Diagnostic Challenges in Detecting Rubella Viral RNA in Cases of Congenital Rubella Syndrome Using RT-PCR in the Era of Elimination.

BACKGROUND: Confirming the detection of rubella virus (RUBV) genotypes is crucial for tracking the transmission and evolution of the virus, which is essential for eliminating rubella. Reverse transcription-polymerase chain reaction (RT-PCR) plays a crucial role in identifying the viral genotype, but it comes with various challenges from sample collection to data interpretation. The present study aimed to explore the complexities of confirming the detection of RUBV in patients with congenital rubella infection using RT-PCR, discussing potential pitfalls and optimization strategies. METHODS: From July 2019 to December 2021, we isolated the RUBV from throat swabs, lens materials, and urine samples obtained from patients with serologically confirmed and clinically compatible congenital rubella syndrome (CRS). The case definition and final classification of CRS were adapted from the World Health Organization-recommended CRS surveillance standard. We utilized the RT-PCR assay to detect the presence of RUBV ribonucleic acid (RNA). RESULTS: During the study period, 126 patients with suspected CRS underwent complete clinical and serological examinations. Of these, 30 patients were included, and 22 were laboratory-confirmed. Using RT-PCR, RUBV was detected in only 42.1% of the laboratory-confirmed group. Overall, the lens material showed the highest positivity for detecting RUBV RNA. No correlation was found between the cycle threshold values and patient age at viral RNA testing. CONCLUSIONS: The present study underscores the critical need for a multifaceted approach for accurately diagnosing CRS, particularly in the context of rubella elimination efforts. RT-PCR testing can be particularly useful for diagnosing CRS in patients over 12 months of age. By addressing the challenges and building upon the insights gained from our research, healthcare systems can enhance CRS diagnosis, guide timely interventions and ultimately contribute to the global rubella.