Infectious aetiology of congenital cataract based on TORCHES screening in a tertiary eye hospital in Chennai, Tamil Nadu, India.

BACKGROUND & OBJECTIVES We undertook this study to determine the infectious aetiology of congenital cataract based on the presence of IgM antibodies to TORCHES [(Toxoplasma gondii (T. gondii), Rubella virus (RV), Cytomegalovirus (CMV), Herpes simplex virus (HSV) and Syphilis (caused by Treponema pallidum)] in the serum samples of congenital cataract patients. METHODS Serum samples collected from 593 infants and children (10 days to 12 months old) with clinically diagnosed congenital cataract at Sankara Nethralaya, a referral eye hospital in Chennai, were tested for the presence of specific IgG and IgM antibodies to T. gondii, RV, CMV, HSV by ELISA and specific treponemal antibodies by T. pallidum haemagglutination test (TPHA). RESULTS IgM antibodies were detected against T. gondii in 1.7 per cent, RV in 8.4 per cent, CMV in 17.8 per cent and HSV in 5.1 per cent, and that of specific IgG in 8.9, 25.0, 66.1 and 2.6 per cent respectively. Presence of IgM antibodies to T. Gondii in the study group was significantly lower when compared to IgM antibodies to RV, CMV and HSV. All serum samples were negative for the presence of anti treponemal antibodies by TPHA. Overall, IgM antibodies to one or more of the four infectious agents were detected in 20.2 per cent of the study population, and among these co-infections to more than one infectious agents were detected in 12.5 per cent. INTERPRETATION & CONCLUSION The results of the present retrospective analysis showed association of RV, CMV, HSV and T. gondii with congenital cataract based on the presence of specific IgM antibodies.