than female adolescents (17.1 [95% CI: 13.6-21.0] versus 3.4 [95% CI: 1.1-7.8]).

Conclusion: The high incidence rate among persons with indeterminate results underscores the public health concerns for HSV-2 spread and underreporting of the HSV-2 burden. Careful consideration is needed when interpreting HSV-2 serology results in these settings.

MeSH terms

  • Adolescent
  • Adult
  • Coinfection / epidemiology
  • Coinfection / virology
  • Female
  • HIV Infections / epidemiology*
  • HIV Infections / pathology
  • HIV Infections / virology
  • HIV-1 / pathogenicity
  • Herpes Simplex / epidemiology*
  • Herpes Simplex / pathology
  • Herpes Simplex / virology
  • Herpesvirus 2, Human / pathogenicity*
  • Humans
  • Kenya / epidemiology
  • Male
  • Sexually Transmitted Diseases / epidemiology

Grants and funding

This study was funded by the Division of HIV/AIDS Prevention, CDC, Atlanta, Georgia, USA through a collaborating agreement with the Kenya Medical Research Institute (KEMRI). KEMRI and CDC staff participated in the design, data collection, analysis, interpretation of the data, writing the report, and the decision to submit the paper for publication.