Interruption of rubella virus transmission in Australia may require vaccination of adult males: evidence from a Victorian sero-survey.
Prior to the introduction of rubella vaccine to Australia in 1970 rubella was primarily a disease of primary school aged children. Vaccination programs have subsequently altered rubella age and sex susceptibility. Between July 2001 and June 2002, 85 per cent of the 32 laboratory-confirmed cases of rubella ascertained from enhanced surveillance in Victoria were males aged 20-42 years. This study aimed to determine rubella susceptibility by age group and sex in Victoria and to examine the implications of susceptibility for the interruption of circulating rubella virus. Rubella immunoglobulin G concentrations were determined for 934 residual diagnostic sera stored at the Victorian Infectious Diseases Reference Laboratory using a standard commercial enzyme immunoassay. Susceptibility was analysed by age groups defined by previous and current Australian rubella immunisation schedules. Among all subjects aged 1-55 years, males were more susceptible to rubella infection than females (10.2% vs 2.6%, p < 0.0001). Although this sex difference occurred in all age groups, it was unlikely to be explained by sampling variation in sera from subjects aged 23-44 years, for whom rubella vaccine had been recommended only for girls aged 10-14 years and rubella susceptible women post-partum. Australia's past rubella immunisation policies have resulted in a susceptible cohort of adult males. If rubella virus transmission is to be interrupted in Australia, consideration needs to be given to a rubella vaccination program targeting men aged 17-44 years. A campaign, targeting both men and women in a similar age group has recently been successful in Costa Rica.
Kelly
Heath
H
Epidemiology and Surveillance, Victorian Infectious Diseases Reference Laboratory, Locked Bag, Carlton South. heath.kelly@mh.org.au
Worth
Leon
L
Karapanagiotidis
Theo
T
Riddell
Michaela
M
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D004198:Disease Susceptibility / Q000453:epidemiology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D017589:Immunization Programs / Q000458:organization & administration*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D011247:Pregnancy; D011322:Primary Prevention / Q000458:organization & administration; D018570:Risk Assessment; D012409:Rubella / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission*; D012411:Rubella Vaccine / Q000008:administration & dosage*; D012412:Rubella virus / Q000302:isolation & purification*; D012698:Serologic Tests; D017678:Sex Distribution; D014611:Vaccination; D014739:Victoria / Q000453:epidemiology
D012411:Rubella Vaccine