Background: Leishmaniasis is a neglected tropical vector-borne disease, which is on the rise in Sri Lanka. Spatiotemporal and risk factor analyses are useful for understanding transmission dynamics, spatial clustering and predicting future disease distribution and trends to facilitate effective infection control. Methods: The nationwide clinically confirmed cutaneous leishmaniasis and climatic data were collected from 2001 to 2019. Hierarchical clustering and spatiotemporal cross-correlation analysis were used to measure the region-wide and local (between neighboring districts) synchrony of transmission. A mixed spatiotemporal regression-autoregression model was built to study the effects of climatic, neighboring-district dispersal, and infection carryover variables on leishmaniasis dynamics and spatial distribution. Same model without climatic variables was used to predict the future distribution and trends of leishmaniasis cases in Sri Lanka. Results: A total of 19,361 clinically confirmed leishmaniasis cases have been reported in Sri Lanka from 2001–2019. There were three phases identified: low-transmission phase (2001–2010), parasite population buildup phase (2011–2017), and outbreak phase (2018–2019). Spatially, the districts were divided into three groups based on similarity in temporal dynamics. The global mean correlation among district incidence dynamics was 0.30 (95% CI 0.25–0.35), and the localized mean correlation between neighboring districts was 0.58 (95% CI 0.42–0.73). Risk analysis for the seven districts with the highest incidence rates indicated that precipitation, neighboring-district effect, and infection carryover effect exhibited significant correlation with district-level incidence dynamics. Model-predicted incidence dynamics and case distribution matched well with observed results, except for the outbreak in 2018. The model-predicted 2020 case number is about 5,400 cases, with intensified transmission and expansion of high-transmission area. The predicted case number will be 9115 in 2022 and 19212 in 2025. Conclusions: The drastic upsurge in leishmaniasis cases in Sri Lanka in the last few year was unprecedented and it was strongly linked to precipitation, high burden of localized infections and inter-district dispersal. Targeted interventions are urgently needed to arrest an uncontrollable disease spread.

Leishmaniasis, a neglected tropical disease, encompasses a spectrum of clinical conditions and poses a significant risk of infection to over one billion people worldwide. Visceral leishmaniasis (VL) in the Indian sub-continent (ISC), where the causative parasite is Leishmania donovani, is targeted for elimination by 2025, with some countries already reaching such targets. Other clinical phenotypes due to the same species could act as a reservoir of parasites and thus pose a challenge to successful control and elimination. Sri Lanka has consistently reported cutaneous leishmaniasis (CL) due to L. donovani as the primary disease presentation over several decades. Similar findings of atypical phenotypes of L. donovani have also been reported from several other countries/regions in the Old World. In this review, we discuss the applicability of different methods in diagnosing CL due to L. donovani and a comprehensive assessment of diagnostic methods spanning clinical, microscopic, molecular, and immunological approaches. By incorporating evidence from Sri Lanka and other regions on L. donovani-related CL, we thoroughly evaluate the accuracy, feasibility, and relevance of these diagnostic tools. We also discuss the challenges and complexities linked to diagnosing CL and review novel approaches and their applicability for detecting CL.

Background: Meditation-based practices have been suggested to result in many biological benefits which include reduction of attrition of telomeres, the protective nucleotide-protein complexes at termini of eukaryotic chromosomes. This systematic review evaluated the effects of meditation on telomere length (TL) in healthy adults. Methods: Randomized controlled trials (RCTs) and observational studies conducted to determine the effects of meditation on TL in healthy individuals, published up to July 2020 were retrieved by searching seven electronic databases (PubMed, Scopus, PsycINFO, EMBASE, Cochrane Library, CINAHL and Google Scholar). The methodological quality of RCTs and observational studies was assessed using the Cochrane Collaboration Risk of Bias Tool and Joanna Briggs Institute critical appraisal checklist, respectively. The data was synthesized narratively and the effect estimates of TL in the RCTs were synthesized using alternative methods as a meta-analysis was not conducted. The certainty of evidence was classified according to the GRADE system. Results: A total of 1740 articles were screened. Five studies comprising two RCTs and three case-control studies (CCS) were included in the final review based on the inclusion and exclusion criteria. The combined sample consisted of 615 participants with 41.7% males. Average age of participants was 47.7 years. One CCS and one RCT reported significant beneficial effects of meditation on TL while the two remaining CCS and the RCT showed positive effects of meditation on TL which were not significant. For all CCS and one RCT, the methodological quality was high while the remaining RCT was of moderate quality. The quality of evidence for the primary outcome was moderate in RCTs. Conclusion: The effect of meditation on TL per se is still unclear. Strictly designed and well-reported RCTs with larger sample sizes are required to provide evidence of higher quality. Systematic review registration: The protocol of this review was registered with the International Prospective Register of Systematic Reviews (PROSPERO) database (registration number: CRD42020153977).

: Leishmaniasis in Sri Lanka was first reported in the early 1990s. Cutaneous leishmaniasis (CL) cases have markedly increased in recent years, demanding due attention from health authorities. The spatial distribution of CL is not homogeneous. This case-control study investigated factors that may contribute to this heterogeneous distribution through a nationwide study. Information on sociodemographic, economic, and environmental characteristics was collected from study participants (cases, n = 303; controls, n = 2,762). All individuals were followed up for 3 years, and signs of CL or associated complications were recorded. Differences in possible risk factors between cases and controls were analyzed. Individuals 2 hours outdoors, visiting jungles/water bodies, and living near CL patients were identified as risk factors. Household members of 1.3% of cases, 2.3% of controls residing within a perimeter of 500 m from a patient, and 0.8% of controls living beyond 2 km from a case developed CL. Thus, CL in Sri Lanka appears intertwined with living environment and host behavior. Common environmental factors may be responsible for the higher risk of CL in individuals living in close proximity to CL patients. This may at least partly explain the clustering of CL cases in selected areas of the country.

Cutaneous leishmaniasis (CL) is a vector-borne parasitic disease, routinely diagnosed by direct light microscopy. The sensitivity of this method is dependent on the number of parasites present in the lesion. Immunoexpression of CD1a surface antigen by Leishmania amastigotes and its application as a diagnostic tool has been recently demonstrated in several species including Leishmania major, Leishmania tropica and Leishmania infantum. Leishmania donovani is the only reported species in Sri Lanka primarily causing CL and its CD1a status remains unexplored. We studied CD1a expression by amastigotes of L. donovani in skin biopsies from 116 patients with suspected CL. The biopsy sections were stained with CD1a clones O10 and MTB1 separately. Slit skin smear (SSS) results were considered the gold standard for diagnosis of CL. 103 cases were confirmed through SSS where 73 of them showed positive parasite staining for CD1a clone MTB1 with 70.9% sensitivity. Positivity was seen mostly in parasites closer to the epidermis. CD1a clone O10 failed to detect any amastigotes. Test sensitivity improved to 74.1% when the analysis was applied only to patients with low/no discernible Leishman-Donovan (LD) bodies in histology. Our findings show that CD1a clone MTB1 successfully stains amastigotes of L. donovani species and can be used as a supplementary diagnostic tool in detecting CL, especially when LD bodies are low in number. This method could be validated to detect other forms of leishmaniasis caused by L. donovani in Indian and sub-Saharan regions.