The zoonoses and paediatrics.

The World Health Organization has adopted and popularized the term ' zoonoses '1 which is applied to those diseases which are transmissible from animals to man. Altogether a total of some 8o diseases are included among the zoonoses, a word used almost universally in the plural. Most of these diseases have been known for many years and in somne parts of the world they constitute a major social and economic problem. In depressed populations the morbidity and mortality amongst children is high and chronic infection and infestation are responsible in part for reduced vigour and capacity for work in the young adult. In the United Kingdom many of the well-recognized diseases of earlier times have been controlled almost to the point of extinction, and because of this the subject has received little attention from British writers in recent years. Even less interest has been shown by paediatricians in the zoonoses, perhaps because they are not an important cause of infant mortality or even a common cause of serious illness. Nevertheless there is evidence that certain of the zoonoses occur with sufficient frequency in the British Isles to be included in the differential diagnosis of many febrile conditions which might otherwise remain unexplained. Although the zoonoses include all diseases transmissible from animals to man, the mode of life in the United Kingdom is such that the source of infection for the majority of persons is likely to be a domestic pet kept in the house though in agricultural communities other domesticated animals may be responsible. Cats, dogs and caged birds have been most frequently incriminated in previous studies but mice, rabbits, fowl and pigeons all feature in their turn. Almost any farm animal may be the source of infection though cattle, sheep, pigs and poultry have been responsible on most occasions. Hu112 tabulates about 20 diseases known to have been carried by dogs and cats, some of them by either animal and approximately half of them infestations. In spite of this knowledge these animals continue to live in close proximity to humans, frequently under unhygienic conditions -to the disadvantage of both parties. Matheson3 estimated in I944 that the cat population of British cities was approximately Io to i5 per cent. of the human population and that a city the size of Cardiff would have supported about 30,000 cats. Households in the poorer and older parts of cities are more likely to keep cats than the modern housing estates; 75 per cent. of households in the dock area kept a cat in I944 as compared with 34 per cent. on a housing estate. Apart from regulations against p)ets, the greater incidence of rodent infestation in the poorer quarters was held to account for the difference. In addition to household pets the number of stray cats in British cities is equivalent to about 3 per cent. of the total human population and about 6,ooo cats are destroyed per annum by various agencies in each of the large industrial cities. Matheson4 also estimated the dog population of Great Britain in. I953 to be equivalent to 6 to 7 per cent. of the adult population and that there were 3,860,ooo dogs in the country in 1950. The numbers of other domestic pets is not estimated but a rapid survey of households in Salford in I955 gave some indication of their popularity. During a routine school medical inspection I28 consecutive children were questioned about pets in the home with the following result: