Provenance and peer review Not commissioned; externally peer reviewed.Data availability statement There are no data in this work.

Background Leptospirosis has globally significant human mortality and morbidity, yet estimating the clinical and public health burden of leptospirosis is challenging because timely diagnosis remains limited. The goal of the present study was to evaluate leptospirosis undercounting by current standard methods in both clinical and epidemiological study settings. Methodology/Principal findings A prospective hospital-based study was conducted in multiple hospitals in Sri Lanka from 2016 to 2019. Culture, whole blood, and urine samples were collected from clinically suspected leptospirosis cases and patients with undifferentiated fever. Analysis of biological samples from 1,734 subjects confirmed 591 (34.1%) cases as leptospirosis and 297 (17.1%) were classified as “probable” leptospirosis cases. Whole blood quantitative PCR (qPCR) did identify the most cases (322/540(60%)) but missed 40%. Cases missed by each method include; urine qPCR, 70% (153/220); acute sample microscopic agglutination test (MAT), 80% (409/510); paired serum sample MAT, 58% (98/170); and surveillance clinical case definition, 53% (265/496). qPCR of negative culture samples after six months of observation was of diagnostic value retrospectively with but missed 58% of positives (109/353). Conclusion Leptospirosis disease burden estimates should consider the limitations of standard diagnostic tests. qPCR of multiple sample types should be used as a leading standard test for diagnosing acute leptospirosis.

Metabolic syndrome (MetS) in pregnancy shows epigenetic associations with intergenerational inheritance of metabolic diseases. The presence of different diagnostic criteria influences MetS prevalence estimates. We evaluated MetS and metabolic derangements to determine the utility of its assessment in early pregnancy. A cross-sectional analysis of metabolic derangements in pregnant women with period of gestation (POG) ≤ 12 weeks was done among Rajarata Pregnancy Cohort participants in Sri Lanka. 2682 women with mean age 27.9 year (SD-5.5) and median POG 8.0wk (IQR-3) were analyzed. Mean levels of triglycerides (TG), total cholesterol (TC), high-density-lipoprotein (HDL), low-density-lipoprotein (LDL), fasting plasma glucose, and 2 h oral glucose tolerance test were 87.71 (SD 38.7), 172.2 (SD 34.7), 49.6 (SD 11.5), 122.6 (SD 32.3), 82.2 (SD 12.8) and 120.3 (SD 11.5) respectively. All serum lipids except LDL increase significantly from 6 to 12 weeks, with TG by 23 and TC by 8 units. High MetS prevalence was observed with AHA/NHLBI (n = 150, 5.6%, 95% CI 4.8–6.5) followed by IDF (n = 144, 5.4%, 95% CI 4.6–6.3), NCEP-ATP III (n = 112, 4.2%, 95% CI 3.4–5.0) and WHO (n = 81, 3.0%, 95% CI 2.4–3.7) definitions respectively. Significant difference in prevalence was noted among different sociodemographic characteristics (p < 0.001). Regardless of the criterion used, the change of metabolic parameters in early pregnancy leads to significant differences in prevalence estimates of MetS. The best MetS definition concerning pregnancy outcomes needs to be determined with prospective studies.

Human leptospirosis involves the classic epidemiological triad (agent, host and environment); hence the investigations should include the knowledge on Leptospira within the animals and the environment. The objectives of this study are to explore the abundance of Leptospira in different climate zones of Sri Lanka and to describe the presence of Leptospira in the same water source at serial time points. First, water and soil samples were collected from different parts of Sri Lanka (Component-1); second, water sampling continued only in the dry zone (Component-2). Finally, serial water sampling from ten open wells was performed at five different time points (Component-3). Quantitative PCR of water and metagenomic sequencing of soil were performed to detect Leptospira. Three replicates for each sample were used for PCR testing, and positive result of two or more replicates was defined as ‘strongly positive,’ and one positive replicate was defined as positive. In the water and soil sample analysis in the whole country (Component-1), two out of 12 water sites were positive, and both were situated in the wet zone. Very small quantities of the genus Leptospira were detected by 16 amplicon analysis of soil in all 11 sites. In the dry zone water sample analysis (Component-2), only samples from 6 out of 26 sites were positive, of which one site was strongly positive. In the serial sample analysis (Component-3), Six, five, four, five, and six wells were positive in serial measurements. All wells were positive for at least one time point, while only one well was positive for all five time points. Proximity to the tank and greater distances from the main road were associated with strong positive results for Leptospira (P<0.05). The presence of Leptospira was not consistent, indicating the variable abundance of Leptospira in the natural environment. This intermittent nature of positivity could be explained by the repetitive contamination by animal urine.

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