World Organisation for Animal Health

Font size:

Language :

Search:

Advanced search

Home > For the media > Press releases

APPENDIX 1

ANIMAL DISEASE STATUS WORLD-WIDE

The most significant epidemiological events that occurred in the world in 1999 are given below. The analysis is based on information received from OIE Member Countries and non member countries up to 21 April 2000.


It should be noted that, at the report date, the following Member Countries have not submitted any information on the animal health status of their country in 1999: Afghanistan, Bahrain, Bolivia, Burkina Faso, Burundi, Central African Republic, Republic of the Congo, Gabon, Iraq, Mauritius, Sierra Leone, Somalia, Togo, Yemen.

I. LIST A DISEASES

1. Foot and mouth disease

1.1. Africa

A foot and mouth disease epizootic broke out in Algeria in February 1999, with the appearance of outbreaks in the Greater Algiers governorate and the wilayas of Setif and Souk Ahras. The disease was spread to central, western and eastern wilayas by trade in cattle. A total of 165 outbreaks occurred over a three-month period, mostly in beef cattle herds.

The disease occurred almost simultaneously in Morocco and Tunisia: in Morocco, 11 outbreaks were reported, including 8 in Oujda, a town close to Algeria, then 3 farther to the west in the provinces of Beni Mellal and Khouribga, probably due to the movement of animals; in Tunisia, only two outbreaks were observed, the first in Nabeul governorate, and the second in Jendouba governorate. Protein VP1 nucleic acid sequencing of the FMD virus type O strain isolated in Algeria, conducted by the World Reference Laboratory for Foot and Mouth Disease (Pirbright, United Kingdom), showed it to be very similar to strains from countries on the west coast of Africa. The implementation of slaughter measures for sick animals, disinfection, the closure of livestock markets and generalised vaccination of cattle allowed the episode to be stamped out in the space of two months in this sub-region of Africa. The aforementioned laboratory results coupled with the report of smuggled zebus (not presenting FMD lesions) having been intercepted in February 1999 in the south of Algeria leads to the conclusion that, contrary to what had recently been thought, the Sahara desert may not constitute an impenetrable epidemiological barrier to animal diseases.

Elsewhere on the African continent, with the exception of southern Africa, the FMD situation was largely unchanged compared to 1998. The available virus serotyping results suggest that only virus type O was circulating in 1999 in West Africa (Côte d'Ivoire, Gambia), whereas virus types O, A, SAT 1 and SAT 2 were identified in East Africa.

In southern Africa, Zambia experienced outbreaks caused by virus type SAT 2, one of which, in the extreme south of the country, was probably the result of contact between buffaloes from a national game park and a herd of cattle. The other outbreaks, situated in the north, were linked to cross-border trade in cattle.

Two outbreaks occurred in Zimbabwe in the FMD control zone (vaccination zone), one in June and the other in July 1999. The two properties involved were only 25 km apart, but typing of the virus involved showed that the two outbreaks were not epidemiologically linked: the virus isolated in the first outbreak was SAT 1, whereas the virus in the second outbreak was SAT 3. However, it seems likely that both outbreaks had originated from wildlife living in adjacent properties. A booster vaccination campaign was carried out and there were no subsequent outbreaks.

1.2. Americas

The countries of North America, Central America, the West Indies, the Guyanas, Chile, Uruguay and the north-west zone of Choco department in Colombia remained free from FMD without vaccination.

Neither did any FMD outbreaks occur in Argentina or Paraguay, countries that the OIE has listed in the category of "FMD free countries where vaccination is practised" since May 1997. Argentina halted vaccination against the disease in April 1999, and Paraguay in July 1999.

Since May 1998, the States of Rio Grande do Sul and Santa Catarina in Brazil have been considered as " FMD free zones where vaccination is practised". In the remainder of Brazil, no FMD outbreaks were reported in the following States since the date shown in parentheses: Federal District (May 1993), Parana (May 1995), Goias (August 1995), Mato Grosso (January 1996), Sao Paulo (March 1996), Espirito Santo (April 1996) and Minas Gerais (May 1996). Overall, the number of outbreaks in Brazil remained virtually stable, moving from 35 in 1998 to 38 in 1999. Two neighbouring properties in the State of Mato Grosso do Sul were affected by the disease in January 1999, the virus involved being serotype O. All the cattle, sheep and pigs on these two properties were slaughtered and their carcasses destroyed. The survey conducted within a 25-km radius did not detect any spread of the virus.

In Colombia, efforts continued to set up an "FMD free zone where vaccination is practised" including the major part of the departments on the Atlantic coast, Antioquia department and a part of Caldas department.

Peru, where FMD virus serotype A had not been isolated since 1996, experienced outbreaks caused by this serotype in 1999, limited to the departments of Ayacucho, Lima and Piura. Modified stamping out and vaccination measures were implemented to eliminate these outbreaks.

1.3. Asia

Five outbreaks of foot and mouth disease were reported In Turkmenistan during the first three months of 1999. In Kazakhstan, four outbreaks caused by serotype O occurred in June 1999 in cattle in Kyzyl-Orda region.

In the People’s Republic of China, eight outbreaks occurred in May 1999, in Fijian, Hainan and Tibet provinces. All other FMD outbreaks reported in the country in 1999 involved only Hong Kong (Special Administrative Region).

In June 1999, the FMD surveillance programme implemented in Taipei China enabled a virus strain of type O to be isolated in cattle not presenting clinical signs. Inoculation tests showed that pigs and goats are susceptible to this strain, and the result of DNA analysis showed that the strain is different from O/Taiwan, a pig adapted strain that was responsible for the epizootic in 1997 and the six outbreaks registered in swine in February and April 1999.

In September 1999, foot and mouth disease occurred on the island of Panay in the Philippines. The FMD virus type O involved was similar to the one circulating in pigs on the island of Luzon.

1.4. Europe

In May 1999, the OIE included the Former Yugoslav Republic of Macedonia in the list of "FMD free countries where vaccination is not practised".

In 1999, the continent of Europe experienced only one FMD episode. It occurred in Georgia, in Adigheni and Akhaltsikhe regions, in August 1999. The virus involved was FMD type A.

1.5. Middle East

In 1999, FMD continued to circulate enzootically in the majority of the Middle East.

In Iran, outbreaks caused by virus type Asia 1 occurred in September 1999 in Khorasan, Qazvin and Tehran provinces. This serotype was identified again during the last quarter of 1999. A serotype A strain, genetically and antigenically different from strain A/Iran/96, was also present in Iran in 1999.

A new serotype A virus strain was responsible for FMD outbreaks in the Anatolian part of Turkey from June 1999, first in eastern provinces (Ardahan, Agri and Igdir) and then central (Samsun) and western (Bursa and Kütahya) provinces. The OIE World Reference Laboratory for foot and mouth disease showed that the vaccines in use in Turkey including the strains A/Mahmatli and A/Ankara/1998 were ineffective against this new strain.

In Israel, where no FMD episodes had occurred since July 1996, 22 outbreaks caused by virus type O were reported between January and September 1999. In Jordan, the incidence of the disease rose sharply from a total of 10 outbreaks in 1998 and reached 101 outbreaks in 1999.

According to the OIE World Reference Laboratory for foot and mouth disease (Pirbright, United Kingdom), regular nucleotide sequencing of serotype virus isolates has shown that, over a ten-year period, the same strain has spread throughout the region, from Taipei China to Turkey. The strain has been detected in Bhutan, Hong Kong, India, Peninsular Malaysia, Nepal, the Philippines, Thailand and Vietnam. In the Middle East the strain has been isolated from samples collected in the Arabian Peninsula, Iraq, Iran, Israel, Jordan, Lebanon and Syria. It was also responsible for the outbreaks that occurred in Bulgaria and Greece in 1996. In this region it has replaced all other serotype O strains. There is no apparent explanation for the dissemination of this pandemic strain of serotype O. The clinical expression of the infection has been highly variable: whereas the infection remained subclinical in cattle in Taipei China, it caused high mortality in lambs in Iraq.

2. Vesicular stomatitis

As in previous years, vesicular stomatitis was diagnosed only in the Americas.

In North America, two outbreaks were reported in Mexico (one in January, one in February) and none in the United States of America (whereas there had been 45 and 130 outbreaks, respectively, in these two countries in 1998). The epizootic that occurred in the United States of America in 1998 was declared officially over, with effect from 22 January 1999.

In Panama, the number of outbreaks rose from 7 in 1998 to 56 in 1999.

In South America, disease occurrence was once again highest in Colombia (more than 400 outbreaks). In Brazil, only 25 outbreaks were reported in 1999, compared to 219 the year before. The peak incidence in Brazil observed in the last quarter of 1998 (200 outbreaks) was not repeated during the equivalent period in 1999 (a single outbreak).

3. Swine vesicular disease

Only two countries reported swine vesicular disease to the OIE in 1999: Italy (16 outbreaks), and Taipei China (2 outbreaks). Most outbreaks reported in Italy involved only the detection of infection through laboratory tests.

4. Rinderpest

No countries reported the presence of rinderpest in 1999.

During the year, additional countries submitted declarations to the OIE to the effect that all or part of their territory was "provisionally free from rinderpest"; these countries were as follows:

  • In Africa: Benin, Cameroon, Eritrea, Ethiopia (for 94% of its territory, corresponding to 92% of the total cattle population), Kenya (centre and south of the country), Mauritania, Niger (eastern department of Diffa, the remainder of the country having been declared provisionally free in November 1997), Nigeria, Uganda (all districts south of the Nile), Sudan (seven States in the north of the country), and Chad (western part of the country comprising eight prefectures).
  • In Asia: Sri Lanka.
  • In Europe / Middle East: Turkey (Anatolian part, the Thrace region having been declared provisionally free in October 1998).

As at 31 December 1999, the total number of countries having declared all their territory provisionally free was 22, and that of countries having declared a zone provisionally free was 5. Through their declarations, these countries entered the "OIE pathway" with a view to eventually being recognised as free of the virus. To this end, they are required to conduct clinical and serological surveillance for the disease. Thus, for example, between November 1998 and November 1999, 806 bovine sera were collected in Senegal in 105 of the 300 herds included in the random sample selected for surveillance; none of these sera tested positive, attesting to the absence of rinderpest virus circulating in young cattle born after vaccination had been halted in the herds examined. In Guinea, negative results were also obtained from serum samples collected from nearly 1,500 cattle aged between six months and three years.

5. Peste des petits ruminants

As in previous years, peste des petits ruminants affected only certain parts of Africa and Asia.

Eleven outbreaks were reported in Jordan in 1999, the previous outbreak dating back to August 1994.

In Turkey, peste des petits ruminants became a notifiable disease in October 1997. It was in September 1999 that the first outbreak in the country was reported, in Elazig province. From October to December 1999, six other outbreaks were reported, in the provinces of Burdur (one outbreak), Denizli (two outbreaks), Diyarbakir (two outbreaks) and Sivas (one outbreak).

6. Contagious bovine pleuropneumonia

6.1. Africa

Contagious bovine pleuropneumonia is still a major concern on the African continent, with the exception of North Africa.

The occurrence of the disease increased in Tanzania, rising from 39 outbreaks in 1998 to 157 outbreaks in 1999.

In March 1999, the disease appeared in Zambia in the westernmost part of Western Province. To control this episode, some 100,000 cattle were vaccinated in the zone at risk.

Contagious bovine pleuropneumonia was suspected in Nigeria during the summer of 1999 in three herds of trade cattle being moved from Jigawa State to Kaduna State to be sold. Ring vaccination was conducted in the area.

6.2. Europe

Portugal, which reported 67 outbreaks of contagious bovine pleuropneumonia in 1997, and 12 in 1998, experienced a single outbreak in 1999 (in the Porto Sanitary Intervention Zone).

7. Lumpy skin disease

Only 14 outbreaks were reported in Ethiopia, whereas there had been 127 the year before.

In Tanzania, the number of outbreaks increased from 22 in 1998 to 146 in 1999.

In the other countries affected, the disease situation remained virtually the same as the previous year.

8. Rift Valley fever

Only a few countries in southern, eastern and western Africa reported the presence of Rift Valley fever in 1999.

In South Africa, a single outbreak occurred in January 1999, in the Kruger National Park. Six out of a group of 30 pregnant buffalo cows (Syncerus caffer) had late-term abortions. Vaccination of susceptible domestic stock was carried out.

Zimbabwe experienced two outbreaks, one in February and the other in May 1999.

Several outbreaks were reported in Mauritania and Senegal during the second half of 1999.

9. Bluetongue

The most significant epidemiological event relating to bluetongue in 1999 was the appearance of the disease in south-eastern Europe and Tunisia.

The first outbreaks were reported in Bulgaria (a country where the disease had never previously occurred) in June 1999 in the department of Burgas, near the frontier with Turkey. In July it spread within Burgas region and reached Yambol region. In August Haskovo and Kardjali regions were infected, and in September outbreaks were still appearing in these four regions. Pirbright Laboratory (United Kingdom), OIE Reference Laboratory for bluetongue, indicated that the viral strain isolated from samples collected in Bulgaria corresponded to serotype 9. In all, from June to September, 85 outbreaks were reported in the country. Vaccination was applied within and around the outbreaks.

During the second half of July and the first half of August three outbreaks occurred in the north of the Thrace region in Turkey (Lalapasa district, Edirne province). Subsequently, other outbreaks of bluetongue were reported in Turkey, but this time in provinces in Anatolia (a total of six outbreaks, in the provinces of Aydin, Denizli Manisa in October, and six other outbreaks in Izmir province in November 1999).

From July 1999, bluetongue surveillance measures were established in Greece. At the beginning of August some cattle in the prefectures of Evros and Rodopi were found to be carrying bluetongue virus antibodies, at a time when the results of clinical surveillance throughout Greece were still proving negative. Several days later, the first clinical cases were detected in sheep in the aforementioned two prefectures. Furthermore, serological surveillance revealed the presence of ruminants carrying specific antibodies in the prefectures of Drama and Serres. A recapitulative survey at the end of 1999 reported clinical and serological evidence of infection in the continental prefectures of Chalkidiki, Evia, Evros, Kavala, Larissa, Magnissia, Pieria, Rodopi and Thessaloniki, and only serological evidence of infection in the provinces of Drama and Serres. In addition to mainland Greece, clinical or serological manifestations of bluetongue were observed in the island of Lesvos, the Dodekanissa islands and the island of Chios. Laboratory tests carried out on isolates collected in different prefectures revealed the circulation of virus serotypes 4 and 9, and the presence of a third serotype was strongly suspected.

In the case of Tunisia, the first clinical cases of bluetongue were observed at the end of December 1999 in the coastal governorates of Monastir, Mahdia and Sfax. Only sheep aged over one year developed the disease. The virus involved was serotype 2.

10. Sheep pox and goat pox

In 1999, two Middle Eastern countries reported the recurrence of sheep pox on their territory, whereas they had not observed any outbreaks for several years: Saudi Arabia (previous outbreak: August 1996) and Egypt (previous outbreak: March 1991).

In line with the trend observed in previous years, the sheep pox and goat pox situation in North Africa further improved in 1999: as in 1998, Morocco did not experience any outbreaks; only 14 outbreaks were reported in Algeria (36 in 1998), and 18 in Tunisia (41 in 1998).

No outbreaks occurred in Greece, whereas seven had occurred in 1998.

11. African horse sickness

In March 1999, outbreaks of African horse sickness (AHS) occurred in Stellenbosch district in South Africa. This district, situated in the Western Cape Province, is included in the AHS surveillance zone which, in that Province, separates the free zone from the infected zone. This episode resulted from two horses being moved illegally without health or vaccination certification from the Free State Province to Stellenbosch district. Movement controls for horses and vaccination measures were instituted in several districts in the surveillance zone, and all exports of horses were suspended. In April 1999, the disease showed a slight tendency to spread, while remaining confined to Stellenbosch district. In all, 18 properties were infected within a radius of about 15 km, in which there were 34 sick horses, of which 28 died and 3 were euthanised. The last case having appeared on 17 May 1999, the Delegate of South Africa reported on 8 July 1999 that the outbreak was considered to have ended.

In Botswana, where the last AHS episode had been in February 1997, 22 outbreaks were reported during the first half of 1999, of which 17 occurred in May. Namibia, which had not experienced any outbreaks since June 1997, reported two in April 1999. In Zimbabwe the number of outbreaks increased from one in 1998 to eight in 1999 (from February to May).

The incidence of African horse sickness in East Africa appears to have regressed in those countries which reported the presence of the disease on their territory in 1998: a single outbreak was reported in Eritrea (seven in 1998), and 35 in Ethiopia (compared to 110 in 1998).

12. African swine fever

12.1. Africa

Madagascar, where African swine fever had been reported for the first time during the second half of 1998, continued to suffer losses due to the disease in 1999. In all, 68 outbreaks (from January to August) were reported during the year.

In Botswana, where the disease had not occurred since November 1987, a farm was infected in June 1999 due to contacts between pigs and warthogs (Phacochoerus aethiopicus).

In Ghana, where African swine fever had never been reported, several pigs died as a result of the disease in September and October 1999, first in the Accra Metropolitan Area, then in other parts of the country.

12.2. Europe

In Portugal, where African swine fever had not occurred since August 1993, an outbreak occurred in the Alentejo region (south of the country) in November 1999. Of the 44 pigs in the affected farm, 6 died and the remainder were slaughtered and their carcasses destroyed. Seropositive pigs were identified in three farms located within the protection zone (with a radius of 3 km around the outbreak) and one farm within the surveillance zone (with a radius of 10 km around the outbreak). Stamping out was applied in the four farms.

13. Classical swine fever

13.1. Americas

In Argentina the classical swine fever control programme launched in July 1998 was maintained. In 1999, there were three outbreaks (compared to seven in 1998). Buenos Aires province experienced one outbreak in January 1999, and Santa Fé province one in January and another in May 1999.

13.2. Europe

In 1999, Germany reported seven outbreaks of classical swine fever in pig farms (breeding or fattening pigs). In addition, the country detected the infection in a large number of wild boar (Sus scrofa<)?a total of 409.

In Croatia, where classical swine fever had not been reported since October 1997, two outbreaks were reported in Pazin district in July 1999. The measures relating to this episode were lifted in September 1999. Italy, where the disease is normally restricted to the island of Sardinia, recorded two outbreaks in Vercelli province (Piedmont region) and another in Parma province (Emilia-Romagna region) in March 1999. The Delegate of Italy declared the territory of his country, with the exception of Sardinia, once more free from the disease, with effect from 30 October 1999.

In Luxembourg, a positive reaction to a serum neutralisation test was obtained from samples taken from a wild boar that had been shot in November 1999 near the northern border of the country. In Switzerland, from May 1998, cases of classical swine fever in wild boar were discovered in several villages in Lugano and Locarno districts. The last wild boar to test positive for the virus was found in March 1999. Positive serological results were obtained until December 1999. No cases occurred in domestic swine in either Switzerland or Luxembourg.

By a Decision of the European Commission dated 28 January 1999, Spain was declared free from classical swine fever.

14. Highly pathogenic avian influenza

On 10 December 1999 the first clinical signs of highly pathogenic avian influenza were observed in a commercial turkey farm in Verona province in Italy. Between that date and 31 December 1999, 66 outbreaks were reported in turkey farms, broiler flocks and layer flocks in the following regions: Friuli Venezia Giulia (1 outbreak), Lombardy (36 outbreaks), Sardinia (1 outbreak) and Veneto (28 outbreaks). All the birds in the affected farms (i.e. more than two millions birds) were slaughtered and their carcasses sent to rendering plants or disposed of by burying.

15. Newcastle disease

15.1. Americas

In June 1999, several pigeons were found to be suffering from Newcastle disease in Buenos Aires province in Argentina, in an urban and semi-urban area without any commercial poultry farms.

In Brazil, a group of imported Passeriformes, placed in quarantine in Parana State in August 1999, were found to be carrying a pathogenic strain of Newcastle disease virus. All the birds in the outbreak were slaughtered and destroyed. Also in Brazil, in the same month, a small, non-commercial property with various types of birds (Gallinae and Anseriformes), were affected by the disease in Rio de Janeiro State. The birds still alive were slaughtered and all the carcasses were incinerated and buried in situ.

In Venezuela, broilers in a commercial farm were affected by the disease in April 1999. Deaths occurred in two-week-old unvaccinated chicks. Chickens that were still healthy at six weeks were sent for slaughter.

In Canada, Newcastle disease was diagnosed in a Phalacrocorax auritus cormorant in the province of Alberta in August 1999.

15.2. Asia

In October and November 1999, Japan reported eight outbreaks of Newcastle disease in hobby flocks of chickens in Chiba, Ibaraki, Kanagawa and Saga Prefectures.

15.3. Europe

Cases of Newcastle disease were observed in a pigeon flock in Luxembourg in November 1999. Cases were observed in France in December 1999, also in a pigeon flock.

15.4. Oceania

In Australia, a farm situated on Mangrove Mountain in New South Wales and mainly comprising layers and broilers was affected by Newcastle disease at the beginning of April 1999. On this farm, nearly 26,000 pullets and ornamental caged birds were slaughtered and their carcasses incinerated. In the surrounding area a surveillance zone 18 km long and 10 km wide was delineated, which led to the detection of raised mortality in poultry, or clinical signs suggestive of infection with a highly pathogenic Newcastle disease virus in eight other commercial farms in April and May 1999. During this period, a virulent virus was also isolated a posteriori from several other commercial farms and small, non-commercial farms. In all, nearly four million birds were destroyed (nearly two million in the declared infected zone, and the remainder in the surveillance zone). The use of an avirulent vaccine has been authorised only in hobby flocks and two small poultry layer flocks situated in the surveillance zone.

In August 1999, the disease was reported in a small poultry layer flock on the outskirts of Sydney (State of New South Wales). Over 9,000 birds had to be slaughtered and their carcasses destroyed. Here, too, an infected zone and a surveillance zone were set up. In September 1999, a virulent virus strain was isolated from samples collected from one of the sheds in a broiler farm adjoining the primary outbreak. As genetic sequence studies on low virulent virus strains isolated from a number of farms seemed to indicate that some isolates were of the strain believed to be the progenitor type for the virulent virus that caused the previous outbreaks, a vaccination approach was adopted in the Sydney region in an attempt to eliminate this low virulent progenitor strain. In December 1999, evidence of the presence of virulent strains was detected in three poultry flocks situated in the vaccination zone. Vaccination operations were completed on 20 December 1999, and it was proposed to continue vaccination of restocked chickens for the following six months.

II. LIST B DISEASES

1. Anthrax

A horse in a polo club in the city of Taipei in Taipei China died of anthrax in November 1999. The polo club was quarantined and disinfected. There were no further cases. The disease had never before been reported in Taipei China.

2. Heartwater

An outbreak of heartwater was reported in the province of Kwanza-Sul in Angola in May and June 1999, in a farm with cattle of exotic breeds (Brahmans and Simmentals). An antibiotic treatment was applied. The region in which the outbreak occurred is one of the zones where Amblyomma pomposum ticks are present and where heartwater was reported well before 1975 (the year the country became independent). Native breeds of cattle are probably resistant to the disease.

3. Rabies

In May 1999, a case of rabies was diagnosed in France in an imported Rousetus aegyptiacus bat (African rousette). The viral strain involved was related to serogenotype 2 ("Lagos bat").

In Austria, a case of canine rabies was reported in an imported dog in September 1999. Five other dogs imported into the country at the same time as the affected animal were all destroyed.

In a communication sent to the OIE in May 1999, the Delegate of Switzerland declared that his country and the principality of Liechtenstein fulfilled the conditions to be declared free from rabies with effect from March 1999, in application of the provisions of Article 3.1.5.2 of the International Animal Health Code.

4. Bovine tuberculosis

In Israel, where the last outbreak of bovine tuberculosis had been in September 1997, an outbreak was reported in May 1999. It involved a herd of 590 cattle that had already been infected on several occasions in the past. The affected cattle were slaughtered.

5. Bovine spongiform encephalopathy

In 1999, indigenous cases of bovine spongiform encephalopathy (BSE) occurred in seven countries:

  • Belgium: 3 cases (6 in 1998);
  • France: 31 cases (18 in 1998);
  • Ireland: 91 cases (83 in 1998);
  • Netherlands: 2 cases (2 in 1998);
  • Portugal: 170 cases (106 in 1998);
  • United Kingdom: 2,157 cases (3,235 in 1998);
  • Switzerland: 50 cases (14 in 1998).

The increase in the number of cases recorded in Switzerland can be explained by a strengthening of the BSE surveillance system from March 1999. The country decided to use an immunoblotting test and apply it in a targeted manner to all cows that have died, have been eliminated for health reasons or have been eliminated for sanitary reasons, and to cows selected at random from those routinely slaughtered. It was not considered opportune to apply the test to all animals, given the fact that consumer protection in Switzerland is ensured by the removal, at slaughter, of organs at risk (in particular, the brain, eyes and, spinal cord) from all cattle aged over six months, so as to exclude them from the human food chain.

6. Scrapie

A case of scrapie occurred in Japan in September 1999. The previous case dated back to June 1996.

7. Equine infectious anaemia

In June 1999, antibodies directed against equine infectious anaemia virus were detected in the North Island of New Zealand in a recently imported brood mare. The mare was slaughtered and its carcass destroyed. The horses imported at the same time as the mare in question and those that had been in contact with her were placed under surveillance and were repeatedly subjected to laboratory tests. The results of these tests were all negative.

8. Glanders

In December 1999, cases of glanders were diagnosed in equids used for the transport of sugar cane in the States of Alagoas and Pernambuco in Brazil. This episode, which was restricted to three districts, did not present a risk for the equid rearing areas of Brazil, due to the great distance from the affected zone.

9. Avian infectious bronchitis

In April 1999, Madagascar reported the first appearance on its territory of avian infectious bronchitis. The affected poultry flock consisted of about 100,000 improved breed layers. The importation of an avian infectious bronchitis vaccine was authorised.

10. Varroosis

Haiti detected the presence of varroosis on its territory in January 1999.

III. OTHER DISEASES

1. Nipah disease

In peninsula Malaysia, a new zoonotic disease of swine spread through pig farms from October 1998 to May 1999. The virus responsible for the disease, a paramyxovirus, caused 265 cases of encephalitis in humans (mostly in pig-farm workers), 105 of whom died. It was named Nipah virus after the name of the village where the worker from whom it was isolated died. All the pigs in the areas to declared infected in the States of Negeri Sembilan, Perak and Selangor were slaughtered and their carcasses destroyed (a total of over 900,000 animals). A surveillance programme implemented in nearly 900 farms from April to July 1999 allowed farms still holding pigs carrying Nipah virus antibodies to be depopulated.

2. West Nile fever

In the United States of America, West Nile fever virus circulated in a limited area, divided between the States of Connecticut, Maryland, New Jersey and New York. Cases in humans and in horses occurred from early August to the end of October 1999, while, at the same time, a rise in mortality was observed in wild birds, primarily crows (Corvus sp.). The 23 horses affected were all in Nassau County or Suffolk County (State of New York). Of these, 8 died or were euthanised, and the remainder recovered. The causal virus was isolated in humans, horses, wild birds and mosquitoes. Genetic sequencing showed it to be similar to isolates collected in the eastern Mediterranean. The manner in which the virus was introduced into the New York region is still not known. Various factors, including weather conditions and mosquito control activities, helped to bring this episode to an end.

In Israel, two flocks of geese situated in Ramla and Yizre’el districts were affected with West Nile fever in November 1999. Stamping out was applied to the flocks, and vaccination and spraying of insecticide were applied in other goose farms.

Contact : Maria Zampaglione

Top