Leptospirosis infections among hospital patients, Sarawak, Malaysia

Leptospirosis in Malaysia: current status, insights, and future prospects

Among zoonotic infections, leptospirosis has a worldwide distribution and high prevalence in tropical regions. It has a broad clinical presentation from mild to severe, life-threatening infection. Leptospires, the etiological agent of leptospirosis, are found in varied ecological niches and animal species, providing a significant source of human infection. This review aims to provide the current status of leptospirosis in Malaysia and the direction for future studies. The literature search for this review was performed using PubMed, Web of Sciences, and Google Scholar databases. The incidence of leptospirosis in Malaysia from 2004 to 2020 varied; however, a large number of cases occurred during floods. Leptospira has been isolated from wild and domestic animals as well as from the environment; among them, several novel species have been identified. In Malaysia, leptospirosis infection and death were mostly associated with recreational and non-recreational water activities. Despite the endemicity of leptospirosis, the public's knowledge, attitude, and practice level are relatively low in this country. More studies are needed in Malaysia to explore the extent of leptospirosis in different settings and locations.

The combination of RPA-CRISPR/Cas12a and Leptospira IgM RDT enhances the early detection of leptospirosis

BACKGROUND

Lack of available sensitive point-of-care testing is one of the primary obstacles to the rapid diagnosis of leptospirosis. The purpose of this study was to test the performance of two point-of-care tests, a clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 12a (CRISPR/Cas12a) fluorescence-based diagnostic assay (FBDA), a Leptospira immunoglobulin M (IgM) rapid diagnostic test (RDT), and the two tests combined.

METHODOLOGY/PRINCIPAL FINDINGS

For the diagnosis of 171 clinical samples, a recombinase polymerase amplification (RPA)-CRISPR/Cas12a FBDA for whole blood and Leptospira IgM RDT (Medical Science Public Health, Thailand) for serum were used. The confirmed cases were determined by using any positive qPCR, microscopic agglutination test (MAT), and culture results. Diagnostic accuracy was assessed on the first day of enrollment and stratified by the day after symptom onset. The overall sensitivity of the Leptospira IgM RDT and RPA-CRISPR/Cas12a FBDA was 55.66% and 60.38%, respectively. When the two tests were combined, the sensitivity rose to 84.91%. The specificity of each test was 63.08% and 100%, respectively, and 63.08% when combined. The sensitivity of the Leptospira IgM RDT rose on days 4-6 after the onset of fever, while the RPA-CRISPR/Cas12a FBDA continued to decrease. When the two tests were combined, the sensitivity was over 80% at different days post-onset of fever.

CONCLUSIONS/SIGNIFICANCE

The combination of Leptospira IgM RDT and RPA-CRISPR/Cas12 FBDA exhibited significant sensitivity for the detection of leptospires at various days after the onset of fever, thereby reducing the likelihood of misdiagnosis. The combination of these assays may be suitable for early leptospirosis screening in situations with limited resources.

Putative Pathogenic Genes of Leptospira interrogans and Leptospira weilii Isolated from Patients with Acute Febrile Illness

Leptospirosis is an important worldwide tropical disease caused by pathogenic Leptospira spp. The determination of virulence genes is important, as it influences patients' clinical manifestations and clinical outcomes. This case report focused on detecting the pathogenic genes of Leptospira in association with the clinical manifestations of patients at the Hospital Universiti Sains Malaysia, Malaysia, who presented with acute febrile illness. Two cases were found and, to the best of our knowledge, these were the first two cases in Malaysia in which patients presented with febrile illness were associated with successful Leptospira isolation from clinical samples. Both clinical isolates were identified by 16S rRNA sequencing as Leptospira weilii and Leptospira interrogans, respectively, and they were classified as pathogenic Leptospira by the presence of different pathogenic genes, based on a polymerase chain reaction (PCR) amplification of targeted genes. This report emphasizes that different infecting Leptospira species and the presence of different virulence factors cause a slight difference in clinical manifestations and laboratory findings of leptospirosis. Genomic sequencing and annotation revealed the detection of classical leptospiral virulence factor genes that were otherwise missed using PCR for detection of Leptospira weilii genome B208.