Spectrum of human Pasteurella species infections in tropical Australia

Abstract

BackgroundAcquired zoonotic infections withPasteurellabacterial species have a wide clinical spectrum of disease from invasive infections to localised bite-wound infections.MethodsThis study reviewed the spectrum of the demographic, clinical, temporal, and microbiological trends of laboratory confirmedPasteurellaspecies infections presenting to a single-centre tropical tertiary hospital over a twenty-year period.Results195 episodes from 190 patients were included. 51.3% patients were female, and 20.5% Aboriginal or Torres Strait Islander peoples. Crude incidence ofPasteurellaspp. infections increased from 1.5 per 100,000 population in 2000, to 11.4 per 100,000 population in 2021. There were 22 (11.3%) bloodstream infections, 22 (11.3%) invasive, 34 (17.4%) deep local, 98 (50.2%) superficial infections, and 19 (9.7%) other or unknown. Adults over 65 years of age accounted for the majority of bacteraemias (63.7%). More severe infections, including bacteraemia, invasive and deep local infections, were more common in lower limb infections and in those with underlying comorbidities. Animal contact with cats was more common in bloodstream infections (36.4%), but dog bites more common in invasive, deep local and superficial infections. 30-day all-cause mortality was low at 1.0%.Pasteurella multocidawas most commonly identified (61.1%), butP.canis,P.dagmatis, and otherPasteurellainfections were also noted. 67.7% of specimens were polymicrobial, with other significant organisms beingStaphylococcus aureus,Streptococcus pyogenes, Group G Streptococcus andPseudomonas aeruginosa.ConclusionPasteurellaspecies remain clinically important pathogens, with the ability to cause severe and invasive infections with associated morbidity. Presentations to hospital are becoming more common, and the polymicrobial nature of bites wounds has implications for empiric antibiotic guidelines.