Leptospirosis infections among hospital patients, Sarawak, Malaysia

Abstract

Background Leptospirosis diagnoses have increased in Sarawak, Malaysia in recent years. Methods To better understand the burden of disease and associated risk factors, we evaluated 147 patients presenting with clinical leptospirosis to local hospitals in Sarawak, Malaysia for the presence of Leptospira and associated antibodies. Sera and urine specimens collected during the acute illness phase were assessed via a commercially available rapid diagnostic test (Leptorapide, Linnodee Ltd., Antrim, Northern Ireland), an ELISA IgM assay (Leptospira IgM ELISA, PanBio, Queensland, Australia) and a pan-Leptospira real-time PCR (qPCR) assay to estimate disease prevalence and diagnostic accuracy of each method. Microagglutination testing was performed on a subset of samples. Results Overall, 45 out of 147 patients (30.6%) showed evidence of leptospires through qPCR in either one or both sera (20 patients) or urine (33 patients), and an additional ten (6.8%) were considered positive through serological testing, for an overall prevalence of 37.4% within the study population. However, each diagnostic method individually yielded disparate prevalence estimates: rapid test 42.2% for sera and 30.5% for urine, ELISA 15.0% for sera, qPCR 13.8% for sera and 23.4% for urine. Molecular characterization of a subset of positive samples by conventional PCR identified the bacterial species as Leptospira interrogans in 4 specimens. A multivariate risk factor analysis for the outcome of leptospirosis identified having completed primary school (OR = 2.5; 95 CI% 1.0–6.4) and weekly clothes-washing in local rivers (OR = 10.6; 95 CI% 1.4–214.8) with increased likelihood of leptospirosis when compared with those who had not. Conclusion Overall, the data suggest a relatively high prevalence of leptospirosis in the study population. The low sensitivities of the rapid diagnostic test and ELISA assay against qPCR highlight a need for better screening tools.

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

“…When test performance was categorized by day after the onset of symptoms, the results were similar to overall performance. The sensitivity of RPA-CRISPR/Cas12a FBDA peaked on day < 4 after the onset of fever and decreased with time whereas sensitivity of Leptospira IgM RDTs increased on day 4–6 and declined on day > 6, similar to previous findings [ 13 , 14 , 22 ].…”

“…When test performance was categorized by day after the onset of symptoms, the results were similar to overall performance. The sensitivity of RPA-CRISPR/Cas12a FBDA peaked on day < 4 after the onset of fever and decreased with time whereas sensitivity of Leptospira IgM RDTs increased on day 4-6 and declined on day > 6, similar to previous findings [13,14,22]. Leptospires are normally present in the blood during the first week and are eliminated by the host-immunity while IgM and IgG antibody levels begin to rise and reach their peak during the second week of illness [11].…”

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

“…In recent years, there have been increasing numbers of leptospirosis infection cases in Malaysia [ 18 , 19 , 20 ]. A case report showed that a real-time PCR assay was successfully used in a postmortem diagnosis of a woman whose death was caused by L. interrogans [ 21 ]. One study reported positively detected Leptospira cases and related risk factors in Sarawak, Malaysia [ 22 ].…”

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

“…A few people also experienced severe leptospirosis after swimming in a waterfall [ 92 ] and kayaking in a river [ 93 ]. In Sarawak, the weekly washing of clothes in local rivers was associated with leptospirosis among hospital patients [ 73 ]. Among wet market workers in two locations were 33.6% [ 76 ] and 46.3% [ 78 ].…”

“…congkakensis[69]. In humans, L. weilii, L. kirschneri, L. wolffii, and L. interrogans[71][72][73][74] were detected.New serovars are also continuously being discovered. A serovar known as Malaysia was isolated from the soil samples of Johor state in 2009[75].…”