School of Veterinary Medicine

Permanent URI for this community

http://hdl.handle.net/11070/3323

Browse

Browsing School of Veterinary Medicine by Author "Cattoli, Giovanni"

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Avian influenza H5N8 outbreak in African penguins (Spheniscus demersus), Namibia, 2019
    (2020) Molini, Umberto; Aikukutu, Gottlieb; Roux, Jean-Paul; Kemper, Jessica; Ntahonshikira, Charles; Marruchella, Giuseppe; Khaiseb, S.; Cattoli, Giovanni; Dundon, William G.
    In January 2019, high mortalities were reported among African Penguins (Spheniscus demersus) in a breeding colony on Halifax Island, Namibia, Africa. Analysis of samples by reverse transcription quantitative PCR indicated the presence of highly pathogenic avian influenza (HPAI) subtype H5N8. Sequence analysis of the hemagglutinin and neuraminidase genes confirmed the presence of the virus in the birds and its high similarity to HPAI subtype H5N8 identified in South Africa in 2017. There have been no previous reports of HPAI H5N8 in Namibia.
  • Thumbnail Image
    Item
    Investigation of infectious laryngotracheitis outbreaks in Namibia in 2018
    (2019) Molini, Umberto; Aikukutu, Gottlieb; Khaiseb, S.; Kahler, Barbara; Van der Westhuizen, Jolandie; Cattoli, Giovanni; Dundon, William G.
    Between July and August 2018, two outbreaks of infectious laryngotracheitis caused the death of over 116,000 commercial poultry (layers and broilers) near the city of Windhoek, Namibia. A third outbreak occurred in September 2018 in the north of the country approximately 800km from the original outbreaks. Sample collection and molecular epidemiological analyses revealed that the outbreaks were most likely caused by poor vaccination practices leading to the reversion to virulence of an ILT vaccine strain. The analyses also indicate that inaccurate declarations were made by one of the farms involved and that illegal movement of animalsmost likely occurred.
  • Thumbnail Image
    Item
    Molecular characterisation of infectious bursal disease virus in Namibia, 2017
    (2019) Molini, Umberto; Aikukutu, Gottlieb; Kabajani, Juliet; Khaiseb, S.; Cattoli, Giovanni; Dundon, William G.
    Between July and September 2017, samples collected from six unvaccinated chickens in Namibia were shown to be positive for infectious bursal disease virus (IBDV) by RT-PCR. Partial sequence and phylogenetic analysis of the VP1 and VP2 genes from six viruses revealed that they all belong to the very virulent pathotype (Genogroup 3) and are genetically very similar to IBDVs identified in neighbouring Zambia. This is the first molecular characterisation of IBDV in Namibia and has implications on the control and management of the disease in the country.
  • Thumbnail Image
    Item
    Molecular characterization of African swine fever virus from outbreaks in Namibia in 2018
    (2019) Molini, Umberto; Mushonga, Borden; Settypalli, Tirumala B. K.; Dundon, William G.; Khaiseb, S.; Jago, Mark; Cattoli, Giovanni; Lamien, Charles E.
    Five samples were collected from four suspected outbreaks of African swine fever in Namibia in 2018. Sequencing of the C‐terminus of the B646L gene (p72 protein), the central hypervariable region (CVR) of the B602L gene, the E183L gene (p54 protein) and the CD2v (used to determine the serogroup) was performed on DNA isolated from the samples. Phylogenetic analyses of the B646L (p72) revealed that one of the samples belonged to genotype I while the remaining samples could not be assigned to any currently known genotype. In contrast, by using the E183L gene three of the samples were shown to belong to genotype Id and only two were of unknown genotype. Based on the analysis of the partial CD2v amino acid sequences of four of the samples, one of the viruses clustered with serogroup 2 while the other three did not cluster within any of the eight known serogroups. Examination of the CVR identified three variants with 8, 18 and 24 tetrameric tandem repeat sequences. This study indicates that at least three different genetically distinct ASFV are currently present in Namibia.
  • Thumbnail Image
    Item
    Molecular investigation of Porcine Circovirus type 3 infection in pigs in Namibia
    (Pathogens, 2021-05-11) Molini, Umberto; Marruchella, Giuseppe; Matheus, Frieda; Hemberger, Maria Yvonne; Chiwome, Bernard; Khaiseb, Siegfried; Cattoli, Giovanni; Franzo, Giovanni
    Porcine circovirus type 3 (PCV-3) infection is widely distributed in domestic pig populations in America, Europe, and Asia. However, no data is currently available about its presence and distribution in Africa. This study investigated the presence of PCV-3 in pigs (n = 122) in Namibia, by means of biomolecular methods. The pig samples collected (n = 122) were representative of the swine industry in Namibia, covering the major pig production facilities in the country. All of the samples tested were negative for PCV-3, and this indicated that the virus was either not present in the country or was circulating at low levels. Further studies are needed to better understand the distribution, if any, of PCV-3 in Namibia.
  • Thumbnail Image
    Item
    The oryx antelope (Oryx gazella): An unexpected host for Porcine Circovirus-2 (PCV-2)
    (Pathogens, 2021-10-29) Molini, Umberto; Coetzee, Lauren Michelle; Hemberger, Maria Yvonne; Khaiseb, Siegfried; Cattoli, Giovanni; Dundon, William G.; Franzo, Giovanni
    For several years after its discovery, Porcine circovirus 2 (PCV-2) represented a major threat to the swine industry through economic losses due to the associated clinical syndromes, decreased production performances in both symptomatic and asymptomatic animals and disease management costs. Widespread vaccination administration has largely reduced the impact of this infection and represents the most effective control measure. The efficacy of vaccination is threatened by the emergence of novel (or uncommon) PCV-2 genotypes. In addition to domestic pigs, PCV-2 has been detected in several other species, a fact which could have an impact on new variant emergence and maintenance. Considering this, the present study assessed the distribution of the minor PCV-2c genotype in non-Suidae ungulates in Namibia. Red hartebeests (Alcelaphus buselaphus caama) (n = 44), kudus (Tragelaphus strepsiceros) (n = 10) and oryxes (Oryx gazella) (n = 54), whose mediastinal lymph nodes were sampled after slaughtering during the period 2019–2021, were included in the study. Two oryxes (3.7%; 95% CI = 0.45–12.75%) were PCV-2-positive by PCR. Complete genome sequence was obtained for the two samples identifying them as PCV-2c genotype. The sequences were identical and shared a high percentage of identity (~99.9%) with those recently obtained from warthogs living in the same area. The present study confirms the presence of the PCV-2c genotype (previously considered extinct) in Namibian wild animal populations and demonstrates greater than expected PCV-2 host plasticity. Because of the role these niches can have in the maintenance and evolution of minor PCV-2 genotypes, more extensive and dedicated studies should be performed to prepare authorities to promptly react to potential emerging threats from these viruses.