No abstract

Between January and July 2017, lumpy skin disease (LSD) outbreaks were reported in cattle in Namibia. DNA was extracted from skin biopsies taken from 32 cattle, and the RNA polymerase 30 kDa subunit (RPO30) gene of the LSD virus (LSDV) was successfully amplified by PCR. Phylogenetic analysis revealed that the newly sequenced LSDV isolates from Namibia were identical to LSDV isolates identified previously in Burkina Faso, Egypt, Greece, Niger, Serbia and South Africa. Given that only unvaccinated herds were affected by LSD, it is recommended that the current vaccination programmes in Namibia be re-evaluated to allow nationwide coverage.

The complete sequences of the fusion (F) protein genes of six Newcastle disease virus (NDV) isolates from backyard poultry in Namibia in 2016 have been determined. The F gene cleavage site motif for all of the isolates was RRQKRF, indicating that the viruses are virulent. A phylogenetic analysis using the full F gene sequence revealed that the viruses belong to a novel subgenotype, VIIk. This is the first genetic characterization of NDV isolates from Namibia, and the findings have important implications for Newcastle disease management and control in the region.

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 800kmfromtheoriginaloutbreaks.Samplecollectionandmolecularepidemiologicalanalysesrevealedthattheoutbreaksweremostlikely causedbypoor vaccinationpractices leadingtothereversiontovirulenceof an ILTvaccine strain.The analysesalsoindicate thatinaccurate declarations were made by one of the farms involved and that illegal movement of animals most likely occurred.

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.