Welcome to the first issue for 2013. We encourage your inputs and comments (see foot of page 2).
Schmallenberg virus (SBV) update
In Vol. 6 Issue 1, we provided a detailed report on this arbovirus which was spreading rapidly in Europe.
Recent reports have included:
- serological confirmation of infection occurring in indigenous animals in Scotland, Northern Ireland, Denmark, Slovenia and Estonia
- cases were reported in goats and an alpaca in the UK and deer, bison and mouflon in Europe
- viral genetic material has been found in the semen of bulls with a history of SBV infection. Archive numbers 20121221.1462748 & 20130123.1511878. This followed the suspected introduction of SBV into Poland by movement of bulls.
- studies of the virus have revealed a marked degree of genetic variability between isolates
- SBV is not reportable to the OIE; hence it is difficult to obtain accurate epidemiological reports of outbreaks. Reports in the European farming press would indicate an increase in cases being recognised this year compared to last. For the latest epidemiological analysis see the EFSA website.
Bovine tuberculosis (BTb)
The US Department of Agriculture has recently approved two new tests for BTb – the IDEXX M.bovis Ab test for detection of infection in herds and the CervidTB Stat–Pak Antibody Test kit as a primary test with the Dual Path Platform as a secondary test in cervids.
Prevalence of BTb in France increased from 0.02% of cattle herds in 2004 to 0.07% in 2010.
Recent outbreaks in the Mayenne and Ardennes departments have resulted in herd slaughter.
In the UK, more than 1400 badgers have been vaccinated in the intensive action area of West Wales. In Northern Ireland the transmission of BTb between cattle and badgers has been tracked at a local level by whole–genome DNA sequencing.
Recent cases in Switzerland have raised concerns of a possible spill over from wildlife or recrudescence of human disease infecting cattle.
Tick borne disease
Borrelia miyamotoi was first described in Japan in 1995, but wasn’t recognised as a zoonosis until cases were reported in 2011 in Russia. It causes similar clinical signs to Lyme disease caused by B.burgdorferi. B. miyamotoi has been detected in deer ticks in the USA. A recent retrospective serological survey of 875 patients living in areas of the USA where Lyme disease is prevalent, found 18 cases (2%) with serological evidence of infection with B. miyamotoi.
In the 1990s, 12,000 ticks were collected from different parts of NSW and were tested for Borrelia bacteria. No evidence of Borrelia infection could be found in any of the ticks collected. A NSW Department of Health panel concluded that although locally-acquired Lyme disease cannot be ruled out, there is little evidence that it occurs in Australia. See fact sheet from NSW Health 2012.
Another interesting paper on common misconceptions about Lyme disease.
Lumpy skin disease (LSD)
In Vol.6 issue 2 we reviewed the current state of the outbreaks in Israel. Cases have recently been reported from Lebanon and Palestine. Israel has changed its vaccination program as the protection provided by use of the live attenuated sheep pox vaccine in cattle was less than complete.
Vaccination is now with the South African Neethling strain live LSD vaccine for cattle or 10–fold enhanced live attenuated sheep vaccine. (20130304.1570870).
Hantavirus in the UK
Hantavirus is notifiable in the UK but no cases originating in the UK had been reported until 2009–10, when two confirmed human cases were reported with no travel history. In 2012 another case was reported near one of the previous cases. Subsequent testing detected hantavirus in trapped brown rats. In 2013 testing detected Seoul hantavirus in pet rats belonging to a human patient in Wales. Subsequent testing of the rat breeder’s colony detected seropositive animals and the breeder and their spouse were seropositive. Whilst there are no reports of human cases in Australia, hantaviruses are widespread across the globe and hantavirus antibody positive rodents have been detected in Australia. Vets treating pet rodents should exercise caution.
Theiler’s disease, an acute hepatitis in horses linked to the administration of blood products, is now believed to be caused by an unusual virus of the Flaviviridae family, Theiler’s disease–associated virus (TDAV).
A close homolog of human hepatitis C virus has been detected in the respiratory secretions of dogs in UK and serological evidence of infection in horses in USA. Called non–primate hepacivirus, it provides further evidence of these viruses infecting mammals.
A novel gammaherpesvirus has been found in oral squamous cell carcinomas of sun bears
A novel polyomavirus has been associated with rare brain tumours in raccoons in the western USA. Ten affected free ranging raccoons were found between 2010 and 2012, suggesting a potential emerging infectious origin.
A new paramyxovirus has been associated with tubulointerstitial nephritis in domestic cats in Hong Kong. It has been called feline morbillivirus.
In the last issue, we reported on the novel coronavirus which appeared in the Middle East in 2012. Recent studies have found closely related betacoronaviruses in Nycteris sp. bats from Ghana and Pipistrellus sp. bats from Europe. Further work is required to identify the reservoir host of the virus detected in humans. To date 41 human cases have been reported from Saudi Arabia, Jordan and in the UK and Germany where cases had previously travelled to Qatar. A case fatality rate of 50% is reported.
The new AVMA Guidelines for the Euthanasia of animals is available at the AVMA website. It does not address humane slaughter or depopulation for disease control purposes.
New diseases do occur. Each time we examine an animal and the clinical signs are not typical of what we expect to see in that species in our area, we need to include exotic diseases in our list of differential diagnoses. You may be looking at the first case and you do not want to become famous as the vet who missed it!
Use the hotline number 1800 675 888 as hundreds of your colleagues do each year. You are not alone.
The recent report of the death of a boy in Queensland due to infection with Australian Bat Lyssavirus should also remind us to protect our clients and staff when handling bats. See the Queensland DPI guidelines for veterinarians.
Recent reports from China record 132 cases (37 deaths) of people in 10 provinces and cities in eastern China due to infection with influenza H7N9. Previously this low pathogenic strain was only reported in birds. The variant is a reassortant derived from three different avian influenza viruses:
- the gene for N protein is from avian H11N9 viruses;
- the gene of the H protein is from Eurasian group of H7 viruses; and
- the genes for internal proteins are from H9N2 viruses
Reports indicate variable association with the poultry trade, variable severity of illness, and lack of evidence of human to human transmission of infection to date. H7N9 virus has been detected in pigeons, chickens and ducks in markets.
Because it has low pathogenicity in poultry it is not causing obvious illness in birds, requiring active surveillance for detection in birds.