Exotic Animal Disease Newsletter Volume 6 Issue 1 - January 2012

Schmallenberg virus

In August/September 2011 it was reported that cattle herds in the Eastern Netherlands and bordering regions of Germany were suffering from severe diarrhoea, fever and milk drop. Cattle appeared to recover after a few days. There were also reports of increased returns to oestrus in sheep.

In December 2011 reports were received in the Netherlands that malformations were being observed in aborted and new born lambs. Germany advised that an Orthobunya virus, Akabane-like, had been detected and named it Schmallenberg virus.

During December 2011 further reports were received of new born lambs showing signs of arthrogryposis, hydranencephaly, ankylosis, torticollis and scoliosis. Affected lambs were born to several breeds. Lambs born in November 2011 were not affected.

18/50 blood samples collected from affected cattle in August/September proved positive for the virus when tested in December. None of the controls were positive. Schmallenberg virus was detected in the brains of some affected lambs.

As of 9 January 2012 reports of affected small ruminants have been wide spread in the Netherlands, northern Belgium and in the North Rhine-Westphalia and Lower Saxony areas in Germany. One affected goat kid and one affected calf  tested positive for the virus.

The virus

The virus has been typed as a member of the Bunyaviridae family, genus Orthobunyaviruses  in the Simbu serogroup. Members of this serogroup have not previously been reported in Europe. It appears to most closely resemble the Akabane and Shamonda viruses in this serogroup. Simbu serogroup viruses are vector borne with Culicoides and mosquitoes as possible vectors. In this outbreak the vector(s) and source of this virus are yet to be identified.

About 30 Orthobunya viruses have been associated with human disease, including some within the Simbu serogroup. Akabane and Shamonda viruses are found only within ruminants; there have been no reports of human infection to this date. The European Centre for Disease Prevention and Control stated “it is unlikely that this virus would cause disease in humans, but it cannot be excluded at this stage”. See the report.

The disease has been made notifiable in the Netherlands. Research has begun to better characterize the virus, develop diagnostic tests, understand the epidemiology of the disease and to investigate the potential for vaccination.

France, Luxembourg and United Kingdom have commenced surveillance programs. Further information.

Bovine TB control in UK

A recent review of bovine TB control measures in the UK from an episystem perspective is an interesting discussion of the many factors that can affect the effectiveness of livestock disease control programs where a wildlife reservoir exists. See the paper by O’Connor et al.

Bovine psoroptic mange UK

In 2009 psoroptic mange was diagnosed in cattle herds in Wales. This was the first detection in the UK since the 1980’s. Recent reports indicate that it has been confirmed on 23 farms in Wales and south-east England, although this is likely an underestimate of the actual level of infection.

Psoroptic mange in cattle is also reported to be a disease of concern in Europe. All breeds are susceptible but cases are most commonly reported in beef cattle in autumn and winter. Infection is spread through the widespread movements of cattle.

Trypanosomiasis

Scientists have recently identified livestock genes which may protect against trypanosomiasis. This disease causes severe hardship in Africa due to reduced animal productivity and also reduced availability of draught animals to till fields.

Humped African cattle breeds are susceptible, whilst the humpless west African breed, the N’Dama, is less seriously affected. However the N’Dama cattle are smaller, less docile and less productive.

Two genes have been discovered that identify cattle resistant to infection that may now be used in breeding programs.

Porcine Reproductive and Respiratory Syndrome – Asia

Previously (Vol. 2 Issue 1) of this newsletter we reported on a new highly pathogenic variant of this virus affecting pigs in China and Vietnam in 2006/07. A recent article has reported the spread of this variant of PRRS to Bhutan, Cambodia, Laos, Malaysia, Myanmar, the Philippines, Thailand and Singapore. Reports were also noted in South Korea, Mongolia and Russia.

Map of world showing spread of Porcine Reproductive and Respiratory Syndrome in Asia (as described in text)
 
The epizootic affects both commercial and backyard farms resulting in concerns for food supply. PRRS virus shows high rates of genetic diversity. This highly pathogenic variant has numerous mutations which differ from those found in earlier isolations.

PRRS virus is spread through pig sales, semen, swill feeding and virus carried on travelers clothing and shoes.

CDC website

FAO website

Shuni virus in horses in South Africa

Shuni virus was first isolated from cattle and sheep in Nigeria in 1960’s and latter from mosquitoes, cattle and goats in South Africa. A recent report from South Africa shows Shuni virus was detected in 7 horses, 5 of which had neurologic signs.

Pigeon fever - horses - USA

In December 2011 more than 30 cases of pigeon fever were reported in horses in Louisiana. Pigeon fever is caused by infection with Corynebacterium pseudotuberculosis (although a different biotype from that which causes caseous lymphadenitis in small ruminants). The disease results in the formation of abscesses in the pectoral and ventral abdomen regions, giving affected horses a ‘pigeon like’ appearance.

Pox viruses

A recent report documents the first confirmed evidence of camel pox virus infection in humans associated with outbreaks in dromedarian camels in northwest India in 2009.

Camel handlers and attendants were reported to have papules, vesicles, ulceration and scabs over the fingers and hands.

A woman in France purchased 2 pet rats imported from the Czech Republic. The rats died a few days later. The woman developed lesions on her finger, ear lobe, neck, check and abdomen. Other rats from the same source also died.

It is now believed that wild rodents, not cows, are the reservoir for cow pox virus. Cowpox virus is widely distributed in Europe, western parts of the former Soviet Union, north and central Asia with increasing reports of human infections.

Malaria claiming more birds

Recent monitoring has shown that Plasmodium relictum, the causal agent of avian malaria, is causing increased losses in endemic and introduced birds in England, France, USA and New Zealand. The percentage of house sparrows found to be infected in Spain has risen from 10% to 30%.

EU funds zoonoses

In November 2011 the EU announced the provision of €203 million to assist member states fight animal diseases including several that affect both animal and human health.

Diseases to be targeted include salmonellosis, transmissible spongiform encephalopathies, rabies, avian influenza, bovine TB, bluetongue, brucellosis and classical swine fever.

Questions

Do you have clients with small numbers of livestock close to a city?

Are you and your clients aware of the likely clinical signs of FMD? (Animal Health Australia (AHA) have released a DVD on recognizing FMD) Do you know how to report a suspected case of an emergency animal disease? Do you know where to find assistance?

If you answer no to any of the last three questions then it may be a good time to make contact with your nearest government veterinary officer or visit the AHA website!


Further information on emergency animal diseases can be obtained from the AUSVETPLAN website.

While you are there check out the latest edition of Animal Health Surveillance Quarterly for information on animal diseases in Australia.

For further information contact Dr. Richard Rubira, Emergency Animal Disease Preparedness, Animal Health Policy Branch, Animal Division, Australian Government Department of Agriculture. Email Richard R​ubira or phone: (03) 5762 2246

Remember

New diseases do occur. You may be looking at the first case. EXOTIC DISEASE WATCH HOTLINE 1800 675 888