Rubella, a viral infection caused by a RNA virus
of family Togaviridae is a transient self-limiting exanthematous febrile
illness of childhood and adolescence. Transplacental infection of fetus
during the first trimester of pregnancy results in a constellation of
congenital anomalies called as Congenital Rubella Syndrome (CRS). The
affected fetus may be born with mental, visual, auditory, and systemic
handicap with resultant lifelong morbidity and loss of function [1].
Though the exact burden of CRS in India is not known, it is one of the
most important causes of preventable blindness and deafness in the
country [2]. CRS is entirely preventable by ensuring vaccination of
pre-pubertal girls with rubella containing vaccine (RCV). Unfortunately,
till date India did not have a national policy on rubella vaccination,
and rubella virus continued to circulate unabated in the country.
In this issue of Indian Pediatrics, Madhanraj,
et al. [3] report an outbreak of rubella in the Union
Territory of Chandigarh. This study is important in face of a virtually
non-existent surveillance system for rubella in the country. According
to WHO, till 2012 Africa and South East Asian Regions had yet to
establish rubella control, prevention or elimination goals [4]. India
has a significant pool of susceptible adolescents, pregnant and
non-pregnant females [2,5-7]; this single outbreak portrays just the tip
of the iceberg as majority of cases go unreported owing to absence of a
surveillance system. Another reported outbreak is from Himachal Pradesh
in 2006-07, in which 11-20 yr age group had the highest attack rate [8].
Outbreak of rubella is defined as two or more confirmed cases which are
temporally related (with onset of rash in cases occurring between 12 and
46 hours after exposure), and epidemiologically or virologically linked
or both [9]. A total of 3219 laboratory confirmed and
epidemiologically-linked rubella cases were reported from the countries
of SEA Region in 2013. There were a total of 189 outbreaks of
exanthematous illness and a total of 2717 laboratory and epidemiology
linked confirmed cases of rubella were reported from these outbreaks
[10].
Rubella virus has a single genotype with no
extra-human host/carrier; a safe and highly effective, live attenuated
RA 27/3 strain vaccine is available which induces seroconversion rates
of 95% or higher after administration of a single dose. So, rubella is
an excellent candidate for elimination. Countries where routine
universal immunization for rubella is in place, the burden of CRS has
strikingly reduced to near zero from the high numbers in pre-vaccination
era [11].
To reduce the burden of CRS, two strategies can be
used: (a) vaccinating only adolescent girls and women of child
bearing age would result in the reduction of CRS that is proportional to
the level of coverage; (b) Introducing RCV into routine childhood
immunization schedule combined with the vaccination of older susceptible
age groups. More extensive the implementation of vaccination strategies,
the shorter will be the time frame for eliminating rubella and CRS.
Thus, when vaccination coverage in children is high (>85%), rubella and
CRS elimination would occur in 20-30 years. Elimination would occur in
10-20 years when catch-up immunization is provided to adolescents along
with routine immunization of children, and within 10 years if
vaccination is provided to young children, adolescents and adults [12].
Outbreaks occur when the population immunity is low
and a large proportion is susceptible. Outbreaks should be investigated
so that their extent and origin can be determined. This information will
lead to a better understanding of their epidemiology and help in
defining and tailoring interventions in order to decrease the size of
susceptible populations and control the outbreaks. Building and
maintaining an effective surveillance system is vital to provide
essential information to set priorities, plan activities, allocate
resources, implement prevention programs, respond to outbreaks and
evaluate control measures and trace importations. Laboratory
confirmation represents an increasingly critical component of effective
surveillance, because it helps to exclude other diseases with fever and
rash. For this, the laboratory networks set-up by WHO should be
effectively used. Any country introducing rubella vaccine in national
immunization schedule should have a surveillance system for CRS and
rubella as per the standards set by WHO [13]. At the 66th SEARC (South
East Asian Regional Committee) meeting, the Member States unanimously
adopted the proposed resolution to eliminate measles and control
rubella/CRS by 2020 in this Region [10].
In India, rubella containing vaccine (RCV) is
recommended by IAP as MMR vaccine, to be administered in two doses at
the age of 9 month and 15 month; and as catch up vaccine till 18 years
of age [14]. Taking cue from this move of IAP, the Govt. of India is
planning to incorporate RCV in the National Immunization Schedule and
has recently announced this [15]. But the strategic plans for the
introduction of vaccine into the immunization schedule are yet to be
revealed. The government is now positive on introduction of new antigens
in the National Immunization schedule. But still, the time to rejoice is
far unless the potential workforce of the country stands fully protected
from the menace and crippling consequences of congenital rubella
syndrome. Reporting of these small outbreaks [3] serves as a wake-up
call to keep the agenda alive.
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Consequences of confirmed rubella at successive stages of pregnancy.
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2. Dewan P, Gupta P. Burden of congenital rubella
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2012;49:377-99.
3. Madhanraj K, Singh N, Gupta M, Singh MP, Ratho RK.
An outbreak of rubella in Chandigarh, India. Indian
Pediatr.2014;51:897-9.
4. World Health Organization: Measles and Rubella
Surveillance and Outbreak Investigation Guidelines. Regional Office for
South-East Asia: World Health Organization; 2009. Available from:
http://www.who.int/immunization/newsroom/Measles_Rubella_Strategic
Plan_2012_2020.pdf. Accessed October 3, 2014.
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Namjoshi G, Parekh S. Serosurveillance to assess immunity to rubella and
assessment of immunogenicity and safety of a single dose of rubella
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9. Surveillance Guidelines for Measles, Rubella and
Congenital Rubella Syndrome in the WHO European Region. Available from:
http://www.ncbi.nlm.nih.gov/books/NBK143259/. Accessed October 8,
2014.
10. Status Report on Progress Towards Measles and
Rubella Elimination. SAGE Working Group on Measles and Rubella (17
October 2013). Available from:
http://www.who.int/immunization/sage/meetings/2013/november/Status_Report_Measles_Rubella21Oct2013
_FINAL.pdf. Accessed October 8, 2014.
11. Centers for Disease Control and Prevention (CDC).
Progress toward elimination of rubella and congenital rubella syndrome —
the Americas, 2003-2008, MMWR Morb Mortal Wkly Rep. 2008;57:1176-9.
12. WHO. Rubella vaccines: WHO position paper –
recommendations. Vaccine. 2011;29:8767-8.
13. WHO-Recommended Surveillance Standard of Rubella
and Congenital Rubella Syndrome. Available from:
http://www.who.int/immunization/monitoring_surveillance/burden/vpd/surveillance_type/active/rubella_standards/en/.
Accessed October 8, 2014.
14. Indian Academy of Pediatrics (IAP). Recommended
Immunization Schedule for Children Aged 0 through 18 years – India, 2014
and Updates on Immunization. Indian Pediatr. 2014; 51:785-800.
15. Government of India. The Three New Vaccines
Including Indigenously Developed Rotavirus Vaccine to be Provided to all
Indian Children. [Press release] 2014 July 03. Available from:
http://pib.nic.in/newsite/PrintRelease.aspx?relid=106055. Accessed
October 3, 2014.