Utility of molecular diagnostic method compared with conventional methods in detection of etiologic agents of central nervous system infections in Rwanda

The incidence of meningoencephalitis in developing countries is high and its diagnosis being inadequate as it is mainly based on conventional methods with a limited diagnostic capacity for bacterial, fungal and viral detection. This results in prescription of a cocktail of antibiotics, antifungal, or anti-viral drugs, since the causative agent is often unknown. There is therefore need for timely and appropriate diagnosis to guide treatment. This study aims at evaluating the utility of molecular diagnostic over conventional methods in detection of etiologic agents of central nervous system infections in Rwanda. Using a cross sectional design, 845 hospitalized patients suspected to have meningoencephalitis were enrolled from 8 study sites across the country. Four sterile tubes of Cerebral Spinal Fluid (CSF) specimens were collected from each patient. Two tubes were analyzed on site for bacteriology, fungal, biochemistry and cytology while the other two were transported to the National Reference Laboratory (NRL) for culture and Real-Time Multiplex Polymerase Chain Reaction (PCR) assays. Data entry and analysis was done using Epi Info7, Excel; SPSS and STATA16. In the study, no viruses were detected using the conventional methods while a range of viruses, 152/845 (18%) were detected using real time multiplex PCR. In addition, 185/845 (22%) samples were detected as positive for different types of bacteria using the PCR compared with the 59/845(7%) that were positive using conventional methods. There was however no difference in the detection capacity of fungal agents between the two methods with a detection level of 6% (49). This study has shown increased capacity for detection of bacterial and viral causative agents of Central Nervous System (CNS) infections using RT multiplex PCR compared with conventional methods. This result facilitated the development of a novel algorithm for both conventional and molecular diagnostic methods for CNS infections.