A One Health investigation of Salmonella enterica serovar Wangata in north-eastern New South Wales, Australia, 2016-2017.

Salmonella enterica serovar Wangata (S. Wangata) is an important cause of endemic salmonellosis in Australia, with human infections occurring from undefined sources. This investigation sought to examine possible environmental and zoonotic sources for human infections with S. Wangata in north-eastern New South Wales (NSW), Australia. The investigation adopted a One Health approach and was comprised of three complimentary components: a case-control study examining human risk factors; environmental and animal sampling; and genomic analysis of human, animal and environmental isolates. Forty-eight human S. Wangata cases were interviewed during a 6-month period from November 2016 to April 2017, together with 55 Salmonella Typhimurium (S. Typhimurium) controls and 130 neighbourhood controls. Indirect contact with bats/flying foxes (S. Typhimurium controls (adjusted odds ratio (aOR) 2.63, 95% confidence interval (CI) 1.06-6.48)) (neighbourhood controls (aOR 8.33, 95% CI 2.58-26.83)), wild frogs (aOR 3.65, 95% CI 1.32-10.07) and wild birds (aOR 6.93, 95% CI 2.29-21.00) were statistically associated with illness in multivariable analyses. S. Wangata was detected in dog faeces, wildlife scats and a compost specimen collected from the outdoor environments of cases' residences. In addition, S. Wangata was detected in the faeces of wild birds and sea turtles in the investigation area. Genomic analysis revealed that S. Wangata isolates were relatively clonal. Our findings suggest that S. Wangata is present in the environment and may have a reservoir in wildlife populations in north-eastern NSW. Further investigation is required to better understand the occurrence of Salmonella in wildlife groups and to identify possible transmission pathways for human infections.

Analysis of pig trading networks and practices in Uganda.

East Africa is undergoing rapid expansion of pig rearing, driven by increasing pork consumption. Introduction and expansion of pig production systems in this biodiverse landscape may create new risks, including zoonotic pathogen transmission. Historically, biosecurity measures have primarily been focused at farm level, ignoring the important function pig traders fulfill between farmers and consumers. This study interviewed pig traders operating at Uganda's only registered pork abattoir to describe their characteristics, business practices, biosecurity practices, and pig health management and reporting practices. All the traders were male, and nearly all (90.5%) relied on pig trading as their primary source of income. Most of the pigs brought for processing at the slaughterhouse were purchased from smallholder farms (87.3%). In addition, there was a significant difference in the high price paid per kilogram at farm gate by region (P = 0.005). High prices paid at farm gate were associated with holiday periods (P < 0.001), harvest season (P < 0.001), and drought (P < 0.001). Traders preferred buying live pigs from male farmers (88.9%) because they were considered the final decision makers and owned the pigs being sold. All pig traders were aware of clinical signs indicating a pig was sick. This study has provided baseline information on pig trader practices in Uganda. Improvements in local pork slaughterhouses and markets will benefit not only pig traders in accessing consistent customers but also individual pig farmers by increasing their market access. Finally, given their role as a link between farmers and consumers, traders would benefit from targeted inclusion in disease control and prevention strategies.

Brucella suis in three dogs: presentation, diagnosis and clinical management.

Brucella suis is an emerging, zoonotic disease predominantly affecting dogs and humans that engage in feral pig hunting in Australia and other countries. Although B. suis infection in dogs shares some clinical similarities to the host-adapted species (B. canis), B. suis remains an incompletely understood pathogen in dogs with limited published data on its pathogenesis and clinical features. This case series describes the presentations, diagnosis, and clinical management of B. suis infection in three dogs: (1) a bitch with dystocia, abortion and mastitis; (2) an entire male dog with septic arthritis and presumptive osteomyelitis; and (3) a castrated male dog with lymphadenitis. Unique features of these cases are reported including the first documented detection of B. suis from milk and isolation from lymph nodes of canine patients, as well as the follow-up of pups born to a B. suis-infected bitch. Consistent with previous reports, all three dogs showed a favourable clinical response to combination antibiotic therapy with rifampicin and doxycycline. Individually tailored drug regimens were required based on the clinical presentation and other factors, including owner expectations and compliance with therapy as well as a zoonotic risk assessment (generally considered low, except around time of whelping). The authors include their recommendations for the clinical management of dogs that are at-risk or seropositive for B. suis with or without clinical signs or laboratory-confirmed infection.

Pneumonia and influenza hospitalization in HIV-positive seniors.

HIV-positive persons and the elderly have increased risk for influenza-related complications, including pneumonia. Using claims data for pneumonia and influenza (P&I) hospitalization in the USA, we described the temporo-demographic trends and in-patient case-fatality in persons aged ≥ 65 years by HIV status. Our results showed a near doubling in the fraction of P&I admissions representing HIV-positive persons between 1991 and 2004 [relative risk (RR) 1·95, 95% confidence interval (CI) 1·80-2·13]. HIV-positive adults were younger (70·3 vs. 79·9 years, P<0·001), and had higher case-fatality (18·0% vs. 12·6%, P<0·001). Adjusting for other variables, case-fatality decreased by 5·8% in HIV-positive persons with the availability of highly active antiretroviral therapy (P=0·032). However, HIV-positive seniors were still 51% more likely to die during hospitalization than HIV-negative persons in 2004 (OR 1·51, 95% CI 1·23-1·85). HIV-infected persons represent a growing fraction of the elderly population hospitalized with P&I. Additional measures are needed to reduce case-fatality associated with P&I in this population.

Interspecific network centrality, host range and early-life development are associated with wildlife hosts of Rift Valley fever virus.

Rift Valley fever virus (RVFV) is responsible for a substantive disease burden in pastoralist communities and the agricultural sector in the African continent and Arabian Peninsula. Enzootic, epizootic and zoonotic RVFV transmission dynamics remain ill-defined, particularly due to a poor understanding of the role of mammalian hosts in the epidemiology and infection ecology of this arbovirus. Using a piecewise structural equation model, this study sought to identify associations between biological and ecological characteristics of mammalian species and documented RVFV infection to highlight species-level traits that may influence wildlife host status. Interspecific network centrality, size of species home range and reproductive life-history traits were all associated with being an RVFV host. The identification of these species-level characteristics may help to provide ecological context for the role of wildlife amplification hosts in the epidemiology of spillover to livestock and humans and may also help to identify specific points of vulnerability at the wildlife-livestock interface.

Clinical management of Brucella suis infection in dogs and implications for public health.

BACKGROUND: Brucellosis caused by Brucella suis is a notifiable disease that has recently emerged in dogs in New South Wales (NSW). Given the potential for zoonotic transmission, euthanasia of affected dogs is recommended, but this action is not mandatory. We report the clinical management of three dogs that underwent treatment at their owners' request. CASE REPORTS: A 14-month-old spayed female crossbreed originally obtained from an urban animal shelter underwent extensive investigations in 2011-12 for lameness and back pain, culminating in decompressive laminectomy. Diagnosis of multifocal discospondylitis and spinal empyema was made, with B. suis cultured from surgical biopsy specimens. The dog responded to long-term treatment using rifampicin and doxycycline. A second case of B. suis infection was diagnosed in January 2016 in a 3-year-old crossbreed pig-hunting dog with unilateral testicular enlargement. Following serological diagnosis the dog was given preliminary therapy using rifampicin and doxycycline, the affected testis was resected and the patient given a further month of combination therapy. In March 2016 a 7-year-old crossbreed pig-hunting dog with brucellosis was handled similarly, although both testes were removed. CONCLUSION: Brucellosis should be considered in the differential diagnosis of back pain, discospondylitis, lameness, abortion, prostatic abscessation and testicular/epididymal enlargement in dogs, especially if there is exposure to feral pigs or consumption of uncooked feral pig meat. Euthanasia is the only guarantee of reducing the public health risk to zero. However, where treatment is desired by the owner, combination therapy using rifampicin and doxycycline appears to be effective, when combined with surgical resection of infected tissues. Further monitoring of dogs during and after treatment is required to document cure.

Client knowledge, attitudes and practices regarding zoonoses: a metropolitan experience.

OBJECTIVE: To assess knowledge, attitudes and practices in relation to zoonoses among pet owners. METHODS: Questionnaire completed by 81 clients attending a small animal practice in Sydney, Australia. RESULTS: Most (64.5%) clients reported that they were not concerned about contracting a disease from their pet, but 7.9% and 3.9% of clients were a little or very concerned, respectively; 23.7% of clients stated that they had not considered the possibility. Although respondents indicated that they had heard of a number of zoonoses, knowledge of animal sources and exposure pathways was generally low, particularly for the more important zoonoses in Australia such as toxoplasmosis, psittacosis and Q fever. Only 37.0%, 12.3% and 11.1%, respectively, of clients had heard of these diseases. Most respondents (84.1%) indicated that they viewed veterinarians as having the primary responsibility for providing information about zoonoses, yet less than half (48.1%) recalled ever getting information from their veterinarian. Likewise, many respondents (48.1%) indicated that medical professionals played a role in providing information about zoonoses, yet less than one-quarter (23.5%) recalled ever getting information from their doctor. CONCLUSION: The low level of knowledge among pet owners about sources and exposure pathways indicates a need to strengthen communication between veterinarians, doctors and their clients around the possible risks of zoonoses and appropriate prevention strategies.