Use of Canonical Single Nucleotide Polymorphism (CanSNPs) to characterize Bacillus anthracis outbreak strains in Zambia between 1990 and 2014.

Anthrax caused by Bacillus anthracis is an old and neglected zoonosis that continues to raise concerns in Southern Africa. In this study, twenty (20) slides with suspected isolates of B. anthracis from anthrax cases between 1990 and 2014 and two (2) from that of a vaccine strain were analysed using MLVA with 15 VNTRs and CanSNPs test. The results from the CanSNPs indicate that all anthrax outbreaks in Zambia between 1990 and 2014 were caused by the lineage A.Br.005/006 of the clade A. This indicates a common ancestral origin of the B. anthracis circulating in the country. This data has described several environmental, wildlife, livestock and human cases that occurred in a 24 year period, from the major areas where anthrax is endemic. The molecular characterization of isolates from anthrax outbreaks in Zambia has revealed a genetic structure in agreement with previous studies from neighbouring countries. Further studies are needed to elucidate how to better manage anthrax outbreaks and define the risk maps of Zambia.

Comparison of complement fixation test, competitive ELISA and LppQ ELISA with post-mortem findings in the diagnosis of contagious bovine pleuropneumonia (CBPP).

The complement fixation test (CFT), the c-ELISA and an indirect LppQ ELISA were compared to post-mortem (PM) inspection for the diagnosis of contagious bovine pleuropneumonia (CBPP). Sera from 797 cattle in the CBPP affected area of Kazungula, Zambia and 202 sera from Lusaka, Zambia, a CBPP-free area were used. The clinical history of CBPP was recorded and all the cattle from Kazungula were slaughtered and PM inspections conducted. The prevalence of CBPP in Kazungula was 67.5% (95%CI 67.2%, 70.8%), 52.6% (95%CI 49.2%, 56.2%), 59.0% (95%CI 55.5%, 62.4%) and 44.4% (95%CI 41.0%, 47.9%) using PM inspection, CFT, c-ELISA and LppQ ELISA, respectively. Three of the 202 negative control animals tested positive on the c-ELISA although they were from a known CBPP negative zone. In this study, the c-ELISA was more sensitive in detecting cattle with lesions in the chronic stage than any other test whilst the CFT detected more during the onset stage. No single serological test could detect all stages of CBPP infection, therefore the use of more than one test is advised.