Browsing by Author "Guan, Y."

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    Molecular Epidemiology of Influenza A (H1N1) pdm09 Virus among Humans and Swine, Sri Lanka
    (Centers for Disease Control and Prevention (CDC), 2014) Perera, H.K.K.; Vijaykrishna, D.; Premarathna, A.G.; Jayamaha, C.J.; Wickramasinghe, G.; Cheung, C.L.; Yeung, M.F.; Poon, L.L.; Perera, A.K.; Barr, I.G.; Guan, Y.; Peiris, M.
    After multiple discrete introductions of influenza A(H1N1)pdm09 virus into Sri Lanka, the virus was transmitted among humans, then swine. The spread of virus between geographically distant swine farms is consistent with virus dispersal associated with a vehicle used for swine transportation, although this remains unproven
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    Sensitive and inexpensive molecular test for falciparum malaria: detecting Plasmodium falciparum DNA directly from heat-treated blood by loop-mediated isothermal amplification
    (American Association For Clinical Chemistry, 2006) Poon, L.; Wong, B.W.; Ma, E.H.; Chan, K.H.; Chow, L.M.; Abeyewickreme, W.; Tangpukdee, N.; Yuen, K.Y.; Guan, Y.; Looareesuwan, S.; Peiris, J.S.
    BACKGROUND: Malaria is one of the most important parasitic infections in humans. A sensitive diagnostic test for malaria that could be applied at the community level could be useful in programs to control the disease. The aim of the present work was to develop a simple, inexpensive moleculartest for Plasmodium falciparum. METHODS: Blood was collected from controls (n = 100) and from patients diagnosed with falciparum malaria infection (n = 102), who were recruited to the study. Heat-treated blood samples were tested by a loop-mediated isothermal amplification (LAMP) assay for P. falciparum. Results were interpreted by a turbidity meter in real time or visually at the end of the assay. To evaluate the assay, DNA from these samples was purified and tested by PCR. Results from the LAMP and PCR assays were compared. RESULTS: The LAMP assay detected P. falciparum directly from heat-treated blood. The quantitative data from the assay correlated to the parasite counts obtained by blood-film microscopic analyses. When we used the PCR assay as the comparison method, the sensitivity and specificity of the LAMP assay were 95% and 99%, respectively. CONCLUSIONS: Unlike PCR, the LAMP assay does not require purified DNA for efficient DNA amplification, thereby reducing the cost and turnaround time for P. falciparum diagnosis. The assay requires only basic instruments, and assay positivity can be verified by visual inspection
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    Swine influenza in Sri Lanka.
    (Centers for Disease Control and Prevention (CDC), 2013) Perera, H.K.K.; Wickramasinghe, G.; Cheung, C.L.; Nishiura, H.; Smith, D.K.; Poon, L.L.; Perera, A.K.; Ma, S.K.; Sunil-Chandra, N.P.; Guan, Y.; Peiris, J.S.
    To study influenza viruses in pigs in Sri Lanka, we examined samples from pigs at slaughterhouses. Influenza (H3N2) and A(H1N1)pdm09 viruses were prevalent during 2004-2005 and 2009-2012, respectively. Genetic and epidemiologic analyses of human and swine influenza viruses indicated 2 events of A(H1N1)pdm09 virus spillover from humans to pigs