17-09-2008 - International disease monitoring, April to June 2008
International disease monitoring, April to June 2008M. Sabirovic1, H. Roberts1, S. Hall1, H. Elliott1 and N. Coulson1
1 Food and Farming Group, International Animal Health, DEFRA, 17 Smith Square, London SW1P 3JR
- African swine fever virus circulating between wild boar and domestic pigs in the Caucasus region
- Bluetongue remains a threat to UK farming, while circulation of both BTV-1 and BTV-8 has been reported in France
- Classical swine fever in wild boar populations in eastern Europe
- Foot-and-mouth disease outbreaks across Africa, South America and the Middle East
- Outbreaks of highly pathogenic avian influenza across Asia, and occasionally in Europe, in wild birds and domestic poultry
- Sporadic reports of cases of rabies in illegally imported domestic dogs in western Europe
- Rift Valley fever continues to be reported in ruminants in Africa
- These are among matters discussed in the international disease monitoring report for April to June 2008, prepared by DEFRA's Food and Farming Group, International Animal Health
AFRICAN SWINE FEVER
African swine fever (ASF) continued to be reported from the Caucasus region. Again, the virus was reported in wild boar and recently in domestic pigs in Russia, suggesting the possibility of long-term establishment of the disease and increased potential for further spread in the region. This situation continues to evolve.
Russia reported an outbreak of ASF in wild boar in the Chechen Republic. The source of the disease was attributed to transboundary migration of the infected animals. The consequent reports of disease in domestic pigs in the same region indicate circulation of the virus between wild and domestic pigs, although there is not yet evidence of long-term establishment of the disease.
Burkina Faso reported that previously reported cases of ASF have now been resolved and no other outbreaks have been detected in the country since April 2007.
Inactivated vaccines for bluetongue virus (BTV)-1, BTV-2, BTV-4 and BTV-8 are all available and are being used in vaccination programmes in several European countries. However, there is no cross-reactivity between serotypes and hence no cross-protection between vaccines. Re-emergence of virus in France (both BTV-1 and BTV-8) suggests that there is an existing threat of disease in naive animals, as well as a threat of emergence of a new serotype in immune or vaccinated animals. Fig 1 on p 320 shows the location of serotypes of bluetongue in Europe during August. For the European Food Safety Authority (EFSA) scientific opinion on bluetongue, see www.efsa.europa.eu/EFSA/efsa_locale-1178620753812_1211902008725.htm
Following previous cases of BTV-1 reported at the beginning of 2008 in south-west France, further outbreaks of BTV-1 were reported from the previously affected areas (Pyrénées-Atlantiques and Landes regions) and from the area at risk for both BTV-1 and BTV-8 (Gironde). Vaccination against BTV-1 is mandatory in the affected zone in France.
Spain reported that BTV-1 infection is now considered to be endemic in the known affected areas and that vaccination against this serotype is being carried out.
Following a report on BTV-4 in sheep in western Portugal in November 2006, no further cases have been reported. Vaccination of sheep and cattle against BTV-4 is carried out in Portugal.
European countries have started vaccination campaigns in BTV-8-affected areas, including the UK, France, Germany, the Netherlands, Belgium, Czech Republic, Denmark, Italy, Spain and Luxembourg. There is evidence of transplacental or oral transmission of BTV-8 occurring in Europe during vector-free periods and contributing to overwintering of the virus. See http://ec.europa.eu/food/animal/diseases/controlmeasures/bluetongue_en.htm for more details.
Following outbreaks reported in March, France reported two further outbreaks of BTV-8 in cattle in eastern France (Isère and Savoie), three further outbreaks of BTV-8 in cattle in central and western France (Lot, Manche and Tarnet-Garonne) and a further five outbreaks in Vendée, Corrèze, Maine-et-Loire, Creuse and Haute-Vienne. Virus is clearly circulating in 2008, initially in the areas affected in 2007.
France has a compulsory vaccination scheme against BTV-8 in cattle, sheep and goats.
Germany reported that BTV-8 is now considered endemic in the known affected areas and that vaccination against this serotype is being carried out.
In the Veneto province of northern Italy, 21 new cases of BTV-8 were reported in cattle in April. Movement controls have been put in place in the Verona and Mantova provinces.
Despite these reports, there is still no indication of virus circulation. It is believed that virus was introduced with cattle imported from France during 2007. Italy is using inactivated vaccine. Historically, BTV-1, BTV-2, BTV-4, BTV-9 and BTV-16 serotypes have been detected in Italy, and modified live vaccines have been used.
Australia notified that BTV-7 serotype had been detected in the Northern Territory. Disease was diagnosed by serology in sentinel cattle showing no clinical signs. Sentinel cattle were subject to regular monitoring and testing as a part of the national surveillance programme. This is the first time that a reaction to BTV-7 has been detected in Australia. BTV-7 has been reported in countries to the north of Australia, and it is believed that infected vectors are periodically blown to Australia on monsoonal winds.
CLASSICAL SWINE FEVER
Sporadic outbreaks of classical swine fever (CSF) have been reported from new areas in Slovakia in addition to those previously under restriction. Under EU rules, trade in live pigs from these areas is not permitted.
An outbreak of CSF was confirmed in fattening pigs in the Nitra province of Slovakia (Levice) in mid-April. Another outbreak was confirmed in a linked herd in the same province. Both outbreaks occurred in the area outside the known restricted areas where CSF had been identified in wild boar and where vaccination of wild boar is carried out.
Following reported cases in March, another case of CSF in a wild boar in the Pest region, Hungary, was reported in April. In May, another 16 outbreaks of CSF in wild boar (19 cases) were reported from the Nógrád and Pest regions. Hungary will continue to use control of wildlife reservoirs, screening and zoning as control measures for future cases.
Hungary controls the disease in wild boar by hunting rather than vaccination and has therefore extended the current CSF-infected area to better control infection in wild boar, increased surveillance around the infected area and improved regulations for disposal of hunted wild boar carcases.
An outbreak of CSF in backyard pigs was located in western Bulgaria, close to the border with Serbia. Disease control measures were put in place and the affected herd was depopulated.
Because of CSF, EU regulation does not permit trade in live pigs, pig semen, embryos, ova and fresh pig meat from Bulgaria to the rest of the EU (www.defra.gov.uk/animalh/diseases/monitoring/pdf/csf-bulgaria080529.pdf).
An outbreak of CSF (virus subgroup 2·3) was reported in a wild boar in the east of Croatia (Vukovarsko-Srijemska province) in May. Disease control measures were applied in line with EU rules. Although no new outbreaks have been reported since May, controls and restriction measures are still in place around the hunting grounds where the infection was found in wild boar. The EU is now working with the western Balkan countries, including Serbia and Croatia, to help them control CSF.
In April, Botswana reported outbreaks of foot-and-mouth disease (FMD) (serotypes SAT-1 and SAT-2) in cattle. The authorities consider that these outbreaks occurred due to spread from the primary outbreak in October 2007, which was reported from the Maun region. Vaccination and control of wildlife to prevent further incursions into cattle populations are in place.
Following outbreaks of FMD (SAT-2) in Caprivi late last year, Namibia reported another outbreak in cattle in the same province in April. Control measures including ring vaccination were put in place. The northern part of Namibia, including the Caprivi strip, and the Maun region of Botswana are not authorised for export of fresh meat to the EU. Game fences maintain the free status of the other parts of these countries.
Mozambique reported an outbreak of FMD (untyped) in cattle in the Gaza province in April, which was attributed to movements of cattle from the central part of the country.
Following an outbreak in March, control measures including vaccination were put in place and Zambia has reported no further outbreaks.
Zambia and Mozambique are not authorised to export fresh meat or meat products to the EU.
Bahrain reported an outbreak of FMD (type O) in Manama in April. Control measures were put in place, including vaccination. According to the report, the virus could have been introduced by the movement of live animals. Bahrain imports live animals and meat from countries in the region. Bahrain is not authorised to export fresh meat or meat products to the EU.
Ecuador, Colombia and Venezuela are not authorised to export fresh meat or meat products to the EU.
An outbreak of FMD (type O) in cattle was reported in western Ecuador. This outbreak started in mid-May and was attributed to the introduction of live cattle. The source of disease is under investigation and disease control measures are in place. Vaccination against FMD is practised in Ecuador. This outbreak co incides with the beginning of the first vaccination phase in 2008 (www.defra.gov.uk/animalh/diseases/monitoring/pdf/fmd-ecuador080523.pdf).
An outbreak of FMD (serotype unknown) in cattle was reported in Norte de Santander, Colombia, close to the border with Venezuela. Three further outbreaks were reported in the same region; two of the premises were bordering or very near the original infected premises. Disease control measures are in place. Vaccination is not used in Colombia.
An outbreak of FMD (type A) has been reported in cattle on seven farms in the Sifontes region of Venezuela. Disease control measures are in place. Type A virus is detected occasionally in Venezuela; the source of the disease is possibly due to vaccination procedure breakdown. The outbreak is now reported to be under control and animals are recovering.
HIGHLY PATHOGENIC AVIAN INFLUENZA
Sporadic outbreaks of highly pathogenic avian influenza (HPAI) H5N1 continue to be reported in both wild birds and domestic poultry over a wide geographic area in Asia, Africa, the Middle East and Europe. These outbreaks appear to be associated with either the migratory movements of wild waterfowl, or, in some cases, by movements associated with unfavourable weather conditions. In some regions (Asia, Africa and the Middle East), the spread can also be linked to certain types of trade and movements of domestic poultry and poultry products.
Poland has now declared itself disease free for HPAI H5N1 after the last outbreak in December 2007.
An outbreak of HPAI H5N1 was reported from the far east of Russia. The virus was detected in backyard (village) chickens and guinea fowl. Control measures were put in place.
Following the outbreak of HPAI H5N1 in the Edirne region in backyard chickens in March, Turkey has reported that the event is now considered resolved.
An outbreak of HPAI H5N1 was confirmed in a layer chicken farm in the Cholla-Bukto province in the Republic of Korea at the beginning of April. Disease control measures have been put in place (see also DEFRA's preliminary outbreak assessment at www.defra.gov.uk/animalh/diseases/monitoring/pdf/ai-republicofkorea.pdf). Another outbreak was reported in a duck farm in mid-April (Cholla-Bukto province), and since then, in total, a further 33 outbreaks have been reported in several provinces in layer chickens, breeder chickens, ducks and backyard poultry, in April and May. The entire country is now under disease surveillance; all parent stock duck farms will be tested and supply vehicle movements traced.
H5N1 was reported in four swans in Japan's Akita province in April, and another two dead wild swans were found to be positive in May (Nozuka peninsula and Hokkaido). Two further cases of H5N1 were reported in swans in Aomori province (Towada city). The last case of H5N1 in Japan was reported in 2007. Domestic poultry have not been affected and there have been no large wild bird die-offs.
An outbreak of H5N1 was reported in village chickens in Tibet (Basu province) in early April, and a further outbreak was reported in ducks in the Guangdong province of China in June. Sporadic outbreaks in China have been occurring since April 2006.
Following outbreaks reported in March, Vietnam reported new HPAI H5N1 outbreaks in farmed chickens and ducks (many unvaccinated) in the north, central and southern parts of the country in April. These outbreaks have been continuing since December 2006. Vietnam also reported that following the outbreak in civet cats in Chrotogale Owstoni (Ninh Binh region) in March, no further cases were found and the event has now been resolved.
Following reports of three outbreaks of HPAI H5N1 in backyard poultry in the east of Myanmar (Shan state) at the end of 2007, no further detections of the virus were reported. Intensive surveillance activity, which has continued since the last outbreak in January was closed, has shown no further outbreaks. Myanmar declared itself disease free from HPAI H5N1 in April 2008, following nationwide active clinical surveillance and virological and serological surveillance around the infected premises.
Bangladesh reported more than 150 further outbreaks of HPAI H5N1 on commercial poultry farms in regions throughout the country in April, May and June. There had been sporadic outbreaks in the country over the previous 15 months and it would appear that the disease is well established.
Following two outbreaks in April in Tripura, India reported two new outbreaks of HPAI H5N1 in village poultry in the same state and two more in village poultry in Darjeeling State, West Bengal. Disease control measures include stamping out (within a 5 km radius zone surrounding the outbreaks) and compensation. Surveillance activities are taking place within a 10 km restriction zone. Live markets have been closed and the sale and transport of live poultry are prohibited in the infected zone.
Following initial detection of HPAI H5N1 in February 2007 in Pakistan, the last reported case was in March 2008, and Pakistan declared itself disease free. However, in June, a new case was reported in a commercial broiler flock in the North-West Frontier province. The source of disease was reported to be wild bird contact. Disease control measures including ring vaccination were put in place.
The HPAI H5N1 situation in India, Bangladesh and Pakistan remains of concern. Despite reports on the successful containment of previous outbreaks, it appears that the outbreaks may be more widespread and under-reported, particularly at the level of village communities.
After an initial outbreak in January, no new outbreaks have been reported in Thailand and the event is now considered resolved.
Following reports of a number of outbreaks of H5N1 in backyard poultry and commercial poultry in the central part of Saudi Arabia during the period from November 2007 to January 2008, no further outbreaks were detected since the end of January. Following completion of disease control measures, Saudi Arabia declared itself free from HPAI with effect from April 30, 2008.
Following an outbreak of HPAI H5N1 in Haifa, Israel, in January, and after intensive surveillance, no further outbreaks were reported. Israel considers the event resolved.
Following the outbreak of HPAI H5N1 in Benin in December 2007, in chickens and turkeys, no further outbreaks were reported and the event is now considered resolved. The outbreak was caused by the illegal importation and movement of birds.
Following an outbreak of HPAI H7N3 in Canada in mid to late 2007, no further outbreaks were reported. The source of the outbreak was reported as most likely to be the introduction of a low pathogenic H7N3 virus from wild waterfowl. On April 17, Canada declared itself disease free for HPAI H7N3.
LOW PATHOGENIC AVIAN INFLUENZA
As part of its surveillance programme for avian influenza in poultry, Denmark detected the presence of low pathogenic avian influenza (LPAI) H7N1 on a poultry farm with geese, ducks and mallards in the Svendborg region on the island of Funen in April. Positive serology for H5 was also detected in some geese. The flock was depopulated and disease control measures have been implemented. No contact holdings were identified; there are no poultry holdings within the established 1 km restricted zone.
In Portugal, following the detection of LPAI H5N2 in gamebirds in the Ribatejo Norte province in September 2007, and as part of an ongoing national surveillance programme, no further cases have been detected. Portugal also reported an outbreak of LPAI H5N3 in two partridge farms and a broiler chicken unit in the Oeste region in January. After surveillance, no further outbreaks were reported and the event is considered to be resolved. Portugal has EU approval to vaccinate a flock of breeding ducks.
Three outbreaks of LPAI H5N2 have been reported in various backyard poultry flocks in Haiti (one in the Nord region, one in the Sud region and one in the Centre region) in June. In all cases, the source of infection was the introduction of live animals following illegal movements. All three backyard flocks included fighting cocks. Disease control measures were put in place.
The USA reported an outbreak of LPAI H7N3 on routine testing in preslaughter surveillance of a commercial poultry broiler operation. Control measures were put in place. To date, all testing of other poultry has yielded negative results.
An outbreak of Newcastle disease was reported in racing pigeons in the Ita-Suomi region, Finland, in June. Five more outbreaks have been reported in the Etela-Suomi and Lansi-Suomi regions, also in racing pigeons, where the source was the introduction of live birds from the first outbreak flock in one case. Disease control measures are in place and no poultry outbreaks have been detected. Vaccination is prohibited in poultry but mandatory in racing pigeons entered for competition.
In Germany, an outbreak of avian paramyxovirus type 1 (APMV-1) was reported in April in pigeons on a farm with mixed avian species. None of the other birds was affected, but stamping out was carried out and movement controls were put in place.
The outbreak reported in March in backyard poultry in Romania is now resolved.
An outbreak of APMV-1 was reported in Sweden in November 2006 in a layer poultry unit. It is now resolved, and Sweden has declared itself free from Newcastle disease. Vaccination is prohibited in Sweden.
LUMPY SKIN DISEASE
Mauritius reported an outbreak of lumpy skin disease (LSD) in a herd of mixed-breed cattle (Friesian and Creole breeds). Disease control measures have been put in place, including movement controls and vaccination using live and inactivated Neethling strain vaccine. The last reported outbreak of LSD in Mauritius was in 2003. Vaccination against the disease ceased in November 2004.
Mauritius is not on the EU-approved list for importation of live ruminants and their products. LSD is mainly confined to countries of sub-Saharan Africa; however, it has gradually spread to Egypt and sporadic cases have been reported in Israel in 2006 and 2007. See www.defra.gov.uk/animalh/diseases/monitoring/pdf/lsd_israel.pdf and www.defra.gov.uk/animalh/diseases/monitoring/pdf/lsd_mozambique150207.pdf.
For recent information on rabies in western Europe, see www.defra.gov.uk/animalh/diseases/monitoring/pdf/poa-rabies080310.pdf. Within western Europe, there are sporadic reports of cases in illegally imported domestic dogs and there are often delays in suspecting the disease. Veterinarians should therefore be alert to the possibility of rabies, even in animals that are not known to have been imported recently.
Following a positive rabies case in a dog from Morocco in February, France reported another case of rabies in a dog imported from the Gambia in April, but no new cases have been detected in in-contact dogs.
Following a positive rabies case in a dog from Morocco in October 2007, Belgium reported that no further cases were found, and the case is now considered resolved.
Following a positive rabies case in cattle in the Rivera region in October 2007, Uruguay reported eight new outbreaks of rabies, serotype RABV, in April to June, seven in cattle and one in a horse. The source of infection is haematophagous bats. The local bat populations are being controlled and vaccination of susceptible cattle and horses is taking place.
RIFT VALLEY FEVER
The distribution of Rift Valley fever (RVF) is almost exclusively in Africa, but also extends to the Arabian peninsula.
An outbreak of RVF in cattle was confirmed in central Madagascar in April. Movement and vector controls have been put in place. This is the first reported case of clinical disease from Madagascar.
Following an outbreak of RVF in goats in March in the Gauteng region, South Africa, another outbreak, this time in cattle, was reported in the same region in April, and another four outbreaks were reported in cattle and sheep in Gauteng and the North-West province in May. Vaccination of cattle, sheep, goats and buffaloes in Gauteng, Limpopo, Mpumalanga and North-West province is being carried out. Before these outbreaks, there had been nine outbreaks of RVF in South Africa since February.
French veterinary services reported the first outbreak of RVF in farmed Zebu cattle on the island of Mayotte (French overseas territory). Cattle showed no clinical signs. The source of the infection is reported as being the illegal movement of animals from Madagascar and Tanzania.
SWINE VESICULAR DISEASE
Following an outbreak of swine vesicular disease, reported in commercial pigs in Beja province, Portugal, in June 2007, no further cases have been reported since. Portugal considers that this case has now been resolved.
WEST NILE VIRUS
The United Arab Emirates has reported an outbreak of West Nile virus in a horse in Abu Dhabi in August, 2007. The horse was reported to have shown mild neurological signs for one week before recovering. Other horses in the herd were screened and tested negative. Control of the mosquito vector is in place.
This article summarises official information on outbreaks of specified animal diseases and other diseases that may be of interest. DEFRA's Food and Farming Group, International Animal Health (FFG-IAH) monitors outbreaks of animal disease in countries that trade with the UK and EU member states. It also notes new epidemiological developments, which may give an early warning of emerging threats to the UK. Where a new disease outbreak could pose a threat, the FFG-IAH carries out a qualitative analysis of the risks to UK livestock. These analyses are publicly available on DEFRA's website (www.defra.gov.uk/animalh/diseases/monitoring/index.htm). The EU and the UK take appropriate safeguard measures to mitigate the potential risks of disease being introduced through legal trade. DEFRA notes that it is also important to recognise the continuing threat to the UK through illegal imports from countries with endemic disease and other routes; for example, highly pathogenic avian influenza or Newcastle disease from migrating birds. The map in this report was produced using ESRI Data and Maps CD (2002); it does not necessarily reflect the true situation in every country and should not be regarded as definitive.
World Organisation for Animal Health (Office International des Epizooties [OIE]), Paris, France
European Commission, Brussels, Belgium
Animal Disease Notification System. Weekly Reports CVO Emergency notifications/SANCO documents EUR-Lex (http://europa.eu.int/eur-lex/en/index.html)
A list of declarations issued by DEFRA in relation to international animal disease and customer information notes can be obtained online at www.defra.gov.uk/animalh/int-trde/animlim/cins/ai_cins.htm, or by contacting the Food and Farming Group, International Animal Health, DEFRA, 17 Smith Square, London SW1P 3JR.
DEFRA has also published a number of preliminary outbreak assessments (www.defra.gov.uk/animalh/diseases/monitoring/poa.htm) and qualitative risk assessments (www.defra.gov.uk/animalh/diseases/monitoring/riskassess.htm).
Details of all European Commission legislation are available online at the EUR-Lex website at http://europa.eu.int/eur-lex/en/index.html
SABIROVIC, M., RAW, L., HALL, S., ELLIOTT, H. & COULSON, N. (2008) International animal disease monitoring, January to March, 2008. Veterinary Record 162,705 -708[Free Full Text] Routine information sources
EUROPEAN COMMISSION - Animal Disease Notification System. Weekly Reports. ec.europa.eu/food/animal/diseases/adns/index_en.htm
EUROPEAN COMMISSION - CVO emergency notifications/SANCO documents
EUROPEAN COMMISSION EUR-LEX - http://eur-lex.europa.eu/en/index.htm
FOOD AND AGRICULTURE ORGANIZATION - www.fao.org
FOOD AND VETERINARY OFFICE - http://ec.europa.eu/food/fvo/index_en.htm
OIE - Disease information. www.oie.int/eng/info/hebdo/a_INFO.HTM
WORLD HEALTH ORGANIZATION - www.who.int/en/