Global losses due to tick-borne diseases (TBDs) have been estimated to be as high as US$18,000 million per annum. Fortunately, in the Philippines and Australia the TBD situation is less complex than in many other countries, with only babesiosis and anaplasmosis, collectively referred to as tick fever, being of economic importance. But an urgent need in the Philippines for reliable, international standard diagnostic capabilities for tick-borne diseases became apparent in recent times. Because their extent within the Philippines was unknown, there were trade disputes over the inferred importation of these diseases in live cattle.
The value of Australia's live cattle trade with the Philippines has been as high as $128 million per annum. But there have been disruptions to that trade, largely due to TBD outbreaks in imported cattle and exacerbated by uncertainties about the disease and the acknowledged lack of diagnostic expertise for TBDs in the Philippines.
This project assisted the regulatory and diagnostic authority, the Philippines Animal Health Bureau (AHB) to acquire technologies that had been developed in other ACIAR-supported projects, in order to understand and deal with tick fever
The principal aim of this project was to build a strong diagnostic and epidemiological capability for tick fever in the Philippines, at strategically located laboratories in Manila and Davao. Secondary aims were to improve existing diagnostic tests for tick fever to make them more user-friendly and therefore more suitable for use in developing countries, to conduct epidemiological surveys to determine the prevalence and distribution of tick fever in the major cattle-producing areas in the Philippines and to establish the technology to culture Anaplasma (one of the causes of tick fever) in tick cell culture at the DPI&F laboratories in Brisbane.
The project built on the training previously provided by ACIAR to Philippines scientists in the diagnosis of TBDs. Staff from the AHB received further training in Australia and the Philippines in the application of these diagnostic tools. The system was tested, and further epidemiological training provided, through the conduct of a survey carried out in a selected region of the Philippines to determine the incidence and impact of tick-borne diseases in smallholder cattle.
The majority of the Australian staff in the project had been associated with the previous ACIAR projects and had a proven track record of delivering project objectives and disseminating project results. They worked with Philippines staff from the Bureau of Animal Industry (BAI), the agency responsible for implementing the outputs of this project, to build a reservoir of expertise in the diagnosis and control of parasite disease of livestock.
The project resulted in the development of centres of expertise in the diagnosis and control of tick fever in the key laboratories in Manila and Davao that service the major cattle producing and cattle importing areas in the north and south of the Philippines. These laboratories are now recognised reference centres for the rest of the country and models for establishing similar expertise in Regional Animal Disease Diagnostic Laboratories (RADDL) throughout the Philippines. Staff from 13 RADDL has already been trained to accurately diagnosis babesiosis and anaplasmosis by microscopic examination of blood smears from sick cattle.
The completion of serological surveys established the distribution of babesiosis and anaplasmosis in the Philippines, with both diseases present virtually throughout the country. DNA based strain-typing tests, developed in the project are now capable of differentiating between Australian and Philippine strains of A. marginale and B. bigemina. These tests will prove invaluable for determining the origin of outbreaks of tick fever that occur periodically in cattle imported from Australia.
Improved diagnostic tests for tick fever are now in routine use in both the Philippines and Australia. As a result of the project the Philippines has been left with a stockpile of diagnostic reagents sufficient to meet foreseeable needs and to conduct further serological surveys as required.
The project facilitated collaboration between the Australian project team and recognized world experts in the USA, that resulted in the capacity to culture A. marginale in tick cells being established in DPI&F laboratories in Brisbane. The ability to culture Anaplasma is critical to ongoing DPI&F research to produce safer and more efficacious vaccines to protect cattle against tick fever.
The project has made a significant contribution toward creating the disease diagnosis and surveillance capability that will underpin the success Philippines government initiatives to build profitable livestock industries. The Philippines government is committed to improving animal health and nutrition and to a programme of importation of breeder cattle to improve the productivity of local beef breeds and to build a viable local dairy industry. A rapid and accurate service for the diagnosis and treatment of tick fever outbreaks in both local and imported cattle is now available. The epidemiological surveys conducted within the project have provided livestock owners and government policy makers with up to date data on the distribution and economic impact of TBD that will allow them to make informed decisions about the future of breeder importation programmes, breed selection and the implementation of tick and TBD control strategies.
The project has benefited both the Philippines and Australia by contributing to the development of a more stable trading relationship based on up to date and clear knowledge. As an example, a recent outbreak of tick fever in cattle imported to the island of Masbate from northern Australia was quickly resolved without any disruption to trade, through rapid and accurate diagnosis of the problem and the ability to demonstrate that the outbreak was due to tick-borne exposure to a local parasite strain after arrival in the Philippines. Demonstration that babesiosis and anaplasmosis already occur throughout the Philippines has largely overcome concerns about the risks associated with the introduction of Australian parasite strains in imported cattle.
The project has also provided a boost to the Philippines government initiative to establish a viable local dairy industry. Cooperation between the project team in Manila and the Philippines National Dairy Authority has identified tick fever as the major cause of disease outbreaks that occur regularly in imported cattle and result in substantial loss of valuable breeding stock. Strategies have now been put in place to minimise tick-borne exposure and vaccinate imported animals on arrival.
The most important impact of the project on rural communities in the Philippines is indirect, and depends largely on the overall success of the government's initiative to improve animal health and nutrition. Should they succeed the long term impact will undoubtedly positive with an increase in rural wealth as a consequence of the increased profitability of livestock industries. A more immediate impact may be and the creation of employment opportunities in rural areas as a result of the growth of feedlots and related industries that rely to a large extent on the smooth operation of the live cattle trade with Australia
Positive benefits to Australia include the availability of improved diagnostic tests and stimulation of ongoing DPI&F research programmes to improve the control of tick fever. In particular, the ability to grow A. marginale in tick cell culture has been a catalyst for the development of several new projects aimed at improving the current tick fever vaccines. The development of an advanced disease diagnosis and surveillance capability in strategic laboratories in Southeast Asia is another positive benefit for Australia in that it contributes to regional biosecurity and acts as an early warning system for Australia's exotic disease surveillance programmes.
Links:
[1] http://www.aciar.gov.au/country/Philippines
[2] http://www.aciar.gov.au/programarea/Livestock Production Systems