Porcine epidemic diarrhoea (PED)
We reported on this disease in the USA in Vol 7, Issue 2. PED is not readily distinguishable from transmissible gastroenteritis (TGE) or other causes of diarrhoea in young pigs. The disease has now spread to more than 6,200 farms in 30 states in the USA. Reports indicate more than 6 million pigs have died and this is influencing the supply and price of pork. It is still unknown how the virus entered the USA. Biosecurity measures centred on transport and farms are the main preventive measures Role of Transportation in Spread of Porcine Epidemic Diarrhea Virus Infection, United States
USDA has recently mandated the reporting of the presence of PED.
There are reports that the disease has spread to Canada Porcine epidemic diarrhea, Canada
Mexico (virtually all states) and Colombia ProMED-mail
It has reappeared in Japan after an absence of 7 years OIE Animal Health Information System
Swine delta coronavirus (SDCv)
This virus was detected in February 2014 in USA swine herds during surveillance for PED. It has now been detected on 87 farms in 12 states in the USA and farms in Canada. This is a new virus closely related to another coronavirus detected in Hong Kong in 2012. It has been associated with vomiting and diarrhoea in all age groups but with a lower mortality rate than PED ProMED-mail
PED and SDCv are not listed by the OIE as notifiable diseases. The USA has commenced reporting these diseases under “swine novel enteric corona virus disease” OIE Animal Health Information System. Canada and Japan have reported PED as exceptional reports.
African swine fever (ASF)
We have reported on the outbreak of ASF in the Caucasus, Balkans, Russia, Belarus and Ukraine in previous issues. Outbreaks continue to be reported and in January 2014 it was reported in wild boar in Lithuania. In February 2014 it was reported in wild boar in Poland OIE Animal Health Information System
Poland and Lithuania are members of the European Union (EU).
Russia banned the importation of pig products from the EU. Control measures implemented to exclude wild boar include hunting and fencing and the implementation of pig exclusion buffer and surveillance zones. In the EU veterinarians are being trained on detection and surveillance techniques, such as bleeding pigs ProMED-mail.
The EU guidelines on the surveillance and control of ASF in feral pigs can be accessed online.
Theileria orientalis has been present in New Zealand since the 1980s. Since 2012 there have been increasing reports of anaemia in cattle resulting in some deaths, mainly in the north island. Surveillance has indicated that the ikeda strain of this parasite is widespread. The vector is the cattle tick Haemaphysalis longicornis. ProMED-mail
Middle East Respiratory Syndrome (MERS)
Cases of the novel coronavirus MERS-CoV continue to be reported in the Middle East. More than 490 cases have been recorded, resulting in more than 120 deaths. During April 2014 there was a marked increase in cases in Saudi Arabia. Many of these cases appear to be nosocomial infections.
Whilst the majority of human cases have been recorded in the Middle East, cases associated with human movements from the Middle East have been reported in UK, Germany, France, Greece, Italy, Tunisia, Malaysia, the Philippines, USA and Lebanon. ProMED-mail
Investigations continue to find evidence of MERS-CoV in a high proportion of camels in the region. Antibodies against MERS Coronavirus in Dromedary Camels, United Arab Emirates, 2003 and 2013.
Very high viral loads have been recovered from nasal and conjunctival swabs from young camels, possibly indicating a respiratory route of infection.Middle East respiratory syndrome coronavirus (MERS-CoV) in dromedary camels, Oman, 2013
Some young camels are reported to show signs of upper respiratory tract infection. Retesting infected camels in Qatar has indicated that infection in camels may be a self limiting disease.
But not all human cases have a history of exposure to camels, camel meat or milk. Indeed those closely associated with camels (herders, breeders, abattoir workers) have not been reported to have higher prevalence of infection.
Given infection has been present in camels in the region since at least 1992 (based on serology on stored sera), why have cases only recently arisen in humans? Is it associated with recent changes in the ways camels are farmed in the region? Has the virus recently mutated, facilitating human infection?
The following outbreaks have been reported since January 2014.
H3N2 is circulating in farm dogs in southern China. Avian-origin H3N2 canine influenza virus circulating in farmed dogs in Guangdong, China.
Outbreaks in birds and human cases have been reported in Cambodia, China, Egypt, India, Korea, Libya, Nepal and Vietnam. Table 1: Cumulative Number of Confirmed Human Cases of Avian Influenza A/(H5N1) Reported to WHO 1 - Since 2003 (Updated 2014-03-24)
Highly pathogenic H5N2 reported in chickens in Taiwan.
First human death reported in China. Low pathogenic H5N6 isolated from the farmer and his poultry. Highly pathogenic H5N6 isolated from poultry in Laos. ProMED-mail
Outbreaks in domestic birds in the Republic of Korea and Japan. An outbreak in migratory birds in Korea preceded outbreaks in domestic birds. Six percent of the poultry population were culled in Korea. ProMED-mail
Italy reported conjunctivitis in a person exposed to H7N7 infected birds.
H7N9 caused disease in humans, finches, parakeets and sparrows in China. Concern was expressed that song birds may spread infection to humans. Possible Role of Songbirds and Parakeets in Transmission of Influenza A(H7N9) Virus to Humans
A good summary of information on this virus can be accessed at Background and summary of human infection with avian influenza A(H7N9) virus – as of 31 January 2014
Because H7N9 produces little evidence of disease in poultry compared to H5N1, it is very difficult to monitor on farms or in markets. March – October 2013, 136 human cases (45 deaths) were reported in eastern China. Since then a second wave has resulted in 286 human cases and more than 80 deaths.
H10N8 caused human deaths in China. It appears the virus has low pathogenicity in birds but causes severe disease in humans. H10N8 death in China; H5N1 in Cambodia, Vietnam; H7N3 vaccine trial; Rapid flu tests; Self-vaccination with patches
Points of interest
A bacteriophage (Tsamsa virus), which attacks anthrax bacteria, was discovered in the carcass of a zebra in Namibia. This finding could lead to new means of decontaminating anthrax sites. Novel Giant Siphovirus from Bacillus anthracis Features Unusual Genome Characteristics
Seal TB in cattle
A recent paper describes 7 cases of Mycobacterium pinnipedii
in beef cattle in New Zealand. Current evidence is that cow-to-cow transmission is uncommon. Source is thought to be the fur seals. This is a reminder to all that diseases can re-emerge from unexpected sources. The seal turberculosis agent, Mycobaterium Pinnipedii, infects domestic cattle in New Zealand: Epidemiologic factors and DNA strain typing
Function of zebra stripes
Where there are tsetse flies, equids tend to come in stripes. Recent work has shown that the flies prefer to alight on all black or all white surfaces rather than stripes. (Caro T et al (2014) Nature Communications 5 Article number: 3535.doi:10.1038/ncomms4535.)
Bovine leukaemia virus (BLV)
BLV is prevalent worldwide in cattle and causes B-cell leukaemia/lymphoma. BLV DNA has been found more abundant in mammary epithelium in cattle than in lymphocytes. Recent work has detected BLV DNA localised in human breast secretory epithelium. Further work is required to determine the significance of this finding. Bovine Leukemia Virus DNA in Human Breast Tissue
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.