Rubella outbreak in the Netherlands, Canada emphasizes importance of vaccination

Individuals belonging to Orthodox Protestant religious denominations who were unvaccinated accounted for 97% of people involved in a rubella outbreak that started in the Netherlands and spread to Canada.

“Our results demonstrate the risks associated with heterogeneity in rubella vaccine coverage,” researchers from both countries wrote.

Surveillance data revealed that 696 rubella cases occurred in both countries between September 2004 and July 2005, with 387 cases in the Netherlands and 309 cases in Canada. More pregnant women experienced rubella infections in the Netherlands (n=32) compared with women in Canada (n=10).

No abnormalities at birth or deaths were reported among the Canadian cases and no follow-up information was available. Outcomes of rubella infection during pregnancy in women from the Netherlands included the following:

Two intrauterine deaths at 16 and 23 weeks gestation following initial infection at weeks four and five.
Eleven infants had defects associated with congenital rubella (85% risk rate; 95% CI, 55%-98%), with all experiencing deafness and no reported cases of cataracts or vision loss.
Disability and/or delayed development in six of the 11 infants with defects reported at follow-up.
Interventions included cardiac operations in three children and cochlear implants in two children.
Lab-confirmed maternal rubellavirus infection was evident in the first trimester for the 11 children with defects.

All 32 of the women from the Netherlands who experienced rubella during pregnancy were Orthodox Protestants, with 30 of them refusing vaccination based on religious beliefs and two for nonreligious beliefs.

Despite small numbers, the researchers stated that the prevalence of deafness was higher than the 70% to 90% reported elsewhere and may suggest an even higher burden than previously thought.

The researchers also warned that incidence of the disease was likely higher than what is documented due to the frequency of asymptomatic rubella infection and estimated that infections during the second and third trimesters may have been underreported anywhere from 20% in the second trimester to 66% in the third trimester, assuming rubella occurred equally distributed across trimesters.

“The WHO for the European Region and the Pan American Health Organization have set a goal to eliminate rubella by 2010. The existence of population subgroups with low vaccine coverage is likely to interfere with achieving this goal,” the researchers wrote.

Hahné S. Pediatr Infect Dis J. 2009;28:795-800.

Although congenital rubella has been eliminated in the US, this report from the Netherlands and Canada emphasizes the need for continued vigilance and the risk that unvaccinated pockets of individuals can pose to both themselves and those around them. Today many people think that rubella has been eradicated. As this report illustrates the virus is still out there waiting for an opportunity to inflict its terrible toll. We all need to be sure that our patients understand this and are vaccinated.

– Steven B. Black, MD

Infectious Diseases in Children Editorial Board