Detection of Congenital Toxoplasmosis and Cytomegalovirus Infections Using Paired Sample Serodiagnosis from Suspected Cases at a Tertiary Teaching Hospital in Malaysia.

Background: Congenital toxoplasmosis and congenital cytomegalovirus (cCMV) infections are noteworthy in Malaysia and can cause serious health problems in neonates. The prompt and effective detection and treatment related to both illnesses may mitigate the possibility of adverse consequences from both infections. Methods: A total of 219 neonates with suspected clinical indications of congenital toxoplasmosis and/or cCMV infections from January 2022 to December 2022 were enrolled. The first samples for IgM and IgG antibodies were screened by electrochemiluminescence immunoassay. For positive results indicative of congenital toxoplasmosis and cCMV infections, second serum samples were requested and tested within a period of 2-4 weeks after testing the first sample. Results: From the 219 first serum samples, the overall seroprevalence of congenital toxoplasmosis antibodies in suspected cases was 53%; meanwhile, the overall seroprevalence of cCMV in the suspected cases was 98.6%. The results of the paired serum sample collected for investigating congenital toxoplasmosis cases revealed that 47% of the cases presented no serological evidence of exposure while the remaining 53% of cases might have acquired passive immunity from the mother. For cCMV, the number of cases with no serological evidence of exposure was 1.4%, whereas acute infection was 1.8% and possible passive immunity from the mother represented 96.8%. Conclusion: This study found a high seroprevalence of congenital toxoplasmosis and cCMV infections, probably because they are suspected cases. This study also indicates that using paired sample analysis in the categorisation of cases can aid in accurate diagnosis and more effective treatment.