Browsing by Author "Malavige, N."

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    Behaviour of Cytokines IL10, IL6 and IFy during late febrile and immediate defervercent phases of Dengue
    (Sri Lanka Medical Association, 2014) Weerasinghe, O.M.S.; Premaratna, R.; Gomes, L.; Perera, J.; Silva, S.; Abeyratna, C.; Kasturiratne, A.; Malavige, N.; de Silva, H.J.
    INTRODUCTION AND OBJECTIVES: Cytokines have been implicated in dengue (DF) pathogenesis. Behaviour of cytokines during the late febrile phase (LFP) and immediate defeversence have not been studied, but may be useful to understand the pathophysiology of disease progression and effect of interventions. METHODS: A preliminary prospective study was performed to investigate 1L-10, IL6 and IFy (pg/ml) responses during the late febrile phase (around fifth day) and immediate defervestence in confirmed (NSlAg positive} dengue patients. Demographic, clinical and laboratory data were collected. Two samples of 1 m! serum were obtained during the above stages of the illness and stored at -80°C to assess cytokine levels. Cytokine levels were compared between phases (LFP and afebrile) and stages (DF, precritical and critical dengue shock syndrome (DSS)). LFP cytokine levels were compared for disease stages using one-way Anova test. RESULTS: 18 patients (11 males, mean age 26 years (SD 10.6)) were studied. There were 3 DF, 9 precritical and 6 criticaj DSS based on national guidelines. Mean temperature during LFP and defervescent phases were 102.07°F (SD 0.98) and 98.53°F (SD 0.26). Median (interquartile range) of IL10, IL6 and IFy in LFP were 164.3 (90.8 - 259.5), 26 (12.7-54.6), 246.5 (117.5-511.8) and during defervescent phase were 17.4 (6A-112.2), 11.9 (4.9-28.2), 2.58 (0.0-58.4) respectively. LFP IL10 significantly correlated with disease stages (F-3.99, P-0.041), IL6 and IFy had no correlation. CONCLUSIONS: All three cytokines rapidly declined with defervecence. IL10 in febrile phase showed significant correlation with disease severity.
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    A cluster-randomized, placebo-controlled trial to evaluate the efficacy of a spatial repellent (Mosquito Shield™) against Aedes-borne virus infection among children ≥ 4-16 years of age in the Gampaha District, Sri Lanka: study protocol (the AEGIS program)
    (BioMed Central, 2023) Tissera, H.; Dheerasinghe, D.S.A.F.; Malavige, N.; de Silva, H.A.; Morrison, A.C.; Scott, T.W.; Reiner, R.C. Jr.; Grieco, J.P.; Achee, N.L.
    BACKGROUND: Spatial repellents (SRs) have been widely used for prevention of mosquito bites, but their efficacy in reducing Aedes-borne viruses (ABV) has not been tested rigorously at large scale in Asia. To address this knowledge gap, a trial to evaluate the efficacy of Mosquito Shield™, a transfluthrin SR, was developed in Gampaha District of Sri Lanka across three Medical Officer of Health areas; i.e., Negombo, Wattala, and Kelaniya. METHODS: This trial is a cluster-randomized, placebo-controlled, double-blinded clinical trial. A total of ~14,430 subjects aged ≥ 6 months in 30 clusters (15 intervention, 15 placebo) from ~3900 households (HH) will be randomly selected for enrolment into a "febrile surveillance cohort." A subset of the surveillance cohort, ~3570 subjects aged ≥4-16 years that test seronegative (naïve) or are serologically positive for a previous single dengue virus (DENV) infection (monotypic) at baseline sampling, will be enrolled into a "longitudinal cohort" for measuring DENV infection based on laboratory-confirmed seroconversion during the trial. Persons identified positive for antibodies against multiple DENV serotypes (multitypic) at baseline will be monitored for secondary analyses. Active ABV disease will be assessed using an enhanced passive surveillance system with case ascertainment performed in designated healthcare facilities. Serum samples will be taken from longitudinal cohort subjects within 1-2 weeks of when intervention is first deployed (T0) with additional samples taken ~12 (T1) and ~24 months (T2) from baseline sampling. DENV seroconversion and ABV active disease rates from baseline (pre-intervention) and follow-up (post-intervention) samples will be compared between intervention and placebo clusters. Participating houses will be monitored entomologically (indoor adult Aedes aegypti population densities and adult female blood fed status) within 3 months before intervention deployment and monthly during the intervention phase. Entomological surveys will monitor indoor adult Ae. aegypti population densities and blood fed status. Dengue incidence in each cohort will be estimated and compared to determine the public health benefit of using an SR. Entomological parameters will be measured to determine if there are entomological correlates of SR efficacy that may be useful for the evaluation of new SR products. DISCUSSION: The trial will serve as an efficacy assessment of SR products in South Asia. Results will be submitted to the World Health Organization Vector Control Advisory Group for assessment of public health value towards an endorsement to recommend inclusion of SRs in ABV control programs.