CASE NOTES
A REVIEW OF A REGIONAL ANIMAL DISEASE INVESTIGATION SURVEILLANCE SYSTEM
Matt Ball- Senior District Veterinarian, NC LHPA, Lismore and Kate Finlayson, Veterinary Intern, Sydney University and Paul Freeman- Regional Veterinary Officer, NSW I&I, Wollongbar
Posted Flock & Herd March 2011
Summary
Animal health policy makers need to be given adequate information about the nature of the animal disease monitoring and surveillance system of their regions. Such information can be used to make decisions regarding resource allocation and appropriate organisational structure. Government, private industry or a combination of both can fund veterinary services and laboratory testing. Finding an appropriate balance of funding is critical for achieving the desired type of surveillance.
In 2010, a review of the general livestock health surveillance activities occurring in the North Coast region of New South Wales (NSW) was instigated. This paper summarises the results of that review. The review did not include other local surveillance activities such as sentinel herds, targeted surveys and abattoir monitoring.
The review highlights the key features of an industry and Government shared funding mechanism for general disease surveillance. The number, geographic location and findings of disease investigations are summarised for a six- month period. The contribution that private veterinarians make to general surveillance is outlined. Challenges of undertaking livestock health surveillance in a region where notifiable[1] diseases are typically absent and where traditional farms are being increasingly subdivided are discussed. The costs of the general surveillance system to industry and Government are estimated and recommendations made.
Introduction
In 2009 the 47 former NSW Rural Lands Protection Boards (RLPB)[2] underwent a significant restructure with the creation of 14 Livestock Health and Pest Authorities (LHPA).[3] These Authorities are legislated to collect rates from the occupiers of all farm holdings greater than 10 hectares in size. Income from these rates is used to employ staff to deliver key services.
As part of its role, the LHPA delivers legislated livestock health functions in partnership with the NSW Government Department of Industry and Investment (I&I NSW). A Memorandum of Understanding (MOU) is in place between the two agencies. The North Coast Livestock Health and Pest Authority (NCLHPA) operational area includes 1,454,653 hectares of land. It has approximately 15,000 ratepayers. In addition the region has a large number of farm holdings that are less than 10 hectares and whose owners do not pay rates.
The North Coast is a popular subtropical region of Australia and traditional farms are increasingly being subdivided into small holdings. Land prices are high and many landowners are new to the region, work off farm and lack experience in livestock production. An increasing percentage of land is being used for environmental conservation or horticulture purposes.
The NCLHPA employs three veterinarians and six para- veterinary officers (Rangers), to carry out a range of livestock health functions as specified in the NSW Rural Lands Protection Act 1998. This Act outlines that Authorities are required to provide resources for conducting animal disease surveillance programs and are to collect, collate, interpret and report animal disease surveillance information. The NCLHPA provides a disease investigation service. Phone advice is available to the public. NCLHPA ratepayers are entitled to property visits to investigate any herd health problem. If the reported syndrome could be consistent with a notifiable disease, then non-ratepayers are also entitled to a property visit. Routine individual animal problems are referred to a private veterinarian.
I&I NSW maintain a State Diagnostic Laboratory and cover the cost of laboratory testing to exclude notifiable diseases. Producers are generally responsible for all other laboratory tests. However, both NSW I&I and the NCLHPA each provide $AUS9000 per annum to pay laboratory fees for selected cases.
Monthly reports on surveillance activities undertaken in the region are provided by the NCLHPA to producers, private veterinarians and the NSW Government. I&I NSW employ a Regional Veterinary Officer (RVO) to assist in the planning, funding and reporting of surveillance activity for the NCLHPA and two other Authorities in the north east region. NSW is divided into 5 regions overall: north east, north west, south east, south west and western.
Private veterinarians carry out the majority (90%) of livestock disease investigations on the North Coast. These veterinarians report any suspected notifiable diseases to the NCLHPA and submit some of their laboratory samples to the State Diagnostic Laboratory. Other samples are sent to private laboratories. The NCLHPA is provided with a copy of all results from the State Diagnostic Laboratory but not from the private laboratories. Private veterinarians undertaking disease investigations occasionally request financial assistance from LHPA or I&I NSW for laboratory testing. These requests are assessed on a case by cases basis evaluating the community benefit that may accrue by undertaking the additional testing. Animal Health Australia also provides some financial assistance for disease investigation through its National Significant Disease Investigation Program
Materials and methods
A disease investigation was defined to be an incident where a veterinarian made a diagnosis of a reported disease sign in cattle, sheep, pigs, horses, camelid, poultry or goats. To obtain a diagnosis the veterinarian may have done one or more of: history collection on phone, history collection on farm, digital photo examination in office, clinical examination, necropsy and/or laboratory test interpretation.
Data on stock and farm numbers was collected from FARMS.[4] NCLHPA veterinarian reports and field diaries from July to December 2010 were collated and analysed for information relating to disease investigations and surveillance reporting activities. Livestock investigations were stratified by geographic location, species and findings. The percentage of livestock holdings where investigations were undertaken was also estimated.
A phone call was made to each private veterinary practice in the region. Practices undertaking any livestock health activities were identified (livestock practices). A phone survey was then undertaken of a veterinarian in each livestock practice. The survey asked for the number of veterinarians who worked with livestock; the percentage of practice work with livestock compared to companion animal [5] work; the percentage of work for different livestock species; the estimated number of livestock disease investigations, necropsies and property visits between July and December 2010; and the geographic range of the practice's farm calls.
Results
The region (Figure 1) has approximately 370,000 beef cattle, 26,000 dairy cattle, 8,000 sheep, 4,000 goats and 750 alpaca on over 7500 farms. Most of these livestock are spread out as small groups on many properties. 723 farms have dairy cattle, with only 87 of those farms having more than 100 cows. There are 6295 farms with beef cattle and these farms have an average herd size of only 60 animals. 15 of the beef herds have more than 1000 animals. Sheep are spread out across 335 farms with 20 farms having more than 50 sheep. A total of 200 farms have goats with 12 having more than 50 goats and 2 having over 400 goats. It is difficult to accurately estimate the numbers of horses, poultry and pigs in the authority. Commercial pig and poultry operations are recorded on the annual land and Stock returns as are horses but stock numbers resident on the large number of small non rateable properties in the authority are not recorded anywhere.
Between July and December 2010 NCLHPA veterinarians carried out 558 disease investigations. 434 (78%) of these disease investigations involved a property visit. 135(24%) of the investigations involved a necropsy. The results by species are shown in Table 1. Of the 558 disease investigations just under 50% had a disease diagnosis that was reported to the NCLHPA livestock health manager. The frequency of diagnoses is shown in Figure 2.
Figure 1: Geographic location of disease investigations by the NCLHPA between July-December 2010
Table 1: Investigations by species
| Species | % of NCLHPA investigations | % of private vet investigations | % total livestock in region* |
|---|---|---|---|
| Bovine | 89.25 | 51.02 | 96.83 |
| Ovine | 4.25 | 3.31 | 1.67 |
| Caprine | 3.95 | 3.31 | 0.98 |
| Camelid | 0.25 | 3.80 | 0.18 |
| Poultry | 1.55 | 0.75 | - |
| Horses | 0.25 | 37.25 | - |
| Pigs | 0.25 | 0.56 | - |
* Only includes sheep, cattle, goats, and alpaca as there was inadequate
census data on poultry, horses and pigs
Figure 2: NCLHPA disease diagnoses July-Dec 2010
The data showed that approximately 370 (5%) of the region's 7553 ruminant farms were visited by the NCLHPA during the six months. A further 2% received a diagnostic service by phone, counter or email. This figure is likely to be an underestimate as data may be lacking for all phone or email investigations where a diagnosis was not recorded.
Thirty nine private veterinarians were identified that undertook livestock health activities on the North Coast. These veterinarians were from 24 veterinary practices. Every farm on the North Coast is included in the service area of a private veterinarian. Most private veterinarians service a radial area of between 40-60 km from the clinic but a couple of veterinarians service an area between 80-200kms. Four veterinarians whose practices are located outside the NCLHPA region also service the region.
In most livestock practices activities are dominated by companion animal work. On average the livestock practices indicated that 35% of their work was on livestock. Four of the practices had less than 10% on livestock. Six of the practices had more than 50% but two of these practices were equine only practices.
Based on the survey it was estimated that approximately 5000 livestock disease investigations were carried out by private veterinarians. A breakdown of these investigations by species is shown in Table 1. Six practices located in Murwillumbah, Lismore, Casino, Coffs Harbour, Kyogle and Grafton undertook 60% of the investigations. Private veterinarians undertook necropsies in 2% (102) of their disease investigations. Disease investigations on average accounted for 46% of private veterinarians livestock health activity. Other activities such as obstetrics, pregnancy testing, surgery and dentistry made up 54% of their activity.
It was not possible to determine the percentage of ruminant holdings that private veterinarians serviced. This would require extensive analysis of practice records. It is likely that private veterinarians substantially increase the percentage of holdings reached. When the private veterinarian disease investigations are added to those carried out by the NCLHPA approximately 5027 disease investigations were carried out in the six months. The rate of return to the same property could not be accurately calculated for either the NCLHPA or the private veterinarians but is estimated to be 15% for the NCLHPA and higher for the private veterinarians.
Each month between July and December the NCLHPA distributed surveillance newsletters to both private veterinarians and producers and summarised surveillance activities for NSW I&I. In addition staff wrote 18 disease case studies and had 8 radio interviews and 6 newspaper articles related to the regions surveillance activities. During the time of the review the NCLHPA collated over 720 laboratory reports.
It is estimated that the total fees charged by private veterinarians for livestock disease investigations during the six-month period would be greater than $AUS700, 000. The North Coast LHPA collects $AUS600, 000 in livestock health rates each year of which at least a third is spent on disease investigation activities. The contribution by I&I NSW was difficult to quantify within this review.
Discussion
Traditional farms on the North Coast have been increasingly subdivided creating an increase in the number of landholders. There are still a significant number of ruminants in the region.
On the North Coast of NSW the combined resources of private veterinarians, NCLHPA and I&I NSW creates a busy general disease surveillance system. The differing activities of the three stakeholders complement each other and enhance the system. The majority of the surveillance is funded by industry including both fees collected by private veterinarians and rates collected by the NCLHPA.
Private veterinarians perform the majority of livestock health work. The 39 private veterinarians carried out 90% of the livestock disease investigations during the six-month period. The NCLHPA only carried out 10% of the investigations but carried out 60% of the necropsies. Necropsies are time consuming and many farmers may be reluctant to pay the commercial hourly rate for them to be undertaken by a private veterinarian.
There are significant differences between private veterinarians' activities and the legislated activities of the NCLHPA. The latter has a 100% focus on herd livestock disease diagnosis with no resources allocated for treatments. NCLHPA veterinarians have easier access to laboratory test subsidies and the flexibility to spend longer time on a single investigation.
The investigations covered a wide geographic area. For the NCLHPA, Figure 1 indicates that areas to the south and south west of Evans Head and Brooms Head, areas to the south and north west of Casino, areas to the north west of Nimbin and the region to the far west of Grafton appear underserviced. Many of these areas can be explained by urban development, horticulture, forestry or national parks. Some of the larger livestock properties in the west of the Authority region are not regularly serviced.
Private veterinarians carry out nearly 100% of the equine work as the NCLHPA only attends occasional notifiable disease exclusions. Equine work typically has an individual animal focus. The number of disease investigations for pigs and poultry seems limited. Contract veterinarians are employed by the larger sized pig and poultry operations but the remaining poultry and piggery sector is probably underserviced.
The ongoing division of traditional farms into smaller units creates challenges for a general surveillance system. Not only are there more farms to contact but many property owners work off farm and lack experience in livestock production. Other challenges have been created by the successful eradication of significant bovine notifiable diseases. Historically, ruminant farm contacts by veterinarians were higher when they were involved in highly funded eradication programs, such as the brucellosis and tuberculosis eradication program (BTEC program).
Increasing the number of disease investigations done by the NCLHPA would be difficult due to limited resources. In addition, almost 1000 of the farms with sheep, cattle or goats are less than 10 hectares in size, do not pay rates to the NCLHPA and are not entitled to property visits for routine disease investigations. The NCLHPA already undertakes a variety of extension activities to help meet these needs. Externally funded, village level biosecurity and syndromic disease workshops would be ideal.
The NCLHPA has legislative obligations to interpret and report on livestock disease in the region. Resources are actively used to spread surveillance information beyond the individual producer. This reporting function is an integral component of any surveillance system. Each month between July and December the NCLHPA distributed surveillance newsletters to both private veterinarians and producers and summarised surveillance activities for I&I NSW. In addition staff wrote 18 disease case studies and had 8 radio interviews and 6 newspaper articles related to the regions surveillance activities. During the time of the review the NCLHPA collated over 720 laboratory reports. Instead of attempting to increase its disease investigation service it may be more effective for the surveillance system overall for the NCLHPA to strengthen its surveillance reporting. To do this adequately the NCLHPA would need access to more data than it is currently provided.
It is beyond the scope of this paper to assess the cost benefit of the North Coast's busy general surveillance system to NCLHPA ratepayers and the wider public. If this was to be attempted it would be necessary to consider the relationship between the level of general surveillance and improvements in disease prevention and control at farm, Authority, State and National levels. Other benefits to ratepayers and the role this surveillance model plays in protecting overseas markets compared to models used in other Australian states could also be considered.
Risk analysis is an ongoing process in Australian livestock health agencies. Hopefully the findings of this review could be helpful for any future risk analysis that looks at particular disease risks to the North Coast of NSW. Disease risk analysis may also indicate what components of the system should be strengthened.
NCLHPA surveillance planning and reporting may be improved if its surveillance activities were focused on methods to detect and report on diseases listed on an annual local 'target list'. This list could consider results of risk analysis, NSW notifiable diseases, changes in local disease patterns and comments from local farmer groups. Decisions could be made about the most appropriate resourcing and surveillance method for each disease. This may be passive data collection, sentinel herds or surveys. The process may enable the NCLHPA to seek additional funding for surveillance beyond the disease investigation service funded by its ratepayers.
Overall the general surveillance activities in the region give enough information to the NCLHPA livestock health manager to monitor disease over time and detect changes in disease patterns. Alone, these activities are not adequate to reliably ensure specific disease detection. It is also difficult to assess the effectiveness of the components of this general surveillance system. This is partially because policy makers have not set key performance indicators (KPIs) for surveillance. In order to assess the effectiveness of the general surveillance system the livestock health manager should assist with the development of state wide KPIs that are related to geographical, enterprise and other risks rather than indicators of activity levels. The relevance of targets related to the number of disease investigations in proportion to farm holdings and to the number of various surveillance reports generated should be considered.
Reviewing data relating to disease investigation activities can provide livestock health managers with useful information to begin assessing the effectiveness of their surveillance system. The development of surveillance KPIs, enhanced surveillance reporting and undertaking of continued risk analysis techniques are considered to be priorities for the livestock health manager.