The burden of parvovirus B19 infection in women of childbearing age in England and Wales

Abstract

A serological survey has been used to investigate the epidemiology of parvovirus B19 infection in England and Wales. A total of 2835 sera representing the complete age range were selected from a convenience collection obtained in 1996 that reflects the general population and screened for parvovirus B19-specific IgG. Antibody prevalence rose nonlinearly with age from 21% in those aged 1-4 years to >75% in adults aged > or = 45 years. Force-of-infection estimates were similar to those previously made in 1991, being highest in those aged <15 years. There was no association between evidence of previous infection and sex or region. Quantitatively strongest antibody responses were found in those aged 15-34 years and IgG levels in females were 28.5% higher than those found in males (P=0.004, 95% CI 8.2-52.6). Applying the upper 95% confidence interval for the force of infection to maternity estimates for England and Wales in 1996, parvovirus infection in pregnancy was estimated to occur on average in up to 1 in every 512 pregnancies each year. This represents 1257 maternal infections, causing up to an estimated 59 fetal deaths and 11 cases of hydrops fetalis annually. An analysis of all available laboratory-confirmed parvovirus infections found a mean of 944 infections per year in women aged 15-44 years highlighting a need for enhanced surveillance of maternal parvovirus B19 infection in England and Wales, including information on both pregnancy and outcome of pregnancy.

Fig. 1

Frequency distribution of parvovirus B19 serological data stratified by age group.

Fig. 2

Positive predictive values (PPVs) for different cut-offs (reactivity groups) for a variety of assumed overall parvovirus B19 prevalence estimates (dashed vertical line shows the lowest cut-off giving a PPV⩾95% with prevalence ⩾50%).

Fig. 3

Age-specific parvovirus B19 antibody prevalence estimates (95% CI).

Fig. 4

(a) Total available laboratory-confirmed cases of parvovirus B19 infection, stratified by year and sex (□, females; ■, males). (b) Laboratory-confirmed cases of parvovirus B19 infection in females only, stratified by year and age group (□, 0–14 years; ■, 15–44 years;, ⩾45 years).