Pasteurellosis and pasteurellae in Zimbabwe: an update

Abstract

Pasteurellosis broadly refers to any of the disease conditions caused by species of the genus Pasteurella. These conditions appear to be prevalent in Zimbabwe, and they range from slow latent infections to rapid fatal septicaemias. Apart from known classical disease syndromes like bovine haemorrhagic septicaemia (HS), snuffles in rabbits and fowl cholera, other conditions which range from polyarthritis, surface wound infections, pneumonia, sinusitis, rhinitis and genito-urinary tract infections have been reported. A wide spectra of hosts affected by species of the genus Pasteurella include cattle, rabbits, chickens, sheep, pigs, goats, crocodiles, dogs and cats. In cattle, the condition has predominantly been the pneumonic form. In pigs, pneumonia has commonly been encountered. Classical progressive atrophic rhinitis was recorded in two farms. Sporadic cases of pneumonia have also been observed in sheep and goats. Besides fowl cholera, keratoconjunctivitis due to Pasteurella haemolytica, sinusitis and arthritis due to P. gallinarum have been reported in chickens. In dogs and cats, Pasteurella species were isolated from bite wounds, rhinitis, pyothorax, bronchitis, uterine and vaginal infections. Pasteurella stomatis, P. dagmatis and P. multocida were isolated from a single dog with chronic bronchitis. We also reported the first isolation of Communicable Diseases Centre (CDC) group EF-4 bacteria from dogs in Southern Africa. Of all identified species, P. multocida was found to be predominant, and serological typing revealed that serogroup A was most prevalent, with serogroups E and F absent. A single outbreak of bovine HS was found to be associated with serogroup B as opposed to an earlier belief that serogroup E was the causative agent in Southern Africa. The significance and implications of observations made on selected disease syndromes are discusssed in detail.