Browsing by Author "Krauss, Scott"

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    Genetic analysis of influenza B viruses isolated in Uganda during the 2009–2010 seasons
    (Virology Journal, 2013) Byarugaba, Denis K.; Erima, Bernard; Millard, Monica; Kibuuka, Hannah; Lukwago, L.; Bwogi, Josephine; Mimbe, Derrick; Mworozi, Edison A.; Sharp, Bridget; Krauss, Scott; Webby, Richard J.; Webster, Robert G.; Martin, Samuel K.; Wabwire-Mangen, Fred; Ducatez, Mariette F.
    Influenza B viruses can cause morbidity and mortality in humans but due to the lack of an animal reservoir are not associated with pandemics. Because of this, there is relatively limited genetic sequences available for influenza B viruses, especially from developing countries. Complete genome analysis of one influenza B virus and several gene segments of other influenza B viruses isolated from Uganda from May 2009 through December 2010 was therefore undertaken in this study. Methods: Samples were collected from patients showing influenza like illness and screened for influenza A and B by PCR. Influenza B viruses were isolated on Madin-Darby Canine Kidney cells and selected isolates were subsequently sequenced and analyzed phylogenetically.
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    Molecular Epidemiology of Influenza A/H3N2 Viruses Circulating in Uganda
    (PLoS ONE, 2011) Byarugaba, Denis K.; Ducatez, Mariette F.; Erima, Bernard; Mworozi, Edison A.; Millard, Monica; Kibuuka, Hannah; Lukwago, Luswa; Bwogi, Josephine; Kaira, Blanche B.; Mimbe, Derrick; Schnabel, David C.; Krauss, Scott; Darnell, Daniel; Webby, Richard J.; Webster, Robert G.; Wabwire-Mangen, Fred
    The increasing availability of complete influenza virus genomes is deepening our understanding of influenza evolutionary dynamics and facilitating the selection of vaccine strains. However, only one complete African influenza virus sequence is available in the public domain. Here we present a complete genome analysis of 59 influenza A/H3N2 viruses isolated from humans in Uganda during the 2008 and 2009 season. Isolates were recovered from hospital-based sentinel surveillance for influenza-like illnesses and their whole genome sequenced. The viruses circulating during these two seasons clearly differed from each other phylogenetically. They showed a slow evolution away from the 2009/10 recommended vaccine strain (A/ Brisbane/10/07), instead clustering with the 2010/11 recommended vaccine strain (A/Perth/16/09) in the A/Victoria/208/09 clade, as observed in other global regions. All of the isolates carried the adamantane resistance marker S31N in the M2 gene and carried several markers of enhanced transmission; as expected, none carried any marker of neuraminidase inhibitor resistance. The hemagglutinin gene of the 2009 isolates differed from that of the 2008 isolates in antigenic sites A, B, D, and to a lesser extent, C and E indicating evidence of an early phylogenetic shift from the 2008 to 2009 viruses. The internal genes of the 2009 isolates were similar to those of one 2008 isolate, A/Uganda/MUWRP-050/2008. Another 2008 isolate had a truncated PB1-F2 protein. Whole genome sequencing can enhance surveillance of future seasonal changes in the viral genome which is crucial to ensure that selected vaccine strains are protective against the strains circulating in Eastern Africa. This data provides an important baseline for this surveillance. Overall the influenza virus activity in Uganda appears to mirror that observed in other regions of the southern hemisphere.
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    Prevalence of influenza A viruses in livestock and free-living waterfowl in Uganda
    (BMC Veterinary Research, 2014) Kirunda, Halid; Erima, Bernard; Tumushabe, Agnes; Kiconco, Jocelyn; Tugume, Titus; Mulei, Sophia; Mimbe, Derrick; Mworozi, Edison; Bwogi, Josephine; Luswa, Lukwago; Kibuuka, Hannah; Millard, Monica; Byaruhanga, Achilles; Ducatez, Mariette F.; Krauss, Scott; Webby, Richard J.; Webster, Robert G.; Wurapa, Kofi; Byarugaba, Denis K.; Wabwire-Mangen, Fred
    Avian influenza viruses may cause severe disease in a variety of domestic animal species worldwide, with high mortality in chickens and turkeys. To reduce the information gap about prevalence of these viruses in animals in Uganda, this study was undertaken. Results: Influenza A virus prevalence by RT-PCR was 1.1% (45/4,052) while sero prevalence by ELISA was 0.8% (24/2,970). Virus prevalence was highest in domestic ducks (2.7%, 17/629) and turkeys (2.6%, 2/76), followed by free-living waterfowl (1.3%, 12/929) and swine (1.4%, 7/511). A lower proportion of chicken samples (0.4%, 7/1,865) tested positive. No influenza A virus was isolated. A seasonal prevalence of these viruses in waterfowl was 0.7% (4/561) for the dry and 2.2% (8/368) for the wet season. In poultry, prevalence was 0.2% (2/863) for the dry and 1.4% (24/1,713) for the wet season, while that of swine was 0.0% (0/159) and 2.0% (7/352) in the two seasons, respectively. Of the 45 RT-PCR positive samples, 13 (28.9%) of them were H5 but none was H7. The 19 swine sera positive for influenza antibodies by ELISA were positive for H1 antibodies by HAI assay, but the subtype(s) of ELISA positive poultry sera could not be determined. Antibodies in the poultry sera could have been those against subtypes not included in the HAI test panel. Conclusions: The study has demonstrated occurrence of influenza A viruses in animals in Uganda. The results suggest that increase in volumes of migratory waterfowl in the country could be associated with increased prevalence of these viruses in free-living waterfowl and poultry.
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    Whole-genome analysis of influenza A(H1N1)pdm09 viruses isolated in Uganda from 2009 to 2011
    (Influenza and Other Respiratory Viruses, 2016) Byarugaba, Denis K.; Erima, Bernard; Millard, Monica; Kibuuka, Hannah; Lukwago, Luswa; Bwogi, Josephine; Mimbe, Derrick; Kiconco, Jocelyn B.; Tugume, Titus; Mworozi, Edison A.; Turner, Jasmine; Mckenzie, Pamela P.; Webby, Richard R. J.; Webster, Robert G.; Foret, Charlotte; Ducatez, Mariette F.; Coldren, Rodney; Wabwire-Mangen, Fred; Krauss, Scott
    We report a whole-genome analysis of 19 influenza A(H1N1)pdm09 isolates from four Ugandan hospitals between 2009 and 2011. The isolates differed from the vaccine strain A/California/07/2009 by three amino acid substitutions P100S, S220T, and I338V in the hemagglutinin and by two amino acid substitutions V106I and N248D in the neuraminidase proteins with consistent mutations in all gene segments distinguishing isolates from the 2009/2010 to 2010/2011 seasons. Phylogenetic analysis showed low genetic evolution, with genetic distances of 0%–1.3% and 0.1%–1.6% for HA and NA genes, respectively. The amino acid substitutions did not lead to antigenic differences from the reference strains.