RECENT CANADIAN DEAFBLIND AND RUBELLA ASSOCIATION RESEARCH ON LATE EMERGING
MANIFESTATIONS OF RUBELLA
Dr Mike Steer
Rubella was once considered the least troublesome of childhood's communicable diseases. Little attention was paid to it until the widespread Australian epidemic in 1941 when Dr Norman Gregg, an ophthalmologist, observed its links to congenital cataract. His research also reported a high incidence of low birthweight, heart defect, deafness and mortality in infants whose mothers had rubella. Very little research followed until the world-wide "pandemic" between 1962 and 1965 which is believed to have affected some 12.5 million individuals. American statistics reveal that during this period approximately 30,000 babies were born there with various congenital problems related to maternal rubella.
The National Office of the Canadian Deafblind and Rubella Association (CDBRA) has recently completed a survey of late emerging medical conditions believed to be associated with the congenital rubella syndrome (CRS). The study was funded through a $30,000 grant from the Federal Government's Disabled Person's Participation Funding Program with survey results announced at the 6th Annual Canadian Conference on Deafblindness in early August this year.
It has now become widely realised that people with disabilities resulting from congenital maternal rubella as they grow older, experience a relatively higher incidence of late emerging medical conditions and problems than is usual in the population. A study conducted at New York's Helen Keller Centre between 1989 and 1991 produced some alarming statistics on these late emerging conditions which have effected many individuals in the deafblind population there, whose disabilities resulted from congenital rubella. For example, 30% of the Americans surveyed had developed glaucoma (compared to the US general population rate of 0.5%). Some 52% of those surveyed experienced cardiac problems (generally observed at birth); 5.7% had developed diabetes (20 times the general population figure) and 6.8% had thyroid problems. The research also produced data showing a growing incidence of such degenerative conditions as progressive Rubella Parencephalitis, epilepsy and loss of physical control.
The 1997-8 CDBRA study surveyed a sample of 75 individuals with congenital rubella, 41% of whom were male. Of those surveyed, 69.3% indicated that their disability was deafblindness. Ten of the respondents' mothers reported that they had been immunised against rubella, suggesting that the immunisation processes of the late 1960's and 1970's had not been a guarantee against infection. A variey of congenital birth defects were reported. Most commonly hearing loss (94.3%), vision loss (83.7%) and heart defects (64.9%). The incidence of microcephaly (small head) was 29.6%. Microphthalmia (small eyes), another manifestation of CRS was reported by 32.0%. This latter condition is also believed to influence rubella-related glaucoma. Among the respondents, 88.7% reported both a vision and hearing loss, with 58.1% reporting vision and hearing loss as well as heart defects.
Of the neurological conditions reported, 20.3% acknowledged the presence
of Alzheimer-like conditions, including aggression, sleeping disorders,
memory loss, eating disorders and loss of the sense of hot and cold. Within
the group, 30.7% reported experiencing seizures, with the average age of
onset between 13 and 30 years. Data on mental health and behaviour tended
to support the late emergence proposition, with 51.2% reporting profound
developmental delay, 86.7% receiving mental health-related medication and
54.7% reporting persistent unusual behaviour of varying sorts. While most
respondents reported walking by the age of six, 21.3% reported a deterioration
in mobility or walking, with most reporting onset from their 20's on.
Some 94.7% of respondents reported having been hospitalised with multiple visits being the norm.
The CDBRA study has highly useful outcomes. It adds further data to information gradually being accumulated from world-wide sources on the CRS phenomenon. Its results appear to support the continued need for widespread immunisation to eradicate this virus, through catalogueing it's appalling consequences. Further, the survey provides health professionals, whether in Canada, Britain, the USA or here in Australia, with indicators about the importance of avoiding future misdiagnosis of the symptoms related to CRS. There appears an obvious need to establish internationally linked data bases to collect information on CRS affected people over time, so that our understanding of its impacts can be improved.
More information on this excellent study is available from: