Rinderpest

P B ROSSITER

GENERAL INTRODUCTION: PARAMYXOVIRIDAE AND PNEUMOVIRIDAE

Introduction

Classical rinderpest is an acute to subacute, highly contagious viral disease of cattle and other artiodactyles. The main gross pathological changes are necrosis and erosion throughout the gastrointestinal tract, which can cause diarrhoea, dehydration, and death. Epidemics of the severe ‘cattle plague’ form of the disease may have morbidity and mortality rates exceeding 90 per cent. However, mild and virtually inapparent infections with very low mortality rates also occur and are perhaps the more typical form in endemic areas.

The decimation of cattle and wildlife populations by rinderpest has influenced human history,^{119, 180, 235} and the ecology of large areas of southern and central Africa.^{369, 376} So serious were the effects of the disease that its control and eradication were major stimuli for the establishment of the first veterinary schools in Europe during the eighteenth century.

Historically, the disease invaded Europe with armies from the Orient, encouraging the view that the disease originated in Asia. Antigenic comparison between morbilliviruses has suggested that rinderpest may be the archetypal morbillivirus from which measles and distemper evolved five thousand or more years ago, possibly in the river civilizations of south-west Asia where the domestication of cattle is thought to have occurred.^{109, 233}

Introductions of rinderpest into Europe, usually as a sequel to wars, were often followed by major epidemics. By the end of the nineteenth century other forms of transport began to replace oxen as the main source of military draught power, effectively removing this source of infection. Strict application of slaughter and quarantine eradicated rinderpest from most of Europe, though a series of outbreaks occurred during and immediately after the First World War, most notably in Poland. The last reported outbreaks in Europe were in Belgium in 1920 and Rome zoo in 1949, both of which were caused by the importation of live infected animals from high-risk areas.^{15, 79} The only recorded outbreaks in the New World, in Brazil in 1920 and Australia in 1923, were also due to the importation of live infected animals. ^{294, 295, 407}

After the eradication of the disease from Europe the scientific study of rinderpest continued in Asia where the disease was widespread in the first quarter of the twentieth century. The first vaccine that allowed large-scale prophylactic immunization of rinderpest was developed in India in 1925 by Edwards,¹⁰⁶ allowing the possibility of mass control and even eradication of the disease in countries where strict control of animal movement or even slaughter were unfeasible. The vast and comparatively unconfined cattle population and even larger goat and sheep populations of India continued to pose an almost insuperable problem for vaccination and control, even with the advent of improved vaccines.

Finally, after focused programmes in the 1980s and 1990s, rinderpest was eradicated from the country in the mid-1990s, setting the example for the rest of Asia and for Africa. Unfortunately, in Asia, at the time of writing, Pakistan remains endemically infected and, although the prevalence of the disease has decreased significantly in the past decade, widespread traffic in live animals still poses a threat to southern Asia and the Middle East.^{219, 304} Effective control in the Near and Middle East decreased during the 1980s because of reduced vaccination and increased movement of cattle resulting from civil and military disturbances. Fortunately, the 1990s saw renewed control and it is increasingly likely that there are no endemic foci in this region.^{1, 20}

In Africa the disease was introduced to North Africa, especially Egypt, and possibly to West Africa on a number of occasions before 1887.^{87, 112, 211} If it reached West Africa it apparently failed to establish itself there, and if it persisted in Egypt it was effectively isolated from the rest of Africa’s cattle. For most historians the history of rinderpest on the continent begins with the ‘Great African Pandemic’ of 1887 to 1897, which was widely described in southern Africa and Ethiopia.^{135, 147, 202, 387, 388} Although the source of the virus that started the pandemic is still unknown, there are several possibilities, all classically associated with military campaigns. The most frequently quoted possibility is the introduction of infected Indian or Arabian cattle to Massawa in Eritrea by the Italian army in either 1887, 1888 or 1889.^{194, 424} The inefficient attempts to use prophylactic and therapeutic control rather than slaughter and quarantine, ⁴²⁴ made it easier for the disease to establish itself. Infection was then transported throughout Ethiopia and into the Nile Valley in Sudan in 1890. Alternatively, the virus may have moved slowly up the Nile from Egypt in cattle used by British military campaigns, which reputedly brought rinderpest to Khartoum in 1884 and 1885. Whichever is true, it seems likely that the disease was not present in this area before the 1880s when the American adventurer James¹³⁷ encountered numerous herds of healthy African buffalo (Syncerus caffer) as he travelled between the Nile and Massawa in 1881. All subsequent work has shown that the African buffalo is probably the most susceptible species to rinderpest. Another possible origin of the pandemic was...