Investigation of the outbreaks of abortions and orchitis in livestock in Namibia during 2016–2018

Abstract

This study investigated outbreaks of seemingly related abortions and orchitis which occurred in Namibia from 2016 to 2018. A combination of epidemiological studies (using questionnaires), necropsies, microbiology, serology, molecular biological techniques like PCR and mineral analytical techniques were used in an attempt to establish the aetiology of these abortion and orchitis outbreaks. The results showed that the outbreaks were limited to Namibia's east and central regions and mainly occurred on farms that reared cattle, sheep and goats and on farms with a mixture of these species. In some cases, horses and game species were also affected. Gross pathological ndings included testicular enlargement, with focal haemorrhages and soft to hard testicular consistency in males. Histopathological ndings included severe chronic orchitis, testicular degeneration, prominent interstitial mononuclear in ammatory cell in ltration with a few multinucleated in ammatory cells. In samples obtained from aborted fetuses, signi cant histopathological ndings included meconium aspiration, funisitis, placentitis and cardiomyopathy in fetal tissues, whereas endometritis was the primary pathology observed in females. Brucella spp., Enterococcus spp., Escherichia coli, Streptococcus spp., Truperella pyogenes, micronutrient imbalances toxic and pathogenic abiotic nanoparticles which resulted from drought conditions that preceded these outbreaks, were identi ed as possible causes.

Epididymitis with Pasteurella multocida isolated from two male Japanese Black beef calves

“…In cattle, most cases of infection of the male reproductive tract are caused by microbes such as bovine herpesviruses (Chastant‐Maillard, 2015), Brucella abortus (Trichard et al., 1982), Bacillus anthracis (Friman et al., 2019), coliforms, Truperella pyogenes , Staphylococcus spp. (Samkange et al., 2022), Salmonella Typhimurium (Mahmoud et al., 2020) and Trypanosoma evansi (Sivajothi & Reddy, 2019). Although the prevalence of orchitis following infection of the male reproductive tract is not high (2.9%–12.2%, Eshetu et al., 2016; Migbaru et al., 2014; Samkange et al., 2022), orchitis can cause abnormal semen quality due to the presence of white blood cells in semen (Statham, 2010).…”

“…(Samkange et al., 2022), Salmonella Typhimurium (Mahmoud et al., 2020) and Trypanosoma evansi (Sivajothi & Reddy, 2019). Although the prevalence of orchitis following infection of the male reproductive tract is not high (2.9%–12.2%, Eshetu et al., 2016; Migbaru et al., 2014; Samkange et al., 2022), orchitis can cause abnormal semen quality due to the presence of white blood cells in semen (Statham, 2010). Moreover, orchitis generally develops unilaterally; however, the remaining testis is indirectly affected because the infection disrupts the scrotal temperature gradient (Statham, 2010).…”