Australian rubella serosurvey 2012–2013: On track for elimination?

BackgroundThe World Health Organization has targeted rubella virus for elimination regionally. Australia was one of the first countries to implement a nationally funded rubella immunisation program, in 1971, and conducts regular national rubella serosurveillance studies. We aimed to estimate the seroprevalence of rubella-specific IgG antibody in the Australian population by age and sex in 2012–2013, to compare the results with three previous serosurveys conducted in 1996–1999, 2002 and 2007 and to estimate the effective reproduction numbers (R_n).MethodsThis study used 2729 serum and plasma specimens, randomly selected from a specimen bank collected in 2012–2013 across Australia. Age groups included in the sample ranged from 1 to 49 years. Sera were tested for rubella-specific IgG-antibody using the Enzygnost anti-rubella IgG enzyme immunoassay and classified as positive, negative or equivocal according to rubella-specific IgG concentrations of >7 IU/ml, <3 IU/ml and 3–7 IU/ml, respectively.ResultsThe overall proportions seropositive, seronegative and equivocal for rubella-specific IgG were 92.1% (95% CI, 91.0–93.2), 6.7% (95% CI, 5.7–7.7) and 1.2% (95% CI, 0.8–1.6), respectively. The proportion of males seropositive was significantly lower than females in the 30–34 (83.1% vs. 96.8%, p = 0.003), 35–39 (86.1% vs. 96.3%, p = 0.02) and 40–44 (86.1% vs. 95.7%, p = 0.03) year age groups. R_n for rubella in 2012–2013 was estimated to be 0.33 (95% CI 0.28–0.39).DiscussionThe 2012–2013 national serosurvey showed levels of rubella-specific IgG seropositivity in the Australian population are relatively high with no evidence of decrease compared to previous serosurveys conducted in 1996–1999, 2002 and 2007. The lower proportion of seropositive males aged 30–44 years likely reflects the initial immunisation program targeting females only. To our knowledge this study represents the longest period of serosurveillance following introduction of a nationally funded rubella immunisation program. The lack of evidence of decreasing rubella-specific IgG seropositivity is therefore reassuring for Australia and other countries with longstanding high vaccine coverage.     

Mumps and rubella surveillance in Victoria, 1993 to 2000.

Despite improving childhood coverage of the measles-mumps-rubella vaccine (MMR) in Victoria during the 1990s, mumps and rubella notifications in age groups eligible for vaccination persisted. This study reviewed the mumps and rubella surveillance data from 1993 to 2000 with a specific focus on method of diagnosis. There were 474 notifications of mumps over the seven-year period (annual median 61, range 40 to 77) and 3,544 notifications of rubella (annual median 297, range 66 to 1,165). The highest notifications rates for mumps were consistently among the 1-4 and 5-9 year age groups, whereas there was a marked change in the age distribution of rubella notifications during this interval. A large rubella outbreak occurred in 1995 with 1,165 notifications; the highest notification rates were males aged 15-24 years, infants under one year of age (males and females), and those aged 5-14 years (males and females), respectively. The susceptibility of 5-24 year olds reflects historical changes to the Australian Standard Vaccination Schedule. Rubella notifications returned to baseline levels in 1998 with the highest notification rates in infants aged under one year, and children aged 1-4 years. For both mumps and rubella, the majority of notifications for all age groups were clinically diagnosed, and were most common in children.     

Comparison of rubella seroepidemiology in 17 countries: progress towards international disease control targets

OBJECTIVE: To standardize serological surveillance to compare rubella susceptibility in Australia and 16 European countries, and measure progress towards international disease-control targets. METHODS: Between 1996 and 2004, representative serum banks were established in 17 countries by collecting residual sera or community sampling. Serum banks were tested in each country and assay results were standardized. With a questionnaire, we collected information on current and past rubella vaccination programmes in each country. The percentage of seronegative (< 4 IU/ml) children (2-14 years of age) was used to evaluate rubella susceptibility, and countries were classified by seronegativity as group I (< 5%), group II (5-10%) or group III (> 10%). The proportion of women of childbearing age without rubella protection (< or = 10 IU/ml) was calculated and compared with WHO targets of < 5%. FINDINGS: Only Romania had no rubella immunization programme at the time of the survey; the remaining countries had a two-dose childhood schedule using the measles, mumps and rubella (MMR) vaccine. The percentage of susceptible children defined five countries as group I, seven as group II and four as group III. Women of childbearing age without rubella protection were < 5% in only five countries. CONCLUSION: Despite the low reported incidence in many countries, strengthening the coverage of the routine two-dose of MMR vaccine among children is needed, especially in group III countries. Catch-up campaigns in older age groups and selective targeting of older females are needed in many countries to ensure necessary levels of protective immunity among women of childbearing age.     

Neural correlates of pediatric obesity

Australia commenced an ongoing school based government funded human papillomaviruses (HPV) (cervical cancer prevention) vaccination program in April 2007 for adolescent females aged 12-13 years. In addition, up to December 31, 2009, a catch-up program for young females 13-26 years of age was offered: a school-based vaccination program was used to offer HPV vaccine to girls enrolled in school (14-17 years), and general practitioners or other community health provider offered vaccine to young women aged 18-26 years. To date, only the quadrivalent vaccine (HPV 6/11/16/18) has been utilized in the funded program. Acceptance of the vaccine is high with coverage of 3 doses of the HPV vaccine in the school age cohort around 70%, and just over 30% in the older age cohort. Since the vaccination program was initiated, a reduction in new cases of genital warts of 73% among vaccine eligible age females has been evidenced in STI clinics across Australia. A reduction of 44% of new cases in young males (not a part of the free program) was also documented during this same time period, suggesting significant herd immunity. Similarly, in the state of Victoria, a small but significant decrease in high grade abnormalities in Pap screening findings has been reported in young women<18 years for the period 2007-9, as compared to pre-vaccination. Challenges for the future include how we can sustain and improve HPV vaccination coverage in young Australian women, while maintaining cervical cancer screening participation and reviewing cervical cancer screening methods.     

Rubella susceptibility among pregnant women in North London, 1996-1999

BACKGROUND: Rubella infection and congenital rubella are currently rare in the United Kingdom, although sporadic cases occur, often associated with travel abroad. Uptake of the combined measles, mumps and rubella (MMR) vaccine has declined in recent years, and there is a danger that rubella infection could start to circulate again, with serious implications for susceptible pregnant women. This could be a particular problem in communities where there are relatively high rubella susceptibility rates because of either poor vaccine uptake over several years or the presence of significant numbers of recent immigrants from countries without routine rubella vaccination programmes. METHODS: Routinely collected data on rubella susceptibility in pregnant women in the former North West Thames region were available for 1996-1999. Associations between year of delivery, maternal age, parity and ethnic group, and rubella susceptibility were explored. RESULTS: Overall rubella susceptibility declined significantly from 2.6 per cent to 2.4 per cent between 1996 and 1999. Whereas less than 2 per cent of British-born women were susceptible, overall susceptibility for other women was about 5 per cent. African and Asian women had particularly high susceptibility rates, and patterns of susceptibility by age and parity varied across ethnic groups. CONCLUSIONS: If rubella were to re-establish itself in the United Kingdom, women who had come to Britain in later childhood or adult life would be at higher risk of acquiring infection in pregnancy than indigenous women. Appropriate local and national strategies should be devised to ensure that all such women are offered rubella vaccination at the earliest opportunity.     

Sero-epidemiology of measles and mumps in Korea: impact of the catch-up campaign on measles immunity

A catch-up campaign targeting children aged 8–16 years using measles–rubella (MR) vaccine was conducted during 2001 in Korea. To evaluate the impact of the campaign and assess mumps immunity, human IgG antibodies were detected using ELISA for measles (5826 samples) and mumps (5890 samples) in a national sample of opportunistically collected sera from a population aged 0–34 years. The measles immunity increased by 5–10% following the catch-up campaign in the targeted age group. Infants lost maternal antibodies rapidly and about 90% of infants were susceptible to measles and mumps at 6–8 months of life. The sero-prevalence of mumps antibody increased slowly with age and stabilized at a lower level when compared with that of measles. Despite an immediate reduction in susceptibility among the targeted age group of the catch-up campaign, continuous efforts to increase immunization coverage are needed to interrupt indigenous measles transmission. Furthermore, our results suggest continuous mumps outbreaks could occur because of the accumulation of susceptible individuals.     

Rubella and measles seroprevalence among women of childbearing age, Argentina, 2002

To assess rubella and measles susceptibility among women of childbearing age we conducted a cross-sectional seroprevalence study in four cities and one rural area in Argentina. A convenience sample of women aged 15-49 years seeking care in public health-care institutions was selected (n=2804). Serum specimens were tested for rubella and measles IgG antibody titres. The overall susceptibility to rubella and measles was 8.8 and 12.5% respectively. Seroprevalence differences were found for both rubella (P<0.001) and measles (P=0.002) across sites. Rubella seroprevalence was higher in women aged >or=40 years than in younger women (P=0.04). Measles seroprevalence tended to increase with age (P<0.001). Approximately 15% of women aged 15-29 years were not immune to measles. No risk factors were associated with rubella seronegativity; however, age (P<0.001) and having less than four pregnancies (P<0.001) were factors associated with measles seronegativity. Our findings support the introduction of supplemental immunization activities targeting adolescents and young adults to prevent congenital rubella syndrome and measles outbreaks over time.     

A resurgence of congenital rubella in Australia?

Two infants with congenital rubella defects (congenital rubella syndrome) have been reported from Queensland in 2003, after an increase in rubella in that State in 2001-2002. The national Measles Control Campaign in 1998 aimed to give measles-mumps-rubella (MMR) vaccine to all unvaccinated preschoolers and a second dose to primary schoolchildren. Following the Campaign no children with congenital rubella defects were born to Australian-born mothers during the five years 1998 to 2002, according to reports to the Australian Paediatric Surveillance Unit. However, three imported cases occurred. Broad immunisation coverage and detection and vaccination of susceptible women of child-bearing age before they become pregnant are necessary to prevent further cases.     

Rubella susceptibility in pregnant women and results of a postpartum immunization strategy in Catalonia,Spain

BackgroundElimination of congenital rubella syndrome depends not only on effective childhood immunization but also on the identification and immunization of rubella susceptible women. We assessed rubella susceptibility among pregnant women and evaluated the adherence and response to postpartum immunization with measles, mumps and rubella (MMR) vaccine.MethodsCross-sectional study of women who gave birth at the Hospital Clinic de Barcelona (Spain) between January 2008 and December 2013. Antenatal serological screening for rubella was performed in all women during pregnancy. In rubella-susceptible women, two doses of MMR vaccine were recommended following birth. We evaluated rubella serological response to MMR vaccination in mothers who complied with the recommendations.ResultsA total of 22,681 pregnant women were included in the study. The mean age was 32.3 years (SD 5.6), and 73.6% were primipara. The proportion of immigrants ranged from 43.4% in 2010 to 38.5% in 2012. The proportion of women susceptible to rubella was 5.9% (1328). Susceptibility to rubella declined with increasing maternal age. Immigrant pregnant women were more susceptible to rubella (7.6%) than women born in Spain (4.6%). Multivariate analyses showed that younger age (≤19 years) aOR 1.7 (95% CI 1.1–2.5), primiparas aOR 1.3 (95% CI 1.1–1.5) and immigrant women aOR 1.6 (95% CI 1.4–1.8) were more likely to be susceptible. The second dose of MMR vaccine was received by 57.2% (718/1256) of rubella-susceptible women, with the highest proportion being immigrant women compared with women born in Spain. After vaccination, all women showed rubella immunity.ConclusionsThe higher rubella susceptibility found in the three youngest age groups and in immigrant women highlights the relevance of antenatal screening, in order to ensure identification and postpartum immunization. The postpartum immunization strategy is an opportunity to protect women of childbearing age and consequently prevent occurrence of CRS, and to increase vaccination coverage against rubella and other vaccine-preventable diseases.     

Use of rubella seroepidemiological data for assessment of previous vaccination policy and for decision making in response to epidemics in Israel

We examined the prevalence of rubella antibodies in a representative sample of the Israeli population. Three thousand three hundred and twenty-six sera collected during 1997 and 1998, from an age-stratified general population sample were tested for specific IgG antibodies against rubella. The sero-positivity rates to rubella were higher among females as compared with males (89.1% versus 82.3%, respectively (p < 0.001). This difference was the result of much lower sero-positivity rates among males in the age group 13-17, with the lowest value (56.3%) among subjects aged 16. Male subjects of this age group were in 2000 the target of an outbreak of rubella among 18-19-year old male recruits of the Israel Defense Force. The data of this study served to assess previous exposure to the wild virus or vaccine strains, to identify pockets of low level of immunity and contributed to decision making in response to the onset of a rubella outbreak.     

2005年山东省部分孕期妇女风疹易感性调查

[目的]了解山东省孕期妇女风疹易感性水平,为调整风疹疫苗免疫策略提供依据。[方法]2005年,采集不同地区到医院准备分娩的20~40岁孕妇血清,采用间接酶联免疫吸附定量法检测风疹IgG抗体。[结果]检测标本3 788份,风疹抗体阳性(>20 IU/ml)的2 942人,阴性(<10 IU/ml)的314人,临界值(10~20 IU/ml)的532人,易感(临界值和阴性者)合计846人,易感率为22.33%。几何平均抗体含量(CMT)为34.93 IU/ml。不同地区风疹易感率和CMT的差异均有统计学意义(P<0.01);风疹易感率有随年龄增长而增高的趋势(P<0.01)。[结论]山东省近1/4的孕妇为风疹的易感者,有必要对育龄期妇女开展风疹疫苗接种。     

The pattern of notification and testing for genital Chlamydia trachomatis infection in Victoria, 1998-2000: an ecological analysis

OBJECTIVE: This ecological study analyses routinely collected chlamydia notification and testing data to investigate any patterns. METHODS: Age and sex-specific chlamydia notification and testing rates for Victoria were calculated for the period 1998 to 2000. RESULTS: Chlamydia notification and testing rates rose between 1998 and 2000. Notification rates were higher among women aged 15 to 24 years than men of the same age (p < 0.01) and higher among 25 to 44-year-olds living in metropolitan rather than rural/regional Victoria (p < 0.01). Testing rates were higher for women than men (p < 0.01) and higher in metropolitan rather than rural/regional areas (p < 0.01) in all groups except women aged 15-24 years. CONCLUSIONS: These increasing rates highlight that chlamydia infection represents a substantial public health problem. IMPLICATIONS: Although these data provide useful information showing these rates vary with age and sex, formal epidemiological prevalence and risk factor studies are required.     

The epidemiology of rubella and congenital rubella in Australia, 1992 to 1997.

Selective rubella vaccination of schoolgirls commenced in 1971 and was followed by a significant reduction in congenital rubella. Infant vaccination with MMR was introduced in 1989 to interrupt circulation of the virus in young children, and in 1994/95 the adolescent school based rubella vaccination program was changed to MMR for both boys and girls. This report reviews the epidemiology of rubella and congenital rubella between 1992 and 1997 using reports to the National Notifiable Diseases Surveillance System (NNDSS) and the Australian Paediatric Surveillance Unit (APSU). Notification rates for rubella exceeded 20 per 100,000 in 1992, 1993 and 1995 and declined to 7.2 per 100,000 in 1997. Sixty-one per cent of notifications occurred between September and December and 68% occurred in males. The incidence rate in males aged 15-22 years peaked at 152.6 per 100,000 in 1995 reflecting the lack of immunisation in this cohort. From 1993 to 1997, 19 children were reported with congenital rubella syndrome, representing 1 in 67,000 live births. Of these, 17 had multiple defects (4 died) and 2 had deafness only. There were also 5 infants with congenital rubella infection but no defects. Australia's rate of congenital rubella syndrome exceeded that of the United Kingdom and the United States of America but this may be partly attributable to differences in reporting practices. The impact of changing the second dose of MMR vaccine to 4 years of age in 1998 will require careful monitoring.     

A serosurvey evaluation of the school-based measles 'catch-up' immunisation campaign in Victorian school-aged children

OBJECTIVE: To determine the proportion of Victorian primary school students protected against measles infection one year after the completion of the measles 'catch-up' immunisation campaign of 1998 and to compare this with the proportion of year 9 and 10 (aged 14-16 years) students. DESIGN & SETTING: Three-stage random cluster survey in Victorian primary and secondary schools. MAIN OUTCOME MEASURES: Proportion of primary and year 9 and 10 secondary school students protected against measles infection one year after the completion of the mass 'catch-up' immunisation campaign. Secondary outcomes: the proportion of both primary and year 9 and 10 secondary school students protected against both mumps and rubella. RESULTS: Of 1,037 Victorian primary and 2,357 years 9 and 10 secondary school students invited to participate in this study, 403 (39%) and 752 (32%) respectively provided a blood specimen for serological testing for antibodies against measles, mumps and rubella. 94.8% (95% confidence interval, 91.5, 96.9) of primary school and 93.1% (90.9, 94.8) of year 9 and 10 students were protected against measles infection. CONCLUSION: One year after the completion of the school-based measles 'catch-up' immunisation campaign the level of protection in Victorian primary school aged students is sufficient to prevent the continuing circulation of measles virus within this age group. The proportion of year 9 and 10 secondary school students protected against measles is also probably sufficient to prevent continuing circulation of wild type virus in Victoria, even though this age group was not specifically targeted by the 'catch-up' campaign.     

Seroprevalence of rubella among Jordanian women of childbearing age

This study was conducted to assess immunity (seroprevalence) to rubella among Jordanian women of childbearing age. A multistage cluster sampling was used to recruit 1125 women of childbearing age (15-49 year) from the 12 Governorates of Jordan. Anti-rubella antibody titers were measured using enzyme-linked immunoassays. The overall immunity rate to rubella among women in childbearing age was 90.9% (CI: 88.8-92.9). However, the immunity rate was significantly lower in younger women aged 15-19 years (83%) compared to the whole cohort (P相似文献   

Apparent effect of immune serum globulin prophylaxis in the military on viral hepatitis incidence in the civilian population in Israel.

Since 1969, extensive use of immune serum globulin in the Israel Defence Force for prophylaxis against hepatitis A virus (HAV) infection has produced a sharp decline in the incidence of the disease. However, it is not clear whether this policy has affected the susceptibility of Israeli adults to HAV infection. In this study, we examined the effect of the immunisation policy on the incidence of hepatitis A virus infection in the civilian population in the 15-44 year age group, which includes all those who have completed compulsory military service since vaccination was introduced. The incidence of viral hepatitis in the Jewish civilian population aged 15-44 increased by approximately 50% 3-4 years after the implementation of the immunisation policy. This rise was not seen in the non-Jewish population of the same age nor among Jews aged 45-64. These findings strongly suggest that the immunisation policy in the military prevents both clinical and sub-clinical disease, but has had the effect of producing more susceptible people at an older age in the civilian population.     

Sero-epidemiology of measles and mumps in Korea: impact of the catch-up campaign on measles immunity

A catch-up campaign targeting children aged 8-16 years using measles-rubella (MR) vaccine was conducted during 2001 in Korea. To evaluate the impact of the campaign and assess mumps immunity, human IgG antibodies were detected using ELISA for measles (5826 samples) and mumps (5890 samples) in a national sample of opportunistically collected sera from a population aged 0-34 years. The measles immunity increased by 5-10% following the catch-up campaign in the targeted age group. Infants lost maternal antibodies rapidly and about 90% of infants were susceptible to measles and mumps at 6-8 months of life. The sero-prevalence of mumps antibody increased slowly with age and stabilized at a lower level when compared with that of measles. Despite an immediate reduction in susceptibility among the targeted age group of the catch-up campaign, continuous efforts to increase immunization coverage are needed to interrupt indigenous measles transmission. Furthermore, our results suggest continuous mumps outbreaks could occur because of the accumulation of susceptible individuals.     

Persistence of antibody induced by rubella vaccine (Wistar RA 27/3 strain) after six years.

A total of 21 rubella seronegative children vaccinated subcutaneously with Wistar RA 27/3 strain live attenuated rubella vaccine in a family study of vaccine virus transmissibility were reviewed after 6 years. Haemagglutinating inhibiting (HAI) antibody titres of sera collected 46 days, 2 years and 6 years after vaccination were compared. Antibody titres in the vaccinated subjects were not significantly influenced by time, infection in susceptible siblings or revaccination.     

Inadvertent rubella vaccination of pregnant women: evaluation of possible transplacental infection with rubella vaccine

During mass campaign for measles/rubella vaccination on December 2003 in Iran, many pregnant women have vaccinated mistakenly. These women were grouped to susceptible and immune against rubella before vaccination by the status of IgG avidity response to rubella vaccine, then susceptible women were followed up to delivery time and their neonates were followed up to one year. In five neonates that were born from susceptible women, rubella-specific IgM has detected in cord blood sera, but they have not shown signs compatible to congenital rubella syndrome.     

The seroepidemiology and transmission dynamics of varicella in Australia

To enhance our understanding of the epidemiology and transmission dynamics of varicella in the pre-vaccine era we performed a serosurvey using opportunistically collected sera submitted to diagnostic laboratories across Australia during 1997-1999. A representative sample by state and sex of 2027 sera from persons aged 1-49 years was tested using an enzyme immunoassay method. The average age of infection and age-specific forces of infection (the probability that a susceptible individual acquires infection) were calculated using published methodologies. Seropositivity increased with age, with 83% of sera positive by ages 10-14 years. The highest force of infection was in the 5-9 years age group (0.195 per susceptible year) followed by the 0-4 years age group (0.139 per susceptible year) and the average age of infection was 8.15 years. These results provide valuable baseline information to measure the impact of vaccination and indicate that vaccination should be aimed at children less than 5 years of age, although further modelling using the serosurvey data is warranted.