Congenital rubella in the Western Cape Province of South Africa : a vaccine preventable condition

Van der Westhuizen, Tarryn (2015-12)

Thesis (MMed)--Stellenbosch University, 2015

Thesis

ENGLISH ABSTRACT : Background: Congenital rubella syndrome (CRS) is characterized by multiple defects causing physical, intellectual and developmental retardation, auditory and visual problems, placing a huge burden on health care services in countries where rubella immunization is not routine. The incidence and extent of CRS in South Africa, where rubella vaccine is not included in the expanded program on immunization (EPI), is unknown. Objective: To determine the minimum prevalence and morbidity of CRS in the public sector of the Western Cape province of South Africa, as well as to describe the clinical presentation and features of all confirmed and probable CRS cases at Tygerberg Children’s Hospital. Methods: A retrospective descriptive study and case series using clinical records. Rubella serology data was retrieved from National Health Laboratory Systems at Tygerberg Academic Hospital between 01 January 2006 and 31 December 2011 and Groote Schuur Hospital between 01 January 2008 and 31 December 2011. For confirmed CRS, detection of rubella by PCR or specific IgM antibodies below 3 months of age was diagnostic. For probable CRS, a PCR or IgM positive at 3 months - 1 year of age with more than two of the following conditions: cataracts, congenital glaucoma, congenital heart disease, hearing impairment or pigmentary retinopathy. Alternatively, one of one of these conditions plus any of the following: purpura, splenomegaly, microcephaly, mental retardation, meningoencephalitis, radiolucent bone disease or neonatal jaundice within 24 hours of birth. Confirmed cases between 01 January 2008 and 31 December 2011 from the two laboratories were used to calculate a minimum prevalence for the Western Cape. Medical records of infants with confirmed and probable CRS under a year of age from Tygerberg between 01 January 2006 and 31 December 2011 were reviewed for inclusion in the case series. Results: Thirty confirmed cases were identified from 01 January 2008 and 31 December 2011 in the two laboratories for a minimum prevalence of 0.073 cases per 1000 population for the Western Cape (95% confidence interval [CI] 0 – 0.1). Twenty confirmed and probable cases were obtained from Tygerberg Children’s Hospital from 01 January 2006 to 31 December 2011. The median gestational age at birth was 37 weeks (interquartile range [IQR] 32 – 38). Fourteen (70%) had low birth weight (LBW), nine (45%) were premature and seven (35%) were small for gestational age (SGA). Six women (30%) gave a history of rubella in pregnancy, five in the first trimester and one in the second trimester. The most common presenting signs were: petechiae in eight (40%), and cataracts in seven (35%) infants. Other presenting signs in the infants included hepatosplenomegaly. Nine (45%) had ophthalmologic involvement, all with cataracts; of these three had pigmentary retinopathy and one had congenital glaucoma. Four of the twelve tested (33%) had hearing impairment and ten (50%) had microcephaly. Cardiac anomalies were noted in eleven of the infants. One infant presented with bilateral knee arthritis, not previously described in CRS. Eleven of fourteen LBW infants (79%) and three of six (50%) with birth weights above 2500g had at least one major congenital anomaly (p = 0.3). All three deaths occurred in SGA term infants. Eight of the twenty infants (40%) required more than one hospital admission, with seven (35%) also requiring intensive care. Hospital stay in LBW infants was also significantly longer than those with birth weights above 2500g (median 27 vs 6 days) (p = 0.01). Seven patients (35%) underwent a surgical procedure with three requiring more than one procedure. PDA ligation and cataract removal were most common. Conclusions: CRS has extensive morbidity and high mortality, requiring a multidisciplinary approach. Rubella immunization should be urgently incorporated into the extended program of immunization in South Africa to prevent this devastating infection.

AFRIKAANSE OPSOMMING : Geen Afrikaanse opsomming geskikbaar nie

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