Eurosurveillance banner




Announcements
Read our articles on the ongoing Ebola outbreak in West Africa

Follow Eurosurveillance on Twitter: @Eurosurveillanc


In this issue


Home Eurosurveillance Weekly Release  2005: Volume 10/ Issue 20 Article 1 Printer friendly version
Back to Table of Contents
Next

Eurosurveillance, Volume 10, Issue 20, 19 May 2005
Articles

Citation style for this article: Hahné S, Macey J, Tipples G, Varughese P, King A, van Binnendijk R, Ruijs H, van Steenbergen J, Timen A, van Loon AM, de Melker H. Rubella outbreak in an unvaccinated religious community in the Netherlands spreads to Canada. Euro Surveill. 2005;10(20):pii=2704. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=2704

Rubella outbreak in an unvaccinated religious community in the Netherlands spreads to Canada

Susan Hahné (susan.hahne@rivm.nl)1, Jeannette Macey2, Graham Tipples2, Paul Varughese2, Arlene King2, Rob van Binnendijk1, Helma Ruijs1,3, Jim van Steenbergen1, Aura Timen1, Anton M van Loon4 and Hester de Melker1

1Centre for Infectious Disease Control, Rijksinstituut voor Volksgezondheid en Milieu (RIVM), the Netherlands
2Public Health Agency of Canada (PHAC), Canada
3Municipal Health Authority (GGD) Rivierenland, the Netherlands
4Department of Virology, University Medical Centre (UMC) Utrecht, the Netherlands

There are indications that the rubella outbreak that started in September 2004 among members of a religious community in the Netherlands, first reported in Eurosurveillance on 3 March 2005 [1], has spread to Canada. This outbreak is specifically affecting some unvaccinated groups within the Gereformeerde Gemeente in Nederland (Netherlands Reformed Community in the Netherlands, a Christian community).

Up to 17 May, 214 laboratory confirmed cases of rubella have been reported in southwest Ontario. Five of these cases have been in pregnant women. The Canadian Christian community where the cases occurred has historical and social links with the affected groups within the Gereformeerde Gemeente in Nederland, and individuals frequently travel between the two communities. A definitive source for the Canadian patient with the earliest date of onset reported (mid-February 2005) has not yet been identified. An isolate has been obtained from the outbreak in Canada and is currently being genotyped. Attempts are being made to isolate rubella virus in the Netherlands so as to genetically link the respective outbreaks. The World Health Organization has recently published a standardised rubella virus genotyping protocol [2].

In the Netherlands, up to 17 May 2005, 309 laboratory confirmed cases have been reported (from 1 September 2004); 23 of these are known to be in pregnant women (nine in their first trimester). The geographical spread of the outbreak in the Netherlands is documented on the Rijksinstituut voor Volksgezondheid en Milieu website (http://www.rivm.nl/vtv/object_class/atl_infparasit.html). The epidemiological curve (Figure) shows three separate peaks, each larger than the last. It is uncertain whether these peaks reflect the true incidence or are the result of a registration artefact.

Figure. Reports of laboratory confirmed cases of rubella by week of onset, the Netherlands (cases reported between 1 September 2004 - 17 May 2005). Source: Osiris.

In both the Netherlands and Canada, the outbreak occurred in a community with low measles, mumps, and rubella (MMR) vaccination coverage and strong social adherence. The proportion of cases in a vaccinated individual is low (0.3% and 0.6%, respectively), indicating that the effectiveness of the rubella component of the MMR vaccine is very high.

Rubella infection acquired during early pregnancy can lead to miscarriage or severe birth defects known as congenital rubella syndrome (CRS). This syndrome occurs in up to 90% of infants born to mothers who are infected in the first trimester [3]. It is important to differentiate primary rubella infection from re-infection because the risk of CRS for re-infection during the first trimester of pregnancy is less than 5 to 10% [2]. Rubella IgG avidity serology has been shown to be a very useful laboratory test for differentiating primary rubella infections from re-infections/past infections in pregnant women where critical patient management/counselling decisions are required [4]. Rubella IgG avidity serology is being used for the investigation of rubella exposure or suspected rubella in pregnant women in the Canadian outbreak.

Rubella and CRS are preventable by immunisation, and both the Netherlands and Canada have a routine two-dose MMR vaccination schedule. During the outbreak, health authorities in Canada and the Netherlands have offered MMR free of charge to unvaccinated individuals (in the Netherlands this has only been offered to those under the age of 18). Public health laws in Ontario allow authorities to exclude unvaccinated children from attending school when there is an outbreak of a vaccine preventable disease. Local public health officials in Ontario have issued indefinite exclusion orders for students who are not immunised or cannot offer proof of immunity. Such a law does not exist in the Netherlands. In addition, the provincial Ministry of Health for Ontario (Ontario Ministry of Health and Long Term Care) has given advice on isolation of cases, quarantining of contacts and travel restrictions. This also differs from the Netherlands, where the emphasis of public health advice is on advising pregnant women to avoid contact with rubella patients.

The effectiveness of both Canadian and Dutch public health advice in preventing spread of rubella and in preventing pregnant women from becoming infected is probably limited. This is firstly because members of the affected communities often decline vaccination, since it contradicts their religious beliefs. Comprehensive information on the uptake of MMR during this outbreak is not yet available in Canada or the Netherlands. Secondly, rubella is most infectious prior to the onset of rash (usual range one week prior to four days post rash onset). Finally, only a minority of cases are diagnosed since rubella virus infection can be asymptomatic in up to 50% of cases and, if symptomatic, usually has a mild course.

Further spread of the outbreak and risk of CRS depends on herd immunity (resulting from vaccination and natural infection) and level of contact with the affected community. In the Netherlands, historical seroprevalence and vaccine uptake data suggest that the level of protection in the general population is high [5]. Even in municipalities where a high proportion of the population declines vaccination, seroprevalence studies suggest that >97% of women of childbearing age are immune (probably through circulation of rubella virus in the past) [5]. In addition to the groups within the Gereformeerde Gemeente in Nederland, Dutch groups with a relatively low seroprevalence may include some groups of immigrants and those supporting the anti-vaccination movement (including followers of homeopathy and anthroposophical teachings).

In Canada, populations with relatively low seroprevalence may include immigrants as well as other groups who resist immunisation for religious and philosophical reasons.
Although Reformed Christian communities exist outside the Netherlands and Canada, to our knowledge vaccine preventable diseases have only spread internationally from the Netherlands Gereformeerde Gemeente in Nederland to Canada [6,7,8]. Canada’s temperate climate, which has synchronic seasons to those of the Netherlands may be one explanation for this. However, onward spread from Canada has been documented in the past: the poliomyelitis outbreak in the Netherlands in 1978 spread to Canada and subsequently into the United States [9].

Public health efforts in the Netherlands and Canada are now focusing on raising awareness amongst the affected community and health professionals, documenting (molecular) epidemiological links, and improving surveillance of CRS.

References:
  1. Hahné S, Ward M, Abbink F, Binnendijk R van, Ruijs H, Steenbergen J van, Timen A and Melker H de. Large ongoing rubella outbreak in religious community in the Netherlands since September 2004. Eurosurveillance Weekly 2005: 10(3): 03/03/2005. (http://www.eurosurveillance.org/ew/2005/050303.asp#3)
  2. WHO. Standardization of the nomenclature for genetic characteristics of wild-type rubella viruses. Weekly Epidemiological Record 2005;14:126-132.
  3. Banatvala JE, Brown DW. Rubella. Lancet 2004;363(9415):1127-37.
  4. Best JM, O’Shea S, Tipples G, Davies N, Al-Khusaiby S, Krause A, Hesketh L, Jin L, Enders G. Interpretation of rubella serology in pregnancy - pitfalls and problems. BMJ 2002;325:147-8.
  5. Haas R de, Hof S van den, Berbers GA, Melker HE de, Conyn-van Spaendonck MA. Prevalence of antibodies against rubella virus in The Netherlands 9 years after changing from selective to mass vaccination. Epidemiol Infect. 1999;123(2):263-70.
  6. Drebot MA, Mulders MN, Campbell JJ, Kew OM, Fonseca K, Strong D et al. Molecular detection of an importation of type 3 wild poliovirus into Canada from The Netherlands in 1993. Appl Environ Microbiol 1997;63(2):519-23.
  7. Hof S van den, Meffre CM, Conyn-van Spaendonck MA, Woonink F, Melker HE de, Binnendijk RS van. Measles outbreak in a community with very low vaccine coverage, the Netherlands. Emerg Infect Dis 2001;7 (3 Suppl):593-7.
  8. Furesz J, Armstrong RE, Contreras G. Viral and epidemiological links between poliomyelitis outbreaks in unprotected communities in Canada and the Netherlands. Lancet 1978 Dec 9;2(8102):1248.
  9. Hatch MH, Marchetti GE, Nottay BK, Kew OM, Heyward JT, Obijeski JF. Strain characterization studies of poliovirus type I isolates from poliomyelitis cases in the United States in 1979. Dev Biol Stand. 1981;47:307-15.

back to top



Back to Table of Contents
Next

Disclaimer:The opinions expressed by authors contributing to Eurosurveillance do not necessarily reflect the opinions of the European Centre for Disease Prevention and Control (ECDC) or the editorial team or the institutions with which the authors are affiliated. Neither ECDC nor any person acting on behalf of ECDC is responsible for the use that might be made of the information in this journal.
The information provided on the Eurosurveillance site is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her physician. Our website does not host any form of commercial advertisement.

Eurosurveillance [ISSN] - ©2007-2013. All rights reserved
 

This website is certified by Health On the Net Foundation. Click to verify. This site complies with the HONcode standard for trustworthy health information:
verify here.