Introduction

• Israel is located within a transition zone between African, Asian and European ecosystems, where small and large ruminants have been domesticated and bred for more than 5000 years. Traditional husbandry methods have been developed in accordance with the prevailing arid and semi arid climatic conditions, characterised by seasonal and long-term periods of draught. Biblical descriptions of flocks moving over thousands of miles – such as the route of the Patriarch Abraham, who moved from 'Ur of the Chaldees' (southern Iraq), along the Euphrates river north-westwards to Haran (Turkish-Syrian border), then southwards to Canaan, and of herdsmen and shepherds struggling on wells and water sources – have not lost their actuality to the present day. The livestock population of the Middle East includes, besides 30 million bovines, more than 120 million small ruminants – sheep and goats – with seasonal, uncontrolled movements in search of pasture, as part of the very extensive grazing system on common pastures. On top of that, there is a significant, steadily increasing imports of bovines, ovines and caprines, exported live from water-abundant, pasture-rich, subtropical and temperate areas in Asia, Africa and Europe into the animal-protein demanding, semi arid and arid Middle East countries.

• Various countries in the region lack sufficient and efficient veterinary infrastructure. The unstable political situation, prevailing in the Middle East, reflects upon a deficient regional co-operation and lacking interchange of epidemiological information. Ritual mass slaughter of animals, which are moved in large numbers over long distances to be crowded in poor conditions before and during their slaughter in sacred sites, adds to the health-risk factors. All these factors contribute to the frequent occurrence of epizootics and the spread of zoonotic diseases, characterising the poor animal health situation in the Middle East.

Foot and Mouth Disease (FMD) is a viral, extremely infectious disease of domestic and wild cloven-hooved animals. The disease is characterised by vesicular lesions and erosions of the epithelium of the mouth, nares, muzzle, feet, teats and udder. Morbidity and mortality are the highest in the young; dairy breeds are particularly susceptible to FMD infection and if survive the acute disease might suffer a serious, lengthy post-infection debility and loss of production. The virus may be spread via aerosols, usually when animals are in close proximity. However, under certain conditions FMD virus (FMDV) may be spread by the wind for long distances; the risk for such a mode of spread is significantly greater and the distance longer when pigs are infected, since they have been shown to produce and excrete very large quantities of the virus. The virus will be found in large quantities in milk and other secretions of infected animals, including semen. Various animal products – such as meat and wool – may be a source of infection. Due to its resistance to external conditions and its high infectivity, FMDV may be mechanically transmitted on clothing, footwear, vehicles, animal feed etc. Recovered animals may retain the virus – mainly in the throat - and may become carriers for short or long terms, which are different in various species. The disease may be difficult to detect in sheep, but they can readily transmit the virus to other species. However, dairy sheep and goats may demonstrate serious symptoms, pregnant animals may abort and young animals may die: high mortalities in very young lambs and kids, sometimes exceeding 50%, have been recorded in various countries.

At least seven distinct serotypes of the FMDV have been identified: O, A, C, South-African- Territories (SAT) 1, 2 and 3, and Asia 1. All the said will not cross-immunise; therefore, separate, type-specific vaccines are needed to protect the susceptible animals against infection with the potentially present strains. In addition, there are numerous strains of the different serotypes, mostly of the O serotype and many of them sufficiently antigenically different to warrant preparation of strain vaccines.

FMD has a world-wide distribution (map 1), though the list of countries which have been recognised by the OIE as "FMD free countries where vaccination is not practised" is steadily growing to include (May, 2001) 47 countries from all continents (OIE doc). Only one Middle Eastern country (Cyprus) belongs presently to the said list. The poor animal health situation in the Middle East has been repeatedly demonstrated by the presence in the region of FMD,  and the Middle East is regarded as the heaviest-FMD-stricken region in the world (map 2). FMD has been recorded in all 17 countries of the region numerous times between 1960 and 2000, with serotype O being the most prevalent one (Table 1: FMD in the Middle East). As can be seen, six FMDV serotypes, namely O, A, Asia 1, SAT 1, C and SAT 2, have been recorded, respectively, in 17 (all), 15, 11, 10, 4 and 3 countries. In the past, exotic strains of FMDV were involved in panzootics, covering large parts of the region and even extending to the frontier of Europe. A remarkable example was the rapid dissemination of virus serotype SAT1 which penetrated Bahrain (most likely through imported sheep from Africa) in December 1961. The virus spread north-westwards to reach Iraq, Jordan, Israel and Syria by April 1962, continuing into Iran and Turkey. In September 1962, it crossed the Bosporus to enter Europe for the first time and in November caused an outbreak further west, near the border between Turkey and Greece. The panzootic of FMDV serotype O strain PanAsia, which has recently spread into Europe (UK, France, Netherlands and Ireland), is an additional alarming demonstration of the potential global risk of the FMDV (map 3).

It seems that three serotypes of the FMDV, namely O, A22 and Asia 1 are endemic in the region, though the latter may remain unrecorded in certain years. During 2000, the FAO/OIE World Reference Laboratory at Pirbright (WRL FMD) identified FMDV serotypes O and A in samples received from Iran, Iraq, Turkey and the United Arab Emirates; serotype Asia 1 was identified in Turkey and neighbouring Greece. Other exotic strains may penetrate the region as well; during 2000, FMDV serotype SAT 2 was identified by the WRL FMD in 16 out of 22 samples received from Saudi Arabia, probably introduced from the Horn of Africa.

The Threat to Israel

Israel is a small country (appx. 22,000 sq/km), lacking natural borders with the four neighbouring countries – Lebanon, Syria, Jordan and Egypt - where FMD is known to be endemic (See map 3). The distance from a fifth FMD-infected country – Saudi Arabia – is scarcely 40 km. The Israeli livestock population comprises appx. 350,000 bovines, 400,000 ovines and 100,000 caprines. The largest livestock sector is the dairy cattle, comprising of appx. 125,000 milking cows of the Israeli-Holstein breed in 1305 farms, most of them in the central and northern regions, including the Northern Negev; there are several dairy operations also in the arid, southern Arava region. The dairy industry is one of the Israeli agriculture's central pillars, supplying practically all domestic demand for milk and dairy products. All producers belong to the Israeli Cattle Breeders Association (ICBA). Appx. 65,000 of the producing cows are maintained in the Kibbutz-type, co-operative farms, each including 250 – 600 lactating cows, while appx. 60,000 are kept in smaller, privately-owned farms of the Moshav type, 40 – 90 lactating cows each. The husbandry is based upon a zero-grazing system, all animals maintained indoors in semi-covered corral-type facilities throughout the year. The total national milk quota, during 2000, was 1,200 million litre milk. During 2000, the Israeli-Holstein Herdbook included 98,485 registered cows, their recorded annual production being 10,489 litre/cow, with 3.26% fat and 3.07% protein. The total milk output, about 1.2 million tonnes, is processed by the dairy plants into a range of over 1,000 dairy products worth more than US$ 1.7 billion. Milk prices to consumers have decreased 18 percent in real terms during the past decade. Despite this decrease, there has been a significant improvement in milk quality.

In addition, there is a smaller, advanced sector of dairy sheep and goats, belonging to members of the Israeli Sheep & Goats Breeders Association (ISGBA). The 81 dairy-sheep member-farms include 25,000 lactating ewes, most of them of the prolific Assaf breed, which has been developed in Israel from a cross between the endemic fat-tail Awassi sheep and the exotic East-Friesian milch sheep The annual sheep-milk quota in 2000 was 8.7 million litre, with 5.7% fat, the annual mean yield being appx. 300 litres/ewe (record yields of individual sheep exceeding 1000 litre). The ISGBA incorporates also 28 goats farms with appx. 5,000 lactating animals which have, during 2000, produced about 3.5 million litres. The other 500 members of ISGBA grow mutton sheep.

More than 200,000 additional sheep – most of them of the fat-tail Awassi breed – and more than 80,000 goats, most of them of the endemic Syrian Mountain Goat  (Mamber Goat) breed, are kept in more than 5,000 flocks/units, about half of them by the Bedouins in the Negev desert. These units include 10 -200 animals per flock, maintained in the old-traditional husbandry methods which have not changed significantly since Abraham's days. This includes nomadism, at least during several months of every year, in considerable number of flocks. Though their milk and mutton yields are lower than in the advanced sector, there is a clear and continuous tendency for improvement in the larger units, both genetically, by introducing the Assaf sheep as well as technologically by the introduction of advanced feeding techniques, artificial insemination, hormonal synchronisation etc. Due to their typical husbandry and their movements, the small ruminants in this sector are less prone to efficient surveillance and animal disease control schemes, therefore posing a serious potential for disease maintenance and spread, FMD included.

Obviously, the record milk-producing animals of Israel – compared to the rugged, resistant beef cattle and the extensively held small ruminants - are extremely vulnerable to diseases, with special reference to FMD. Their protection, allowing uninterrupted production and annual improvement of the yields, is the responsibility of the Veterinary Services and Animal Health (VSAH) in the Ministry of Agriculture and Rural Development. A great effort is invested in activities related to the prevention and control of FMD. Israel is one of the 33 members of the European Commission for Foot & Mouth Disease (EUFMD). The head of the KVI laboratory for FMD, Dr. Hagai Yadin, is one of the 12 members of the EUFMD Research Group; the annual meeting of this group, in 1996, was carried out in Israel.

Economical aspects

It has been estimated that the current FMD prevention /control policy limits the mean, direct and indirect, annual losses, in the dairy industry, to less than US$ 200,000 per year. On the other hand, a major Israeli outbreak, without vaccination, could cause losses as high as US$30 million.

In one dairy operation, including 200 lactating cows and 265 offspring (younger than 2 years), the losses were US$ 80,000. This included 6.5% mortality (and emergency slaughter) in animals above 1 year, and 11% mortality in animals younger than 1 year. During the three weeks of clinical disease, there was a daily loss of 3,400 litre milk.

An outbreak in one dairy-sheep flock, including 600 milking Assaf sheep, caused losses of appx. US$ 30,000, equivalent to 3.5% of the annual income of the farm.

The direct costs, for the Israeli animal breeders, of vaccinations, during 2000 were US$ 1,615,706 for cattle and US$ 225,539 for small ruminants, totalling 1,841,245 US dollars.

Epidemiology

FMD has been recorded in Israel since the latter years of the Ottoman rule, namely the late 19th and the early 20th C, as well as during the British Mandate years (1917 – 1948). After the establishment of the State of Israel (1948), the dairy farming began its rapid development and the disease reached record numbers of outbreaks between 1956 – 1967, when it was found to be present in each and every year, causing serious economical losses.  The mean annual number of recorded outbreaks during the said 14 years was 71 (5 - 215). In  1958, the Kimron Veterinary Institute (KVI) was established at Beit Dagan and began to type all obtained FMDV strains. Most of the isolates were of the serotype O; however, during 1958 - 1964, a major epizootic was caused by FMDV serotype Asia 1, which affected the entire Middle East. This strain caused not less than 324 recorded outbreaks in Israel during the said period, most of them (300 outbreaks) during 1959/60. In 1962, FMDV serotype SAT1 - which spread in the Middle East after its penetration into the Gulf states - entered Israel, causing 111 recorded outbreaks, followed by serotype A22, which - during 1964/5/6, caused 114 recorded outbreaks. The situation seemed to significantly improve after the introduction, in 1965, of general annual vaccinations of the entire cattle population with a trivalent, inactivated vaccine (A22, O, Asia 1). Initially, small ruminants were vaccinated to a lesser extent. The vaccination regime has later undergone several modifications. Since 1974, passive and active surveillance have been intensified: during the 27 years between 1974 – 2000, a total number of 257 outbreaks have been recorded, the majority of them in unvaccinated small ruminants and in extensively-kept, grazing beef cattle of the Baladi and crossed beef breeds. FMD was present in 18 out of these 27 reviewed years (Table 2: Reported outbreaks of FMD in Israel, 1974-2000). As can be seen, the most prevalent was FMDV serotype O (244 outbreaks), affecting cattle, sheep, goats, gazelles and wild boars during 15 years. FMD serotype A22, was recorded during 3 years (the last one in 1981), causing 10 outbreaks – all of them in cattle on the Golan heights. It seemed to leave (clinically) unaffected the adjacent/contact, unvaccinated small ruminants. FMDV serotype Asia 1 was the cause of 3 outbreaks, during 1984 and 1989, infecting beef (2 outbreaks) and dairy (1 outbreak) cattle on the northern frontier. However, during the Asia1 epizootic of 1958-1964, the virus was demonstrated to be infective for small ruminants as well. Undoubtedly, the most invasive and wide-spectral of the three FMD serotypes, recorded in Israel during the last 27 years, is serotype O. Very severe outbreaks, characterized by high mortality rates in young lambs and kids, with typical cardiac lesions, have been observed in 1994, 1996 and 1999. Clinical manifestations in older animals were less common; in rare cases, clear oral lesions were seen in goats. A particularly malignant outbreak was observed in Mountain Gazelles in 1985.

Since the introduction of PCR into routine use in the laboratory, epidemiological studies have improved. Genetic analysis of the virus isolates is routinely carried out in the KVI laboratory of  molecular virology, by elucidating the sequence of 292 bases (320 - 613) of the VPI genes. Such a study has enabled, during the outbreaks, to trace back different origins of the virus strains involved. For example, it was demonstrated that the extensive outbreak in 1994 was caused by two distinct cycles of FMD O1 of differing genetic profiles: the first cycle, causing 32 foci, 15 of which in the West Bank (including the primary focus in Marj en-Na'ja on the Jordanian border), 1 in Gaza and 16 in Northern Israel. A second cycle, causing 4 foci in  Northern Israel, adjacent to the Lebanese/Syrian borders (map 4). The gene sequencing techniques have also allowed the KVI to carry out, in 1994, within a trilateral, regional research project, genetic studies of Israeli isolates compared with those from Egypt (dendograms 1, 2). The values of the modern molecular techniques for epidemiological studies was demonstrated again when, in 1996, seven nucleotide sequences from Israel were sent by the KVI to the WRL FMD at Pirbright, where they could be compared with Jordanian and Lebanese isolates. A strikingly close relationship was found there between Jordanian (1995) and Israeli (1996, 1998) FMDV O1 strains (dendogram 3).

Not always is it possible to recognise with certainty the primary focus of FMD within a developing outbreak. However, if first reported cases are to be regarded as primary ones, it seems that most outbreaks have begun on the northern and north-eastern frontiers (map 5). This might be an indication - which needs further studies - that the disease in Israel is, generally, of an external origin.

A remarkable feature of FMD in Israel is its seasonality. First cases appear in December – February, the peak of outbreaks being April – June (70% of all annual totals). During the reviewed period, not a single case was recorded in November (graph). The reasons for that phenomenon have not been clarified so far; it has, however, been postulated that one of the reasons might be the timing of lambing (November – January) and kidding (December – March) in the traditionally-maintained flocks in the Middle East, but there might be additional factors involved: a candidate subject for regionally co-ordinated further studies. The seasonality has been taken into consideration for the vaccination's timing.

FMD in wildlife has become an important issue for investigation and surveillance since the outbreaks in gazelles in 1985 (For paper in Vet Record, click here). It was caused by FMD serotype O, the mortality exceeding 50% in adult animals. There has been no recurrence of such an outbreak in the same region since 1985. In 1992, clinical cases of FMD, caused by serotype O, were recorded in wild boars in Northern Israel. A serological and virological survey in wildlife has been initiated by the Veterinary Services (For details, click here). Remarkbly, during the outbreak of 1994, it was reported that one holding of 36 gazelles and ibexes, in a small game enclosure, was affected with FMDV O1; 20 of the animals died.

The current Israeli policy to prevent and control FMD

The Israeli Veterinary Services and Animal Health (VSAH) have the legal powers, the infrastructure and the personnel to carry out the necessary measures in order to prevent, control and eradicate outbreaks of FMD [FMD Regulations].

The policy of FMD Prevention, adopted since decades, is based upon the following principles:

1. Control upon imports [regulations re animals, meat, and animal products].
2. Control upon animal movement [regulations re Cattle Regist./ident./transport, Animal Movement Regu., and Animal Movement Notification].
3. Identification of animals by ear tagging and I.D. certificates.
4. A strict surveillance and monitoring system [a gazelle PM station].
5. State-of-the-art diagnostic facilities (To see the high-containment FMD Laboratory at the Kimron Veterinary Institute,  click here).
6. Mass animal vaccinations of cattle, sheep and goats (For details, click here).
7. Monitoring of post-vaccination immunity (For details, click here).

Based upon the antigenic analysis of past isolates, the O component of the vaccine used includes, since 1996, FMDV serosubtypes O Manisa (Turkey) and O Geshur (Israel).

The vaccinations and other preventive measures have contributed to the favourable health status of the intensively held ruminants. This is especially relevant to dairy cattle; there have been very few outbreaks of FMD in dairy farms during the reviewed period (1981 excluded – when five dairy farms were infected, due to the non-efficiency of the vaccine used during that particular year). The effectiveness of the vaccination regime has been demonstrated many a time throughout the years; its best proof is the complete absence of FMD from dairy farms during most of the recent ten years. An extreme example was recorded in 1995, when a big Kibbutz dairy cattle herd remained unaffected in spite of a massive outbreak in fattening (young) cattle on the same premises.

Steps in an infected farm

In case of an FMD suspicion on a farm, a herd or a flock, the notified Regional State Veterinarian pays immediately a visit to the relevant site in order to make a clinical assessment, notifies by phone the Headquarters at Beit-Dagan, samples the suspected animals, sends the samples by special courier to the FMD lab at the KVI, carries out an emergency epidemiological investigation and implements temporary quarantine measures, to be maintained at least until the accomplishment of the laboratory investigation. The diagnosis of FMD in sheep is a comlex issue. Even if the typical foot lesions are seen, it is difficult ro obtain sufficient material for the laboratory testing from suspected sheep. Hence, if the suspected animals are sheep, probangsampling is the prescribed procedure.

Speedy laboratory diagnosis(in most cases – available in less than one day) enables the required decisions for direct implementation; besides the quarantine upon the relevant farm/village, animal movement restrictions are imposed within the region, and in case of a wide-spread epizootic – within several regions or the entire country, including the closure of slaughterhouses and animal markets. The restrictions are meant to prevent the virus spread through all possible means – animals, their products, vehicles, fomites and persons (e.g. inseminators, veterinarians, milk-tank drivers, agri-advisers, animal-feed providers etc.). The restrictions are published immediately upon their application through the media, internet included, while an official publication follows in the Government's Official Gazette [example from "Yalkut Hapirsumim"].

The epidemiological investigation is carried out according to a prescribed schedule, in order to trace back potential contacts of the animals of the affected farm with other locations/farms during at least three weeks prior to the first suspected case. Animals which had left the affected farm for breeding or fattening during the preceding three week period are to be traced back and slaughtered, while the contact farms are put under quarantine. Ring-revaccinations around the focus and revaccinations in the potential contact farms are carried out if necessary.

According to the law, the cattle I.D's of all the animals in the infected farm are kept in the District Veterinary Office (DVO) for six months following an outbreak. During this period, no animal is allowed to leave the farm and reach another farm. However, if the regional/country vaccination status allows, disinfection requirements accomplished and three weeks have elapsed since the last clinical case, animals are permitted to be transported, with special permits, to designated slaughterhouses for "sanitary slaughter".

Future prospects

Control measures hopefully leading to eradication of FMD from the Middle East are of the utmost  importance for the regional countries and, not to a lesser extent, to the adjacent regions – foremost (unvaccinated) Europe. This goal might have a (remote) chance only if and when regional co-operation is implemented. Common, co-ordinated epidemiological studies leading to a common control policy should be sought and supported by the international community. Some promising steps have been already made (for details, click here).