Book reviews 237

poses a risk to man. Nevertheless, the chapter on EMC has more than 200 references. On the other hand the chapter on influenza quotes only 36 publications.

However, these inconsistencies are more or less unavoidable. More important are the inconsistencies that are due to the editors’ intention to be as complete as possible, as for example with salmonellosis. This topic is described in two chapters - ‘Salmonellosis in Mammals’ and ‘Avian Salmonellosis’ - which do not truly represent the real zoonotic aspect of the salmonellae. The host adapted salmonellae like Sulmonellu choleruesuis,

S.dublin. and S.pullorum-gallinarum are of less ‘zoonotic’ interest that the salmonellae that are not host-specific, such as, Senteritidis, S.infantis, and Styphimurium, though S.cholemesuis infections when they occur can be lethal for humans. For these zoonotic serovars, the differentiation between mammalian and avian salmonellosis is of no relevance. Here less would have been more if there had been just one chapter holisticly covering the general ecology of the zoonotic salmonellae in animals, the environment, and in people.

A last remark on inconsistency is that some authors use the term ‘epidemiological’ and others ‘epizootiological’, which does not follow the principle of ‘One Medicine’, though most contributors used only ‘epidemiological’ for both people and animals.

From the point of view of correctness, one should ask whether disease due to mycotoxlns and most fish diseases mentioned in these volumes really meet the definition of zoonoses, namely that the causative agent under normal conditions is transmissible between vertebrate animals and people. While the appearance of HIV and similar immunosuppressive effects has made apparent zoonoses of a number of fish diseases that are normally totally harmless, they are not strictly zoonotic, merely opportunistic. Again, less would have been more.

All in all, however, it must be said that all these criticisms should not diminish the value of the two volumes. Everybody interested in zoonoses will find a rich encyclope- dic fund of current knowledge of the most important zoonotic diseases. This is enormously helpful for the understanding of the biology, epidemiology, aetiology, and pathogenesis of zoonoses. For the library of any institution concerned with zoonoses, the two HandbooMs) of Zoonoses are a must.

THOMAS BLAHA Aussenstellefuer Epidemiologie

Tieraerztliche Hochschule Hannover

Buescheler Strasse 9

D-49456 Bakum Germany

Infectious diseases of livestock

Infectious Diseases of Livestock with Special Reference to Southern Africa, J.A.W. Coetzer, G.R. Thomson and R.C. Tustin (Editors), Oxford University Press, 1994, 2 vols, 1,605 + viiipp, $245.00, ISBN 0-1957-0506-S.

This new text book on the infectious diseases of livestock is a magnificent work, which not only sustains the unique reputation of its predecessor, Henning’s Animal

238 Book reviews

Diseases of South Africa, but also enhances it substantially in a variety of ways. It is an impressive work by both physical and scientific standards. These include the sheer presence of the two volumes (weighing in at an arm-wrenching 6.3 kgs), the quality of the production (printed on high quality paper and attractively bound and presented), the eye-catching cover illustrations (colour paintings of livestock in the southern African bush by Mr. C. Tugwell, with a different painting on the cover of each of the two volumes), the extensiveness of the coverage provided (193 chapters describing virtually all the infectious conditions of livestock in southern Africa, as well as some that do not

occur in the region), and the high quality of the contributions. It is one of those books which provides pleasure merely by its physical presence, an emotion which is enhanced substantially during its perusal, exploration and use.

If the length of a book review were to be proportional to the length of the book, I would require considerably more space in this issue of Preventive Veterinary Medicine

that the Editors are prepared to give me! So how to conduct a review of such a magnum

opus? I had considered taking an approach consistent with the quantitative epidemiologi- cal philosophy of the journal, namely to randomly select chapters (with appropriate sample size considerations, of course!) for in-depth analysis. However, I rejected this methodology when my initial random selections yielded topics on which I felt I had insufficient personal experience. With a set of evaluation criteria defined, I therefore went first, and in some depth, to those chapters which covered my pet topics, and I then

surveyed the others for consistency with my evaluation of a highly biased subsample! I purchased my own copy of Henning’s 1956 edition of Animal Diseases in South

Africa (there were three editions: 1932, 1949 and 1956) in a second hand book shop in Harare, Zimbabwe, almost 15 years ago, and I have treasured it ever since as the most detailed and comprehensive account ever assembled of the diseases that affect the southern part of the African continent. It was particularly strong on the historical aspects of early investigations and control measures, the main reason for me purchasing it some 25 years after it was last published. But the book went far beyond that. It was a goldmine of information on many aspects of infectious diseases of the region, often drawing on results of studies which had been buried in poorly accessible government reports. After the 1956 edition, there were numerous calls for yet another revision of the book, but with the death of Henning in 1962, the chances of this occurring faded. Nevertheless, there has been a long-standing sense of responsibility in South Africa to pursue the unique initiative of Henning, and the present editors and authors must be proud to see their ambitions realised. With the explosion in information on diseases affecting the region in the almost 40 years since the last edition appeared, it was virtually inconceivable that any one individual would take on the task. The challenge has been met by a team of editors, led by Koos Coetzer at the Veterinary Faculty at the University of Pretoria, who commissioned contributions from a total of over 100 authors, 70% of whom are from South Africa. This has meant that the new volume is not a revision of Henning’s work, but a return to the drawing board to provide a comprehensive account of each disease.

The editors spell out the scope of the book as covering infectious diseases of cattle, sheep, goats, horses, donkeys, mules and pigs. They also provide their geographical boundaries of southern Africa, to include Angola, Namibia, Botswana, Zimbabwe, South

Book reviews 239

Africa, Swaziland, Lesotho, Zambia, Malawi and Mozambique, although in many chapters there is an inevitable bias towards South Africa. The book has seven sections,

each containing a varying number of chapters. The first section is an interesting mixture of subjects under the title of ‘Aspects influencing the occurrence of infectious diseases in southern Africa’. The second and subsequent sections are more traditionally struc- tured on the basis of the microbial aetiology of diseases, with sections covering protozoa1 diseases, rickettsial and chlamydial diseases, viral diseases, bacterial and mycoplasmal diseases, mycotic and algal diseases, and finally disease complexes and

diseases of unknown aetiology. Chapters are well laid out and presented, and well illustrated (there are over 500 illustrations in the two volumes). Each chapter follows a generalised format, with the following contents: introduction; aetiology (and life cycle);

epidemio:logy; pathogenesis; clinical signs; pathology; diagnosis; differential diagnosis; and control. Some of these headings are combined in certain diseases, depending on their relevance. Each chapter has its own reference list, with references numbered in the

text. Figures are referred to in the text in bold print, a helpful feature in locating the text relevant to a particular figure. I particularly enjoyed the outstanding colour illustrations of arthropod vectors, prepared by Andre Olwage. Relevant epidemiological life cycles have been redrawn and presented in a standardised style. Many chapters have useful tables which have been compiled especially for the book.

I looked with some interest at the first section, entitled ‘Aspects influencing the occurrence of infectious diseases’, which comprises 10 chapters. The first six of these are on the different vectors of infectious diseases, such as ticks and tsetse flies. They all provide systematic, authoritative and well illustrated reviews of subjects that have

consumed the attention of so many eminent entomologists and acarologists over the last century. The authors of these chapters assign slightly different emphases within their chapters, swith some spending more time on taxonomy and others on distribution, but all

deal with the range of infectious agent they transmit, which are generally summarised in tabular form. There is a good link therefore between the chapters dealing with the vectors, and the later chapters dealing with the infectious agents themselves, and I noticed only one or two minor inconsistencies. One inconsistency is the use of the nomenclature Ornithadorous porcinus porcinus to describe the soft tick responsible for transmitting African swine fever virus in the tick chapter, and the use of Ornithodoruus moubatu in the chapter on African swine fever itself.

Following the six chapters on vectors is a set of four chapters on less-traditional subjects. The first is an overview of the anthropod-borne viruses, a fascinating and well-referenced chapter written by Bob Swanepoel, a world authority on the subject. This is followed by a chapter on vaccines, herd immunity and economics - a rather curious chapter presenting a mixture of subjects, and is the closest the book gets to

considering the sort of epidemiology and economics which dominates the papers published in Preventive Veterinary Medicine. The first section of this chapter provides an undergraduate overview of vaccines, including a most useful inventory of vaccines manufactured at the Onderstepoort Veterinary Institute in South Africa. The second section of this chapter describes some mathematical modelling techniques, particularly those involving the basic reproductive rate (Ro) of infectious agents. The final section of this potpourri discusses economic analyses of disease control, including a rather

240 Book reviews

superficial account of benefit cost analysis. This chapter was one of my few disappoint- ments in the book, as it gave the impression of being somewhat of a hastily prepared after thought when compared to the more professionally presented chapters of infectious diseases themselves. It is followed by a brief chapter on the genetic resistance of livestock to infections, which presents a very general and brief overview of the subject. The last chapter in the first section of the book deals with the role of wildlife in the occurrence of livestock diseases. This provides a good historical perspective on the role of wildlife in the epidemiology of six major infectious diseases, but presents little that

does not appear in the disease chapters of the book. The chapter is also disappointing in its coverage of the subject outside South Africa, and, more importantly, of the rapidly

evolving use of wildlife as a commercial enterprise in southern Africa, often in conjunction with domestic livestock, and the disease implications of these new produc-

tion systems. The rest of the two volumes comprises what the South Africans do best, describing

the long list of infectious diseases affecting livestock, and providing, on the whole, comprehensive and well-referenced reviews. To me, these chapters epitomise the

strength and comparative advantage of the South African veterinary profession in having had to deal with a wider variety of infectious diseases within a highly developed livestock industry than most other regions of the world. For the sophisticated livestock industries of Europe and North America, the infectious diseases now play a relatively

minor role, and as such, the expertise in this area is becoming increasingly scarce. With the emergence of South Africa from their political isolation of recent years, hopefully the knowledge and expertise they possess can be applied more widely to other areas of the developing world where infectious diseases remain a serious constraint to agricul- tural production and human development.

The strengths among these chapters on specific diseases lie in those endemic to the region on which the local experts who prepared the chapters are also the global experts. These include besnoitiosis (Rudolph Bigalke), babesiosis (Bert de Vos), heartwater (Durr Bezuidenhuit and Jean du Plessis), anaplasmosis (Fred Potgieter), bluetongue (Daan Vervoerd), African horse sickness (Baltus Erasmus), rabies and Rift Valley fever (Bob Swanepoel), rinderpest (Paul Rossiter), foot and mouth disease (Gavin Thomson), and anthrax (Valerius de Vos), among others. With so may different diseases covered, it

is not possible to discuss the content of each chapter. Suffice it to say that this is an authoritative work, rendering it a high quality reference volume. There is one drawback, the significance of which varies from disease to disease and from chapter to chapter. As

the editors confess, seven years elapsed between the inception and the publication of the book. As such, some recent exciting findings do not appear. Thus those chapters that were submitted promptly by their authors tend to be rather out of date. Examples within my biased sample are the chapters on tick vectors, which has in the reference list a citation of Norval et al. (1988) as in preparation. This is further illustrated in the chapters on East Coast fever and other theilerial diseases where the trinomial nomencla- ture for Theileria parva is used (dividing the species into T.parva parva, T.parva bovis and T.parva lawrencei) despite the fact that this nomenclature was abandoned in 1988. This means that much of the new published knowledge on the epidemiology of theileriosis and heartwater, for example, do not appear.

Book reviews 241

So who are the likely owners and readers of this book? I would suggest that it is an essential item in every veterinary school in the world, given its unique value as a reference volume. I would also like to see it well distributed in animal health depart- ments of research institutes and in disease control implementation organizations, particu- larly in departments of veterinary services in Africa. Beyond that, it will make a valuable contribution to most branches of the veterinary profession, including private practices, as well as being informative specialist reading for members of the general public. Unfortunately, however, it has two obstacles to its optimal distribution to this

wide ran,ge of potential clients. These are its cost (US.% 245) and weight. Hopefully, we can look forward to seeing the digital version before too long which will at least help

overcome the latter obstacle. As far as its cost is concerned, one can only say that it represents good value, given both the range and the quality of material presented. But there is another fact to consider as one ponders the investment. This will be a hard act to follow, and we might be in for another 40 years wait before we see the next edition!

BRIAN PERRY

International Livestock Research Institute (IL.RI) P. 0. Box 30709

Nairobi

Kenya