Pasteurella species bloodstream infections in Queensland, Australia, 2000-2019

Post-mortem diagnosis of septic arthritis by Pasteurella multocida: a case report and literature review of fatal septic arthritis

The diagnosis of septic arthritis remains challenging in the clinical setting, often leading to a suspicion for medical liability. Our purpose is to describe an unusual case of a post-mortem diagnosis of P. multocida fatal septic arthritis, in a healthy 67-year-old woman presenting with pain in the right shoulder. Moreover, a literature review of cases of fatal septic arthritis is provided. The multidisciplinary approach consisted of a forensic autopsy and additional post-mortem analyses (microbiology, biochemical analyses, histopathology, and revision of radiological images) carried out during the prosecutor's investigation for medical liability. A systematic review of the literature was performed to collect cases of fatal septic arthritis and to understand its frequency and characteristics. No clear cause of death was determined after the autopsy, that only highlighted swelling and purulent exudation in the right glenohumeral joint. The microbiological swab performed on the shoulder tested positive for P. multocida, while histopathological and biochemical data were consistent with a sepsis. These results guided the interview with the woman's relatives, until a history of a previous contact with a stray cat emerged. The cause of death was deemed as fatal septic arthritis caused by P. multocida, occurred after cat scratches and bites and only diagnosed post-mortem. The review of the literature provided 15 articles about fatal septic arthritis, only 1 caused by P. multocida, and all with ante-mortem diagnosis. Given the nonspecific symptoms, usually including a localized pain, and the absence of a clear history, e.g. of animal contact, septic arthritis might represent an under-reported clinical and pathological diagnosis, leading to a judicial autopsy for the suspicion for medical liability. The post-mortem examination, following a multidisciplinary approach including integration of the clinical history, microbiological and histopathological analysis, could represent the only opportunity for the diagnosis of the cause of death.

Pasteurella Infections in South Korea and Systematic Review and Meta-analysis of Pasteurella Bacteremia

Pasteurella spp. can cause fatal zoonotic infections in humans. We performed a multicenter study to investigate the prevalence and clinical features of Pasteurella infections in South Korea during 2018‒2022. We also conducted a collaborative systematic review and meta-analysis of the global burden of Pasteurella bacteremia. The study included 283 cases found an increasing trend in Pasteurella infections. Blood cultures were positive in 8/35 (22.9%) cases sampled, for overall bacteremia-associated rate of 2.8% (8/283). Aging was a significant risk factor for bacteremia (odds ratio 1.05 [95% CI 1.01-1.10]), according to multivariate analyses. For the meta-analysis, we included a total of 2,012 cases from 10 studies. The pooled prevalence of bacteremia was 12.4% (95% CI 7.3%-18.6%) and of mortality 8.4% (95% CI 2.7%-16.5%). Our findings reflect the need for greater understanding of the increase in Pasteurella infections and the global burden of Pasteurella bacteremia to determine appropriate case management.

Elderly and their companion animals, cause for pleasure or for harm, a case report of a non-bite Pasteurella multocida bacteremia in an 85-year-old woman with a fatal outcome

We present a case of an elderly woman suffering from Pasteurella multocida (P. multocida) bacteremia, without obvious bite marks, but owning a pet dog. Although the patient was not immunocompromised, and prompt treatment with intravenous antibiotics was initiated, she developed severe septic shock with multiple organ failure and died. In healthy individuals, an infection caused by these bacteria is easy to treat and often harmless, whereas in elderly serious complications can occur. We believe this report of a fatal outcome of a P. multocida bacteremia in a non-immunocompromised, but elderly patient is important, given the growing cohort of elderly pet-owners seeking medical care. A greater awareness of this zoonosis and its potentially fatal outcome is warranted.

Bloodstream Infection and Colorectal Cancer Risk in Queensland Australia, 2000-2019

BACKGROUND

Bloodstream infections may occur as a complication of colorectal cancer or be a marker for its occult presence. The objectives of this study were to quantify the overall and etiology-specific risks for incident colorectal cancer-associated bloodstream infection.

METHODS

Population-based surveillance for community-onset bloodstream infection was conducted among adults aged 20 years and older in Queensland, Australia between 2000 and 2019. Statewide databases were used to identify patients with incident colorectal cancer and collect clinical and outcome information.

RESULTS

After exclusion of 1794 patients with prior colorectal cancer, a cohort of 84,754 patients was assembled, of which 1030 had colorectal cancer-associated bloodstream infection and 83,724 had no colorectal cancer. Bloodstream infection was associated with a 16-fold annualized increased risk for diagnosis of colorectal cancer (incidence rate ratio 16.1; 95% confidence interval [CI], 15.1-17.1) in the adult population. Patients who had colorectal cancer-associated bloodstream infection were more likely to be older and male, have hospital-onset and polymicrobial infections, and have fewer non-cancer-related comorbidities. The organisms associated with highest risk for colorectal cancer included Clostridium species (relative risk [RR] 6.1; 95% CI, 4.7-7.9); especially C. septicum (RR 25.0; 95% CI, 16.9-35.7), Bacteroides species (RR 4.7; 95% CI, 3.8-5.8); especially B. ovatus (RR 11.8; 95% CI, 2.4-34.5), Gemella species (RR 6.5; 95% CI, 3.0-12.5), Streptococcus bovis group (RR 4.4; 95% CI, 2.7-6.8); especially S. infantarius subsp. coli (RR 10.6; 95% CI, 2.9-27.3), Streptococcus anginosus group (RR 1.9; 95% CI, 1.3-2.7), and Enterococcus species (RR 1.4; 95% CI, 1.1-1.8).

CONCLUSION

Although much attention has been afforded to S. bovis group over the past decades, there are many other isolates associated with higher risk for colorectal cancer-associated bloodstream infections.

Spectrum of human Pasteurella species infections in tropical Australia

BACKGROUND

Acquired zoonotic infections with Pasteurella bacterial species have a wide clinical spectrum of disease from invasive infections to localised bite-wound infections.

METHODS

This study reviewed the spectrum of the demographic, clinical, temporal, and microbiological trends of laboratory confirmed Pasteurella species infections presenting to a single-centre tropical tertiary hospital over a twenty-year period.

RESULTS

195 episodes from 190 patients were included. 51.3% patients were female, and 20.5% Aboriginal or Torres Strait Islander peoples. Crude incidence of Pasteurella spp. 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 multocida was most commonly identified (61.1%), but P. canis, P. dagmatis, and other Pasteurella infections were also noted. 67.7% of specimens were polymicrobial, with other significant organisms being Staphylococcus aureus, Streptococcus pyogenes, Group G Streptococcus and Pseudomonas aeruginosa.

CONCLUSION

Pasteurella species 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.

Determinants and outcomes of bloodstream infections related to obesity

Although obesity is a major healthcare problem that is increasing in many populations worldwide, there are limited studies that have examined its contribution to infectious diseases morbidity and mortality. The aim of this study was to examine the clinical determinants and outcomes of bloodstream infections among patients with obesity. All adults within the publicly funded healthcare system in Queensland, Australia, identified with a BSI during 2017–2019 were included and the presence of obesity was based on discharge International Classification of Diseases (ICD-10) codes. Clinical features, microbiology, and outcomes were compared among obese and non-obese subjects. A total of 24,602 incident BSI were identified among 21,613 Queensland residents; of which 4,579 (21.2%) and 17,034 (78.8%) were classified as obese or non-obese, respectively. Obese patients were less likely to have community associated infections and were more likely to be younger, female, have higher comorbidity scores, and have bone and joint or soft tissue infections as compared to non-obese subjects. Obese patients had a lower proportion of Escherichia coli BSI and higher proportions of b-haemolytic streptococci. Although obese patients had longer hospital admissions and more repeat incident BSI within 1 year, they had lower overall case fatality. In a logistic regression model, obesity was associated with a lower risk for 30-day case fatality (adjusted odds ratio 0.51, 95% confidence interval 0.45–0.58). Obesity is associated with significant differences in the determinants and outcome of BSI. Increasing rates of obesity is likely to influence the epidemiology of BSI in populations.