PROJECT SYMBOL: TCP/CVI/8823 CONTROL AND ERADICATION OF AN
AFRICAN SWINE FEVER (ASF)
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PROJECT SYMBOL: TCP/CVI/8823 CONTROL AND ERADICATION OF AN
AFRICAN SWINE FEVER (ASF)
|
3.1 The African swine fever (ASF) situation in West Africa and the epizootic in Cape Verde Republic
4. ACTIVITIES DURING THE CONSULTANCY IN RELATION TO THE TERMS OF REFERENCE
4.2 Evaluation of field situation to determine training needs
4.3 Evaluation of existing audiovisual training material
5. LEGISLATION FOR THE CONTROL OF AFRICAN
SWINE FEVER AND OTHER EXOTIC DISEASES IN
CAPE VERDE
6. STRATEGY FOR CONTROL OF ASF IN CAPE VERDE BASED ON TRAINING
- The present and historical ASF situation in the West African region was reflected in reports of delegates from 13 countries that participated in the Technical Meeting in Lom�, Togo, 3 - 4 June 1998. Cape Verde, S�n�gal, Cameroon, and probably The Gambia and Guinea Bissau have a long history of infection with ASF. In view of an oubreak in 1973, as well as 1997/8, and given the size of the country and the pig population, Nigeria may belong to this category, while the situation in Liberia is unclear. Guinea, Burkina Faso and Ghana remain uninfected, as does C�te d'Ivoire since the epizootic in 1996. In the most recently infected countries, the situation in B�nin appears to have stabilised with the southern half of the country infected, but ASF is apparently spreading in Togo and there is a serious threat to Ghana, Burkina Faso and the hitherto uninfected Atacora province in B�nin.
- Pigs are extremely important at the family level in Cape Verde as a major contributor to household food security and family income. Losses to ASF arre experienced virtually annually in at least Santiago island and probably Maio, and the disease is apparently endemic in these two islands. There is at present no effective legislation to control ASF and other epizootic diseases, although adequate draft legislation exists. Improved ASF control would ensure that pig owners will not suffer periodic heavy losses, and would enable the development of commercial pig farming where conditions are suitable. However, an eradication campaign would likely bring more hardship than relief. In view of the shortage of veterinary staff and infrastructure, a control strategy based on training farmers in pig management and disease prevention has the best chance of success.
- Training and assisting pig farmers to improve pig farming systems and act as an information network for disease surveillance, early warning and early reaction was identified as a priority for economical and sustainable ASF management in West Africa.
My grateful thanks are due to all those who assisted in the consultancy in Cape Verde: the FAO representative in Cape Verde, Mme Marie-No�l Koyara and all the staff of the FAO office in Praia; Dr Gilberto Silva, Director of Livestock (DGASP) for his support, especially with regard to the training programme; Dr Jos�-Lu�s Barros, Director of Veterinary Services and National Consultant, for his enthusiastic assistance during the consultancy, which went far beyond the call of duty; Dr Fernando Boinas, International Consultant, for his excellent cooperation during the short period that we were able to work together; to the staff of the Department of Rural Extension, in particular Mr Brito, for their excellent video work, and to all those who attended the workshop for their enthusiastic participation.
I am grateful to he FAO Representative in Lom�, Togo, Mr Ke�ta, and the Programme Manager, Mr de Medeiros, and their staff for their warm welcome and support, including supplying excellent working facilities during my stay; to my colleagues Drs Georges Edoukou, Khaled El Hicheri, Pierre-Charles Lefevre, David Nyakahuma, Felicit� Agbohoun-Beaudj� and Prof. Antoine Verhulst, as well as all the participants, for their excellent cooperation; and to the Ministry of Agriculture for making us very welcome in Togo. I am especiallly grateful to Drs Edoukou and Nyakahuma who ensured that my stay was very enjoyable and gave me a valuable insight into the ASF situation in Togo.
I am grateful to the following colleagues at the Onderstepoort Veterinary Institute: Dr D.W. Verwoerd, Director, for permission to perform the consultancy, Dr Errol Nevill for supplying slides for use in my lectures, and Dr Leon Prozesky and my colleagues in the Pathology Section for allowing me to be away for a protracted period.
The terms of reference of the present consultancy, as far as Cape Verde was concerned, were very limited, the activities of the consultant being restricted to an investigation of the legislation and initiation of and support for training. However, in order to adequately address those aspects, the ASF situation in Cape Verde had to be evaluated and placed in the context of the situation in the West African region. The terms of reference also included participation in the Regional Technical Meeting held in Lom�, Togo (3 - 4 June 1998). This report therefore covers a considerably wider field than do the terms of reference. The recommendations include certain aspects of control.
In order to place the ASF epizootic reported in 1998 in Cape Verde in perspective, it is necessary to summarise the situation in West Africa as known at present. The information below is derived from OIE bulletins, published data, reports of countries during the Technical Meetings in Abidjan (March 1997) and Lom� (June 1998), and recent experience in the region. The countries are discussed in geographical sequence, starting from the south, which is closest to the known area of endemicity in central Africa that includes the two Congo republics and Angola.
ASF was first reported in Cameroon in 1982. Massive outbreaks reduced a burgeoning pig industry from 2 million to 1 million pigs. One of the virus strains that affected Europe was incriminated. The presence of large numbers of warthogs in the country, as well as the economic difficulty of adequately compensating owners for compulsory slaughter of pigs, led Cameroon to opt for control rather than eradication. Although the disease is considered to be endemic in Cameroon, the OIE bulletins do not reflect any outbreaks since 1987. However, sporadic outbreaks still occur (Dr Tchoubia, personal communication). No evidence exists that warthogs are implicated in transmission of the disease.
The OIE bulletins up to 1997 do not reflect any outbreaks in Nigeria, which recently declared ASF in two provinces on the border of B�nin. This outbreak has resulted in a technical cooperation project, TCP/NIR/7822. However, during the recent Technical Meeting it emerged that Nigeria had suffered a serious and relatively widespread outbreak in commercial piggeries in 1973. A limited investigation failed to find ASF virus in Nigerian warthogs (Taylor, Best & Colquhoun, 1977).
An epizootic was declared in October 1997, episodes or suspected episodes being traceable at least to July or August in the south-eastern part of the country. Outbreaks continued until January 1998, resulting in the southern half of the country being infected, with a loss of approximately 50% of the estimated 650 000 standing pig population. The situation is reported in full in the reports relating to TCP/BEN/6715. The fact that no further commercial pig farms have become infected since the consultancies carried out in December 1997 and January/February 1998 is very encouraging.
Togo experienced outbreaks of ASF for the first time in September 1997, in villages close to the B�nin border, and linked to the introduction of pigs from that country. It would appear that, following the outbreaks of ASF in B�nin, the normal direction of pig trade reversed, due to large numbers of pigs becoming available at favourable prices in B�nin. The first recorded outbreak, in the village of Djeta, was well controlled by a special decree that included quarantine, stamping out by compulsory slaughter of all pigs with compensation at one third of the market price, and burning of carcasses. However, further outbreaks occurred in the border area, and the disease at present appears to have spread throughout the country, with reports of high mortality in pigs during the last few months emanating from Kara in the north-east, Dapaong in the north, and various suburbs of Lom� itself (Dr Georges Edoukou, personal communication). These localities are very close to the borders of B�nin (the hitherto uninfected Atacora province), Burkina Faso, and Ghana respectively. In all cases, the people living on either side of the border are closely related and keep free-ranging pigs, so the danger of transboundary transmission is very real.
ASF occurred for the first time in C�te d'Ivoire in early 1996, in piggeries in the city of Abidjan. The origin of the Ivoirean outbreak was not traced, but it was presumed to concern infected meat that entered Abidjan from outside the country and found its way into pig feed. In spite of early efforts to stamp out the epizootic, the disease spread to village pigs in various parts of the southern, western and central parts of the country. Eradication has apparently been successful. The last known focus of ASF occurred in October 1996, and subsequent serological surveys did not reveal any sera positive for antibody to ASF (reports to Technical Meeting for the Control/Eradication of ASF held in Abidjan 19 -21 March 1997 and the Technical Meeting for Control/Containment of ASF in West Africa held in Lom� 3 - 4 June 1998). The cost of eradication was extremely high, not only in money but in pigs. An estimated 120 000 pigs, representing more than 25% of the national herd, were lost; this included the bulk of the commercial herd. The ratio of commercial to village pigs altered from 25:75 to 10:90. Owing to fear of rekindling the disease, and in spite of the encouraging serological results and the results of the sentinelisation programme, commercial pig farming has not resumed in the Abidjan area. It is highly questionable whether, after an absence of 2 - 3 years, rapid recovery of the industry will be possible, since the vacuum is likely to have been filled to some extent by other industries, and the former pig farmers and other operatives in the sector will have had no option but to seek alternative sources of income.
These two countries need to be considered together, since the actual situation in Guinea Bissau is officially unknown. However, repeated reports of a highly fatal haemorrhagic disease that decimates pigs in Guinea Bissau, as well as remarkable precautions for preventing ASF at a large, at present abandoned state piggery in Bissau, suggest that ASF is certainly present (Dr David Nyakahuma and Prof. Antoine Verhulst, personal communication).
S�n�gal has reported ASF virtually annually since 1987. However, unpublished reports exist indicating that an endemic focus of infection in southern S�n�gal and Guinea Bissau is probable (Sarr , 1990; Sarr & Diop, 1990; Sarr, Diop & Dieme, 1990). The reports indicate that African swine fever (ASF) has been recorded in the Casamance province of Senegal and in neighbouring Guinea Bissau at least since 1959. A high number of village pigs serologically positive for antibodies against ASF were detected in Casamance (Sarr, 1990), suggesting a similar situation to that found by Haresnape, Lungu & Mamu (1985, 1987) in Malawi.
Outbreaks of ASF were recorded in Chad in 1983, 1984 and 1985 (Plowright, Thomson & Neser, 1994). These were presumably linked to the epizootic in Cameroon. The remaining countries in the region are currently considered to be free of ASF. Liberia has never reported ASF and at present the pig industry has apparently not normalised since the war that ended in 1996. Unfortunately, owing to present unrest, Sierra Leone was not represented at the meeting, but has never reported ASF (Plowright et al., 1994).
Several factors suggest strongly that all the West African outbreaks have been associated with movement of infected domestic pigs (or their products). Warthogs (Phacocoerus africanus) occur throughout the West African savanna, often with ample opportunity for contact with free-ranging domestic pigs. However, the outbreaks in C�te d'Ivoire and B�nin apparently started in the forested coastal belt, where there are no warthogs, while the northern savanna areas remained uninfected. Furthermore, eyeless ticks of the Ornithodoros moubata complex have never been recorded from West Africa (Leeson, 1952). The related O. erraticus, which acted as a vector for ASF in Spain and Portugal, has been recorded from S�n�gal and other sahelian countries including Chad, but is not known to be associated with warthogs.
Bush pigs (Potamochoerus porcus) occur in the forested areas of West Africa, where traditional pig production is concentrated, as well as in the areas of known endemicity in central Africa. They are known to be susceptible to infection with ASF virus but resistant to disease (Plowright, Thomson & Neser, 1994). However, their role in the epidemiology of ASF, if any, is unknown.
Although the standing herd of pigs in Cape Verde is relatively small (75 000), pigs are extremely important as a source of high quality protein and an easily mobilised source of money for numerous families who live in conditions of poverty on these barren and windswept islands. Pork is one of the staple constituents of the national dish, cachupa, and accounts for 49% of the meat consumed in the islands. Commercial pig-farming is virtually non-existent. With rare exceptions, pigs are of the "indigenous" type seen in Africa (probably largely derived from Alentejan pigs introduced by Portuguese settlers in both cases). The pigs are almost invariably fed from the table, as the islands during most of the year offer little if any natural grazing and very few agricultural by-products. On at least Santiago and Maio islands, most of the pigs are free-ranging and are able to supplement their diet by scavenging on the local garbage dumps.
The present TCP resulted from the declaration of suspected ASF to the FAO in January 1998, which was rapidly confirmed. The outbreak occurred on the main island, Santiago, and cases were confirmed from most parts of the island. To date, no cases were confirmed in the other islands, but enquiries on Maio island indicated that very high mortality had occurred among pigs during the latter half of 1997 and the early months of 1998, and were apparently still continuing. Owners reported clinical signs suspicious for ASF.
The bulletins of the OIE do not reflect any outbreaks of ASF in Cape Verde. Nevertheless, ASF was confirmed for the first time in Santiago in 1980, and several outbreaks were confirmed subsequently (1982, 1983, 1986....). Anecdotal evidence indicates that the disease may have been present in Cape Verde since at least 1966. Since, without laboratory confirmation, classical swine fever was also suspected, a vaccination programme was instituted, and part of the islands' pig population is vaccinated at intervals. Classical swine fever has never been confirmed in the laboratory. However, it is not possible to say at this stage whether both diseases are present. Sera with antibodies to classical swine fever were confirmed during the present epizootic, but it may be difficult to ascertain whether the pigs in question had been vaccinated.
The low number of pigs in the islands, the relatively small numbers of pigs per owner, and the failure of owners to report mortality may result in a false impression of the importance of disease. Losses appear to have been numerically minimal (approximately 2000 pigs) compared to the losses recorded in other countries in the West African region. Numbers refer to actual mortality, as, apart from the pigs at the Experimental Station at Trindade where the first outbreak was reported, the number of pigs lost has not been augmented by compulsory slaughter. However, the importance to the owners of the loss of an entire herd of 3 - 20 pigs that have been fed by sacrificing part of the family's food should not be underestimated. It is furthermore clear that the presence of recurrent ASF will militate against the development of the pig industry. In 1993, a large modern piggery (approximately 5000 pigs) at Justino Lopes (Santiago) was annihilated by ASF. Both the piggery and the well-equipped abattoir and processing plant were abandoned, and the latter is now a ruin littered with high-tech equipment that is damaged beyond hope of repair.
All the evidence, including sera positive for antibodies to ASF from apparently healthy pigs on Santiago, points towards ASF being endemic at least in Santiago, and probably in nearby Maio as well. If infection occurred for the first time after 1957, it is rather likely that it reached Cape Verde from Portugal, as its ties with Europe have traditionally been considerably stronger than with the much closer African continent, and most meat imports still emanate from Portugal. However, exchange of people with Guinea Bissau has always occurred as well, offering a possible alternative source of infection/re-infection.
Declaration of suspicion of ASF to the FAO in January 1998 resulted in a visit by Drs K Wojciechowski (AGAH) and D Nyakahuma (EMPRES) of the FAO to Santiago under the EMPRES Programme. ASF was confirmed at CSIA-INIA, Madrid, and it was established that the disease was widely disseminated in the island of Santiago. A Technical Cooperation Project, TCP/CVI/8823, was established for the control/eradication of ASF in Cape Verde. Two international consultants, Drs Fernando Boinas and Mary-Louise Penrith, were appointed, as well as a national consultant, Dr Jos� Lu�s Barros. The objectives of the consultancy are to determine the ASF situation in Cape Verde, evaluate the capacity of the veterinary services to control the disease, put in place a training and information programme, and recommend a strategy for the control/eradication of ASF. At the time of writing, no response to a request by the FAO representative in Praia to meet with the consultants had been received from the Minister of Agriculture, Food and the Environment, who is responsible for execution of the project. No particular zoosanitary measures are in place.
- To evaluate the legislation concerning ASF and other priority infectious diseases
- To initiate information workshops for the surveillance and control of ASF, using all available audiovisual means
- To supply support and assistance in the utilisation of communication systems, radio, television, newspapers, to alert the village communities to the problems of ASF
- To cooperate with national and international personnel to put in place an effective reaction to the ASF epidemic based on a system of early warning and rapid reaction
- To establish a basis of competence concerning ASF among the veterinary services at national and regional levels, to enable them to put into action the emergency measures for effective control of ASF
- To implicate the FAO/IFAD programme for the development of small-scale farming in the above activities
- To prepare a report according to the norms of the FAO
- To participate in the regional seminar on ASF in Togo
- To execute any other necessary task
An itinerary and brief diary of activities is given in Appendix I.
A document containing Decree 63/89, embodying legislation for animal health, and a document containing draft legislation intended to replace Decree 63/89, were examined and evaluated.
Visits were made to the municipal abattoir in Praia, abattoirs at Assomada and Pedro Badejo, two butcheries in Assomada and one in Pedro Badejo and the meat market in Vila Maio during meat inspection. National and international ports of entry visited were Praia and Maio airports and the port of Praia.
During discussions officials of DGASP and the delegations in the islands it was possible to assess the strength of the veterinary presence in the different islands. A participatory workshop enabled the level of knowledge and interest of a highly representative sample of veterinary technicians to be evaluated. Pig-farming and marketing practices and the attitudes of pig owners to ASF were evaluated in two islands, Santiago and Maio.
A video film that was used to inform the rural population about ASF was examined, as well as a set of 35 mm slides for use in technical training. Video clips filmed during the consultancy were also studied and evaluated.
A 2-day training workshop for veterinarians and veterinary technicians was held at the training centre at S�o Jorge on 27 - 28 May. It was attended by 31 veterinary officials from rural delegations and in training, representing the islands of Santiago, Maio, Fogo, Boavista, Sal and Santo Ant�o. The workshop comprised one day of theoretical training with the emphasis on group discussions, and one day of practical work. The students visited pig owners and were shown how to bleed pigs and carry out epidemiological enquiries. Post mortem examination of pigs was demonstrated in the laboratory facility (not yet functional but partly equipped) at INIDA, and the students were shown how to take appropriate diagnostic samples and pack them for dispatch to a laboratory. The students were supplied with copies of the lectures and summaries of group discussions. A programme, list of attendants and summaries of group discussions are given in Appendix II.
Participation in the Technical Meeting, which was attended by delegates from 13 countries in the West African region, included delivering two technical lectures, acting as moderator for the first session and as rapporteur (English) throughout, and assisting with formulation of the recommendations and translating them into English. A summary of the round table discussions was made and a copy left in Lom� for translation. Copies of the two papers delivered, summaries of the contributions of the anglophone countries and Cape Verde (translated from Portuguese) and the round table discussions, and a copy of the recommendations are included in Appendix III.
Decree 63/89 of 14 September constitutes the basis of legislation relative to animals and livestock. It includes chapters covering import and export of animals and animal products, taxes and charges, campaign against animal diseases (regulation of veterinary technical assistance and registration of veterinary medicines), campaign against contagious diseases, domestic animal production, sale of domestic animals, and the fate of dead animals. All the major aspects of control of contagious diseases of animals are covered. Specific measures for particular diseases are not included, but general provisos such as "wandering animals will be considered to be abandoned" and Article 5.4 of Chapter 10 (Fate of dead animals), which states that it is against the law to offer for consumption the meat of an animal that died from disease, are significant for the control of ASF during an epizootic.
Unfortunately, the above decree was never promulgated and there is therefore effectively no legal mechanism in place to control animal diseases.
A proposal has been made to replace the above decree with a more comprehensive decree. Meat hygiene aspects are fully covered. Article 14 is devoted to haemorrhagic diseases of pigs. In the case of ASF, animals should be isolated within a 15 km radius and affected animals should be killed. Adequately treated meat may be used for human consumption. The law makes provision for compensation of owners for compulsory slaughter of animals, with deduction of the price of any meat permitted to be sold. Importation of meat from countries infected with ASF is prohibited.
The proposal adequately covers most aspects. The killing of affected pigs in cases of ASF should be expanded to include in-contact pigs. In spite of the dangers involved in informal slaughter, the law should exempt owners of animals slaughtering them for home consumption, in view of the impossibility of imposing control on this activity. It should be clear, however, that such meat should under no circumstances be offered for sale. A recommendation to this effect was made to DGASP.
Evaluation of the general situation and the strength of the veterinary services in Cape Verde suggested that, should the above proposed legislation become law, application would be a very real problem.
A country consisting of 9 inhabited islands, poses administrative problems. The ratio of officials to population must necessarily increase in order to police the scattered population of each island. The veterinary services are represented by a central service in Praia and rural delegations in each concelho. In practice, there are only 7 qualified veterinarians in Cape Verde, the majority based in Santiago. In addition, poor remuneration and few prospects of advancement result in heavy losses of veterinary technicians, so that coverage cannot be considered to be adequate in any of the islands. For example, Santo Ant�o has three concelhos, with one veterinarian and one veterinary technician to cover the entire island. The islands are not large but on several of the islands mountainous terrain slows travel down considerably.
Official importation of live animals is reputed to be minimal, and no live pigs are imported. Inter-island movement of pigs was also reported to be minimal, but enquiries in Maio revealed a certain traffic in pigs between Maio and Praia. Organoleptic inspection of imported products of animal origin is performed at international ports of entry. However, as in most countries, the potential for illegal entry is very real. An example occurred during my flight to and arrival in Praia. The passenger next to me requested and obtained permission from the flight attendant to take her lunch with her rather than eat it on board. The lunch, which included two generous slices of ham, was duly placed in her handbag. It escaped the attention of the veterinary technician who was present at customs control, and whom I later recognised at the training course. Events of this nature must be frequent, and it would be foolish to suppose that effective control could be implemented. Yet a similar route of entry for ASF was suspected, rightly or wrongly, in C�te d'Ivoire, implying that a single episode could have far-reaching and expensive results.
Controlled slaughter according to legal prescriptions is virtually impossible at present. Where abattoirs exist they are inadequate, and are avoided by most livestock owners. If the municipal abattoir of Praia is typical, informal slaughter can be considered to be more hygienic. The entire operation was carried out in a filthy, partially roofed concrete shed. The shed, yard and holding pens were carpeted with the detritus of many years of slaughter; the room where carcasses were inspected and stored was marginally cleaner. No water supply exists; sea water is brought in buckets from the nearby harbour. A pool of bloody water at the gate made entry difficult, although no animals had been slaughtered that day. High taxes apparently prevent the majority of livestock owners from using the abattoir, which has a throughput of about 5 animals a week, mainly bovine. Butcheries, on the contrary, appeared to be relatively hygienic, with a meat inspector in evidence at one of them. However, the contribution that post-mortal meat inspection can make to the control of ASF, bearing in mind the capacity for spread by apparently healthy pigs in the incubation stage, is very slight.
Whatever its origin, ASF in Cape Verde is undoubtedly spread largely by contact between wandering pigs, feeding of contaminated pig remnants to pigs (either directly or by careless disposal), and sale of infected animals. Pigs that show signs of disease are often killed and eaten; consumption of pigs that have died of disease is also common. These activities, which take place at home level in small towns and villages throughout the islands, would be impossible to police even if the veterinary services increased tenfold and other departments such as the army and the forces of law and order were involved. Furthermore, although past and present proposed legislation makes provision for compensation of owners for compulsory slaughter of livestock, I was assured that no funds were available for this, particularly if stamping out on a large scale were to be undertaken. It was clear that in any case, even were compensation to be offered, owner compliance would be difficult to achieve, particularly where breeding stock and young piglets are concerned. Pigs are almost part of the family, and have been fed at some sacrifice in most cases. As one owner was quoted, when asked why pigs that died of disease were eaten: "We do not fatten our pigs in order to bury them!"
It is therefore clear that, while legislation for control of animal health in general and livestock diseases in particular is essential, its existence will not necessarily make a significant contribution to disease control in Cape Verde.
The difficulties facing the veterinary services have been described in 5.2 and can be summed up as lack of manpower and resources. The economic situation in Cape Verde suggests that these problems will not easily be addressed in the long term.
Eradication
In an island situation, from which the natural hosts are absent, it is tempting to consider that eradication would be relatively easy, and could be achieved in the same way as it was in Malta and the Caribbean. The realities of the Cape Verdean situation make eradication potentially impossible and of questionable desirability, even if money for compensation could be found, for the following reasons:
Probability of endemism. This would mean that either all the pigs in the islands where ASF may have occurred should be slaughtered (complete depopulation), or that a policy of complete serological testing and slaughter of positive animals should be instituted. The latter policy would be complicated by the lack, at present, of diagnostic laboratory capacity, so that sera would have to be sent away.
Effect on pig owners. There is no doubt that to do without any pigs on an island for a period of two or more months would occasion great hardship in view of their importance for the survival of their owners. The effect would be far greater than the effect of the present losses due to disease, since at present islanders who have lost their pigs can at least consume some of the pigs, obtain pig meat for food and replace the pigs fairly rapidly from other sources.
Lack of suitable pigs for replacement. In rare instances, one or two pigs of modern breeds may be kept, but in general the input required for these pigs to survive and produce is too high. The smaller, coloured local breeds are far better adapted to survival on a fairly scant diet supplemented by scavenging, with relatively little water available and little or no protection from the continual sunshine. Restocking after depopulation would therefore need to be from Africa rather than Europe, with some possibility of reintroducing African swine fever.
Lack of support by the Directorate of Livestock who, recognising the above problems, would be reluctant to embark on a programme of eradication.
Control
If it is accepted that sporadic outbreaks will probably continue to occur as they have done in the past three decades and more, a control policy needs to be developed that will contain an outbreak within the original focus, preventing widespread losses and minimising the risk of exporting the disease to other countries. Such a policy would need to include the following measures:
Quarantine of the infected area, with prohibition of all movement of animals and animal products
Establishment of a zone of surveillance around the infected area, the extent of which would depend on the proximity of other settlements
Alerting of all pig owners in the island via the national media
Closure of all pig markets in the affected island at least until the full extent of the outbreak has been established
Tracing of all pig movements in and out of the infected area during the period (at least two weeks) before the first case was observed, and before quarantine was imposed
Slaughter, with compensation, of all affected and in-contact pigs, preferably after but if necessary before laboratory confirmation is received
Disposal of the carcasses and infected material by deep burial (lack of combustible material on the islands makes burning impractical in most cases)
Disinfection of premises where pigs were kept
A one- to two-month period of complete depopulation, followed by the introduction of sentinel pigs, before restocking
In addition to these measures, permanent confinement of pigs in pig-proof pens or sties should be strongly encouraged if not enforced, and feeding of uncooked pig swill to pigs should be actively discouraged.
It is clear that the veterinary services do not have the manpower for either the rapid recognition of a focus of ASF or to carry out the above measures adequately. The only possibility for success lies in an informed public who will recognise ASF, understand its importance, and immediately report it to the relevant authorities and initiate the necessary measures for control. This can be achieved by training pig owners and local officials of all departments. A training programme is suggested below, to be carried out by the veterinary and rural extension services in all the islands. To offer one example of the advantages of this approach, illegal entry of infected meat would cause no harm to pig owners who understood the dangers of feeding uncooked swill to pigs.
Following the field training carried out in the islands of Santiago, Santo Ant�o, S�o Vicente, Sal, Fogo and Maio by Dr Boinas and the training workshop held on 27 - 28 May, it was recommended that further field training and follow-up workshops should be carried out by the national consultant. In view of the shortage of manpower, rural extension and other agricultural officers in the field should be included in the training programme.
The training programme should incorporate recognition of ASF (clinical signs and post mortem lesions), disease reporting and communication, control measures, performing an autopsy and taking samples, packaging and dispatch of samples, obtaining blood samples from pigs and processing them for dispatch, carrying out an epidemiological enquiry, and training of pig owners. It should be supported by a video of about 15 minutes duration, for which most of the footage already exists. Regular follow-up training will be required and may be modified and expanded as indicated by the experiences of the officers in the field.
An information campaign using posters, pamphlets, the national media, in particular radio and television, and, most importantly, direct contact during organised public meetings should be instituted. Information meetings are considered to be most important because they offer the pig owners an opportunity to ask questions and express any problems that they foresee. It is very important that the information be made available in Crioulo, which is the lingua franca of the islands and will ensure optimal comprehension. The meetings should be supported by a video of about 15 minutes duration featuring the following:
Pig production in the islands (types of production and breeds, including if possible modern pigs - a suitable white sow with a litter of 10 healthy piglets in a reasonable stye was identified at S�o Jorge)
The importance of pig production (e.g. a family eating pork, selling a pig to buy new clothes for a child about to go to school)
Pigs sick and dead as a result of ASF (clinical signs, lesions - very brief, empty sties)
Possible causes of disease: wandering pigs, close contact between pigs, careless disposal of carcasses and remains
How to prevent disease: confine the pigs, dispose of carcasses and any uncooked remains by deep burial, control entry to pigsties, disinfection, responsible action if disease is suspected
Much of the necessary footage already exists. However, it would be helpful if the existing sequence showing clinical signs in white pigs in a laboratory could be replaced by a sequence showing clinical signs in the type of pigs used in the islands. The rural extension journalists involved in the campaign are aware of this and will be actively looking for an opportunity to film sick pigs.
Adding value to pigs is a useful aid to enlisting owner cooperation in disease surveillance and reporting. The pigs in Cape Verde are already valued relatively highly by their owners. However, training in general aspects of pig management, health and production would encourage owners to keep pigs in confinement and monitor their health more closely. Confinement does not present a great problem in the islands, as ample stones are available (and often used) to construct pigsties, and there is little organic matter available in the environment to significantly supplement the diet of pigs left to forage.
The meeting was held in the Ministry of Agriculture, Lom�, Togo. Delegates of 13 countries (B�nin, Burkina Faso, Cameroon, Cape Verde, C�te d'Ivoire, The Gambia, Ghana, Guinea Bissau, Guin�e, Liberia, Nigeria, S�n�gal and Togo) participated. Unfortunately a simultaneous translation service was not available, but bilingual delegates provided assistance where necessary.
The opening of the meeting, by the representative of the Ministry of Agriculture, was attended by representatives of various organisations including the United Nations Development Programme, the European Union and the World Bank, and by journalists from the national media including the television service. The FAO representative in Togo, Mr Ke�ta, delivered an introductory speech emphasising the importance of ASF and the contribution that the FAO is making towards control.
Since time was limited, the programme was modified to permit as much time as possible for discussion by the participants. Technical lectures were limited to the following: Introduction and overview of ASF in Africa (M-L Penrith), Laboratory diagnosis of ASF (F Agbohoun-Beaudj�), Epidemiological and environmental risk factors (M-L Penrith), Surveillance and extension (G Edoukou), Legislation, public information, prioritization of the issue of ASF control (K El Hicheri), and Policy for breeding and restocking (A Verhulst). After the introductory lecture, one of the delegates from each country delivered a brief summary of the situation in his/her country. From these reports some very interesting information emerged. The veterinary services in Guinea Bissau and Liberia are unsure whether ASF is present in their countries and also do not have reliable statistics on the pig populations. The representatives from Togo were unaware that ASF had spread to the north of the country (this was discovered by the international consultant, Dr Edoukou). Nigeria experienced ASF for the first time in 1973! The meeting provided a useful means of warning the delegates from Ghana, Burkina Faso and B�nin of the immediacy of the threat to their countries.
Two round table discussions, one on the sources of infection and means of spread of disease, and the other on early warning, early reaction and strategies for control, were held. A summary of these discussions is included in Appendix III. The discussions highlighted various problems, some of which could be addressed immediately. It became clear that considerable confusion exists about the involvement of warthogs in transmission of ASF. The situation was clarified and delegates were assured that, while further investigation of wild suids and possible arthropod vectors in West Africa is indicated, particularly in endemic areas, the recent epizootics can certainly be ascribed to movements of infected domestic pigs.
With regard to control, many difficulties emerged, including free-ranging pigs, informal cross-boundary movement, inability to confirm the diagnosis, numerically inadequate veterinary personnel, overloading of senior veterinary staff so that they were unable to give any particular problem their full attention, lack of funds for compensation, lack of support at higher levels of government, and bureaucratic problems that prevented cooperation between different public sectors and even direct communication between CVO's in neighbouring countries. These issues are embodied in the recommendations made during the final session of the meeting.
It must be noted that information and training of pig owners so that they can constitute a network for disease surveillance and actively cooperate in disease control was identified as a priority, because it offers the only hope for successful control of ASF.
Closure of the meeting by the Minister's representative and Mr Ke�ta, was attended by members of the national press and television services. After the closure, an interview with Drs El Hicheri, Edoukou, Nyakahuma and Penrith and the Minister's representative was recorded for national television.
During a meeting with Mr Ke�ta attended by Drs Lefevre, El Hicheri, Edoukou, Nyakahuma, Penrith and Prof. Verhulst, it was agreed that the proceedings should become available as soon as possible and that the cost should be kept as low as possible. It was therefore decided that contributions would be published in the language in which they were presented, with the exception of the Cape Verde contribution, of which the written submission was in Portuguese, which would be translated into English. Only the opening speech by Mr Ke�ta, the summaries of the round table discussions and the recommendations would be published in both languages. The English and French contributions would be submitted via e-mail to FAO Rome as soon as possible by Drs Penrith and Edoukou respectively.
The English section of the proceedings is attached as Appendix III of this report.
ASF has been present in Cape Verde for a long time and is endemic in the island of Santiago and probably Maio. Outbreaks occur at irregular intervals. Losses are relatively small numerically, but are of considerable importance bearing in mind the value of pigs in the family sector.
Eradication in Cape Verde will be difficult for a number of reasons, and it is likely that a cost-benefit analysis would favour improved control rather than eradication.
Constraints for improvement of control include lack of veterinary personnel, lack of funds for compensation, the pig farming system and the impossibility of policing activities that take place in individual homes, lack of valid legislation, and lack of adequate facilities for controlled slaughter and marketing of pigs.
Veterinary capacity could be expanded by training not only veterinary technical staff but technicians in other fields, e.g. rural extension and other agricultural officers, to recognise, report and control ASF.
Control will only be achieved with the full cooperation of pig owners, who should therefore be trained in all aspects of recognising, controlling and preventing ASF, as well as in improved pig management, in order to add value to the pigs.
Persuading owners to confine pigs should be easier than on the West African continent, as most if not all of their food is supplied in any case, and the stony terrain offers ample material for building sties.
The meeting provided a useful forum in which participants could learn more about ASF, share problems and discuss solutions, and improve communication in the region.
Valuable information about the situation in the region became available, for example the possibility of long-term infection in Nigeria, the lack of communication between different countries in the region, and the seriousness of the threat to countries bordering Togo.
Technical meetings of this type may have a positive influence on governments and international organizations by underlining the importance of the ASF problem.
The recommendations all refer to Cape Verde, as the recommendations of the Technical Meeting are contained in Appendix III and there is nothing that can usefully be added.
- A serological survey should be carried out in all the islands, to include at least 10% of all adult pigs on each island (pigs of 30 kg and over), to establish the degree of endemicity of the disease
- Molecular typing of the virus, and comparison with African as well as European strains, is advised (the most important African strains would be S�n�gal, Angola, recent strains from West Africa, and, considering that the local authorities appear to regard South Africa as a possible source of infection in view of imports, South African strains as well)
- In view of the situation in Cape Verde, a strategy for control of ASF based on training of officials and pig owners and public awareness should be developed. Such a strategy would incorporate most of the population in a surveillance network and would enable pig owners to take a large measure of the responsibility for prevention and control of ASF
- Confining pigs and an integrated approach to improving pig health and production should form part of the training programme
- The process of legislation should be speeded up to permit the proposed draft legislation to come into force; even if difficult to apply, the necessary structure should exist
- Legislation for control of ASF should provide for slaughter of in-contact as well as affected pigs.
- Legislation re slaughter and meat inspection should include a clause that exempts animals slaughtered for home consumption/gifts from inspection (since it is quite impossible to either forbid a farmer to slaughter his own animals for own use or have them inspected), but should specify that meat offered for sale should be formally slaughtered and inspected
- Personnel in various departments (e.g. police, army) who can help to apply the animal health laws, particularly in cases of urgence, should be identified
- Infrastructure for controlled slaughter and marketing of pigs (specifically abattoirs) should be upgraded and expanded to facilitate compliance with the norms for public health.
- In order to strengthen veterinary services, training must be extended to include extension officers and other field personnel to increase the veterinary capacity
- Training content, for veterinarians and technicians:
- Short term: ASF recognition, confirmation and control
- Long term: holistic approach to animal health and disease control
- Training content, for farmers:
- Short term: ASF recognition, control and prophylaxis
- Long term: improved animal husbandry and health management
- Training programme
- Veterinary officers (vets and technicians) who attended the training workshop on 27 - 28 May should continue with a programme of similar workshops at appropriate level for all field personnel in each island
- National team to organize information days in each concelho for pig farmers, using video, slides and lectures
- National team, in collaboration with Directorate for Rural Extension, to continue with radio and television programmes relating to ASF in Cape Verde
- Materials for training
- Posters: priority should be given to the designing and printing of posters similar to those used elsewhere (the national consultant tells me he has examples) for dissemination to the population as soon as possible
- Pamphlets: pamphlets similar to those used elsewhere should be designed, printed and disseminated as soon as possible. In addition, another pamphlet demonstrating do's and don'ts for pig owners should be designed, printed and disseminated as soon as possible
- Videos:
Two short videos, one directed at veterinary and extension personnel and another directed at pig owners, are required
The local team should be financed to capture as much material as possible, especially of diseased pigs, autopsies, and pig-keeping, for incorporation into the existing video and for use in a comprehensive video on ASF in Africa (see below)
If possible, the video sequence showing clinical signs in white pigs in Europe should be enhanced or replaced by a sequence showing the signs in indigenous types of pigs (these need not necessarily be Cape Verdean pigs)
For training of veterianarians/technicians, it is strongly recommended that any available funding should be put towards the completion of a quality video on ASF in Africa with soundtrack in English, French and Portuguese for use in all countries, to contain sequences from as many countries as possible. To attempt to do this separately for each country will be a waste of money and result in products of poorer quality
In the long term, a video for training in the recognition and control of all List A diseases should be conceptualized and commissioned. Much of the necessary material already exists in various videos on the different diseases. It is contended that such a video will aid in promoting a holistic approach to control of serious infectious diseases and will help to avert emergency situations.
- Evaluation: The international consultants, during their final missions, should evaluate progress and effectiveness of the information campaign and training programme by visits to several concelhos
Haresnape, J.M., Lungu, S.A.M. & Mamu, F.D. 1985. A four-year survey of African swine fever in Malawi. Journal of Hygiene, Cambridge 95: 309 - 323
Haresnape, J.M., Lungu, S.A.M. & Mamu, F.D. 1987. An up-dated survey of African swine fever in Malawi. Epidemiology & Infection 99: 723 - 732
Leeson, H.S. 1958. The recorded distribution of Ornithodoros moubata (Murray) (Acarina). Bulletin of Entomological Research 43: 407 - 411
Plowright, W., Thomson, G.R. & Neser, J.A. 1994. African swine fever. In Coetzer, J.A.W., Thomson, G.R. & Tustin, R.C. (eds). Infectious diseases of livestock with special reference to southern Africa. 1. Oxford University Press, Cape Town : 568 - 599
Sarr, J. 1990. Etude de la peste porcine africaine au S�n�gal. Rapport final., Ref. No 50/Path.Inf., Institut s�n�galais de recherches agricoles (I.S.R.A.)
Sarr, J., Diop, M. 1990. Situation epizootiologique de la peste porcine africaine. Ref. No 51/Path.Inf., Institut s�n�galais de recherches agricoles (I.S.R.A.)
Sarr, J., Diop, M., Dieme. Y. 1990. La peste porcine africaine au S�n�gal: isolement et edentification de souches virales a partir de foyers recents. Ref. No 51/Path.Inf., Institut s�n�galais de recherches agricoles (I.S.R.A.)
Taylor, W.P., Best, J.R. & Colquhoun, I.R. 1977. Absence of African swine fever from Nigerian warthogs. Bulletin of Animal Health and Production in Africa 25: 196 - 203
12/05/98 Travel Johannesburg - Abidjan
13/05/98 Travel Abidjan - Dakar - Praia
Visit to FAO office and informal discussion with Dr Gilberto Silva
14/05/98 Meeting with FAO Representative
Meeting with Dr Gilberto Silva, Director of Livestock (DGASP)
Planning of work and examination of legislation and documents on animal health
15/05/98 Completion of work on legislation and animal health documentation
Meeting with Dr Jos�-Lu�s Barros (national consultant)
Meeting with the Director of Rural Extension and staff members
Viewing of video made for local television
16/05/98 Meeting with Dr Barros and planning of work
17/05/98 Meting with Dr Barros and Dr Fernando Boinas
18/05/98 Travel to Ilha Maio and visit to Morrinho, Cascabulho and Calheta
19/05/98 Visit to Pedro Vaz, Alcatraz and Figueira da Horta
20/05/98 Visit to pigsties in Vila Maio and travel to Praia
21/05/98 Preparation for training of trainers workshop
22/05/98 Attendance at meeting for debriefing of Dr Fernando Boinas
Continued preparation for training workshop
23/05/98 Debriefing by Dr Boinas before his departure for Rome.
24/05/98 Preparation of lectures and material for workshop
25/05/98 Completed preparation of lectures and material for workshop
26/05/98 Visit to S�o Jorge to see venue for workshop and necropsy facility
27/05/98 Training workshop - theory (lectures and discussion in groups)
Preparation of summaries of group discussions for distribution
28/05/98 Training workshop - practical (farm visits and necropsies)
Visit to the Praia municipal abattoir
Preparation of recommendations for DGASP
29/05/98 Meeting with Drs Silva and Barros to discuss recommendations
Meeting with journalists of Department of Rural Extension
Viewing of video film (Maio and training workshop)
30/05/98 Visit to pig market and butcheries at Assomada
Visit to village south of Tarrafal
Visit to abattoir at Pedro Badejo
31/05/98 Preparation for technical meeting in Togo
01/06/98 Travel from Praia to Lom� via Dakar and Abidjan
02/06/98 Meeting with FAO Representative
Preparation for technical meeting
03/06/98 Technical meeting
04/06/98
05/06/98 Preparation and translation of recommendations
Discussion with FAO Representative about proceedings of meeting
Collation of English contributions to meeting
06/06/98 Visit to border posts (Ghana and B�nin), Djeta village and piggeries in Lom�
07/06/98 Discussions with Drs Nhakahuma, Edoukou and Makedonski
Travel to Johannesburg via Abidjan, arriving 08/06/98
Training workshop held at S�o Jorge, 27 - 28 May 1996
27 May 1998
09h15 Opening Mme Marie-No�l Koyara, FAO*
Dr Gilberto Silva, DGASP
09h35 Overview of ASF Dr Mary-Louise Penrith
10h00 ASF in Cape Verde Dr Jos� Lu�s Barros
10h30 - 10h50 Break
10h50 Discussion in groups
12h30 - 13h30 Lunch
13h30 - 17h30 Discussion in groups, report back and summary
Practical: Visits to pig owners: blood sampling and epidemiological enquiry
Autopsies and demonstration of sampling technique
*Mme Koyara was unable to attend owing to another commitment but sent a message of support
FAO: Dr Mary-Louise Penrith
DGASP: Dr Jos� Lu�s Barros
Dr David Monteiro
Dr Concei��o �vora
Delegations: Dr Francisca Mendes R. Barbosa S. Ant�o
L�cia Correia S. Ant�o
Jaime Vera Cruz Fogo
Rui Jorge Dias Fogo
Teresa Fernandes P.V. Tavares Santiago: Praia
Maria Antoni�ta Ramalho Santiago: Praia
Odete Esmeralda C. dos Santos Santiago: Santa Catarina
Alexandre Lopes da Veiga Santiago: Tarrafal
Daniel Bas�lio ?
L�gia Maria M. Matos Sal
Jo�o de Deus Delgado Ara�jo S. Nicolau
Francisco Ines Maio
Aur�lio Monteiro Gomes S. Vicente
Maria Jos� Boa Vista
Students: Maria do Carmo dos Reis
Jos� Lenine M. Carvalho
Alcinda Horta Varela
Iolanda da Mata Santos
Lucialina Maria Tavares Silva
Albertina Delgado dos Reis
Isabel Maria Varela da Lomba
Domingos dos Santos Andrade
Ivaldina Mendes Vaz
Eduino Gil P. Fernandes
Jorge da Luz Nascimento
Adelina Pires Morais
Belarmino Vieira do Carvalho
Jos� Aureliano de G. Almeida
Arlindo Varela Gon�alves
David Andrade Vieira
I. Geographic localisation: continent, region, country, island
II. Morbidity and mortality: high (85 - 100%)
III. Animal species: exclusively pigs
IV. Symptoms and lesions (these were described and showed adequate knowledge)
V. Inquiry: mortality, wandering animals, isolation of the pig unit, type of food, strange animals
VI. Laboratory examination: blood samples of live animals, organs from carcasses
VII. Differential diagnosis: classical swine fever, erysipelas and other septicaemias
I. Idenfication and localisation of the zone
II. Isolation of the suspected zone
III. Confirmation of the disease: clinical diagnosis, inquiries (previous similar cases, mortality rate, frequency and prevalence of the disease), laboratory diagnosis
IV. Quarantine of the affected zone: isolation of infected animals, prohibition of entry and exit of animals. zoosanitary measures (raising in sties and pens, hygiene and disinfection of sties and pens, food cooked at 30�C at 60�C before giving to animals, training and information of owners and handlers and the public in the affected zone)
V. Periodic monitoring of farms by inquiries
VI. In an epizootic situation, total slaughter of all pigs with destruction and burial of the carcasses: burial should be effected in such a way as to prevent disinterment
I. Make farmers aware about ASF
II. Necessary material: laboratory coat, rubber boots, gloves; cool box; alcohol, cotton wool, syringes, scalpel; collecting tubes with stoppers; tube holder
III. In the field: contact the owner, restrain the animal. If the animal is alive: collect blood (disinfect site with alcohol and cotton wool, extract blood with syringe, place blood in tubes, identify tubes). If dead: Open with scalpel, collect fragments of kidney, spleen, lungs, mesenteric and gastro-hepatic lymph nodes, tonsils; place in tubes in cool box with ice and send to DGASP Praia as quickly as possible; disinfect autopsy area with caustic soda; burn in deep hole and bury; wash and disinfect all equipment used in the autopsy
I. Visit to the territory: contact owners, census of the number of owners and pigs
II. Type of production: intensive or extensive
III. Objective of production: fattening, breeding, both
IV. Type of feed: commercial rations, kitchen waste
V. Health situation in the zone: diseases that have occurred in recent years, number of animals present, number of sick and healthy animals, morbidity
VI. Movements of animals: animals entering and leaving, fate of dead animals
I. At the first appearance of foci of ASF, communicate with the local delegation, the central services, international organisations and neighbouring countries
II. Contact community leaders and pig owners in the zone, the health delegation and the municipality
III. Organise the rural extension officers (information and training)
IV. Disseminate information via the social media for communication: radio (local and national), television
V. Disseminate information via posters, pamphlets and direct contact with pig owners
I. Control of frontiers (airport and port): live animals (health certificate), products of animal origin (sanitary certificate)
II. Control in the field: training of farmers (information, awareness); measures (permanent enclosure of pigs, keep sties clean and disinfect periodically with caustic soda, give pigs clean water and uncontaminated feed, do not buy or sell sick animals, burn and bury animals that die, never give pigs uncooked remains of pork, immediately inform the authorities when animals are sick)
1 ARC-Onderstepoort Veterinary Institute
Private Bag X05
Onderstepoort, 0110 South Africa
