Journal/Magazine Articles

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This collection contains original research articles, review articles and case reports published in local and international peer reviewed journals by the staff members of the Faculty of Medicine

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100 Years of Mass Deworming Programmes: A Policy Perspective From the World Bank's Disease Control Priorities Analyses
(London : Academic Press, 2018) Bundy, D.A.P.; Appleby, L.J.; Bradley, M.; Croke, K.; Hollingsworth, T.D.; Pullan, R.; Turner, H.C.; de Silva, N.
For more than 100 years, countries have used mass drug administration as a public health response to soil-transmitted helminth infection. The series of analyses published as Disease Control Priorities is the World Bank's vehicle for exploring the cost-effectiveness and value for money of public health interventions. The first edition was published in 1993 as a technical supplement to the World Bank's World Development Report Investing in Health where deworming was used as an illustrative example of value for money in treating diseases with relatively low morbidity but high prevalence. Over the second (2006) and now third (2017) editions deworming has been an increasingly persuasive example to use for this argument. The latest analyses recognize the negative impact of intestinal worm infection on human capital in poor communities and document a continuing decline in worm infection as a result of the combination of high levels of mass treatment and ongoing economic development trends in poor communities.
17p11. 2 and Xq28 duplication detected in a girl diagnosed with Potocki-Lupski syndrome
(Biomed Central, 2015) Sumathipala, D.S.; Mandawala, E.N.; Samanmalee, P.S.; Vajira, H.W.D.
BACKGROUND: Potocki-Lupski syndrome is a microduplication syndrome associated with duplication at 17p11.2. Features include facial dysmorphism, moderate to mild cognitive impairment and behavioural abnormalities including autism spectrum disorders. CASE PRESENTATION: We describe a patient from Sri Lanka that was referred for genetic assessment at 4 years of age due to subtle facial dysmorphism and expressive language impairment. She was diagnosed with Potocki-Lupski syndrome through multiplex ligation probe amplification. She carried two duplications; one in 17p11.2 consistent with Potocki-Lupski, and one in Xq including the region for X-linked intellectual disability. CONCLUSION: Despite the absence of expected behavioural symptoms, many features of this patient are in accordance with Potocki-Lupskisyndrome. This is the first diagnosed patient in Sri Lanka.
2'-Deoxy-5-ethyl-beta-4'-thiouridine inhibits replication of murine gammaherpesvirus and delays the onset of virus latency
(International Medical Press, 1999) Barnes, A.; Dyson, H.; Sunil-Chandra, N.P.; Collins, P.; Nash, A. A.
The antiviral thionucleoside analogue 2'-deoxy-5-ethyl-beta-4'-thiouridine (4'-S-EtdU) was shown to be a more potent inhibitor of gammaherpesvirus infection than acyclovir. This compound inhibits replication of murine herpesvirus (MHV)-68 in the lungs of mice when given 3 days post-infection. However, as with other nucleoside analogues, it was unable to prevent the establishment of latency, despite delaying the onset of latent infection in the spleen. In contrast, virus persistence in the lung was inhibited following drug treatment, although persistence was re-established in mice when treatment was suspended after 12 days. These data suggest that 4'-S-EtdU is a highly effective inhibitor of murine gamma herpesvirus replication and as such provides a powerful tool to study the pathogenesis of this virus in vivo.
2021 Asia-Pacific Graves' Disease consortium survey of clinical practice patterns in the management of graves' disease
(Humana Press, 2023) Parameswaran, R.; de Jong, M.C.; Kit, J.L.W.; Sek, K.; Nam, T.Q.; Thang, T.V.; Khue, N.T.; Aye, T.T.; Tun, P.M.; Cole, T.; Miller, J.A.; Villa, M.; Khiewvan, B.; Sirinvaravong, S.; Sin, Y.L.; Muhammad, R.; Jap, T.S.; Agrawal, A.; Rajput, R.; Fernando, R.; Sumanatilleke, M.; Suastika, K.; Shong, Y.K.; Lang, B.; Bartalena, L.; Yang, S.P.; Asian Graves Consortium Study.
Aim: Although Graves' disease (GD) is common in endocrine practices worldwide, global differences in diagnosis and management remain. We sought to assess the current practices for GD in countries across Asia and the Pacific (APAC), and to compare these with previously published surveys from North America and Europe.Methods: A web-based survey on GD management was conducted on practicing clinicians. Responses from 542 clinicians were received and subsequently analysed and compared to outcomes from similar surveys from other regions. Results: A total of 542 respondents participated in the survey, 515 (95%) of whom completed all sections. Of these, 86% were medical specialists, 11% surgeons, and 3% nuclear medicine physicians. In addition to serum thyroid-stimulating hormone (TSH) and free thyroxine assays, most respondents would request TSH-receptor autoantibody (TRAb) measurement (68%) during initial work-up. Thyroid ultrasound is requested by about half of respondents (53%), while the use of nuclear medicine scans is limited. The preferred first-line treatment is anti-thyroid drug (ATD) therapy (79%) with methimazole (MMI) or carbimazole (CBZ), followed by radioiodine (RAI; 19%) and surgery (2%). In case of surgery, one-third of respondents would opt for a subtotal rather than a total thyroidectomy. In case of mild Graves orbitopathy (GO), ATDs (67%) remains the preferred treatment, but a larger proportion of clinicians prefer surgery (20%). For a patient with intention to conceive, the preferred treatment pattern remained unchanged, although propylthiouracil (PTU) became the preferred ATD-agent during the first trimester. In comparison to European and American practices, marked differences were noted in the relatively infrequent usage of nuclear medicine scans and the overall higher use of a ATDs and β-blockers and adjunctive ATD-treatment during RAI in the APAC-group.Conclusion: Although regional differences regarding the diagnosis and management of GD are apparent in this first pan-Asia-Pacific survey, this study reveals the overall approach to the management of this disease in Asia-Pacific generally tends to fall between the trends appreciated in the American and European cohorts.
24 h activity guidelines in children and adolescents: A prevalence survey in Asia-Pacific cities
(MDPI, 2023) Quah, P.L.; Loo, B.K.G.; Mettananda, S.; Dassanayake, S.; Chia, M.Y.H.; Chua, T.B.K.; Tan, T.S.Z.; Chan, P.C.; But, B.W.; Fu, A.C.; Wong, S.M.; Nagano, N.; Morioka, I.; Kumar, S.; Nair, M.K.C.; Tan, K.H.
This study aimed to examine the prevalence of adherence to 24 h activity guidelines in children and adolescents from Asia-Pacific cities. In 1139 children aged 5-18 years, moderate-to-vigorous physical activity (MVPA), screen viewing time (SVT), sleep duration, child weight, height, sex, and age were parent-reported. Descriptive statistics were used to assess the number of guidelines met, and prevalence of adherence to activity guidelines by city and child sex. Prevalence of meeting all three 24 h activity guidelines was low across all countries (1.8-10.3%) (p < 0.05). Children from Thiruvananthapuram, India had the highest [10.3% (95% CI: 6.0-17.0)], while those from Tokyo, Japan had the lowest prevalence [1.8% (95% CI: 0.5-7.0)] of meeting all three guidelines. The highest prevalence of meeting individual MVPA, SVT and sleep guidelines was found in India [67.5% (95% CI: 58.8-75.1)], Kelaniya, Sri Lanka [63.2% (95% CI: 58.7-67.4)] and Kowloon, Hong Kong [59.4% (95% CI: 51.1-65.3)], respectively. Overall, a higher prevalence of boys met all three guidelines, compared to girls [5.9% (95% CI: 4.1-8.1) vs. 4.7% (3.1-6.6), p = 0.32]. The prevalence of adhering to all three activity guidelines was low in all five participating cities, with a higher proportion of boys meeting all guidelines.
A 9-year-old male with fever, proptosis and hemodynamic instability
(Baltimore, Md, 2021) Gunaratna, G.P.S.; Howard-Jones, A.R.; Khatami, A.; Huynh, J.; Kesson, A.M.
No abstract available
A novel mutation in the SLCO2A1 gene presenting as persistent hypoproteinaemia and refractory iron deficiency anaemia due to chronic enteropathy: A case report
(BioMed Central, 2024-11) Mettananda, S.; Bandara, P.; Rajeindran, M.; Padeniya, P.
BACKGROUND The SLCO2A1 gene encodes a prostaglandin transporter and we report a novel mutation causing hypoproteinaemia and refractory anaemia due to chronic enteropathy.Case PRESENTATION An 18-year-old boy of consanguineous parents was investigated for hypoproteinaemia and anaemia. He was short, pale and had generalised oedema. Investigations revealed haemoglobin 5.8 g/dL; hypochromic microcytic anaemia; low serum protein, albumin, globulin, ferritin and iron. Bone marrow aspiration revealed low iron stores. Upper and lower gastrointestinal endoscopies showed moderate gastritis, duodenitis, and non-specific patchy inflammation in the rectum. The whole exome sequencing revealed a homozygous missense mutation in SCLO2A1 gene (NP_005621.2:p.Arg97Cys; rs761212094). Sanger sequencing of the sibling with milder phenotype revealed same homozygous mutation, and carrier father was heterozygous.CONCLUSION We report a novel mutation of SLCO2A1 gene causing severe persistent hypoproteinaemia and refractory iron deficiency anaemia due to chronic enteropathy helping to delineate genotype-phenotype correlation of SLCO2A1 variants.
AARC score determines outcomes in patients with alcohol-associated hepatitis: a multinational study
(Springer, 2023) Maiwall, R.; Pasupuleti, S.S.R.; Choudhury, A.; Kim, D.J.; Sood, A.; Goyal, O.; Midha, V.; Devarbhavi, H.; Arora, A.; Kumar, A.; Sahu, M.K.; Maharshi, S.; Duseja, A.K.; Singh, V.; Taneja, S.; Rao, P.N.; Kulkarni, A.; Ghazinian, H.; Hamid, S.; Eapen, C.E.; Goel, A.; Shreshtha, A.; Shah, S.; Hu, J.; Prasad, V.G.M.; Yuemin, N.; Shaojie, X.; Dhiman, R.K.; Chen, T.; Ning, Q.; Panackel, C.; Niriella, M.A.; Lama, T.K.; Tan, S.S.; Dokmeci, A.K.; Shukla, A.; Sharma, M.K.; Sarin, S.K.
BACKGROUND AND AIM: Acute-on-chronic liver failure (ACLF) is a severe form of alcoholic hepatitis (SAH). We aimed to study the natural course, response to corticosteroids (CS), and the role of the Asian Pacific Association for the Study of Liver (APASL) research consortium (AARC) score in determining clinical outcomes in AH patients. METHODS: Prospectively collected data from the AARC database were analyzed. RESULTS: Of the 1249 AH patients, (aged 43.8 ± 10.6 years, 96.9% male, AARC score 9.2 ± 1.9), 38.8% died on a 90 day follow-up. Of these, 150 (12.0%) had mild-moderate AH (MAH), 65 (5.2%) had SAH and 1034 (82.8%) had ACLF. Two hundred and eleven (16.9%) patients received CS, of which 101 (47.87%) were steroid responders by day 7 of Lille's model, which was associated with improved survival [Hazard ratio (HR) 0.15, 95% CI 0.12-0.19]. AARC-ACLF grade 3 [OR 0.28, 0.14-0.55] was an independent predictor of steroid non-response and mortality [HR 3.29, 2.63-4.11]. Complications increased with degree of liver failure [AARC grade III vs. II vs I], bacterial infections [48.6% vs. 37% vs. 34.7%; p < 0.001); extrahepatic organ failure [66.9% vs. 41.8% vs. 35.4%; p < 0.001] respectively. The AARC score better discriminated 90-day mortality. Harrell's C-index was 0.72 compared to other scores. CONCLUSION: Nearly 4 of 5 patients with AH present with ACLF. Such patients have a higher risk of infections, organ failures, lower response to CS, and higher mortality. Patients with AH and ACLF with AARC grade 3 should be considered for an early liver transplant.
Abdominal migraine in children: association between gastric motility parameters and clinical characteristics
(BioMed Central, 2016) Devanarayana, N.M.; Rajindrajith, S.; Benninga, M.A.
BACKGROUND: Approximately 0.2-1 % of children suffers from abdominal migraine (AM). Pathophysiology of AM has not been adequately studied. This study evaluated gastric motility in children with AM. METHODS: Seventeen children (6 boys), within an age range of 4-15 years, referred to a tertiary care paediatric unit, North Colombo Teaching Hospital Ragama, Sri Lanka, from 2007 to 2012, were screened. Those fulfilling Rome III criteria for AM were recruited after obtaining parental consent. None had clinical or laboratory evidence of organic disorders. Twenty healthy children (8 boys), with an age range of 4-14 years, were recruited as controls. Liquid gastric emptying rate (GE) and antral motility parameters were assessed using an ultrasound method. RESULTS: Average GE (41.6 % vs. 66.2 %, in controls), amplitude of antral contractions (A) (57.9 % vs. 89.0 %) and antral motility index (MI) (5.0 vs. 8.3) were lower and fasting antral area (1.8 cm(2) vs. 0.6 cm(2)) was higher in children with AM (p < 0.01). No significant difference in the frequency of antral contractions (F) (8.8/3 min vs. 9.3/3 min, p = 0.08) was found between the two groups. Scores obtained for severity of abdominal pain had a negative correlation with A (r = -0.55, p = 0.03). Average duration of abdominal pain episodes correlated with GE (r = -0.58, p = 0.02). Negative correlations were observed between duration of AM and A (r = -0.55), F (r = -0.52), and MI (r = -0.57) (p < 0.05). CONCLUSIONS: GE and antral motility parameters were significantly lower in children with AM. A significant correlation was found between symptoms and gastric motility. These findings suggest a possible role of abnormal gastric motility in the pathogenesis of AM.
Abdominal pain predominant functional gastrointestinal disorders in adolescent Nigerians
(Lippincott Williams and Wilkins, 2016) Udoh, E.; Devanarayana, N.M.; Rajindrajith, S.; Meremikwu, M.; Benninga, M.A.
AIMS: To determine the prevalence, pattern and predisposing factors of abdominal painpredominant functional gastrointestinal disorders (AP-FGIDs) in adolescent Nigerians. METHODS: A cross sectional study was conducted in two states in the southern part of Nigeria in June 2014. Adolescents aged 10 - 18 years were recruited from 11 secondary schools using a stratified random sampling technique. A validated self-administered questionnaire on Rome III criteria for diagnosing AP-FGIDs and its determinants were filled by the participants in a class room setting. RESULTS: A total of 874 participants filled the questionnaire. Of this, 818 (93.4%) filled it properly and were included in the final analysis. The mean age of participants was 14.6 ± 2.0 years with 409 (50.0%) being males. AP-FGIDs were present in 81 (9.9%) participants. Among them, 46 (5.6%) had irritable bowel syndrome (IBS), 21 (2.6%) functional abdominal pain, 15 (1.8%) abdominalmigraine while 3 (0.4%) had functional dyspepsia. The difference in AP-FGIDs between adolescents residing in rural and urban areas was not statistically significant (P = 0.22). AP-FGDs was significantly associated with frequent punishment at school (P = 0.03), Intestinal and extra-intestinal symptoms occurred more frequently in those with AP-FGIDs. loss of appetite (56.8% vs. 38.4% in controls), nausea (51.6% vs. 30.0%), headache (76.5% vs. 65.0%), photophobia (56.8% vs. 34.6%) and light-headedness (50.6% vs. 32.6%). Nausea was the only symptom independently associated with AP-FGIDs (p = 0.015). Multiple regression analysis showed no significant association between stressful life events and FGIDs. (P < 0.05). CONCLUSIONS: AP-FGIDs are a significant health problem in Nigerian adolescents. In addition to the intestinal symptoms, most of the affected children had other them also had extra-intestinal symptoms. None of the stressful life events evaluated was significantly associated with FGIDs. Frequent punishment in schools was significantly associated with the condition.
Abdominal pain-predominant functional gastrointestinal diseases in children and adolescents: prevalence, symptomatology, and association with emotional stress
(Lippincott Williams and Wilkins, 2011) Devanarayana, N.M.; Mettananda, S.; Liyanarachchi, C.; Nanayakkara, N.; Mendis, N.; Perera, N.; Rajindrajith, S.
BACKGROUND AND OBJECTIVE: Functional gastrointestinal disorders (FGD) are common among children, but little is known regarding their prevalence in developing countries. We assessed the prevalence of abdominal pain-predominant FGD, in addition to the predisposing factors and symptomatology, in Sri Lankan children. PATIENTS AND METHODS: A cross-sectional survey was conducted among a randomly selected group of 10- to 16-year-olds in 8 randomly selected schools in 4 provinces in Sri Lanka. A validated, self-administered questionnaire was completed by children independently in an examination setting. FGD were diagnosed using Rome III criteria. RESULTS: A total of 2180 questionnaires were distributed and 2163 (99.2%) were included in the analysis (1189 [55%] boys, mean age 13.4 years, standard deviation 1.8 years). Of them, 270 (12.5%) had at least 1 abdominal pain-predominant FGD. Irritable bowel syndrome (IBS) was seen in 107 (4.9%), functional dyspepsia in 54 (2.5%), functional abdominal pain in 96 (4.4%), and abdominal migraine (AM) in 21 (1.0%) (2 had AM and functional dyspepsia, 6 had AM and IBS). Extra intestinal symptoms were more common among affected children (P < 0.05). Abdominal pain-predominant FGD were higher in girls and those exposed to stressful events (P < 0.05). Prevalence negatively correlated with age (r = -0.05, P = 0.02). CONCLUSIONS: Abdominal pain-predominant FGD affects 12.5% of children ages 10 to 16 years and constitutes a significant health problem in Sri Lanka. IBS is the most common FGD subtype present. Abdominal pain-predominant FGD are higher in girls and those exposed to emotional stress. Prevalence of FGD decreased with age. Extra intestinal symptoms are more frequent in affected children.
Abdominal resection rectopexy with pelvic floor repair versus perinealn rectosigmoidectomy and pelvic floor repair for full-thickness rectal prolapse
(1994) Deen, K.I.; Grant, E.; Billingham, C.; Keighley, M.R.
A randomized trial was performed to compare abdominal resection rectopexy and pelvic floor repair (n = 10) with perineal rectosigmoidectomy and pelvic floor repair (n = 10) in elderly female patients with full-thickness rectal prolapse and faecal incontinence. There were no recurrences of full-thickness prolapse following resection rectopexy but one after rectosigmoidectomy. Continence to liquid and solid stool was achieved in nine patients, with faecal soiling reported in only two, after resection rectopexy and in eight, with soiling in six, following rectosigmoidectomy. The median (range) frequency of defaecation was only 1 (1-3) per day following resection rectopexy compared with 3 (1-6) per day after rectosigmoidectomy. There was an increase in the mean(s.d.) maximum resting pressure after resection rectopexy (19.3(15.28) cmH2O) compared with a reduction following rectosigmoidectomy (-3.4(13.75) cmH2O) (P = 0.003). Mean(s.d.) compliance was also greater after resection rectopexy than following rectosigmoidectomy (3.9(0.75) versus 2.2(0.78) ml/cmH2O, P < 0.001). Abdominal resection rectopexy gives better functional and physiological results than perineal rectosigmoidectomy.
The Ability of ICU admission to detect maternal near misses as defined by the who near-miss criteria
(Sri Lanka College of Obstetricians & Gynaecologists, 2015) Bower, G.; Dias, T.; Shanmugaraja, V.; Lee, M.; Cooper, D.; Crofton, H.; Kumarasiri, S.; Padeniya, T.
OBJECTIVE: to assess the ability of intensive care unit (ICU) admission in pregnancy, or the postpartum period, to detect cases of obstetric near-miss. METHODS: All obstetric admissions to the ICU were included retrospectively and data collected as specified by 2011 World Health Organization (WHO) guidelines on evaluating obstetrics near-misses between 2010 and 2013 in a Sri Lankan Hospital. Proportion of ICU admissions which fulfilled the WHO criteria for Severe Acute Maternal Morbidity (SAMM), maternal mortality ratio (MMR), maternal near-miss mortality ratio (MNM: MM)), and maternal near-miss ratio (MNMR) were analysed. RESULTS: A total of 9,608 live births were reported. 118 ICU admissions and four maternal deaths were analysed. MMR was 42 per 100,000. MNMR was 9.7 per 1000, and MNM: MM was 23:1. From all ICU admissions 99 cases (79.8%) met additional WHO near-miss criteria and were classified as true SAMM. Pregnancy-induced hypertensive disorders accounted for majority of ICU admissions (37.7%). Out of eight published studies from our region none of them had a MNM: MM higher than ours. CONCLUSIONS: Obstetric near-misses may be over-diagnosed if ICU admission is considered an independent inclusion criterion for SAMM. Reporting the proportion of patients admitted to ICU which are true near-miss may illustrate differing admission thresholds for a given institution.
Abnormal functions of pottasium channels in the platelets of patients with Alzheimer's disease
(Lancet Publishing Group, 1998) de Silva, H.A.; Aronson, J.K.; Grahame-Smith, D.G.; Jobst, K.A.; Smith, A.D.
BACKGROUND:Reports of abnormalities of potassium-channel function in various cultured cells of Alzheimer's disease patients led us to attempt to characterise the pharmacological characteristics of the abnormal channel.METHODS: We studied platelets from 14 patients with Alzheimer-type dementia and 14 non-demented controls matched for age and sex. The effects of specific inhibitors of K+ channels on the efflux of rubidium-86 ions, a radioactive analogue of K+, from the platelets were measured.FINDINGS: Normal platelets contain three types of K+ channel, sensitive to the inhibitory actions of apamin (small-conductance calcium-dependent potassium channels), charybdotoxin (of less specificity, but probably intermediate-conductance calcium-dependent K+ channels), and alpha-dendrotoxin (voltage-sensitive K+ channels). However, 8Rb+ efflux from the platelets of patients with Alzheimer-type dementia was not inhibited by either apamin or charybdotoxin. By contrast, inhibition by alpha-dendrotoxin did occur. INTERPRETATION: Our results suggest that calcium-dependent K+ channels in platelets are selectively impaired in Alzheimer's disease. A similar abnormality in neurons could contribute to the pathophysiology of the disorder.
ABO-blood-group types and protection against severe, Plasmodium falciparum malaria
(Academic Press, 2005) Pathirana, S.L.; Alles, H.K.; Bandara, S.; Phone-Kyaw, M.; Perera, M.K.; Wickremasinghe, A.R.; Mendis, K.N.; Handunnetti, S.M.
An ABO-incompatible living donor liver transplant in an infant with acute liver failure in the Sri Lankan setting
(The Sri Lanka Medical Association, 2023) Fernando, M.; Tillakaratne, S.; Gunetilleke, B.; Liyanage, C.; Appuhamy, C.; Weerasuriya, A.; Dissanayake, J.; Siriwardana, R.
Liver transplant (LT) is the standard therapy for medically refractory acute liver failure (ALF). Finding a deceaseddonor graft in an emergency is challenging and often overcome by living-donation. Blood group matching is practised for LT though ABO-incompatible liver transplant (ABOi-LT) is performed inselected circumstances. We report an infant who underwent successful ABOincompatible living donor LT for ALF of unknown aetiology. This being the country’s first ABOi-LT, the youngest LT recipient to date and the youngest receiving emergency LT for ALF; we describe the novel experience at a resource-limited setting in Sri Lanka (SL).
Absence of anti-Purkinje cell antibodies in patients with cerebellar ataxia following falciparum malaria
(SEAMEO Regional Tropical Medicine and Public Health Project, 1994) de Silva, H.J.; Senanayake, N.
Immunological mechanisms have been implicated in the pathogenesis of delayed cerebellar ataxia following falciparum malaria (DCA). We tested serum and CSF samples obtained from 39 Sri Lankan patients with DCA for the presence of antibodies (Ab) directed against cerebellar Purkinje cells by an immunofluorescence (IF) technique and Western blot analysis. For the IF test 7 mu thick frozen sections of histologically normal cerebellum obtained at post mortem were used. Proteins obtained from crude preparations of Purkinje cells isolated from the cerebellum were used for Western blot analysis. Sera obtained from patients known to have antineuronal antibodies associated with cerebellar degenerations and paraneoplastic disorders (anti-Hu and anti-Yo Ab) and sera from normal blood donors served as positive and negative controls, respectively. All serum and CSF samples obtained from patients with DCA were negative for Ab directed against cerebellar Purkinje cells. Humoral mechanisms are, therefore, unlikely to be important in the pathogenesis of this delayed complication of falciparum malaria.
Absence of Wolbachia endobacteria in Sri Lankan isolates of the nematode parasite of animals Setaria digitata
(Elsevier, 2015) Voronin, D.; Abeykoon, A.M.; Gunawardene, Y.I.N.S.; Dassanayake, R.S.
Setaria digitata is an animal filarial parasite with natural hosts of cattle and buffaloes that causes mild disease conditions. Infection of non-permissive hosts such as goats, sheep and horses, by this nematode can cause cerebrospinal nematodiasis that leads to lumbar paralysis and the eventual death of the animals and inflicts considerable economic losses on livestock farmers. Wolbachia are obligate mutualistic endosymbionts for some filarial nematodes and are currently being targeted for the control of diseases caused by these parasites. However, little is known about the occurrence of this endosymbiont in the Setariidae family. In this work, worms collected from infected cattle in Sri Lanka were morphologically identified as S. digitata and tested for the presence of Wolbachia by PCR screening using the WSP- and Wolbachia-specific 16S rRNA and multilocus sequence typing primers that were designed to amplify the gatB, coxA, hcpA, ftsZ and fbpA sequences of Wolbachia. The presence of endobacteria in S. digitata was also examined by whole-mount immunofluorescence staining of the parasites and transmission electron microscopic studies. These analyses did not produce evidence of presence of Wolbachia or any other endosymbiotic bacteria in S. digitata, whereas such evidence was found in Brugia malayi, which was used as a positive control in this study. Copyright © 2014 Elsevier B.V. All rights reserved
Abundance and taxonomic characterization of chigger mites (Acari: Trombiculidae and Walchiidae) associated with rodents in selected scrub typhus-prone areas in Southern and Western provinces of Sri Lanka
(University of Kelaniya, 2024) Liyanage, A.; Gunathilaka, N.; Premarathne, R.; Chandrasena, N.; Jacinavicius, F.D.C.; Silva, R.B.
Larval trombiculid mites (chiggers) are the vectors and reservoirs of the potentially lethal infectious disease, scrub typhus (ST) caused by Orientia tsutsugamushi. Small rodents are natural hosts of parasitic larval stage of the chigger mites. This study focused on determining the abundance of chigger mites associated with rodents in Sri Lanka and the taxonomic characterization of field-caught chiggers. Field sampling was conducted in the districts of Galle, and Hambantota of the Southern Province, and Gampaha of the Western Province, in 2019 and 2020. Sampling sites were selected according to the patient distribution. Rodents were captured using baited traps (7.62 cm x 7.62 cm x 25.4 cm) set up just before sunset at peri-domestic or work premises of ST fever patients. A total of 422 traps were placed at identified possible exposure locations in Galle (n=122), Hambantota (n=120) and Gampaha (n=178). A total of 58 small mammals were captured [Galle (n=19), Hambantota (n=7), and Gampaha (n=32)] under three small rodent species, namely; Rattus rattus (Black rat), Rattus norvegicus (Brown rat), Tatera indica (Indian gerbil), Gollunda ellioti (Indian bush rat) and Suncus murinus (Asian house shrew). The trapped rodents were anaesthetized with ketamine (75 mg/kg) /xylazine (10 mg/kg) and examined for larval mites. Mites detected were removed carefully with a brush, collected, and washed individually with 10% PBS and slidemounted in Hoyer’s medium. Chiggers were speciated morphologically by visual inspection and morphometry using a camera-mounted light microscope (x100). A total of 394 life stages of mites were collected. Three different genera were identified, including Leptotrombidium, Schoengastiella, and Microtrombicula. Leptotrombidium imphalum (72.59%; n=286) was the predominant species, followed by Schoengastiella punctata (8.12%; n=32). Some specimens were identifiable only up to genus level, Leptotrombidium sp. (3.55%; n=14) and Microtrombicula sp. (4.82%; n= 19). Some (7.11%; n=28) were not trombiculid mites, while 3.81%; n=15 was damaged beyond identification. Leptotrombidium imphalum was detected for the first time parasitizing the murids - Rattus novergicus and Tatera indica in the district of Galle, a new locality. In addition, S. punctata was recorded in a new locality in the Gampaha district, Western province with a new host association, Golunda ellioti. This study emphasizes the need for further entomological surveys in ST disease-endemic areas. Developing a morphological identification key for chigger mites in Sri Lanka is a top priority to facilitate field surveys.
Abuse, maltreatment and bullying in childhood
(Sri Lanka College of Psychiatrists, 2015) Williams, S.S.; Ariyasinghe, D.