Spatially varying correlation between environmental conditions and human leptospirosis in Sarawak, Malaysia

The spatial distribution of environmental conditions may influence the dynamics of vectorborne diseases like leptospirosis. This study aims to investigate the global and localised relationships between leptospirosis with selected environmental variables. The association between environmental variables and the spatial density of geocoded leptospirosis cases was determined using global Poisson regression (GPR) and geographically weighted Poisson regression (GWPR). A higher prevalence of leptospirosis was detected in areas with higher water vapour pressure (exp(â): 1.12; 95% CI: 1.02 - 1.25) and annual precipitation (exp(â): 1.15; 95% CI: 1.02 - 1.31), with lower precipitation in the driest month (exp(â): 0.85; 95% CI: 0.75 – 0.96) and the wettest quarter (exp(â): 0.88; 95% CI: 0.77 – 1.00). Water vapor pressure (WVP) varied the most in the hotspot regions with a standard deviation of 0.62 (LQ: 0.15; UQ; 0.99) while the least variation was observed in annual precipitation (ANNP) with a standard deviation of 0.14 (LQ: 0.11; UQ; 0.30). The reduction in AICc value from 519.73 to 443.49 indicates that the GWPR model is able to identify the spatially varying correlation between leptospirosis and selected environmental variables. The results of the localised relationships in this study could be used to formulate spatially targeted interventions. This would be particularly useful in localities with a strong environmental or socio-demographical determinants for the transmission of leptospirosis

Low prevalence of the BCR–ABL1 fusion gene in a normal population in southern Sarawak

The BCR–ABL1 fusion gene is the driver mutation of Philadelphia chromosome-positive chronic myeloid leukemia (CML). Its expression level in CML patients is monitored by a real-time quantitative polymerase chain reaction defned by the International Scale (qPCRIS). BCR–ABL1 has also been found in asymptomatic normal individuals using a non-qPCRIS method. In the present study, we examined the prevalence of BCR–ABL1 in a normal population in southern Sarawak by performing qPCRIS for BCR–ABL1 with ABL1 as an internal control on total white blood cells, using an unbiased sampling method. While 146 of 190 (76.8%) or 102 of 190 (53.7%) samples showed sufcient amplifcation of the ABL1 gene at>20,000 or>100,000 copy numbers, respectively, in qPCRIS, one of the 190 samples showed amplifcation of BCR–ABL1 with positive qPCRIS of 0.0023% and 0.0032% in two independent experiments, the sequence of which was the BCR–ABL1 e13a2 transcript. Thus, we herein demonstrated that the BCR–ABL1 fusion gene is expected to be present in approximately 0.5–1% of normal individuals in southern Sarawak

Evaluation of BOX-PCR and ERIC-PCR as Molecular Typing Tools for Pathogenic Leptospira

In the last decades, leptospirosis had gained public health concern due to morbidity and mortality rates caused by pathogenic Leptospira. The need for rapid and robust molecular typing methods to differentiate this zoonotic pathogen is of utmost importance. Various studies had been conducted to determine the genetic relatedness of Leptospira isolates using molecular typing methods. In this study, 29 pathogenic Leptospira isolates from rat, soil, and water samples in Sarawak, Malaysia, were characterized using BOX-PCR and ERIC-PCR. The effectiveness of these two methods with regard to the ease of interpretation, reproducibility, typeability, and discriminatory power was also being evaluated. Using BOX-PCR, six clusters and 3 single isolates were defined at a genetic distance percentage of 11.2%. ERIC-PCR clustered the isolates into 6 clusters and 2 single isolates at a genetic distance percentage of 6.8%. Both BOX-PCR and ERIC-PCR produced comparable results though the discriminatory index for ERIC-PCR (0.826) was higher than that for BOX-PCR (0.809). From the constructed dendrogram, it could be summarized that the isolates in this study were highly heterogeneous and genetically diverse. The findings from this study indicated that there is no genetic relatedness among the pathogenic Leptospira isolates in relation to the locality, source, and identity, with some exceptions. Out of the 29 pathogenic Leptospira isolates studied, BOX-PCR and ERIC-PCR successfully discriminated 4 isolates (2 isolates each) into the same cluster in relation to sample sources, as well as 2 isolates into the same cluster in association with the sample locality. Future studies shall incorporate the use of other molecular typing methods to make a more thorough comparison on the genetic relatedness of pathogenic Leptospir

Seroepidemiological study of leptospirosis among the communities living in periurban areas of Sarawak, Malaysia

Introduction: Leptospirosis is endemic to tropical regions of the world and is re-emerging as a new danger to public health in Malaysia. the purpose of this particular study was to determine the common leptospiral serovars present in human communities living around wildlife reserves/disturbed forest habitats. the objective of this study was to estimate the seroprevalence of leptospirosis and finding infecting serovars in villages surrounded habitats where wildlife lives in Sarawak, Malaysia