One Medicine - One Oncology – Incidence and Geographical Distribution of Tumors in Dogs and Cats in Switzerland 1955-2008
1Collegium Helveticum, University of Zurich / ETH Zurich, Switzerland; 2Department of Geography, University of Zurich, Switzerland; 3Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
Dogs and cats have been sharing their habitat with humans for millennia by being exposed to similar environmental conditions over time. This intimate coexistence is confirmed by distinct co-evolution patterns, namely in the development of similar diseases. Genetic predisposition and the presence of specific environmental circumstances are regarded as main variables for comparative disease etiology. In this context, our research intends to challenge the knowledge on spontaneous tumors development through the study and comparison of tumor incidence and geographic distribution in dogs, cats and humans.
We benefit from the availability of diagnostic data about tumors in dogs and cats, which have been collected between 1955 and 2008 at the two Swiss university institutes of veterinary pathology based in Berne and Zurich and at a private laboratory. We consolidated the data by coding tumor location and morphologic diagnostic terms to fulfil comparative research standards and by computing meaningful spatial references. Then we conducted an epidemiological study, using a regression model, to describe dog and cat tumors distribution and malignancy. We also tackled the tumor geographic distribution by assessing the presence of tumor clusters and we compared the results against explanatory environmental factors through spatial statistic methods.
Our research allowed creating an animal tumor registry, composed by 121,963 dog and 51,322 cat patient data, which provides continuous information for over 50 years. The epidemiologic study linked dog and cat tumor distribution to factors like breed, age and sex. With some exceptions, results were generally consistent with existing literature. The geographic distribution of incidence cases showed that tumor risk is not homogeneously distributed across Switzerland. The analysis of the environmental causes for this phenomenon is currently in progress. These results will be followed by the comparison with human tumor incidence and its geographical distribution.
Fostering Intersectoral Collaboration For Control Of Taeniasis And Cysticercosis In Humans And Pigs
1GALVmed, South Africa; 2GALVmed
Taeniasis and cysticercosis in humans is recognised by WHO, FAO and OIE as a neglected tropical disease and important zoonosis requiring collaboration between human and veterinary public health sectors. The disease is common in South and South East Asia, Sub-Saharan Africa and Latin America. Taeniasis is caused by the human tapeworm, Taenia solium. Humans are infected by eating undercooked pork or ingesting contaminated food or water. Pigs are infected by eating contaminated human faeces or parasite eggs from the environment. In pigs, eggs develop into cysticerci in the muscles but cause no clinical disease. In humans, cysticerci may cause severe and sometimes fatal symptoms including the most common preventable form of epilepsy with associated socio-economic losses. Porcine cysticercosis (PC) reduces the value of village pig production and availability of safe pork, an important protein source. Control of taeniasis and cysticercosis by education, sanitation, meat inspection and pig husbandry has limited success. An alternative, economically effective method to interrupt the life-cycle is direct reduction of PC prevalence to control and eliminate the disease in not only pigs but also humans. The combined use of two, new tools in pigs, oxfendazole (30mg/kg, commercially available, MCI, Morocco) for PC treatment and TSOL18 vaccine (M. Lightowlers, University Melbourne. Registration expected 2016, IIL, India) for PC prevention has been shown safe and effective. In 2015, GALVmed (funding by DfID, UK and BMGF) is starting a collaborative series of field trials in Uganda, Tanzania, South Africa and Nepal to evaluate, over two years, the systematic use of oxfendazole and TSOL18 in free-roaming pigs to reduce PC prevalence as assessed by necropsy. In Uganda (in collaboration with Imperial College London), the trial will also evaluate the effect of annual, praziquantel, human community, mass drug administration to school children and adults given concurrently in the same villages.
Planning for Rabies Incursions in Remote, Northern Australian Indigenous Communities
The University of Sydney, Australia
Rabies has high impact on human and animal health globally. The coastal border of northern Australia is a remote area with a credible risk of rabies incursion and large populations of domestic dogs, mostly in Indigenous communities. The relationship between these Indigenous people and their dogs is complex; thus research informing response and control plans for rabies is critical to minimize adverse impact in the event of an incursion
We developed a novel stochastic spatio-temporal model. It is based on individual dogs informed by dog census data and incorporates three types of rabies spread (within household, between households and between communities; where the second is based on a distance kernel fitted to field collected GPS data on the roaming behaviour of dogs). Three types of control strategy are implemented in the model: a) vaccination (50 and 70% coverage); b) culling (30, 50 and 70% level); and c) movement restrictions between communities, within communities (dog confinement) or both, with dog owner compliance of 50 or 80%.
Outcomes suggest that vaccination would significantly reduce the outbreak size (number of dead dogs) while the other strategies only show a slightly positive effect when applied at high levels (70% culling and 80% compliance with movement bans). Importantly in these Indigenous communities, culling of dogs is unlikely to be successful. Also, movement bans (which culturally would be difficult to implement) would have minor impact unless there was high compliance.
This is, to the best of our knowledge, the first time a rabies model has been applied to compare control strategies for an epidemic situation with absence of rabies prior to the simulated incursion. It provides evidence on which to base preparedness plans, and to manage recent incursions in a culturally-sensitive manner.
Quantification Of Roaming Behaviour Of Free-Ranging Domestic Dogs To Inform Zoonosis Transmission
1Veterinary Public Health Institute, University of Bern, Switzerland; 2The University of Sydney, Faculty of Veterinary Science, Australia
The close relationship between animals and humans facilitates zoonosis transmission. Since dogs have been domesticated, they live in close proximity to humans. Rabies is probably the most severe zoonosis that is transmitted by dogs, which act as the main reservoir. The spread of infectious diseases depend on the roaming behaviour of their hosts. The investigation of the dog movement can therefore provide information on contact rates between individuals and disease spread.
In remote northern Australia domestic dogs are numerous and free-roaming. Rabies is absent from Australia but there is a risk of incursion from neighbouring, rabies-endemic Indonesia. Knowledge of roaming behaviour of dogs would enable evidence based preparedness plans for such an incursion, but this information has been lacking.
We collared 105 free-roaming dogs in six Aboriginal and Torres Strait Islander communities in northern Australia during different seasons to investigate their roaming behaviours. The dogs were found to roam generally around the dog owner’s home with relatively small home range sizes of 0.4 and 4.9 ha for the median core and extended home range, respectively. However, some individuals were found to roam much more widely (HR size of 40–104 ha) and cover large areas of their community or beyond. These far roaming dogs are of particular interest for infectious disease transmission. Season and age-gender interactions were found to influence home range sizes significantly. Contact rates were estimated from the GPS data collected. The daily contact rates between individuals ranged from 0–400 and were highly dependent on the distance between the dogs’ homes. A logistic regression model was used to fit a distance kernel function to the data to describe disease transmission between individuals.
Such information can further be implemented in theoretical rabies transmission models to estimate spread and control options for rabies in both dogs and humans within these communities.
Landscape Heterogeneity and Taenia spp. Distributions in Humans and Pigs: Evidence of Environmental Influences on Disease Transmission
1University of Southampton, United Kingdom; 2University of Edinburgh, United Kingdom; 3Kenya Medical Research Institute, Kenya; 4University of Liverpool, United Kingdom
Landscape factors have been demonstrated to influence the observed distribution of a range of infectious diseases, including schistosomiasis and soil transmitted helminths. Despite previous evidence of spatial clustering in Taenia spp. infections (human taeniasis, human cysticercosis and porcine cysticercosis) and the role of environmental factors (e.g. temperature and humidity) in the survival of eggs in the environment, little research has thus far explored the potential role of environmental factors on the observed distribution of Taenia spp. infections. This research aimed to examine the epidemiology of Taenia spp. infections in humans and pigs and to assess the role of environmental factors in observed disease distributions, while accounting for socio-economic and behavioural risk factors.
A cross-sectional survey for human taeniasis, human cysticercosis and pig cysticercosis in 416 households in western Kenya was carried out. These data were linked to questionnaire responses and additional datasets to provide information on socio-economic, behavioural and environmental factors. Multi-level logistic regression was used to examine the relationships between socio-economic, behavioural and environmental factors and disease occurrence (for human taeniasis, human cysticercosis and porcine cysticercosis).
The prevalence was 19.5% for taeniasis (95% CI 17.8%–21.3%), 6.6% for human cysticercosis (95% CI 5.6%–7.7%), and 17.2% for porcine cysticercosis (95% CI 10.2%–26.4%). The outcomes were significantly associated with a range of factors, including positive correlations with land cover: vegetated land was correlated with human taeniasis; agricultural and grassland was correlated with human cysticercosis; and flooding agricultural land and grassland was correlated with porcine cysticercosis.
These results indicate a complex interaction between socio-economic, behavioural and environmental factors in Taenia spp. transmission patterns. Environmental contamination with Taenia spp. eggs is a key issue and these results indicate that landscape factors influence patterns of taeniasis and cysticercosis occurrence in pigs and humans.
Dog Population Management: Integrated Solutions for Animals and People
1World Animal Protection, United Kingdom; 2World Animal Protection, Africa
Public health is influenced by animal health and welfare. In some instances, in efforts to protect humans, animal welfare suffers. Stray dog populations are considered a problem in many developing countries and are sometimes dealt with by mass inhumane culling. The misconception that culling is the most effective method of reducing dog populations often results in severe animal suffering. Application of a full cycle of dog population management methodology (for example, as set out in the International Companion Animal Management Coalition guidelines), or steps towards this, can help tackle the spectrum of problems associated with roaming dogs, such as disease transmission, nuisance, injury and fear, dog bites and livestock predation more humanely and effectively .
To achieve this, the World Animal Protection works with global governments, IGOs, NGOs and communities to ensure sustainable solutions for animals and people alike are put in place.
For example, World Animal Protection partners with the Zanzibar Department of Livestock Development (via the Veterinary Department), who are implementing a humane dog population management programme. Following the initial success of the project, the Department have expanded objectives to include rabies elimination, which is an achievable goal and which will help reduce the animal welfare and public health burden of the disease.
As a key element of the management cycle, education is of critical importance. Changes in perception, attitude and behaviour are fundamental to long term success. World Animal Protection therefore invests in curricula mainstreaming and ‘Training of Trainers’ programmes, often for local authorities and municipal councils.
In conclusion, World Animal Protection supports a holistic approach which sees animal and human health as inextricably connected, and works through cooperation between municipalities, public health and veterinary sectors. By coupling humane dog population management with responsible dog ownership, conflicts between humans and dogs can be mitigated, creating harmonious co-existence.