Epidemiology of Herpes Simplex Virus infection in pregnancy: a pilot study.

Herpes simplex virus (HSV) infection is one of the most common sexually transmitted viral diseases worldwide. HSV type 2 causes most genital herpes and HSV type 1 is usually transmitted via non-sexual contacts. We have studied 109 pregnant women between January 2007 and December 2008, in relation to their age, condom use, number of sexual partners, age at first intercourse, parity and smoking habit. The aim of this study was to evaluate the prevalence of HSV cervical infection and HSV co-infection with other genital microorganisms associated with poor neonatal outcome. Our results showed that of the 109 enrolled outpatients, 30% was HSV1 and/or HSV2 positive, of which 30% was infected with both HSV1 and HSV2, 18% was infected with HSV1 only and 52% with HSV2 only. A significant association between HSV1 and HSV2 infection was found and the prevalence of HSV2 infection in women infected with HSV1 was 63%. The prevalence of HSV1/2 varied in presence of other vaginal microorganisms but a statistical significant association was not found. This pilot study is probably too small to obtain statistically significant results. Nevertheless using these observed results we have calculated that about 530 patients with comparable features should be enrolled to detect an increase of 50% in HSV infection due to the presence of other genital infection and potential risk factors.