Congenital Rubella Infections among the Pregnant Women at a Tertiary Care Hospital in Karachi, Pakistan

Introduction: Rubella virus is an important human pathogen that causes an acute and contagious disease known as rubella and also, causes congenital rubella syndrome more commonly occur during the first trimester of pregnancy. The incidence of CRS varies in different populations and the highest burden found in developing countries where rubella vaccination is not included in their national immunization programs. Therefore, the aim of this study was to determine the burden of CRS-related birth defects and its incidence in the pre-vaccine era in Karachi Pakistan.

Objective: The aim of the study to determine the rate of congenital rubella infection among the pregnant women at a Tertiary Care Hospital.

Methods: The retrospective descriptive cross sectional study was conducted in different departments of Dr Ruth PFAU Civil Hospital Karachi, including Eye OPD and Pediatric units from Jan 2016 till December 2019. The medical records of clinically suspected infants or confirmed cases were reviewed. The confirmed cases were positive for maternal IgM rubella antibodies and tested by ELISA (Enzyme Linked immunosorbant assay) where as the rubella IgM antibodies in suspected infants were lost to follow. Inclusion criteria were infants admitted less than or equal to 1 year of age with history of either congenital cataract, congenital glaucoma, pigmented retinopathy, congenital heart defects like (patent ductus arteriosus, periphery pulmonary stenosis, ventricular septal defects), hearing impairment, deafness or microcephaly were included in the study.

Results: Out of total 142 infants that were admitted in the hospital during 4 years period from 2016 to 2019 only 7 (4.93%) infants were diagnosed as confirmed cases of congenital rubella infection where as 14 (9.86%) infants were found to be clinically suspected. The ocular manifestation were more common among 6 infants which presented with cataract (85.7%) and 2 infants presented with pigmented retinopathy (28.6%). Besides this other manifestations like developmental delay were seen in only 2 patients DD (28.6%) and 3 infants presented with congenital heart diseases CHD (42.9%). The combinations of clinical features of congenital heart defect with cataract and developmental delay were seen in only 1 infant whereas cataract with pigmented retinopathy and developmental delay was seen in 1 infant and 2 infants presented with combination of congenital heart defects and cataracts.

Conclusion: Our study reported the rate of congenital rubella infection was 4.93% in a four years study period. Therefore, with a rising trend in congenital rubella infections in the last past years there is a need to built strong surveillance system and to introduce a childhood immunization in the national immunization program to eliminate the Rubella infection.