title: The prevalence, incidence and risk factors of herpes simplex virus type 2 infection among pregnant Zimbabwean women followed up nine months after childbirth.
abstract: BACKGROUND
  Herpes simplex virus type 2 (HSV-2) is the leading cause of genital ulcer disease worldwide. The virus can be transmitted to neonates and there are scarce data regarding incidence of HSV-2 among women in pregnancy and after childbirth. The aim of this study is to measure the incidence and risk factors for HSV-2 infection in women followed for 9 months after childbirth.
  
  
  METHODS
  Pregnant women were consecutively enrolled late in pregnancy and followed at six weeks, four and nine months after childbirth. Stored samples were tested for HSV-2 at baseline and again at nine months after childbirth and HSV-2 seropositive samples at nine months after childbirth (seroconverters) were tested retrospectively to identify the seroconversion point.
  
  
  RESULTS
  One hundred and seventy-three (50.9%) of the 340 consecutively enrolled pregnant women were HSV-2 seronegative at baseline. HSV-2 incidence rate during the 10 months follow up was 9.7 (95% CI 5.4-14.4)/100 and 18.8 (95% CI 13.9-26.1)/100 person years at risk (PYAR) at four months and nine months after childbirth respectively. Analysis restricted to women reporting sexual activity yielded higher incidence rates. The prevalence of HSV-2 amongst the HIV-1 seropositive was 89.3%. Risk factors associated with HSV-2 seropositivity were having other sexual partners in past 12 months (Prevalence Risk Ratio (PRR) 1.8 (95% CI 1.4-2.4) and presence of Trichomonas vaginalis (PRR 1.7 95% CI 1.4-2.1). Polygamy (Incidence Rate Ratio (IRR) 4.4, 95% CI 1.9-10.6) and young age at sexual debut (IRR 3.6, 95% CI 1.6-8.3) were associated with primary HSV-2 infection during the 10 months follow up.
  
  
  CONCLUSIONS
  Incidence of HSV-2 after childbirth is high and the period between late pregnancy and six weeks after childbirth needs to be targeted for prevention of primary HSV-2 infection to avert possible neonatal infections.
authors.affiliation: Department of Obstetrics and Gynaecology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe. marshall@uz-ucsf.co.zw
authors.forename: Marshall W
authors.initials: MW
authors.lastname: Munjoma
authors.forename: Edith N
authors.initials: EN
authors.lastname: Kurewa
authors.forename: Munyaradzi P
authors.initials: MP
authors.lastname: Mapingure
authors.forename: Grace V
authors.initials: GV
authors.lastname: Mashavave
authors.forename: Mike Z
authors.initials: MZ
authors.lastname: Chirenje
authors.forename: Simbarashe
authors.initials: S
authors.lastname: Rusakaniko
authors.forename: Akhtar
authors.initials: A
authors.lastname: Hussain
authors.forename: Babill
authors.initials: B
authors.lastname: Stray-Pedersen
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000453:epidemiology; D006558:Herpes Genitalis / Q000175:diagnosis* / Q000453:epidemiology*; D018258:Herpesvirus 2, Human / Q000302:isolation & purification*; D006801:Humans; D015994:Incidence; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors; D012747:Sexual Partners; D014247:Trichomonas Vaginitis / Q000453:epidemiology; D047568:Unsafe Sex / Q000706:statistics & numerical data; D055815:Young Adult; D015030:Zimbabwe / Q000453:epidemiology
chemical_list: D000914:Antibodies, Viral