Prevalence of antibodies to herpes simplex virus types 1 and 2 in pregnant women, and estimated rates of infection

Methods for estimating the incidence of primary infection in pregnancy: a reappraisal of toxoplasmosis and cytomegalovirus data

Accurate incidence information is required to plan and evaluate screening programmes which have been proposed for the detection of primary toxoplasmosis and cytomegalovirus infection in pregnancy. Appropriate statistical methods are described for deriving incidence rates and their confidence intervals from three types of data: change in age-specific seroprevalence, seroconversion, and IgM studies. These methods are applied to seven published studies on toxoplasmosis and cytomegalovirus carried out in the UK. In these publications only one estimate of the infection rate per pregnancy was correctly derived, and none were accompanied by confidence intervals. Using the proposed methods, most estimates of the primary toxoplasmosis rate in these studies were between 2.5 and 5.5 per 1000 pregnancies, compared to the 2 per 1000 usually cited. Most cytomegalovirus incidence estimates were between 4 and 10 per 1000 pregnancies.

Longitudinal study of Toxoplasma seroprevalence in South Yorkshire

Serum samples collected from individuals of a wide range of ages in South Yorkshire between 1969 and 1990 provided the basis for a longitudinal seroprevalence survey of Toxoplasma gondii antibodies. Sera numbering 3868 were screened for T. gondii specific antibodies using a commercial latex agglutination test. The resultant temporal series of serological profiles revealed a rise, with age, in seroprevalence, the rate of which showed a decrease through time. A plateau of around 40-50% prevalence was attained by the 41- to 45-year age-class in 1969 which was not approached until the 66- to 70-year class in the 1988-90 data set. This trend for decline in seroprevalence was confirmed by statistical analysis for the age range 21-60 years. These results may be indicative of a decrease in the rate of toxoplasma exposure in this study community over the 20-year period. The survey of 1988-90 provides a base-line profile of present-day seroprevalence in which 11% of individuals in the age range 16-45 years (roughly corresponding to the childbearing age-range) show evidence of past infection. The representative nature of the serum collection and public-health implications of these results are discussed.

Management of genital herpes simplex infection

Herpes simplex infection of the genitals is a common condition, more often due to herpes simplex virus (HSV) type 2 than to type 1 virus. There is a severe first attack followed by mild recurrences which are more common and more frequent after HSV-2 than after HSV-1 genital infection. Clinical features with prodrome, vesicles and erosions may be characteristic allowing rapid clinical diagnosis. When possible laboratory confirmation should be attempted. General management includes simple hygiene, avoidance of sexual transmission, use of condoms, and notifying partners. Oral acyclovir (Zovirax, Wellcome) is the drug of choice for initial attacks and should be considered for all women with this diagnosis. Intravenous acyclovir may be used for very severe attacks. Men with initial attacks may be treated with oral acyclovir but mild disease affecting only skin may be treated with 5% acyclovir cream. Recurrences are short so acyclovir has less effect. Frequent recurrences can be troublesome and may be suppressed by continuous oral acyclovir, or individual attacks may be aborted with intermittent therapy. Various systemic complications may occur; an important but rare problem is primary herpes in late pregnancy. Acyclovir is effective in the treatment of the troublesome herpes simplex disease associated with human immunodeficiency infection. Acyclovir is one of the more expensive treatments for sexually transmitted diseases. At present in many countries costs are being examined, and application of the principles outlined here should help to minimize cost and maximize care.