Browsing by Author "Gunawardena, N.K."

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Achieving millennium development goal 4 in 2015: are we really on track?
(Sri Lanka College of Paediatricians, 2011) Mettananda, S.; Rajindrajith, S.; Warnakulasuriya, T.; Fernando, M.; Devanarayana, N.M.; Gunawardena, N.K.
INTRODUCTION: Millennium development goal (MDG) 4 aims to reduce under 5 mortality by two thirds from 1990 (22.2 per 1000 live births) to 2015 (7.4 per 1000 live births). In achieving this, proper and accurate description of the causes of deaths is crucial. OBJECTIVES: To describe the timing, causes and distribution of under 5 child deaths in Sri Lanka and to predict the likelihood of achieving MDG 4. DESIGN, SETTING AND METHOD: Information regarding all under 5 child deaths between 2002-2006 was obtained from the Registrar Generals' Department. Place, sex and age at death were retrieved. Causes of deaths documented accordingly to the ICD-10 classification were reclassified into clinically relevant and user-friendly categories. Mortality rates and predictions for 2015 were calculated using Microsoft Excel. RESULTS: A total of 26,273 deaths have occurred during 2002-2006 [55% neonatal, 21% post-neonatal infant and 24% child (l-5year)]. Tsunami wave in 2004 had caused 2,868 (11%) deaths and they were excluded from further analysis. Prematurity had caused 4,603 (31.8%) neonatal deaths; 2389 (16.5%) were due to infections and 1149 (7.9%) were due to birth asphyxia. Congenital anomalies have contributed to 1830 (12.6%) neonatal deaths, of which, the majority [1389 (9.6%)] were heart diseases. Leading causes for post-neonatal infant deaths include congenital anomalies [1772 (35%)], infections [1516 (29.9%)] and trauma [393 (7.7%)]. in children, 910 (23.4%) deaths were due to infections (10.2% respiratory, 2.0% gastroenteritis and 0.9% dengue). One fifth of deaths were due to congenital anomalies of which half were due to heart defects. Trauma/ accidents and malignancies had contributed to 731 (18.8%) and 279 (7.1%) deaths respectively. Colombo district reported the highest number of deaths (24%). More males (54.7%) have died compared to females. Reduction in mortality rates were observed from 2002-2006; neonatal mortality from 8.3 to 7.6, infant mortality from 11.4 to 10.4 and under 5 mortality from 13.7 to 12.3. Projections of data showed that the neonatal, infant and under 5 mortality rates in 2015 would be 4.6, 6.7 and 7.7 per 1000 live births respectively. CONCLUSIONS: Prematurity was the leading cause of neonatal mortality. Congenital heart diseases are an important cause of death throughout childhood. Trauma and accidents contribute to a significant proportion of child deaths. Predictions from data suggest that Sri Lanka may fall marginally short of achieving MDG 4.
Adjusting for spatial variation when assessing individual-level risk: A case-study in the epidemiology of snake-bite in Sri Lanka
(Public Library of Science, 2019) Ediriweera, D.S.; Kasturiratne, A.; Pathmeswaran, A.; Gunawardena, N.K.; Jayamanne, S.F.; Murray, K.; Iwamura, T.; Lalloo, D.G.; de Silva, H.J.; Diggle, P.J.
BACKGROUND:Health outcomes and causality are usually assessed with individual level sociodemographic variables. Studies that consider only individual-level variables can suffer from residual confounding. This can result in individual variables that are unrelated to risk behaving as proxies for uncaptured information. There is a scarcity of literature on risk factors for snakebite. In this study, we evaluate the individual-level risk factors of snakebite in Sri Lanka and highlight the impact of spatial confounding on determining the individual-level risk effects.METHODS:Data was obtained from the National Snakebite Survey of Sri Lanka. This was an Island-wide community-based survey. The survey sampled 165,665 individuals from all 25 districts of the country. We used generalized linear models to identify individual-level factors that contribute to an individual's risk of experiencing a snakebite event. We fitted separate models to assess risk factors with and without considering spatial variation in snakebite incidence in the country.RESULTS:Both spatially adjusted and non-adjusted models revealed that middle-aged people, males, field workers and individuals with low level of education have high risk of snakebites. The model without spatial adjustment showed an interaction between ethnicity and income levels. When the model included a spatial adjustment for the overall snakebite incidence, this interaction disappeared and income level appeared as an independent risk factor. Both models showed similar effect sizes for gender and age. HEmployment and education showed lower effect sizes in the spatially adjusted model.CONCLUSIONS:Both individual-level characteristics and local snakebite incidence are important to determine snakebite risk at a given location. Individual level variables could act as proxies for underling residual spatial variation when environmental information is not considered. This can lead to misinterpretation of risk factors and biased estimates of effect sizes. Both individual-level and environmental variables are important in assessing causality in epidemiological studies.
Allergic sensitization in children
(The Sri Lanka College of Paediatricians, 2008) Amarasekera, N.D.D.M.; Gunawardena, N.K.; de Silva, N.R.; Weerasinghe, A.
BACKGROUND :Allergic sensitization is considered a significant risk factor for the development of atopic diseases. Appropriate allergen avoidance measures can be taken only when the pattern of sensitization to allergens in a particular population is known. No data is available regarding allergic sensitization among Sri Lankan children. OBJECTIVE: To identify the common allergens causing sensitization in a selected group of schoolchildren. DESIGN, SETTING AND METHOD: A cross-sectional study was carried out in 640 children in grade 5 (age group 9-11 years), from 17 schools in the Western Province. Data regarding atopic diseases was collected using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Specific IgE was estimated by ImmunoCAP method for five common aeroallergens (the dust mites Dermatophagoides pteronyssinus and Blomia tropicalis, cockroach, cat epithelium and dander, grass pollen) in a sub-sample of 203. RESULTS: Aeroallergen sensitivity was detected in 163 (80.3%) children. No significant difference for sensitization between boys and girls was noted (P= 0.549). The pattern of allergens in the two groups was similar. Mite allergen sensitivity was the most prevalent (B. tropicalis 84.0%, D. pteronyssinus 69.9%), followed by cockroach (67.5%), cat dander (46.0%) and grass pollen (35.6%). Twenty seven (13.3%) children were sensitized to all allergens tested; 28 (13.8%) children were sensitized to only one allergen; and 68.7% were sensitized to both B. tropicalis and D. pteronyssinus. Children with rhinitis or eczema (but not those with asthma) were significantly more likely to show sensitization to cat dander than asymptomatic controls (P=0.02 and P=0.002 respectively), but not to other allergens. The likelihood of being sensitized to one allergen was well correlated with sensitization to other allergens as evident by the significant correlation coefficients. CONCLUSION: Mites and cockroaches were the most common aeroallergens causing sensitization among schoolchildren in the Western Province.
Association between asthma and rhinitis
(Sri Lanka Medical Association, 2010) Amarasekera, N.D.D.M.; Gunawardena, N.K.; de Silva, N.R.; Weerasinghe, G.A.K.
INTRODUCTION AND OBJECTIVES: It has been suggested that'both asthma and allergic rhinitis are manifestations of a single disease and they are related epidemiologically and pathophysiologically. The objective was to assess the relationship between asthma and allergic rhinitis in terms of serum total IgE (tlgE) and allergic sensiti-satipn in children. METHODS: Children attending grade 5 in 17 schools in the Western Province of Sri Lanka were recruited to the study. Data were collected using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Their serum total IgE (tlgE) and allergen-specific IgE (slgE) for five common aeroallergens (Dermatophagoides pteronyssinusr Blomia tropicalis, cockroach, cat epithelium and dander, grass pollen) were measured by ImmunoCAP method. RESULTS: A total of 640 schoolchildren were recruited. Their mean age was 10 years (SD ± 0.5) Prevalence (95% CI) of asthma and rhinitis was 17% (13.7-20.3) and 21.4% (17.8-25.1) respectively. Male preponderance was seen for both diseases, but was significant only for rhinitis. Among children with asthma, 44.4% had rhinitis. The geometric mean tlgE level was higher in children with asthma (804.6 kU/L) than with rhinitis (708.9 kU/L), but the difference was not statistically significant. Univariate analysis showed that sensitization to allergens from cat epithelium and dander was strongly associated with rhinitis (OR 2.104, 95% CI 1.1.16 - 3.969, P = 0.022) but not with asthma. CONCLUSION: Asthma and rhinitis appear to be different in our study population with respect to sensitising allergens and gender. The risk factors and development of these two diseases may vary in different populations.
Association between serum total IgE, allergic diseases and geohelminth infections in Sri Lankan children
(BioMed Central, 2007) Amarasekera, N.D.D.M.; Gunawardena, N.K.; de Silva, N.R.; Douglass, J.; O’Hehir, R.E.; Weerasinghe, A.
BACKGROUND: Elevated levels of total IgE (tIgE) in serum are characteristic of allergic diseases. Levels of tIgE are influenced by genetic predisposition, age, sex and helminth infections. However, the association between tIgE and allergic diseases in children living in areas endemic for helminth infections is not clear. The aim of our study was to assess the relationship between tIgE, allergic diseases and geohelminth infections in children. METHODS: A total of 640 schoolchildren 9Y11 years of age was selected by stratified random sampling. Data regarding allergic diseases (asthma, rhinitis and eczema) were collected by a standard questionnaire given to the parent or guardian. Screening for helminth infections was done by examining their fresh stool samples by modified Kato-Katz technique. Serum tIgE was measured by Fluoroenzymeimmunoassay in 67 geohelminth-positive subjects and in a comparable group of geohelminth-negative subjects. RESULTS: The mean age in the study population was 10 years (SDT0.3). The prevalence of geohelminth infection was 15.5%. Trichuris trichiura (14.3%) was the most common followed by Ascaris lumbricoides (4.2%) and hookworm (0.2%). Mixed infection was detected in 20.3% of infected children. Infection intensity was light in 68.9% of infected children while 28.4% and 2.7% showed moderate and heavy infection respectively. The cumulative prevalence of allergic diseases was 33.7%. Prevalence of asthma, rhinitis and eczema was 17%, 21.4% and 5% respectively. Serum tIgE concentrations showed a positively skewed distribution. Geometric mean (GM) for tIgE for the geohelminth infected group (1039.9kU/L) was significantly higher than that of the non-infected group (575.4kU/L) (p = 0.004). It was also higher in the allergic group (933.3kU/L) than in the non-allergic group (639.7kU/L) but the difference was not statistically significant (p = 0.068). The GM for tIgE for non-allergic children in the study population was much higher than that seen in non-allergic children in developed countries. CONCLUSION: Serum tIgE concentration was strongly associated with the presence of geohelminth infections in children. Serum tIgE may not be a useful marker for allergic diseases in children living in areas endemic for geohelminth infections. © 2007 World Allergy Organization
Bihar's pioneering school-based deworming programme: lessons learned in deworming over 17 million Indian school-age children in one sustainable campaign.
(San Francisco, CA : Public Library of Science, 2015) Drake, L.J.; Singh, S.; Mishra, C.K.; Sinha, A.; Kumar, S.; Bhushan, R.; Hollingsworth, T.D.; Appleby, L.J.; Kumar, R.; Sharma, K.; Kumar, Y.; Raman, S.; Chakrabarty, S.; Kihara, J.H.; Gunawardena, N.K.; Hollister, G.; Kumar, V.; Ankur, A.; Prasad, B.; Ramachandran, S.; Fishbane, A.; Makkar, P.
A Case of imported malaria: the first report of Plasmodium malariae infection in Sri Lanka after 37 years
(Sri Lanka Medical Association, 2008) Hapuarachchi, H.A.C.; Gunawardena, N.K.; Senevirathne, M.P.; Abeyewickreme, W.; de Silva, N.R.
We report a case of Plasmodium falciparum and P. malariae mixed infection in a patient who had been living in Malawi. This is the first case of P. malariae reported in Sri Lanka in 4 decades. The presence of both parasites was confirmed by microscopy and polymerase chain reaction (PCR). The history strongly indicated that the infection had been acquired from Malawi. The patient had liver dysfunction and a transient glomerulonephritis, both of which subsided with antimalarial treatment.
Chemotactic response of Brugia pahangi infective larvae to jird serum in vitro
(Springer International, 2003) Gunawardena, N.K.; Fujimaki, Y.; Aoki, Y.
The Brugia pahangi infective larval response to jird serum was studied using an agar plate assay. Larvae placed onto the agar remained at the same place for 60 min. Once the larvae were stimulated by serum, more than 95% oriented towards the serum and reached it within few minutes. This larval response was inhibited by an activator of phosphodiesterase (imidazole), adenylate cyclase inhibitors (SQ22536 and MDL-12330A) and protein kinase A inhibitor. An inhibitor of phosphodiesterase (IBMX), an activator of adenylate cyclase (forskolin) and an membrane permeant analogue of cAMP (8-bromo-cAMP), caused a number of larvae to move out from the inoculation area towards the other zones. To our knowledge, this is the first report of a chemotactic response by B. pahangi larvae to host serum. We conclude that B. pahangi larvae show a chemotaxic response to host serum, and that cAMP and cAMP dependent protein kinase are involved in the signal transduction.
Cluster randomized trial of the impact of school based deworming and weekly iron supplementation on haemoglobin level of plantation primary school children
(College of the Community Physicians of Sri Lanka, 2013) Ebenezer, R.; Gunawardena, N.K.; Kumarendran, B.; Pathmeswaran, A.; de Silva, N.R.
BACKGROUND: School-based deworming and iron supplementation are being promoted as effective interventions to deal with the high prevalence of anaemia among school children. OBJECTIVE: The objective of this study was to determine the effectiveness of school based deworming and weekly iron supplementation on increasing the haemoglobin level of primary school children in the plantation sector in Sri Lanka. METHODS: A placebo-controlled cluster randomized trial was conducted in which the treatment group received a single dose of 500 mg mebendazole and 6-months of weekly iron supplementation (200 mg ferrous sulphate) while the control group received placebo for both anthelmintic and iron. The tablets were administered by the class teacher. Children attending grade 4 in schools in the plantation sector were recruited. The treatment arm was allocated with 813 children attending 49 schools and the placebo arm with 808 children attending 49 schools. Height, weight and haemoglobin were measured at baseline and after 6-months. A regression model adjusting for the cluster design was used to assess the effectiveness of the intervention on the haemoglobin level. In order to increase the precision of the estimates, various background variables were controlled for in regression models. RESULTS: Complete data were available for 633 children in the treatment group and 613 children in the control group. The mean age was 9 years and 6 months and 52% of them were males. In the treatment arm 98% had received mebendazole and over 80% had received 16 doses of iron. A reduction in the prevalence of soil-transmitted helminth (STH) infection (from 25.1% to 16.4%) was found in the treatment group, with significant differences between treatment and control groups in the levels of Ascaris and Trichuris. There was a small non-significant reduction in the mean haemoglobin level (at baseline 12.6g/dl, sd - 1.2) of both groups. No impact of treatment was found on haemoglobin levels. CONCLUSIONS: Though the intervention was effective in reducing the prevalence of STH infection there was no evidence of effectiveness in increasing haemoglobin levels.
Community incidence of snakebite and envenoming in Sri Lanka; results of a national survey
(Sri Lanka Medical Association, 2014) Pathmeswaran, A.; Kasturiratne, A.; Gunawardena, N.K.; Wijayawickrama, B.A.; Jayamanne, S.F.; Ediriweera, D.S.; Isbister, G.; Dawson, A.; Lalloo, D.G.; de Silva, H.J.
INTRODUCTION AND OBJECTIVES: We undertook the first ever country-wide community-based survey to determine the incidence of snakebite in Sri Lanka. METHODS: Data were collected through household interviews by trained data collectors.125 clusters were allocated to each of the 9 provinces of the country. Within each province the clusters were divided among the districts in proportion to their population. A Grama Niladhari (GN) division was defined as a cluster for data collection. The clusters were selected using simple random sampling, and in each cluster 40 households were sampled consecutively from a random starting point. RESULTS: Data relating to 165,665 individuals (0.8% of the population of Sri Lanka) living in 44,136 households in 1,118 clusters was collected from June 2012 to May 2013. 695 (males 418) snakebites and 323 (males!93) significant envenomings (local tissue necrosis or systemic envenoming) were reported during the 12 months preceding the interview. The overall community incidence of snakebites and significant envenoming were 398 and 151 per 100,000 population, respectively. 446 (64.2%) bites and 208 (64.4%) envenomings were in people aged 30 to 59 years. There was wide variation between districts, the worst affected being Mullaitivu, Anuradhapura, Batticaloa, and Poionnaruwa, ali in the dry zone, mainly agricultural areas of the country. CONCLUSIONS: Sri Lanka has a high community incidence of snakebite and envenoming with a marked geographical variation.This variation underlines both the inaccuracy of extrapolating data of localised surveys to national or regional levels and the need to prioritise distribution of resources for treatment of snakebite even in small countries.
Community incidence of snakebite in the Amiradhapura district
(Sri Lanka Medical Association, 2013) Kasturiratne, A.; Gunawardena, N.K.; Wijayawickrama, B.A.; Jayamanne, S.F.; Pathmeswaran, A.; Isbister, G.; Dawson, A.; de Silva, H.J.
INTRODUCTION AND OBJECTIVES: The community incidence of snakebite in Sri Lanka is unknown. To investigate incidence of snakebite, we undertook a community study in the Anuradhapura district as part of an ongoing countrywide survey on snakebite. METHODS: The survey was designed to sample at least 1% of the population in each district Within the district, a Grama Niladhari (GN) division, was defined as a cluster for data collection. The number of clusters required to sample at least 1 % of the population was first determined, and clusters were then selected using simple random sampling. In each selected cluster 40 households were sampled consecutively from a random starting point. Population estimates of snakebite were constructed for the district. RESULTS: The Anuradhapura district has a total of 694 GN divisions, and 84 were surveyed. This included 3357 households and a population of 13,428 (1.6% of the district's population). Eightysix snakebites were reported within the last 12 months. Extrapolating this to the district (mid-year population=855,373), the estimated snakebites in Anuradhapura district was 5478. The crude community incidence of snakebite in the Anuradhapura district was 640.5 per 100, 000 population. CONCLUSIONS: The incidence of snakebite in the community is high in the Anuradhapura district, with one in 156 persons bitten annually.
Comparison of five DNA extraction methods from human blood for the detection of Wuchereria bancrofti by polymerase chain reaction assays
(Sri Lanka Association for the Advancement of Science, 2008) Wijegunawardana, N.D.A.D.; Gunawardene, Y.I.N.S.; Manamperi, A.; Hapuarachchi, H.A.C.; Gunawardena, N.K.; Abeysundara, S.; Abeyewickreme, W.
Introduction: Lymphatic filariasis (Lf) is the second most common vector-borne disease globally. Approximately 90% of global burden of Lf is caused by Wuchereria bancrofti. W. bancrofti is routinely diagnosed by morphological identification of microfilariae (Mf) by microscopy which is a labour intense, low sensitive and time consuming method. Detection of W. bancrofti Deoxyribonucleic acid (DNA) using polymerase chain reaction (PCR) technique has become popular today, because of its high sensitivity and specificity. The overall success of the PCR strategy in detecting a filarial parasite in human blood varies between sample preparation methods. The objective of this study was to compare five DNA extraction methods (Lysis + centrifugation, Chelex method, Mf pellet method, Q1Aamp DNA Mini Kit commercial system, and Phenol-chloroform) with regard to duration of completion, labor involvement and PCR analytical sensitivity in-relation to DNA quality and quantity for the detection of W. bancrofti in human blood. Five blood samples positive for mf of W. bancrofti were tested for each DNA extraction method and were compared with respect to the sensitivity, time and quality/quantity of DNA and also by PCR analysis. Of the 5 methods tested, Mf pellet method was found to be the most simple and effective technique for the isolation of W. bancrofti Mf in human blood. This method was quick (15 min to complete), simple (5 min of manual labor), and very economical. It does not require any organic solvents, and the entire extraction procedure uses only two steps requiring supernatant transfer between tubes, hence minimizing the possibility of cross-contamination. Moreover, the PCR analytical sensitivity of the Mf pellet method was comparable to that of the commercial kit used. No PCR inhibitors were detected, independently of Mf count in the blood. Same method (optimal DNA extraction method) can be also used for the detection of parasite DNA from the field collected Mf positive mosquitoes using a PCR. Therefore, we recommend the Mf pellet method for processing large numbers of blood samples in community surveys aimed at determining the prevalence of W. bancrofti infection.
Comparison of laboratory techniques for diagnosis of hookworm infections
(Sri Lanka College of Microbiologists, 2011) Manamperi, N.H.; Anjalee, K.G.C.; Gunawardena, N.K.; Sudusinghe, H.; Nilaweera, T.H.W.T.; de Silva, N.R.
INTRODUCTION: Hookworm infection may be diagnosed by detection of eggs or culturing of larvae from stools. OBJECTIVE: To compare the efficacy of modified Kato-Katz (K-K) technique, saline smears, Harada-Mori (H-M) and nutrient agar culture plate (NACP) methods in diagnosis of hookworm infections. METHODOLOGY: A total of 324 stool samples, from the plantation sector families in Ratnapura district were examined by modified Kato-Katz technique and saline smears, and cultured by Harada-Mori and on NACP according to standard protocols, at the Faculty of Medicine, Ragama. Harada-Mori and NACP were maintained for 7-10 days and larvae or larval tracts observed by a stereomicroscope. Positivity in any two of the four techniques was considered the gold standard positive. Statistical analysis was done using SPSS version 16. RESULTS: A total of 172 (53.1%) samples were positive by at least one method. The positivity rates with K-K, H-M, NACP and saline smears were 42.3% (137/324), 37.7% (122/324), 23.5% (76/324) and 22.2% (72/324) respectively. The highest sensitivity (89.8%) and lowest specificity (88.3%) was seen in modified K-K, the lowest sensitivity (50.4%) in saline smears and the highest specificity in NACP (98.5%). Detection rates with saline smears, H-M and NACP rose with increasing intensity of infection as determined by K-K technique. Harada-Mori had the highest detection rate (70.7%) in light infections. It also detected 11.8% of K-K negative samples. CONCLUSIONS: The modified K-K technique is a reasonably good diagnostic method for detection of hookworm infections. A combination of methods will increase the diagnostic accuracy in hookworm infections.
Correction: Double burden of maternal and child malnutrition and socioeconomic status in urban Sri Lanka.
(Public Library of Science, 2020) Shinsugi, C.; Gunasekara, D.; Gunawardena, N.K.; Subasinghe, W.; Miyoshi, M.; Kaneko, S.; Takimoto, H.
[This corrects the article DOI: 10.1371/journal.pone.0224222.]. Erratum for Double burden of maternal and child malnutrition and socioeconomic status in urban Sri Lanka. PLoS One.2019;14(10):e0224222.
Development of a Snakebite risk map for Sri Lanka
(Sri Lanka Medical Association, 2016) Ediriweera, D.S.; Kasturiratne, A.; Pathmeswaran, A.; Gunawardena, N.K.; Wijayawickrama, B.A.; Jayamanne, S.F.; Isbister, G.K.; Dawson, A.; Giorgi, E.; Diggle, P.J.; Lalloo, D.G.; de Silva, H.J.
INTRODUCTION: Snakebite is a public health problem in Sri Lanka and about 37,000 patients are treated in government hospitals annually. At present, health care resources which are required to manage snakebite are distributed based on the administrative boundaries, rather than based on scientific risk assessment. OBJECTIVES: The aim of the study is to develop a snakebite risk map for Sri Lanka. METHOD: Epidemiological data was obtained from a community-based island-wide survey. The sample was distributed equally among the nine provinces. 165,665 participants (0.8%of the country’s population) living in 1118 Grama Niladhari divisions were surveyed. Generalized linear and generalized additive models were used for exploratory data analysis. Model-based geostatistics was used to determine the geographical distribution of snakebites. Monte Carlo maximum likelihood method was used to obtain parameter estimates and plug-in spatial predictions were obtained. Probability contour maps (PCM) were developed to demonstrate the spatial variation in the probability that local incidence does or does not exceed national snakebite incidence. RESULTS: Individual point estimate snakebite incidence map and PCM were developed to demonstrate the national incidence of snakebite in Sri Lanka. Snakebite hotspots and cold spots were identified in relation to the national snakebite incidence rate. Risk maps showed a within-country spatial variation in snakebites. CONCLUSIONS: The developed risk maps provide useful information for healthcare decision makers to allocate resources to manage snakebite in Sri Lanka.
Differential effects of diethylcarbamazine, tetracycline and the combination on Brugia pahangi adult females in vitro
(Elsevier, 2005) Gunawardena, N.K.; Fujimaki, Y.; Aoki, Y.; Mishima, N.; Ezaki, T.; Uni, S.; Kimura, E.
Anti-filarial effects of diethylcarbamazine (DEC), tetracycline (TC) and the combination on Brugia pahangi adult females were studied in 7-day cell-free culture, in terms of microfilaria release, parasite motility, MTT assay for parasite viability and embryogram. TC 50 microg/ml (TC50) effectively reduced microfilaria release from day 1 of culture. Combined with DEC 100 microg/ml (DEC100) or DEC 500 microg/ml (DEC500), microfilaria release reduced further and synergistically. TC50 also reduced motility, but DEC100 and DEC500 did not. Thecombination of TC50 and DEC500 reduced motility synergistically. The MTT assay supported the results of motility study in general. The embryogram showed that only DEC500 reduced the total number of intrauterine embryos, especially ova, indicating that DEC500 inhibited early embryogenesis. TC50 did not affect the total number of embryos, but resulted in apparent accumulation of microfilariae in the uterus, suggesting that the drug inhibited release of microfilariae in this in vitro system. These results clarified different anti-female mechanisms between DEC and TC. A PCR-based study showed that endosymbiont bacteria, Wolbachia, in B. pahangi females decreased significantly after TC treatment. However, this study could not determine whether the effects of TC were direct or Wolbachia-mediated.
The Diversity of Human Dirofilariasis in Western Sri Lanka
(Hindawi Pub. Co, 2019) Chandrasena, T.G.A.N.; Premaratna, R.; Mallawaarachchi, C.H.; Gunawardena, N.K.; Gunathilaka, P.A.D.H.N.; Abeyewickrama, W.Y.; de Silva, N.R.
BACKGROUND:Human dirofilariasis is an emerging zoonosis in many countries. Dirofilariasis caused by Dirofilaria repens may present with diverse clinical manifestations in humans due to aberrant localization of worm lesions causing diagnostic dilemmas. The aim of this retrospective study was to describe and update the demography and clinical spectrum of human dirofilariasis in western Sri Lanka. Nematode or nematode fragments isolated from excision biopsies that were confirmed as D. repens at the Department of Parasitology, Faculty of Medicine, University of Kelaniya, Sri Lanka, between 2012 and 2018 were included. Data on age, gender, and clinical details were obtained from case files. Identity of worms was established by morphometry and cuticle characteristics on wet-mount preparation. Specimens from unusual case presentations were further analyzed by PCR with specific primers for internal transcribed spacer region 2 (ITS2) of the ribosomal DNA. RESULTS:Sixteen nematode specimens isolated from subconjunctiva (n=2), subcutaneous (n=13) and intramuscular (n=1) locations were identified as D. repens by morphometry (average length 11.5 cm) and the characteristic longitudinal striations on cuticle visualized by microscopy. The age distribution of cases ranged from 1 to 65 years with a mean of 21.5. Females were more frequently affected (n=10, 62.5%) and worm locations were commonest in the orbital region (5/16) and scrotum (3/16). Imaging techniques were of use in detecting infections in deeper tissue levels. PCR analysis of DNA extracted from a worm in an intramuscular granuloma of the temporal region elicited the expected band at 484bp for D. repens. CONCLUSIONS: Human dirofilariasis is on an upward trend in incidence. Imaging techniques were of use in clinical diagnosis and molecular speciation in establishing the species identity in unusual case presentations. We suggest a more conservative approach in the management of human dirofilariasis and recommend a one health approach for control.
Double burden of maternal and child malnutrition and socioeconomic status in urban Sri Lanka
(Public Library of Science, 2019) Shinsugi, C.; Gunasekara, D.; Gunawardena, N.K.; Subasinghe, W.; Miyoshi, M.; Kaneko, S.; Takimoto, H.
Child malnutrition and maternal obesity are serious public health issues in Sri Lanka. This study explores the associations between socioeconomic status and the double burden of malnutrition among school-aged children and within their household. A total of 543 primary school children aged 5-10 years (204 boys and 339 girls) in Gampaha District, Sri Lanka, were included in the analysis. The nutritional statuses of thinness, normal, overweight, and obesity for children and mothers were defined according to WHO growth references and body mass index. Maternal education, household equivalent income, and maternal employment were used as socioeconomic status indicators. The proportion of child thinness and overweight was 19.3% and 13.4%, respectively, and that of maternal overweight (body mass index ≥ 25 kg/m2) was 36.5%. A positive correlation was found between maternal body mass index and the child's body mass index for age z-score in older boys and younger girls. A multivariate stepwise logistic regression analysis showed that lower education of mothers posed a higher association with child thinness (adjusted odds ratio = 2.33, 95% confidence interval: 1.08-5.00). Mothers with overweight and obesity were less likely to have a child with thinness (adjusted odds ratio = 0.30, 95% confidence interval: 0.16-0.58). Maternal employment status and household equivalent income were not significantly, but marginally, associated with child overweight and obesity. Socioeconomic inequality combined with maternal nutritional status affected child malnutrition. These findings suggest that the underlying circumstances within households should be considered to improve child malnutrition. Erratum in: PLoS One. 2020;15(3):e0230785.
Effect of genotyping on the severity of rotavirus Gastroenteritis
(Sri Lanka College of Paediatricians, 2011) Chandrasena, T.G.A.N.; Rajindrajith, S.; Gunawardena, N.K.; Silva, G.M.K.S.; Pathmeswaran, A.; Kazuhiko, M.; Kamruddin, A.
INTRODUCTION: Rotavirus is the commonest cause of paediatric gastroenteritis. There remains a controversy regarding disease severity being related to rotavirus genotype G9. OBJECTIVE: Study the genotype related severity of rotavirus gastroenteritis. DESIGN, SETTING AND METHOD: All children under 5 years of age who were admitted with acute diarrhoea to North Colombo Teaching Hospital and submitted a sample of stool for analysis from April 2005 to October 2008 were selected for the study. Clinical information was collected regarding the study group. Acute diarrhoea was defined as passage of 3 times or more stools over a period of 24 hours. Stools were collected from cases with blood and mucus diarrhoea as well. The stool compliance rate was around 75-80%. Faecal specimens were tested and genotyped for rotavirus using the ELISA kit, Rotaclone® (Meridian Diagnostics, Cincinnati) and reverse transcription (RT) PCR respectively. Severity of gastroenteritis was assessed using the 20 point scoring system ofVesikariand Ruuska. RESULTS: The total number of stool specimens collected during the study period was 813 and of this 178 were positive for group A rotavirus; all the rotavirus positive stool specimens were genotyped. The two predominant VP7 genotypes were G9 (76; 42.7%) and Gl (35; 19.7%) followed by G2 (22; 12.4%), G3 (22; 12.4%), G12 (18; 10.1%) and G4 (4; 2.2%) respectively. The mean severity scores of, Gl, G2, G3, G4, G9 and G12 were 12,12,12,14,13 and 13, respectively. Comparison of clinical features between the two common G types, G9 and Gl revealed the following: duration of diarrhoea was longer among G9 (mean 4±2 days) than Gl (mean 2±1 day) and a higher percentage of cases were febrile and had vomiting in G9 (84.9 and 86.3 respectively) than Gl (76.7 and 65.5 respectively) infections (p>0.05). The rest of the clinical features were similar. The percentage with severe disease (score >14) was higher among the G9 (38.4) than among Gl (26.7) infections (p>0.05). CONCLUSION: Although rotavirus G9 genotype was associated with a more severe gastroenteritis than the common Gl genotype, this association was not significant (p>0.05).
The Effect of intestinal nematode infections on atopic diseases in children
(Allergy and Immunology Society of Sri Lanka, 2009) Amarasekera, N.D.D.M.; Gunawardena, N.K.; de Silva, N.R.; Douglas, J.; O'Hehir, R.; Weerasinghe, A.
BACKGROUND : The effect of helminth infections on atopic diseases and allergic sensitization is controversial. Little is known about the effect of infection on atopic diseases in children living in areas where both intestinal nematodes and Toxocara infections are prevalent. OBJECTIVE : To examine the association between atopic diseases and helminth infection among children exposed to both intestinal nematodes and Toxocara. METHODS: Children attending grade 5 (age group 9-11 years) in 17 schools in the Western Province of Sri Lanka were recruited. The association of atopic diseases (asthma, rhinitis, eczema) with active intestinal nematode infections (excreting eggs in faeces) and with exposure to Toxocara (specific IgG antibodies in serum) was investigated. A child was deemed sensitized if positive for at least one of the allergens tested (Dermatophagoides pteronyssinus, Blomia tropicalis, cockroach, cat epithelium, grass pollen), based on specific IgE levels in serum. RESULTS: A total of 640 children participated in the study; serum analysis was done in 203. Active intestinal nematode infection appeared to reduce the risk of atopic diseases (OR 0.47, P=0.016) whereas Toxocara exposure did not (OR 0.85 P=0.602). When specific IgE levels against Blomia tropicalis, the most common allergen in the study group (67.5%), were expressed as percentages of the total IgE levels for each child, infected children had significantly lower levels compared to uninfected children (P=0.001). CONCLUSIONS : Intestinal nematode infections seem to protect against atopic diseases in children in Sri Lanka. Polyclonal IgE synthesis may be involved in this protection.