Medicine

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This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty

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    Content analysis of policy documents related to non-communicable diseases prevention and control in Sri Lanka: a developing country in the South-East Asia
    (F1000 Research, 2024) Talagala, I.; Abeysena, C.; Wickremasinghe, R.
    BACKGROUND: Health policies form the foundation for provisioning best level care and are important for all stakeholders including patients and healthcare providers. Health policy analysis and evaluation allows policy makers to improve an existing policy, terminate a non-effective policy and to successfully implement future policies. The objective was to assess the coherence between the two local policy documents on NCD prevention and control in Sri Lanka, the national NCD policy (NCD policy) and the multisectoral action plan (MSAP), and to assess the consistency of MSAP with the global action plan for NCDs. METHODS: The content analysis of the NCD policy and MSAP of Sri Lanka was conducted based on the modified criteria developed to the ‘Analysis of determinants of policy impact’ model, by two reviewers independently. Coherence between MSAP and the global NCD action plan were also assessed by two reviewers independently. Consensus for discrepancy was achieved through discussion. RESULTS: Accessibility was the strongest criteria for the NCD policy, while, resources and obligations were the weakest. Goals and monitoring and evaluation criteria were the strongest in the MSAP. Requirement for improvement were identified in policy background, goals, monitoring and evaluation, and public opportunities for the NCD policy. Accessibility, policy background, resources, public opportunities and obligations require further improvement in the MSAP. The MSAP is well coherent with the global road map for NCD prevention and control. CONCLUSION: Policy documents related to NCD prevention and control in Sri Lanka are coherent with the global action plan, while, there are areas within the local policy documents that need to be improved to enhance the coherence between the local documents. Lessons learnt by this activity need to be utilized by Sri Lanka and other countries to improve the uniformity between the NCD policy documents within the country as well as internationally.
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    Distribution and seasonal variation of malaria vectors in the Mannar and Jaffna Districts; an entomological investigation during the phase of prevention of re-establishment of malaria in Sri Lanka
    (Springer Link, 2024) Jude, J.; Gunathilaka, N.; Wijerathna, T.; Fernando, D.; Wickremasinghe, R.; Abeyewickreme, W.
    Sri Lanka has been declared “malaria-free” since 2016. The presence vectors and the cent establishment of new vectors are key challenges. This study documents the distribution of malaria vectors in previously high malaria endemic areas in Sri Lanka. Three locations were selected in Mannar and Jaffna districts. Entomological surveillance was carried out during January 2019 to January 2020 in both districts using cattle baited net (CBNT), hand collection (HC), and larval collection. The variation of mosquito abundance with selected climatic variables were evaluated using Pearson’s correlation. A total of 44,526 anophelines belonging to 12 species was encountered from both districts. The CBNT was the most productive technique that represented 78.65% (n = 35,022) of the total collection. Anopheles subpictus was the predominant species among adult collections in both districts, while in larval surveys, An. stephensi (60.1%; n = 2963) and An. varuna (40.9%; n = 1026) were observed in Jaffna and Mannar districts, respectively. The adult density indicated significantly strong positive correlations to the rainfall (r = 0.619, P < 0.05) and humidity (r = 0.524, P < 0.05) in both Jaffna and Mannar (rainfall: r = 0.553, P < 0.05; humidity: r = 0.553, P < 0.05). The number of larvae was not directly correlated with climatic variables. The present study reports the presence of An. culicifacies, An. subpictus and An. stephensi. Considering the fact that imported malaria cases are reported across the country the fact that there is an entomological risk to transmit malaria locally is a challenge. This warrants the continuous monitoring of vector population and seasonal variation, especially in previous malaria endemic regions.
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    Approach to study the efficacy and safety of new complementary and alternative medicine formulations: Lesson during COVID-19 from Sri Lanka
    (Wolters Kluwer - Medknow, 2023) Pilapitiya, S.; Jayasinghe, S.; Silva, A.; Wickremasinghe, R.; Paranagama, P.; de Silva, J.; Lekamwasam, S.; Kularatne, S.A.M.; Wanigasuriya, K.; Kaluthota, S.; Sumathipala, S.; Rathnnasooriya, C.; Siribaddana, S.
    COVID-19 affected Sri Lanka from early 2020, a time of considerable ignorance accompanied by wide media coverage of a devastating epidemic in Italy and Europe. Many were attracted to complementary and alternative medicine (CAM) or traditional medicine (TM) in this desperate situation. Several preparations were claimed to be effective against COVID-19 globally. Dammika Bandara Syrup© was one such preparation promoted for preventing and treating SARS-CoV-2 infection. It was based on bees' honey, pericarp and mace of Myristica fragrans (nutmeg), the seed of Foeniculum vulgare and fresh rhizome of Zingiber officinale, all believed to have anti-viral properties. Following an unpublished clinical study claiming efficacy, Dammika Bandara Syrup© gained wide media publicity and political patronage. The producer claimed of Goddess Kali revealing the formula added an anthropological, cultural, and religious complexity to the issue. The demand for the product increased rapidly as a debate raged both in public and in the parliament on utilizing such products in combating COVID-19. The Department of Ayurveda, which is statutorily responsible for regulating CAM/TM had to respond to the situation. The legislation to regulate such indigenous medicinal products was weak, and the crisis deepened as thousands converged to the production facility, defying mobility restrictions introduced to control COVID-19. This led to the Ministry of Health requesting academics to form a team and conduct a clinical trial to prove its efficacy. This paper outlines the process and issues faced during the regulatory approval for the trial in a polarized political environment. Some health professionals accused the researchers of bowing to political pressure and questioned the scientific justification for the trial. However, the team considered this as an opportunity to streamline a path for research into CAM/TM therapies in situations such as COVID-19. Several processes were identified and addressed, such as the provisional registration of CAM preparations, assessing the potential efficacy of a CAM product, confirmation of authenticity and safety, standardization and supervision of production respecting cultural identities, obtaining approval for human use, choice of comparators, and ethical issues. We believe the study has helped set standards and a benchmark for CAM and TM research in Sri Lanka.
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    Effect of daily stressors and collective efficacy on post-traumatic stress symptoms among internally displaced persons in post-war northern Sri Lanka
    (Cambridge University Press, 2023) Somasundaram, D.; Jayasuriya, R.; Perera, R.; Thamotharampillai, U.; Wickremasinghe, R.; Tay, A.K.
    BACKGROUND: Daily stressors have been shown to mediate the relationship of war trauma and trauma-related distress among refugees and internally displaced persons exposed to war and conflict. AIMS: To examine the extent to which the relationship between war-related trauma and mental distress was mediated by daily stressors and collective efficacy among internally displaced communities a decade after exposure to war. METHOD: In a cross-sectional study, we recruited a random sample of residents in villages severely affected by conflict in five districts in the Northern Province of Sri Lanka. Measures of war trauma, daily stressors, collective efficacy and post-traumatic stress symptoms (PTSS) were examined. Statistical analyses of the mediating and moderating effects of daily stressors were conducted using regression based methods. RESULTS: Daily stressors mediated the association of war trauma and PTSS, as both paths of the indirect effect, war trauma to daily stressors and daily stressors to PTSS, were significant. The predictive effect of war trauma on PTSS was positive and significant at moderate and high levels of daily stressors but not at low levels. Higher levels of neighbourhood informal social control, a component of collective efficacy, function as a protective factor to reduce effects of war trauma and daily stressors on mental distress in this population. CONCLUSIONS: Daily stressors are an important mediator in the well-established relationship between war exposure and traumatic stress among internally displaced persons, even a decade after the conflict. Mental health and psychosocial support programmes that aim to address mental distress among war-affected communities could reduce daily stressors and enhance collective efficacy in this context.
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    Prediction equation for physical activity energy expenditure in 11-13-year-old Sri Lankan children
    (MDPI Publishing, 2023) Dabare, P.; Wickramasinghe, P.; Waidyatilaka, I.; Devi, S.; Kurpad, A.V.; Samaranayake, D.; de Lanerolle-Dias, M.; Wickremasinghe, R.; Hills, A.P.; Lanerolle, P.
    This study aimed to develop a regression equation to predict physical activity energy expenditure (PAEE) using accelerometry. Children aged 11-13 years were recruited and randomly assigned to validation (n = 54) and cross-validation (n = 25) groups. The doubly labelled water (DLW) technique was used to assess energy expenditure and accelerometers were worn by participants across the same period. A preliminary equation was developed using stepwise multiple regression analysis with sex, height, weight, body mass index, fat-free mass, fat mass and counts per minute (CPM) as independent variables. Goodness-of-fit statistics were used to select the best prediction variables. The PRESS (predicted residual error sum of squares) statistical method was used to validate the final prediction equation. The preliminary equation was cross-validated on an independent group and no significant (p > 0.05) difference was observed in the PAEE estimated from the two methods. Independent variables of the final prediction equation (PAEE = [0.001CPM] - 0.112) accounted for 70.6% of the variance. The new equation developed to predict PAEE from accelerometry was found to be valid for use in Sri Lankan children.
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    Comparative analysis of the larvicidal activity of temephos (EC50) and novaluaron (EC10) to control Anopheles stephensi in Sri Lanka
    (Elsevier, 2023) Jude, J.; Gunathilaka, N.; Udayanga, L.; Fernando, D.; Premarathne, P.; Wickremasinghe, R.; Abeyewickreme, W.
    Background: Anopheles stephensi was first recorded in the coastal area of Mannar District, Sri Lanka, in December 2016. Since then, this vector has been isolated from other districts in the Northern and Eastern Provinces of Sri Lanka. Chemical control is the main arm of vector control that can be used to reduce the vector densities within a short period. Thus, the present study aimed at evaluating the efficacy of using selected insecticides for the control of An. stephensi larvae. Method: The third and fourth instar larval stages of An. stephensi (F2 generation) of field mosquitoes that were caught using cattle baited net trap collections from Columbuthurai, Kurunagar, and Navanthurai areas in Jaffna District, Sri Lanka, were obtained from the laboratory colony established at Jaffna. Batches of 100 larvae were taken for experiments and introduced separately to a concentration series of temephos and novaluron (0.04-400 ppm). A control test was also performed at each setup without introducing insecticides. The mortality rates of An. stephensi larvae exposed to different concentrations of larvicides were recorded at 1, 24 and 48-h intervals. The experiment was replicated five times at individual concentrations for each selected chemical. Data were analyzed using the General Linear Model (GLM) and Probit analysis. Results: The highest mortality rate (100%) at a 1-h exposure period was observed from temephos at >100 ppm. The mortality rates varied significantly for different concentrations and larvicides (p < 0.05). At 24-h of the exposure period, the 100% mortality of An. stephensi larvae were observed from both temephos and novaluron even at 0.04 ppm. Conclusion: Both temephos and novaluron reported 100% mortality rates in An. stephensi larvae at 1-h and 24-h exposure periods. Based on the findings, temephos and novaluron can be recommended as effective larvicides for chemical-based control of An. stephensi in Jaffna, Sri Lanka. Further, it is recommended to conduct a field-based study, where habitat types and water quality are highly heterogeneous and may affect the residual activity.
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    Biology, bionomics and life-table studies of Anopheles stephensi (Diptera: Culicidae) in Sri Lanka and estimating the vectorial potential using mathematical approximations
    (Elsevier, 2023) Jude, J.; Gunathilaka, N.; Udayanaga, L.; Fernando, D.; Premarathne, P.; Wickremasinghe, R.; Abeyewickreme, W.
    Background: Anopheles stephensi is an invasive mosquito in Sri Lanka that can potentially transmit malaria. The transmission intensity is linked with biology, bionomic and behavioral aspects of a vector that are associated with the Vectorial Capacity (VC). However, the influence of larval conditions eventually affects the vectorial potential of An. stephensi are not well understood. Methods: A colony of An. stephensi was established at the Regional Centre of the Open University of Sri Lanka, Jaffna District. The colony was maintained under confined conditions according to standard protocols. Biotypes of An. stephensi were characterized by referring to the number of egg ridges. Information on (a) biological aspects of eggs (duration for egg hatching, egg development and hatchability), (b) larval development time, larval survivorship pupation success, resting depth of larvae), (c) pupae (adult emergence rate, average time for adult emergence) and (d) adults (biting frequency, mating success gonotrophic cycle, fecundity, duration for egg-laying, percentage of sexes, adult survival/longevity) were evaluated under life-table analysis. Further, selected morphometric characters of each life cycle stage were recorded from the eggs (length and breadth), larvae (head length, width of head, length of thorax, width of thorax, length of abdomen, width of abdomen, and the total length of larvae), pupae (cephalothoracic length and width) and adults (length & width of wing, thorax and abdomen). The VC was calculated using a mathematical-based approach. Descriptive statistics, General Linear Model (GLM) and independent-sample t-test were used for the statistical analysis. Results: All three biotypes were identified based on egg morphology. Mysorensis biotype (47%; n = 470) was predominant followed by type (38.1%; n = 381) and intermediate (14.9%; n = 149). The mean egg length (F(2,997) = 3.56; P = 0.029) and breadth (F(2,997) = 4.57; P = 0.011) denoted significant differences among the three biotypes. The mating success of females observed was 80.7 ± 4.45%. The mean hatching period was 1.9 ± 0.03 days, with a hatching rate of 86.2 ± 0.77%. Overall, 8.0 ± 0.14 days were required for larval development and 30.3 ± 0.14 h were spent in the pupal stage. The pupation success was 94.5 ± 0.37%, and the majority were males (53.1 ± 0.73%). The mean fecundity was 106.5 ± 6.38 eggs and a gonotrophic cycle of 3.4 ± 0.06 days. The female survival rate was 43.2 ± 2.4%, with a mean biting frequency of 66.6 ± 3.5%. The average VC of adult An. stephensi was estimated to be 18.7. Conclusions: The type biotype, which is an effective vector in the Indian subcontinent is present in Sri Lanka. According to the mathematical approximation, An. stephensi found locally has a vectorial capacity of over 18. Therefore, this study warrants the health authorities and vector control programmes to continue the entomological surveys, monitoring of vector densities and implementing appropriate vector control interventions based on biology and bionomic information of vectors.
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    A Comprehensive analysis on abundance, distribution, and bionomics of potential malaria vectors in Mannar District of Sri Lanka
    (Hindawi Publishing Corporation, 2019) Gunathilaka, N.; Hapugoda, M.; Wickremasinghe, R.; Abeyewickreme, W.
    BACKGROUND:A detailed knowledge of the distribution of the malaria vectors in Mannar district of Sri Lanka has not been studied after 1927. Past records indicated the presence of only seven species of anophelines, namely, An. culicifacies, An. subpictus, An. barbirostris, An. peditaeniatus, An. nigerrimus, An. Jamesii, and An. maculatus. There have been many changes in terms of distribution of Anopheles in the district over time. METHODS: Entomological surveillance was conducted on a monthly basis, comprising indoor hand collection, window trap collection, cattle-baited net collection, cattle-baited hut collection, and larval survey from June 2010 to June 2012 in 12 study areas under three entomological sentinel sites. The relationship between seven abiotic variables of the breeding habitats was measured. Pearson's correlation coefficients were used to determine the associations between climatic variables and anopheline densities. RESULTS:A total of 74,181 mosquitoes belonging to 14 Anopheles species were recorded. An. subpictus was the most predominant species from all techniques representing 92% (n=68,268) of the total anopheline collection. However, Anopheles culicifacies was not recorded from any site during the study period. Larval surveys identified 12 breeding habitat categories including waste water collections, lagoon water collections, and drains which were not recorded as breeding habitats by previous studies. The mean dissolved oxygen level of waste water collections was 3.45±0.15 mg/l. The mean salinity and conductivity of lagoon water collections were 21105±1344 mg/l and 34734±1974 μs/cm, respectively.CONCLUSION: The present study provides the updated knowledge on anopheline distribution and vector bionomics. Therefore, documentation of the current knowledge would be useful for learners and health authorities to design appropriate vector control measures in the prevention of reintroduction of malaria.
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    Deciphering Chronic Kidney Disease of Unknown etiology in Sri Lanka
    (RTI Press, 2016) Redmon, J.H.; Elledge, M.F.; Wanigasuriya, K.P.; Wickremasinghe, R.; Levine, K.E.
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    Evaluation of rapid extraction and isothermal amplification techniques for the detection of Leishmania donovani DNA from skin lesions of suspected cases at the point of need in Sri Lanka
    (BioMed Central, 2018) Gunaratna, G.; Manamperi, A.; Bohiken-Fascher, S.; Wickremasinghe, R.; Gunawardena, K.; Yapa, B.; Pathiana, N.; Pathirana, H.; de Silva, N.; Sooriyaarachchi, M.; Deerasinghe, T.; Mondal, D.; Ranasinghe, S.; Abd EI Wahed, A.
    BACKGROUND: Leishmaniasis is a disease caused by vector-borne protozoans. In Sri Lanka, the cutaneous form of the disease is predominant, which is usually diagnosed using Giemsa-stained slit skin smear examination and by histology. However, the sensitivity of slit skin smears and histology are reportedly low. Moreover, facilities for the highly sensitive polymerase chain reaction (PCR) are available only in a few highly-equipped parasitology laboratories. Therefore, there is a need for low cost, sensitive and specific screening tests for diagnosis of leishmaniasis at the point of need. RESULTS: In this study, a mobile suitcase laboratory applying novel extraction (SpeedXtract) and isothermal amplification and detection (recombinase polymerase amplification assay, RPA) methods were evaluated for the diagnosis of cutaneous leishmaniasis in Sri Lanka. First, the developed assay was applied to three different sample types (punch biopsy, slit skin smears and fine needle aspirates) at a local hospital. The results showed that the 2 mm punch biopsy sample produced the best exponential amplification curve and early fluorescence signal in the RPA assay. Secondly, punch biopsies were collected from 150 suspected cutaneous leishmaniasis cases and screened with SpeedXtract/RPA, RNAlater/PCR and ATL buffer/PCR, in addition to Giemsa-stained slit skin smears. Fifty-seven samples were negative in all detection methods. In total 93 samples were positive with assay sensitivities of 65.5% (SpeedXtract/RPA), 63.4% (RNAlater/PCR) and 92.4% (ATL buffer/PCR). The Giemsa-stained slit skin smear delivered the worst clinical sensitivity (32.2%). CONCLUSIONS: The SpeedXtract/RPA method under field conditions took 35 min, while almost 8 h were needed to finalize the extraction and detection by PCR in the laboratory. The SpeedXtract/RPA method produced similar sensitivity to samples preserved in RNAlater and subjected to PCR amplification, but both were less sensitive than ATL-preserved samples subjected to PCR amplification. There is a need for a standardization of sample collection and nucleic acid extraction methods.
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