Indirect immunofluorescence assay for Leptospirosis and spatial study of the disease in Selangor districts, Malaysia

Leptospirosis is a significant bacterial zoonosis found worldwide, including in Selangor, Malaysia. This study aimed to determine the geospatial distribution of the disease and its association with socioeconomic factors in Selangor districts and to develop an indirect immunofluorescence assay (IFA) to validate the method with microscopic agglutination test (MAT) as the gold standard in clinical diagnosis. Ethical clearances with identification numbers NMRR-18- 4007-40480 (IIR) and NMRR ID-22-00490-GTO (IIR) for the 10,353 confirmed cases of leptospirosis and sera for the indirect IFA were obtained from the Selangor Department of Health. Spatial distributions and Moran’s I were performed to determine the distribution and high risk of the disease in the region. Geographically weighted regression (GWR) was conducted to predict the socioeconomic drivers associated with the disease distribution. An indirect IFA was developed and validated with MAT to contribute to managing and controlling the disease. The assay was conducted by fixing Leptospira antigen on Teflon printed 12 welled glass slides and used to detect anti-Leptospira antibodies with Fluorescein-5-isothiocyanate (FICT) and Alexa Fluor 488- labeled specific secondary antibodies. Cases in Sabak Bernam were the most dispersed throughout the study period. The LISA plots indicate Hulu Langat, Petaling, and Gombak as high-risk districts; other districts were sporadic throughout the research period. The population was shown to be a predictor of the disease distribution with a high R2 value across the districts. People associated with recreational activities are more predisposed to leptospirosis (p<0.05, Multiple R2 and Global R2 were closer to +1). The local R2 for the association with animals was plotted, with cattle-associated coefficients being the highest (62.2%) and the buffalo-associated being the lowest (7.2 - 8.4%). Association with cattle and cattle products was also found to predict leptospirosis. For the indirect IFA, 870 sera were collected from the public health laboratory in Ipoh, Perak, Malaysia; fifty (50) sera were collected from a high-risk population. The sera were processed using the indirect IFA, which demonstrated a sensitivity of 71.2% and specificity of 96.0%. It is recommended that the method be further improved and validated with other techniques for routine clinical diagnosis to help control the disease, especially in the endemic areas. High incidences of leptospirosis were found in Selangor districts with Gombak, Hulu Langat, and Petaling spotted as high-risk districts. Socioeconomic drivers were found to predict the disease. The developed indirect IFA demonstrated high sensitivity and specificity, coupled with safety and time saving compared to MAT, hence can be used for clinical diagnosis of the disease. Healthcare providers should allocate resources more efficiently and provide specific measures such as health education, better sanitation, rodent control, and public awareness campaigns, especially at higher-risk locations.

Text FPSK (p) 2024 15 - Declaration Form.pdf Restricted to Repository staff only Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (420kB) Text FPSK (p) 2024 15.pdf Restricted to Repository staff only Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (9MB) Text FPSK (p) 2024 15 - Full Text.pdf Restricted to Repository staff only until May 2029. Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (9MB)

Actions (login required)

View Item