Demographic data

We conducted a cross sectional seroprevalence study on anonymous banked blood samples taken from adults for various reasons, between January and September 1998 at “La Sapienza” University Hospital, Rome, Italy. Blood samples were available for the following four groups of individuals:

1. military recruits, from various Italian regions, undergoing routine medical examination for enrolment in the military service

2. people attending an outpatient facility for either vaccination against viral hepatitis B or post-exposure prophylaxis

3. blood donors

4. pregnant women undergoing routine serological controls.

Methods

TEST USED

All samples were tested with a commercially available kit approved by the US Food and Drug Administration: the herpes simplex virus (HSV) type 2 specific gG ELISA test manufactured by Meridian Diagnostics Inc (Cincinnati, OH, USA). The sensitivity and specificity of the test are 98% and 97%, respectively.¹

STATISTICS

To test the difference between prevalence rates, we calculated χ² and χ² for linear trends and 95% confidence intervals.

Results

The study population consisted of 673 individuals. Table 1 presents the HSV-2 seroprevalence by sex, age, and group studied.

Seroprevalence was 4.9% (95% CI: 3.1–7.3) among males and 6.7% (95% CI: 3.8–10.8) among females, with no statistically significant difference between the two.

We did not observe an increase in seroprevalence with age. No significant differences were observed among age groups in either males or females.

Discussion

Individuals included in this study are at low risk for HSV-2 infection and therefore are probably representative of the general population, although not enough information was available on behaviour to substantiate this statement.

The observed seroprevalence of 5.5% is similar to the 3.6% found in Spain among males and females from the general population,² and four times lower than the 21.9% found in the United States among adults from the general population.³

The seroprevalence observed among military recruits is comparable with that reported by other studies conducted among individuals of a similar age, yet it is much higher than the 0.086% seroprevalence found in a previous Italian study on military recruits, based on blood samples drawn in 1981.⁴ However, these two studies used different HSV-2 antibody tests, and we cannot exclude a lower sensitivity of the older test.

With regard to blood donors, the seroprevalence found in our study is similar to that among blood donors in the United Kingdom.⁵

Among pregnant women, the 7.6% seroprevalence observed in our study is consistent with the 8.4% seroprevalence found in northern Italy in a similar setting,⁶ yet it is lower than that reported among pregnant women in other countries,⁷ although the wide confidence interval should be taken into consideration.

In agreement with the study conducted in Spain,² we found no significant sex difference in seroprevalence and no increase in seroprevalence with age.

If our data are indeed representative of the general population, then they suggest that the seroprevalence of HSV-2 infection in Italy is lower than that reported in other industrialised countries, though the comparison between our data on military recruits and that from previous studies suggests that seroprevalence may have increased in Italy over the past 20 years.