Systematic Review of the Manifestations of Congenital Rubella Syndrome in Infants and Characterization of Disability-Adjusted Life Years (DALYs)

Congenital rubella syndrome (CRS) continues to cause disability among unvaccinated populations in countries with no or insufficient rubella vaccine coverage to prevent transmission. We systematically reviewed the literature on birth outcomes associated with CRS to estimate the duration, severity, and frequency of combinations of morbidities. We searched PubMed, the Science Citation Index, and references from relevant articles for studies in English with primary data on the frequency of CRS manifestations for ≥20 cases and identified 65 studies representing 66 study populations that met our inclusion criteria. We abstracted available data on CRS cases with one or more hearing, heart, and/or eye defect following maternal rubella infection during the period of 0-20 weeks since the last menstrual period. We assessed the quality and weight of the available evidence using a modified Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Most of the evidence originates from studies in developed countries of cohorts of infants identified with CRS in the 1960s and 1970s, prior to the development of standardized definitions for CRS and widespread use of vaccine. We developed estimates of undiscounted disability-adjusted life years (DALYs) lost per CRS case for countries of different income levels. The estimates ranged from approximately 19 to 39 for high-income countries assuming optimal treatment and from approximately 29 to 39 DALYs lost per CRS case in low- and lower- middle-income countries assuming minimal treatment, with the lower bound based on 2010 general global burden of disease disability weights and the upper bound based on 1990 age-specific and treatment-specific global burden of disease disability weights. Policymakers and analysts should appreciate the significant burden of disability caused by CRS as they evaluate opportunities to manage rubella.

Causes of birth defects: lessons from history

Environmental causes of birth defects have increasingly been recognized since the mid-20th century. The teratogenic effects of maternal infections such as rubella and therapeutic drugs such as thalidomide were first reported by alert clinicians. Among clinicians and researchers who have contributed significantly to our knowledge of these environmental causes, Norman Gregg was a Sydney ophthalmologist whose seminal study in 1941 identified maternal rubella as a cause of birth defects. The teratogenic effects of thalidomide were first noted in 1961 by William McBride, a Sydney obstetrician, and independently confirmed by Widukind Lenz, a German pediatrician. Marsh Edwards, an Australian veterinary scientist, showed experimentally that maternal hyperthermia caused birth defects in various animal species. While it is likely that alert individual clinicians or researchers will continue to signal the first clues about new environmental causes of birth defects, especially therapeutic drugs, it is now usually teams of laboratory researchers and epidemiologists who are more likely to provide definitive evidence of these new teratogens.

Causes of deafness in schools for the deaf in Madras

Information has been collected by questionnaire from parents and teachers of 928 deaf school children in South India. 374 of these children were examined during a 21-day visit to Madras. These findings are part of the outcome of the visit by a working party organised and financed by the Commonwealth Society for the Deaf. The Society has organised surveys of deafness in West Africa and Gambia. In this survey the causes of severe deafness in Madras have been identified. Streptomycin injections were responsible for 3.6% of cases and meningitis for 5.3%. Examination found 29% of children with ophthalmic signs of intrauterine rubella. These could be prevented. Only a third of Indian mothers of children with eye signs are aware of having had rubella infection during pregnancy.

Direct and indirect effects on the lateral geniculate nucleus neurons of prenatal exposure to methylazoxymethanol acetate

In this study the morphology of the lateral geniculate nucleus and occipital cortex in rats with methylazoxymethanol acetate (MAM Ac)-induced micrencephaly was examined. The aim was to examine the relative contributions of (a) the direct cytotoxic action of the drug on precursors of dorsal lateral geniculate nucleus (dLGN) neurons in the fetal brain and, (b) the postnatal degeneration of the dLGN following prenatal destruction of target neurons in the occipital cortex, to the final extent of damage to the dLGN. Exposure to MAM Ac on E13 produced severe necrosis in the fetal thalamus and caused a 77% deficit in neuronal numbers in the mature dLGN. Exposure to MAM Ac on E15 did not cause necrosis in the fetal thalamus but when animals exposed at this time were examined at 5 weeks postnatal age there was an 87% deficit in neuronal numbers in the dLGN. The hypothesis that this deficit was the result of postnatal death of the dLGN neurons following the destruction by MAM Ac of their normal target population in laminae iii and iv of the occipital cortex was supported by the observation of severe postnatal degeneration in the dLGN of animals exposed to MAM Ac on E15. The significance of these direct and indirect effects of the cytotoxic teratogen, MAM Ac, for understanding the mechanisms by which brain abnormalities in human micrencephaly are produced is discussed.

Congenital cataract following German measles in the mother. Abstracts from the publications of the late Sir Norman McAlister Gregg

This paper contains abstracts from publications of the late Sir Norman McAlister Gregg, published in 1941 and 1944, in which he demonstrated the association between rubella in pregnancy and defects in the baby. Besides cataract and retinopathy with which ophthalmologists are familiar, there occur deafness, deafmutism, cardiac defects, mental retardation, pulmonary and renal abnormalities and diabetes.

Viral disease of the labyrinth. I. Review of the literature and discussion of the role of cytomegalovirus in congenital deafness

Review of the literature concerning the histopathology of viral induced deafness indicates two general patterns of viral infection of the inner ear: 1) An endolymphatic labyrinthitis secondary to viremia via the stria vascularis is described in rubella, mumps, rubeola, and cytomegalovirus. 2) A perilymphatic infection secondary to meningeal, perineural, or endoneural spread is seen in varicella-zoster. Pathologic changes of degeneration and atrophy are due to inflammation and seem to be constant no matter if the infection is prenatal or postnatal. Two published reports of prenatal and perinatal cytomegalovirus infection show endolymphatic labyrinthitis similar to that casued by the other viruses. Subsequent clinical studies indicate the presence of hearing loss in mildly symptomatic and/or asymptomatic children with cytomegalovirus infections. Cytomegalovirus infection may prove to be the most significant cause of congenital and/or viral induced deafness in the future as the number of children infected with rubella, rubeola, and mumps decreases due to the use of appropriate vaccines.

VIRAL AND DRUG HAZARDS IN PREGNANCY

Should pregnant mothers be immunized against smallpox? Poliomyelitis?

What is the incidence of fetal loss or major congenital anomalies if a pregnant woman contracts rubella? Poliomyelitis? Rubeola? Mumps? Or varicella? Is there a relationship to the time of the infection during pregnancy and congenital anomalies?

Is there a higher fetal mortality associated with the use of the sulfonylurea drugs for pregnant diabetic mothers?

Are progesteroids harmless to the fetus when given to a pregnant woman? Anti-thyroid drugs? Thiazides?