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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Author: search.filters.author.Dayanath, M.Y.D.

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Now showing 1 - 6 of 6
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    A Comparative retrospective study of RT-PCR-based liquid hybridization assay for early, definitive diagnosis of dengue
    (Oxford University Press, 2010) Hapugoda, M.D.; de Silva, N.R.; Khan, B.; Dayanath, M.Y.D.; Gunesena, S.; Prithimala, L.; Abeyewickreme, W.
    Dengue is an important flaviviral infection in tropical and subtropical regions. Early diagnosis of dengue infection helps in monitoring the disease, determining when hospital admission is necessary and reducing case fatalities. The objective of this study was to carry out a retrospective comparison of an RT-PCR-based liquid hybridization (RT-PCR-LH) assay with PCR amplification, virus isolation and serological techniques for laboratory diagnosis of dengue infection. Amplified products of non-structural 3 gene were hybridized with a mixture of four dengue type-specific DNA probes in liquid phase. The assay was validated in a comparative retrospective study using acute serum samples collected from 119 fever patients with or without dengue, confirmed by haemagglutination inhibition (HAI) assay, the gold standard assay for diagnosis of dengue infection. The RT-PCR-LH assay was highly specific for dengue and, as an early laboratory diagnostic method, had 100% sensitivity in detecting dengue patients confirmed by HAI assay. A high analytical sensitivity of two fluorescent focus units of dengue virus/reaction was achieved. This RT-PCR-LH assay using a single serum specimen offers distinct advantages of specificity and sensitivity over other diagnostic techniques for early definitive laboratory diagnosis of dengue infection when serological methods are of little value.
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    Molecular markers of chloroquine resistance in Plasmodium falciparum in Sri Lanka:frequency before revision of the antimalarial drug policy
    (Academic Press, 2009) Hapuarachchi, H.A.C.; Abeysundara, S.; Dayanath, M.Y.D.; Manamperi, A.; Abeyewickreme, W.; de Silva, N.R.
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    Intestinal parasites and the growth status of internally displaced children in Sri Lanka
    (Sage Publishing, 2007) Chandrasena, T.G.A.N.; Hapuarachchi, H.A.C.; Dayanath, M.Y.D.; Pathmeswaran, A.; de Silva, N.R.
    The growth status and intestinal parasitic infections among a group of children displaced by war in Sri Lanka was investigated. There was a high prevalence of growth retardation (wasting, stunting and underweight being 41 percent, 28percent and 69.9 percent, respectively) and intestinal parasitic infections (40.2 percent) among the study population. Provision of adequate food, purified drinking water, sanitation and broad-spectrum anthelmintics is recommended.
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    Point mutations in the dihydrofolate reductase and dihydropteroate synthase genes of Plasmodium falciparum and resistance to sulfadoxine-pyrimethamine in Sri Lanka
    (American Society of Tropical Medicine and Hygiene, 2006) Hapuarachchi, H.A.C.; Dayanath, M.Y.D.; Bandara, K.B.A.T.; Abeysundara, S.; Abeyewickreme, W.; de Silva, N.R.; Hunt, S.Y.; Sibley, C.H.
    Sulfadoxine-pyrimethamine (SP) is the second-line treatment for Plasmodium falciparum malaria in Sri Lanka. Resistance to SP is caused by point mutations in the dihydrofolate reductase (Pf-dhfr) and dihydropteroate synthase (Pf-dhps) genes of P. falciparum. We determined the genotype of Pf-dhfr and Pf-dhps and the clinical response to SP in 30 field isolates of P. falciparum from Sri Lanka. All patients treated with SP had an adequate clinical response. Eighty-five percent (23 of 27) of pure field isolates carried parasites with double mutant alleles of Pf-dhfr (C59R + S108N) and showed about 200-fold higher levels of resistance to pyrimethamine than the wild type in a yeast system. None of the isolates had either known or novel mutations at other positions in the dhfr domain. In contrast, 67% (20 of 30) of the isolates carried parasites that were wild type for Pf-dhps. In Sri Lanka, detection of the triple mutant allele of Pf-dhfr will require tracking mutations at codon 51
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    Intestinal Parasitoses and the nutritional status of internally displaced children in Vavuniya
    (Sri Lanka Medical Association, 2005) Chandrasena, T.G.A.N.; Hapuarachchi, H.A.C.; Dayanath, M.Y.D.; de Silva, N.R.
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    Chloroquine resistant falciparum malaria among security forces personnel in the Northern Province of Sri Lanka
    (Sri Lanka Medical Association, 2004) Hapuarachchi, H.A.C.; Dayanath, M.Y.D.; Abeysundara, S.; Bandara, K.B.A.T.; Abeyewickreme, W.; de Silva, N.R.
    OBJECTIVE: To determine the occurrence and species distribution of malaria and the extent of chloroquine resistance among security forcespersonnel in a selected region of the Northern Province of Sri Lanka. DESIGN: A descriptive study. SETTING: Mannar District in the Northern Province. METHODS: Nine hundred and seventy five security personnel were screened for malaria by microscopy. Those who were positive were treated withchloroquine and were subjected to 28 day in vivo assay to determine chloroquine resistance. In vitro microtest assay was performed to determine the response of Plasmodium falciparum isolates to chloroquine in vitro. RESULTS: Of the 975 personnel screened, 181 (18.6%) were positive for malaria. P. falciparum was the predominant species (n = 125; 69.1%). The rest were due to P. vivax (n = 42; 23.2%) and mixed infections (n = 14; 7.7%). This was an inversion of the usual species distribution pattern in the country. In vivo assay revealed 38 (53.5%) P. falciparum infections as chloroquine resistant. Fifteen of 23 (65.2%) P. falciparum isolates showed evidence of resistance in vitro. None of the P. vivax infections showed evidence of chloroquine resistance. There was no significant difference in the severity of clinical disease between chloroquine resistant and sensitive infections at first presentation. Recrudescent P. falciparum infections had significantly lower mean parasite densities as well as lower clinical scores at recrudescence than at first presentation. CONCLUSION: Results demonstrate the high prevalence of malaria and chloroquine resistance in the study area and explains several contributory factors for this. There is an urgent need to review antimalarial drug policies in Sri Lanka