Zoonoses
Wednesday, 06 January 2010 08:41

The zoonosis programme is a collaborative project between the Australia Centre for International Agricultural Research (ACIAR), the Secretatiat of the Pacific Community (SPC), and the Mordoch University. 

Background

There is increasing concern amongst Agricultural services in the Pacific Islands that major human and animal problems will arise as a result of increasing human and animal populations. This project was developed to determine the extent of the problem posed by zoonotic disease as a result of this increasing human and animal density and to develop control strategies to reduce their impacts. The Permanent Heads of Agriculture and Livestock Production Services (PHALPS) in the South Pacific region have identified this as a priority. Three zoonotic infections that have the potential to cause the greatest impact on animal production and human health have been chosen for this project. They are trichinellosis, leptospirosis and angiostrongylosis:

Leptospirosis causes production loss in livestock and has emerged as a serious public health concern, especially for owners of livestock and workers in the processing industry (map of leptospirosis in the region).
Trichinella infection in pigs is a barrier to livestock trade and the potential rejection of carcasses at slaughter could become a significant loss to producers.
Angiostrongylus is an unquantified threat to livestock health and is emerging as a serious public health problem.

Objectives


The objectives of this project are:

  • To develop the capacity for effective surveillance of Trichinella, Leptospira and A. cantonensis infection in the South Pacific region through the development and transfer of diagnostic technologies,
  • To determine the prevalence of Trichinella, Leptospira and A. cantonensis infection in livestock in Fiji and Kiribati and risk factors associated with their transmission,
  • To determine which species of Trichinella are present in Fiji and Kiribati,
  • To investigate the pathogenesis of T. papuae in pigs and Angiostrongylus cantonensis in ruminants.


Approach

At Murdoch University serological assays for the detection of Trichinella, A. cantonensis and Leptospira infection will be transferred from collaborating institutions (International Trichinella Reference Centre) and obtained from published information. Tests will be optimised and validated for use in the Pacific region and transferred to the National Veterinary Laboratory (NVL), PNG and the Secretariat of the Pacific Community (SPC), Fiji through “hands-on” training at Murdoch University. In addition, equipment necessary to conduct enzyme-linked immunosorbent assays ( ELISA) will be supplied to the SPC. Training will also be provided in PNG to enable technical staff from partner countries to collect internal parasites, tissue and serum samples from livestock and rodents required for epidemiological studies. Further diagnostic capacity will be established at Murdoch through the validation of a PCR-based test for detection of Leptospira infection in urine and tissues from rodents and pigs that has applications for surveillance in Australia. This will enhance capability for surveillance for three important zoonotic diseases in the SPC and NQIA in PNG. This generic technology will also enhance surveillance for other important diseases of livestock.

A survey will be conducted in PNG to obtain new isolates of T. papuae. Experimental studies using these isolates will then be conducted at the NVL to determine the pathogenicity of infection in pigs and dogs. Further surveys will be conducted in Fiji and Kiribati where there is serological evidence of Trichinella infection in pigs (including T. spiralis) and significant occurrence of human leptospirosis (Fiji). The surveys will be designed to determine the seroprevalence of each organism in livestock species and rodents and to obtain isolates of Trichinella from pigs and rodents that will be identified to species level. In addition, risk factors associated with infection in livestock will be identified. This information will be used to determine control priorities and develop control strategies for these zoonotic infections in livestock in the Pacific Region.

Links with an another ACIAR project, which will study the environmental impact of animal waste, will enable sampling of animals in Tonga where the density of pigs and the likelihood of zoonotic transmission is high (2.11 pigs per person). Information on zoonotic infection rates in pigs in these sites will then be available to LWR2 2001/038 to enable an assessment of the likely impact improved pig waste management will have on the zoonotic transmission. In addition, staff from Murdoch University will provide technical input on the detection of zoonotic enteric pathogens of pigs, e.g. Cryptosporidium.

The findings of the project will be disseminated through a workshop in the final year that will involve key personnel from the Department of Agriculture and Health Departments of Fiji and Kiribati. The outcomes of this workshop will be the formulation of an education and control program for zoonotic diseases where applicable and the establishment of a regional network on zoonoses.