BLUETONGUE…comparison

 

· Compare Australia to your country…if you live in Europe.

THs is an accurate map of Australia overlaid over the majority of Europe.

This map alone, shows you why there is no risk of Bluetongue Virus reaching the southern states of Australia, and why the zones and Australia's NAMP research and continual mapping systems ‘gives your country assurances they need.

There has been 1 naturally occurred case of BTV tested in Australia, and that was in 1979.

That was in a cattle, at a place called Dumpty Doo, which is approx. near the red oval dot, in the ocean at the top of Norway on the left.

I am situated in Melbourne which is approx. in the Mediterranean near Crete.

And in between is a huge desert.

Lets see how big Australia is

- Australia-

· 7, 692, 030 square km

· (China: 9,597,000 sq km)

· Lowest, flattest, geographically uniform continent

· very old

Land use: 6% arable, 58% pasture, 14% forest, 22% other (mostly desert)

· Blue Tongue- Australia

1 Bluetongue is an insect-borne, viral disease primarily of sheep, occasionally goats and deer and, very rarely, cattle. The disease is non-contagious and is only transmitted by insect vectors. Bluetongue is different from most other diseases covered by AUSVETPLAN. The causes of most other exotic diseases are not present in Australia, whereas a number of types of the bluetongue virus are present in Australia, but natural bluetongue disease has not occurred in Australia. The disease is caused by a virus belonging to the family Reoviridae.

History of BTV in Australia

• free until 1977, BTV isolated from mixed pool of Culicoides in 1977, and has been, the vectors or virus does not change

• Extensive cross-sectional surveys -Sentinel cattle to search for new viruses

• Sentinel cattle are the mainstay of Australia’s BTV surveillance programme. Monitoring of sentinel herds taken in place almost every year since the late 1970s. From 1990 to the present there have been between 57 and 93 sentinel herds distributed around Australia every year.

• State based programmes coalesced into the NAMP in 1992. This national programme continues to run and provides ongoing information.

• Sentinel programs have existed in Australia for over 30 years

• Strategically distributed around Australia, based on history

• Continuous and ongoing surveillance

• Research into BT viruses

• distribution, virulence, pathogenesis, teratogenicity, semen studies, vaccines, molecular biology

• Expansion of vector research

• ecology,distribution, competence

•

National Arbovirus Monitoring Program (NAMP)

• Monitors the distribution of important arboviruses of livestock and their vectors

• An integrated national program

• Funded by government (2/3) and national industry bodies (1/3)

• Managed by Animal Health Australia

• See

– http://www.namp.com.au

– http://www.aahc.com.au

– At least 10 animals per herd

– 5 to 7 months old and seronegative at start of monitoring

– Sampled throughout the year

– Tested by ELISA, VI & SNT on positives

– Molecular characterisation of isolates

–

– Austvetplan…action plan in place in case of Outbreak

–

Vector Monitoring

• Conducted under National Arbovirus Monitoring Program

• Network of monitoring by light traps

• Collections identified to species

• Counted (total numbers, stages)

• Ongoing research

NAMP Database Management

• Sentinel herds and vector monitoring results are entered online onto the National Arbovirus Monitoring Program website

– password protected area prompt data entry

• Rapid searching & sorting of current national data possible

• Computerised national BTV risk forecasting system now developed

• Export & Trade

• Export and trade is very Important for Australia.

• Before any alpaca is sourced for Export, I as an Exporter will contact the Department of Primary Industries or Dept of Lands (NSW), to obtain the disease status of the property of source.

• The CVO of the department of the region sourced will look up the NAMP and confirm that the property is free from any Bluetongue Virus

• Export Permit is only issued when AQIS issues Export Health Certificate

• AQIS certifies according to current BTV zone map, providing acceptable to importing country

Elements relevant to zoning

Constructing the zones

Animal Husbandry

• Mainly extensive livestock grazing in Australia

• Cattle, sheep & goats rarely housed

– no opportunity for vectors to “over-winter” in animal houses

– Recognition of Australia’s BTV zoning by other countries

• USA formally recognised in 2000

• Canada formally recognised in 1999

• Mexico recognised in 1998

• Japan, South Africa & Israel have recognised for many years

EU endorses concept of zoning

Using the BTV free zone

• Ruminants for export live in the free zone for at least:

• a) 60 days without test OR

• b) 28 days with negative ELISA OR

• c) 7 days with negative VI or PCR

AND were not transported through an infected zone en route to the port

Countries importing livestock and their products from Australia have varying definitions of the “BTV Free Zones”. It is generally accepted that Tasmania, Victoria, South Australia and Western Australia south of the 26th parallel, are free of both BTV and the midges that spread it.

Zoning now adopted in UK & Europe is based on the same principle as Australia

BTV-Alpacas

Study 1

Instituto de Virología, Centro de Investigaciones en Ciencias Veterinarias (CICV), Instituto Nacional de Tecnología Agropecuaria (INTA), Castelar, Morón, Argentina

Abstract

This study analysed sera from 390 llamas (Lama glama) from nine farms located in three different Argentine provinces: Buenos Aires, Cordoba and Jujuy. The samples were tested for antibodies against 8 virus known to infect cattle: bovine herpesvirus type 1 (BHV-1), bovine viral diarrhea virus (BVDV), bovine adenovirus (BAdV III), bovine enterovirus (BEV), bovine rotavirus (BRV), bluetongue virus (BTV), bovine leukaemia virus (BLV), and foot-and-mouth virus (FMDV) by conventional methods such as seroneutralization, immunoperoxidase staining, and agar gel immunodiffusion.

The antibody prevalences detected in llamas were: BHV-1 in 0.77 % (3/390), BVDV in 2.05 % (8/390), BAdV III in 5.13 % (20/390), BEV in 4.10 % (16/390), BRV in 87.69 % (342/390). No antibodies against BTV, BLV and VIAA (FMDV infection associated antigen) were detected.

Study 2

In January 1993, two healthy adult male llamas obtained from Llamas of Michigan Caledonia, Michigan, USA) were housed in an insectproof animal isolation room of a biocontainment facility of the Animal Diseases Research Institute, Nepean, Ontario, Canada. Each llama was inoculated by intravenous (10.0 ml), subcutaneous (1.0 ml) and intradermal (1.0 ml) routes with a suckling mouse brain stock of BTV serotype 10, containing approximately 10ıı/ml plaque forming units of the virus. Serum samples were obtained prior to inoculation and on weekly intervals post inoculation for 9 wk. The llamas were housed in isolation facilities and were cared and handled according to the guidelines of the Canadian Council on Animal Care.

Both llamas inoculated with BTV serotype 10 remained healthy throughout the period of this study and had no clinical signs suggestive of bluetongue. However, both animals developed antibodies to BTV infection. B!uetongue virus antibodies were

detected by the C-ELISA test, at approximately 70% inhibition value as early as 1 wk post-infection (WPI) in one llama and 2 WPI in the other. The C-ELISA group specific antibodies to BTV increased exponential!y during the first four weeks in both llamas before becoming relatively stable at elevated levels of 90% inhibition values during the remaining 5 wk of the

experiment. Neutralizing antibodies first were detected by the MTSN test, at 1:20 serum dilution, between 2 and 3 WPI in the llamas and then elevated to higher 1evels of 1:80 to 1:160 during the remaining period of the experiment. Al! sera with the exception

Study 3

http://www.efsa.europa.eu/EFSA/Scientific_Opinion/ahaw_report_bluetongue_en,7.pdf

In South America, Rivera et al. (1987) showed that camelids can be infected with BTV when 21%

of over 100 sampled alpaca (Lama pacos) were positive for BTV-specific antibodies. All of these

animals were clinically healthy.

In the recent Outbreak, in Europe ,2007

Report

Lethal bluetongue virus infection in an alpaca

M. Henrich¹, M. Reinacher¹ and H. P. Hamann²

¹ Institut für Veterinär-Pathologie, Justus-Liebig-Universität Giessen, Frankfurter Strasse 96, 35392 Giessen, Germany
² Landesbetrieb Hessisches Landeslabor, Marburger Strasse 54, 35396 Giessen, Germany

SIR, - We would like to report a case of lethal bluetongue virus infection in an alpaca in Germany. The affected animal was a five-year-old female alpaca, born and raised in a flock in a low mountain range area in central Germany. This area was affected by the bluetongue virus outbreak in Germany in 2007. Within a radius of 5 km, clinically evident bluetongue virus infection in sheep and cattle was reported, with high mortality in affected sheep.

The alpaca herd was housed in an open stable with unrestricted access to pasture during daytime, but was kept inside the stable at night (including dusk and dawn); however, the stable was not completely protected against flying insects.

Three months before its death the alpaca gave birth to a healthy cria, which was weaned at the time of death of the mother. Four weeks before the animal died, it showed signs of colic with recumbency and tympanic abdomen. The animal was degassed via nasogastric intubation and recovered quickly, but the cause of the clinical signs remained undetected.

Immediately before the fatal bluetongue virus infection, mother and cria were in excellent body condition, and both showed no signs of an underlying disease.

Acute clinical signs started with 'hiccup-like' breathing and a stertorous sound discernible via auscultation. One hour later the animal was inappetent, recumbent and lethargic. Seven hours later the animal was observed coughing and mildly disorientated. Fourteen hours after the first observation of signs the animal died.

On postmortem examination, the animal showed severe, acute, diffuse, interstitial and alveolar oedema of the lungs. In the oral cavity, single small erosions and ulcerations on the tongue, palate and buccal mucosa could be observed.

As well as postmortem changes and acute congestion of the liver, spleen and kidneys, histopathology revealed severe congestion, interstitial and alveolar oedema of the lung, and mild hypertrophy of type II pneumocytes.

Focal haemorrhages in the tunica media at the base of the pulmonary artery, a common finding in bluetongue virus infections in sheep, were not observed.

PCR revealed sequences of bluetongue virus in tissue samples (blood, lymph nodes and spleen), whereas no sequences of ovine herpesvirus type 2 were detectable.

The rest of the herd, including the cria, remain healthy and show no signs of bluetongue virus infection.

In the above case, the report it says that there were evidence that alpaca had come in contact with BTV, but no evidence the alpaca died of BTV.

The report says the alpaca was sick approx 1 month previous, and theory is the alpaca was immune suppressed, which made it more susceptible, and most likely died of the later.

Studies in Africa

There have been many studies performed in Africa on One Humped Camels.

They do throw up antibodies when exposed to BTV, although lower in numbers than other species.

The camels do not get sick with BTV, and there has been no reports of camels having died of BTV, and no evidence that they or Camelids are carriers of the disease.

It is considered that Camelids are a “low risk species”

lets look at the map again