Exotic Animal Disease Newsletter Vol 5 Issue 1 - January 2011

​​Foot and Mouth Disease

In Vol. 4 Issue 1 we reported on outbreaks in Japan and the Republic of Korea. The Japanese outbreak of type “O” FMD virus commenced in March 2010 and continued until July, by when Japan had culled a total of 220,034 pigs (2.2% of the national herd) and 68,314 cattle (1.5% of national herd) on 292 premises. Vaccination was used to help control this outbreak.

In South Korea (Republic of Korea), the first outbreak of FMD in 2010 was caused by type A virus and affected only cattle (7 outbreaks, beginning on 2 January and was declared eradicated 11 March 2010). The second outbreak, caused by type O virus started on 8 April and affected both pigs and cattle. 14 herds were affected before it was declared eradicated in June. 

In November 2010 South Korea reported another outbreak of FMD caused by type O virus. To date (18/01/11), 119 infected premises have been confirmed and more than 1.98 million animals have been destroyed or identified for destruction on 4,155 premises (pre-emptive culling used), 2.13 million animals had been vaccinated and 11 million doses of vaccine sourced in response to the epidemic. Total cost estimated at US$1.8 billion.

The interesting aspect of these outbreaks was the reported possible source of initial infection being linked to migrant farm workers or recent travel by farmers to FMD endemic areas. The outbreaks in the UK in 2001, and in Japan and the most recent in Korea affected many farms due to delays in detection of the initial infection. They serve as a useful reminder of the need for continued awareness and early reporting of suspected cases. 

Bulgaria in January 2011 reported that a wild boar shot within 2 km of the Turkish border was found to have foot lesions and tested positive for FMD type O virus. Wild boar and deer are prevalent in the area. Surveillance detected infection in cattle (1) sheep (14) goats (12) and pigs (8) on two premises in the nearby village of Kosti

Image of a Map showing Bulgaria, Black Sea and Turkish border 

Human carriage of FMD

A recent study in the UK involving 51 people exposed to FMD virus reported that FMD viral genome could be detected by PCR on nasal swabs from 35 persons after 8 hours exposure to the virus. Only one person was positive on PCR the following day, well within the current recommendation that persons exposed to FMD virus should be isolated from susceptible stock for 72 hours. Find out more

Animal health funding

EU has earmarked an additional €250 million to support programs to eradicate, control and monitor animal diseases in 2011 to better protect human and animal health.

Peste des petits ruminants

In Vol.1 Issue 2 we reported on PPR. In November 2010 FAO issued a warning that the outbreak of PPR in Tanzania presented a risk to 50 million sheep and goats in southern Africa. Vaccination and movement controls were recommended. Large outbreaks have also recently been reported in Ethiopia in sheep and goats.

Recent reports linking PPR to mortality in camels in Sudan (An outbreak of peste des petits ruminants (PPR) in camels in the Sudan Acta Tropica Vol. 116(2), 161-165) have been followed by reports of high mortality (50%) in dromedary camels in Pakistan, possibly caused by PPR. Affected camels show similar clinical and post mortem signs to those seen in small ruminants – lung congestion and consolidation, enlarged and haemorrhagic lymph nodes and inflamed and haemorrhagic stomach and small intestine.

Possible frog recovery

A recent report in New Scientist indicated that some species of frogs decimated by chytridiomyces infection are returning to areas in Australia from which they had disappeared. The frogs seem to be adapting to the presence of the fungus. Similar reports are also originating from the USA.

Leishmaniasis – new vector

Seven years ago a new strain of leishmaniasis was reported to infect kangaroos and wallabies in northern Australia. No human cases have been reported to date.

Research funded by DAFF has recently found that the new species of leishmania parasite identified in Australia is transmitted by day feeding midges of the Lasiohelea sp. This is the first evidence that an insect other than a blood sucking Dipteran of the Phlebotominae subfamily (also known as sandflies) is capable of transmitting leishmania and if confirmed could have important implications for the control of leishmania worldwide.

Bovine TB – UK

DEFRA has made public the supporting data behind the licensing of the first tuberculosis vaccine for badgers.

Laboratory studies with captive badgers demonstrated that the vaccine significantly reduces the progression, severity and excretion of Mycobacterium bovis.

A field study of a population of more than 800 naturally infected wild badgers found a 74 per cent reduction in the proportion of badgers testing positive on antibody testing. While indicating a clear effect of the vaccination on badger disease the study does not indicate either the efficacy of the vaccine in badgers not does it provide information on the effect of badger vaccination on reducing the incidence of TB in cattle.

DEFRA also published the results of computer modelling, which examined different strategies for controlling TB in badgers. Results indicated that ring vaccination combined with culling badgers was more successful than cull only. Culling needs to persist for 4 years. Early cessation of culling was likely to lead to an increase in cattle herd breakdowns.

New viruses

A new adenovirus which caused severe pneumonia and inflammation of the liver (40% morbidity and a case fatality rate of 83%) in a colony of Titi monkeys in California, was reported to have infected a scientist investigating the outbreak. The scientist recovered  from pneumonia and there was no evidence of human to human spread.

Scientists in Nigeria have reported the discovery of a SARS like corona virus in Commerson’s leaf nosed bats. They named the virus Zaria bat coronavirus. It has not yet been associated with a disease entity.

Tabanid flies - host preference

Tabanid flies are the potential vectors of Trypanosoma evansi, the causative organism of surra.

Recent research in northern Queensland has studied the host preference of these flies by identification of ingested blood in trapped flies.

Macropods were the most frequent food source for each of six major tabanid species in the area.

All tabanid species fed on at least three of the species tested (horse, cattle, pigs and macropods) and mixed meals were commonly encountered.

Results indicated that horse, cattle and macropods species investigated could be affected, but macropods face the highest transmission risk of T. evansi.

Control of neglected tropical diseases

The WHO recently released a report on working to overcome the global impact of neglected tropical diseases (many zoonotic).

A number of global pharmaceutical companies pledged support to provide drug donations to support the program.

Results to date include:

  • Preventative chemotherapy reached 670 million people in 2008
  • Dracunculiasis (guinea worm) will be the first disease eradicated by health education and behavioural change not vaccination
  • Reported cases of sleeping sickness lowest for 50 years.

More work is required on helminthiasis, schistosomiasis, rabies, dengue, Buruli ulcer, Chagas disease, trachoma, leishmaniasis, onchocerciasis, echinococcosis, leprosy, foodborne trematodes,  cysticercosis to name a few.

Further information on these 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 diseases in livestock in Australia.

For further information contact Dr. Richard Rubira, Animal Health Programs, Biosecurity Services Group
Department of Agriculture, Fisheries and Forestry, Canberra
Email: Richard ​Rubira 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