
Senaka RajapakseUniversity of Colombo · Department of Clinical Medicine
Senaka Rajapakse
MBBS MD FRCP(Lon) FRCP(Edin) FCCP FACP FNASSL
About
171
Publications
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Introduction
Leptospirosis
Skills and Expertise
Additional affiliations
August 1996 - present
Education
January 1997 - August 2001
Publications
Publications (171)
Resistant hypertension (RHTN) is defined as uncontrolled blood pressure despite treatment (>140/90 mmHg) with concurrent use of three antihypertensive agents of different classes, one of which should be a diuretic. A comparative analysis of the extended APPROPRIATE trial was conducted on measures of reactive nitrogen species (NO2-and NOx) and antio...
Objectives
To perform a comparative analysis of the extended APPROPRIATE trial of measures of reactive nitrogen species and antioxidant capacity in patients having resistant hypertension with controlled hypertension and healthy controls.
Results
Mean serum NO2- and NOx levels were significantly lower and mean AOC was significantly higher in patien...
Background
Leptospirosis caused by pathogenic spirochaetes of Leptospira spp remains the most widespread zoonotic disease in the world. Clinical status in leptospirosis patients vary from asymptomatic, mild and severe/fatal outcomes. The objective of this study was to determine the species/genotypes of Leptospira that cause mild and severe infectio...
Background Leptospirosis caused by pathogenic spirochaetes of Leptospira spp remains the most widespread zoonotic disease in the world. Clinical status in leptospirosis patients varies from asymptomatic infection to mild illness to severe/fatal outcomes. The objective of this study was to determine the species of Leptospira that cause mild and seve...
Background
Leptospirosis is a zoonotic disease caused by Leptospira species. Variations in lipopolysaccharide (LPS) structure in Leptospira are known to be associated with the serovar diversity and antigenicity. Development of immunodiagnostics for early detection of leptospirosis based on immune responses against different pathogenic antigens as w...
Citrate is widely used as an anticoagulant for platelet function tests (PFTs). Due to an intrinsic inhibitory effect of citrate on platelet function, hirudin is used as an alternative. However, studies comparing the effect of these anticoagulants on rotational thromboelastometry (ROTEM) platelet whole blood impedance aggregometry in thrombocytopeni...
All four serotypes of the dengue virus (DENV1–4) cause a phenotypically similar illness, but serial infections from different serotypes increase the risk of severe disease. Thus, genomic surveillance of circulating viruses is important to detect serotype switches that precede community outbreaks of disproportionate magnitude. A phylogenetic analysi...
Background
At least a third of dengue patients develop plasma leakage with increased risk of life-threatening complications. Predicting plasma leakage using laboratory parameters obtained in early infection as means of triaging patients for hospital admission is important for resource-limited settings.
Methods
A Sri Lankan cohort including 4,768 i...
Background
Dengue could cause complications with an estimated 10,000 deaths per annum. It mostly affects low- and middle-income countries such as Sri Lanka with limited healthcare resources to handle seasonal outbreaks. A third of dengue patients usually have a critical phase characterized by plasma leakage with increased risk of life-threatening c...
Given the structural similarity between Zika and dengue viruses, prior infection from one virus is hypothesized to modulate the severity of a subsequent infection from the other virus. A previous paediatric cohort study observed that a prior Zika infection may increase the risk of a subsequent symptomatic or severe dengue infection. The Colombo Den...
Post-chikungunya joint pain (arthritis or arthralgia) is a clinical concern in endemic regions as it may cause a debilitating illness sometimes years after the acute infection. This systematic review analyses evidence from controlled clinical trials regarding the efficacy of pharmacological and non-pharmacological interventions to treat post-chikun...
Background:
The critical phase of dengue carries a high risk of bleeding. Associations of coagulation test parameters and the risk of bleeding in the critical phase is unclear. This study examines the association of rotational thromboelastometry (ROTEM delta and ROTEM platelet) with bleeding risk of patients with dengue in the critical phase.
Met...
Plasma leakage is a precursor to life-threatening complications of dengue, but this group is poorly defined and not often reported in literature. Patients with Dengue haemorrhagic fever (DHF) as defined in the 1997 World Health Organization classification are often reported, and they all have plasma leakage, but some patients with plasma leakage do...
Introduction
The cost in managing hospitalised dengue patients varies across countries depending on access to healthcare, management guidelines, and state sponsored subsidies. For health budget planning, locally relevant, accurate costing data from prospective studies, is essential.
Objective
To characterise the direct costs of managing hospitalis...
Objectives
To compare the traditional haematocrit‐based criteria (>20% rise above baseline) with ultrasonography for diagnosing plasma leakage in dengue fever and to identify clinical indicators for triaging patients in resource‐limited settings when the demand for ultrasonography is high.
Methods
The Colombo Dengue Study is a prospective observat...
Background
Leptospirosis is most often clinically diagnosed and a laboratory test with high diagnostic accuracies is required.
Methodology
IgM and IgG-ELISAs using Leptospira antigens were established and evaluated in relation to the Microscopic Agglutination Test (MAT). Antigen preparation consisted either saprophytic Leptospira biflexa to detect...
Objectives:
The objective was to assess the effect of propranolol on oxidative stress and anti-oxidant potential in patients with resistant hypertension as a secondary analysis of the APPROPRIATE trial. This randomized double blinded clinical trial recruited patients with resistant hypertension and allocated forty patients to propranolol and place...
Background
Chemoprophylaxis is an effective tool for individuals to minimize their risk of contracting malaria and serves an important public health role in preventing imported malaria. Yet, it is only effective if the traveller is fully compliant with the prescribed regimen. For many destinations, a choice of prophylactic agents is available, so h...
Background
Previous studies on post-infection fatigue in dengue are few but suggest that up to 25% of dengue patients may suffer from fatigue. This study aimed to evaluate the prevalence and associations of post-infection fatigue in dengue patients compared with non-dengue fever patients.
Methods
Post-infection fatigue and its demographic and clin...
Current methods for dengue virus (DENV) genome amplification, amplify parts of the genome in at least 5 overlapping segments and then combine the output to characterize a full genome. This process is laborious, costly and requires at least 10 primers per serotype, thus increasing the likelihood of PCR bias. We introduce an assay to amplify near ful...
Background:
Plasmodium vivax malaria has a persistent liver stage that causes relapse of the disease and continued P vivax transmission. Primaquine (PQ) is used to clear the liver stage of the parasite, but treatment is required for 14 days. Primaquine also causes haemolysis in people with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Tafen...
Context
Coagulation abnormalities have been observed among leptospirosis patients. However, coagulopathy in severe leptospirosis has not been further characterized.
Aims
The aim of this study was to evaluate conventional coagulation and rotational thromboelastometry (ROTEM®) parameters in leptospirosis patients.
Settings and Design
This prospecti...
Leptospirosis is endemic in Sri Lanka. There is a need for updated seroprevalence studies in endemic areas, to improve the understanding of disease dynamics, risk factors, control methods, and for clinical diagnosis. The cut-off titres for the microscopic agglutination test (MAT) for diagnosis of acute leptospirosis depend on community seroprevalen...
Background
Repurposing hydroxychloroquine (HCQ) and chloroquine (CQ) as antiviral agents is a re-emerging topic with new viral epidemics.
Objectives
To summarize evidence from human clinical studies for using HCQ or CQ as antiviral agents for any viral infection.
Data sources
PubMed, EMBASE, Scopus, Web of Science for published studies without ti...
Background:
Carica papaya (CP) extract is becoming popular as an unlicensed herbal remedy purported to hasten recovery in dengue infection, mostly based on observations that it may increase platelet counts. This systematic review and meta-analysis aims to critically analyze the evidence from controlled clinical trials on the efficacy and safety of...
Introduction:
Sri Lanka has a predominantly rural population. However, there is a dearth of research on health and socioeconomic issues in this group.
Objective:
To describe basic socioeconomic characteristics and health profile in a rural population.
Methods:
A descriptive cross-sectional household survey was conducted in 1950 households in t...
Abstract Background A major challenge in dengue management in resource limited settings is the confirmation of diagnosis. Clinical features of dengue often overlap with other infections and molecular diagnostic tools are not readily accessible to clinicians at hospitals. In addition, the prediction of plasma leakage in dengue is also difficult. Hem...
Background:
Elevated blood pressure incurs a major health and economic burden, particularly in low-income and middle-income countries. The Triple Pill versus Usual Care Management for Patients with Mild-to-Moderate Hypertension (TRIUMPH) trial showed a greater reduction in blood pressure in patients using fixed-combination, low-dose, triple-pill a...
Primaquine was the only licenced antimalarial hypnozoiticidal drug available until recently. Now there is a newly approved alternative: tafenoquine. This review explores the efficacy of tafenoquine as a primary and terminal prophylactic agent in malaria. Multiple databases (Cochrane Central Register of Controlled Trials [CENTRAL], MEDLINE [PubMed],...
Dengue infection classically presents with fever, thrombocytopaenia, and varying degrees of plasma leakage, giving rise to shock. However, a myriad of other manifestations, involving the cardiovascular system, the nervous system, the liver, the kidneys, the gut and the haematological system have been reported in dengue. This review summarizes these...
Importance
Poorly controlled hypertension is a leading global public health problem requiring new treatment strategies.
Objective
To assess whether a low-dose triple combination antihypertensive medication would achieve better blood pressure (BP) control vs usual care.
Design, Setting, and Participants
Randomized, open-label trial of a low-dose t...
The aim of this study was to assess the inflammatory cytokine response and possible association with antimicrobial treatment with penicillin, ceftriaxone and doxycycline in acute leptospirosis. In the early acute stage, IL-10 was higher in mild cases compared to severe cases (p=0.01). IL-6 and IL-8 levels were low in patients who received >5 antimi...
Background:
Blood smear changes have never been investigated as a potential tool to aid in the diagnosis of leptospirosis.
Methods:
Blood smears prepared from patients with leptospirosis, dengue and sepsis within the first 5 days of illness were reported by haematologists blinded to the diagnosis.
Results:
A total of 20, 28 and 22 patients wit...
The global incidence of dengue has increased sevenfold between 1990 and 2013. Despite a low case fatality rate (<1%), during epidemics, due to the large number of people affected, overall mortality rates can be significant. The risk of clinically significant bleeding in dengue is unpredictable and often contributes to an adverse outcome. This syste...
Objective
The objectives of this study were to; (a) evaluate the current practices of peer assisted learning among second year and final year medical students of Faculty of Medicine, University of Colombo, Sri Lanka; (b) identify reasons for engaging in peer assisted learning; (c) identify perceived weaknesses in current learning activities; and (d...
Objectives:
The aim of this review is to evaluate the evidence for use of different formulations of amphotericin B, minimum effective dose for each formulation and its comparative efficacy against other drugs in achieving definitive cure of visceral leishmaniasis.
Methods:
This systematic review and meta-analysis included following data sources;...
Toxoplasmosis is an infection caused by the intracellular protozoan parasite Toxoplasma gondii, and is associated with clinically significant infection in immunocompromised individuals. Vertical transmission during pregnancy can manifest as congenital toxoplasmosis in the neonate, and can have serious consequences. This review aims to describe the...
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
To assess the efficacy of vector control measures against Ae. albopictus and Ae. aegypti in reducing the incidence of viral infections spread by these mosquito species.
The mite-borne rickettsial zoonosis scrub typhus is widely prevalent in parts of Southeast and Far East Asia, and northern Australia. The disease is an acute febrile illness, associated with rash and often an eschar, which responds dramatically to treatment with antibiotics. In some cases it results in a serious illness leading to multiple organ in...
Background:
Resistant hypertension is defined as an uncontrolled blood pressure despite treatment at best-tolerated doses with at least three antihypertensive agents including a diuretic. It is an emerging public health problem. At present clinical trial data on management of resistant hypertension is limited. Management is largely based on observ...
Introduction:
In the last two decades, chronic kidney disease of unknown etiology (CKDu) has emerged as a significant contributor to the burden of chronic kidney disease (CKD) in rural Sri Lanka. It is characterized by the absence of identified causes for CKD. The prevalence of CKDu is 15.1-22.9% in some Sri Lankan districts, and previous research...
Abstract
Background
Leptospirosis is a zoonotic infection with significant morbidity and mortality. The clinical presentation of leptospirosis is known to mimic the clinical profile of other prevalent tropical fevers. Laboratory confirmation of leptospirosis is based on the reference standard microscopic agglutination test (MAT), direct demonstrati...
Background:
Leptospirosis is a zoonotic infection with significant morbidity and mortality. The clinical presentation of leptospirosis is known to mimic the clinical profile of other prevalent tropical fevers. Laboratory confirmation of leptospirosis is based on the reference standard microscopic agglutination test (MAT), direct demonstration of t...
STROBE Checklist.
(DOCX)
Coordinates of the ROC curve.
(XLSX)
Dataset utilized for analysis.
(SAV)
Pathogenesis of disease severity in leptospirosis is not clearly understood whether it is due to direct damage by pathogen or by adverse immune responses. Knowledge on biomarkers of oxidative stress which could be used in identifying patients with severe illness has shown to be of great value in disease management. Thus, the main aim of this study...
Serum parameters of patients and healthy subjects.
(DOCX)
Protein carbonyl and lipid hydroperoxide levels of severe and mild leptospirosis patients, who had acute MAT titre below the positive cut-off.
(DOCX)
This is the protocol for a review and there is no abstract. The objectives are as follows: To assess the effectiveness of primaquine and tafenoquine for primary prophylaxis againstPlasmodium vivax andPlasmodium falciparum infections. To assess the effectiveness of tafenoquine for terminal prophylaxis of vivax malaria. To compare the safety profile...
Leptospirosis is often treated based on clinical diagnosis. There is a need for rapid laboratory diagnosis for this condition. The aim of this study was to compare the diagnostic accuracy of two rapid IgM based immunodiagnostic assays with the microscopic agglutination test (MAT), in acute leptospirosis infection.
MAT, IgM based immunochromatograph...
Chronic kidney disease of unknown etiology (CKDu) is a major healthcare issue in Sri Lanka. This study included 125 consecutive
patients with a diagnosis of CKDu undergoing renal biopsy at one hospital from 2008 to 2012. Associations between renal outcome
parameters, epidemiological data, and histopathological findings were examined and regression...
Use of reference sources for medical knowledge has changed dramatically over the last two decades with the introduction of online sources of information. This study analyses the medical knowledge seeking behaviours of pre interns and early career doctors in Sri Lanka.
This cross sectional survey with a convenience sample was conducted at two sites...
BACKGROUND:
Leptospirosis results in significant morbidity and mortality. This study elucidates markers of severity in a cohort of Sri Lankan patients.
METHODS:
Patients presenting to three healthcare institutions in the Western province of Sri Lanka with leptospirosis serological confirmed by the microscopic agglutination test (MAT) were included....
Sri Lanka has eliminated local transmission of malaria. Assessing physician preparedness for early case detection is important, in order to prevent re-establishment of local transmission.
Adherence to malaria screening practices in patients admitted with fever to 12 hospitals in a previously malaria endemic district was evaluated using a cross sect...
Leptospirosis is diagnosed on clinical grounds, and confirmed by microscopic agglutination test (MAT). IgM-ELISA (Serion-Virion) and immunochromatography test (Leptocheck-WB) are two immunodiagnostic assays for leptospirosis. Their sensitivity, specificity and applicability in Sri Lanka have not been systematically evaluated.
Clinically diagnosed l...
Background:
Plasmodium vivax malaria is widespread, and the persistent liver stage causes relapse of the disease which contributes to continued P. vivax transmission. Primaquine is currently the only drug that cures the parasite liver stage, but requires 14 days to be effective and can cause haemolysis in people with glucose-6-phosphate dehydrogen...
Dengue is endemic in the tropics, and complications involving organ systems are seen with varying incidence.
We performed a systematic review. MEDLINE, EMBASE, Scopus SciVerse, Google Scholar, and LILACS were searched for papers providing information on cardiac involvement in dengue.
Cardiac involvement is not uncommon in dengue infection and is of...
Leptospirosis is an illness with a wide spectrum of clinical manifestations, and severe illness affects nearly all organ systems. Serious and potentially life threatening clinical manifestations of acute leptospirosis are caused by both direct tissue invasion by spirochaetes and by the host immune responses. In its severe form, leptospirosis can ca...
Introduction
The success of treatment of depression in rural Sri Lanka is under-assessed. Given the limited facilities, social stigma associated with mental illness and cultural beliefs, clinic attendance and treatment compliance was expected to be poor
Objectives
To ascertain the default rates of patients treated for depression
Methods
This stud...
Leptospirosis is a zoonotic spirochaetal illness that is endemic in many tropical countries. The research base on leptospirosis is not as strong as other tropical infections such as malaria. However, it is a lethal infection that can attack many vital organs in its severe form, leading to multi-organ dysfunction syndrome and death. There are many g...
Venous thromboembolism (VTE) is an important cause of morbidity and mortality among patients admitted to hospital. Pulmonary embolism results in 5-10% of deaths, and is the commonest cause of preventable deaths in hospitalised patients . In addition, considerable morbidity results from VTE, such as post-thrombotic syndrome and chronic thromboemboli...
Dengue is potentially fatal unless managed appropriately. No specific treatment is available and the mainstay of treatment is fluid management with careful monitoring, organ support, and correction of metabolic derangement. Evidence with regards to the role of calcium homeostasis in dengue is limited. Low blood calcium levels have been demonstrated...
Migration of medical professionals is a long recognized problem in Sri Lanka but it has not been studied in depth. Undergraduate and postgraduate medical education in Sri Lanka is state sponsored and loss of each trained personnel is a loss of an investment. This study assessed the intention of migration of medical students and newly passed out gra...