Outbreaks in the United States.—Foot-and-mouth disease has appeared in the United States on six different occasions—1870, 1880, 1884, 1902, 1908, and 1914.
An extensive outbreak in 1870 was introduced by way of Canada, where the infection was brought by an importation of cattle from Scotland. It spread into the New England States and New York and appears to have been arrested within a few months. Its failure to spread more extensively and its early disappearance have been ascribed to favorable conditions, such as the movement of live stock from west to east, the limited trading at that period as compared with the present time, the restriction of traffic by winter weather, and the infrequency of travel which obtained at that time among people.
About 1880 two or three lots of animals affected by this disease were brought to the United States, but there was no extension from the animals originally affected.
In 1884, at Portland, Me., there was a small outbreak caused by imported cattle, and the disease spread to a few herds outside the quarantine station. Owing to the small number of animals affected and the limited area of territory covered by the disease, it was easily controlled by the ordinary measures of quarantine and disinfection.
It will be observed that in all these early outbreaks the contagion was introduced with imported animals. Since the development of a stringent system of inspection and quarantine of imported live stock, no instance of that kind has occurred. On subsequent occasions the infection has evidently been brought in with contaminated products or materials and not by means of live animals.
In November, 1902, the disease was discovered in Massachusetts and Rhode Island. The earliest cases were traced to Chelsea, Mass., near the docks, and it was suspected for a time that the infection was brought in with foreign shipping, by some such means as hay, straw, halters, ropes, hides, hair, wool, etc. Later developments, however, and especially investigations into the cause of the 1908 outbreak, led to the belief that a more probable source of the infection was cowpox vaccine virus imported from a country (probably Japan) where foot-and-mouth disease existed, the vaccine virus being contaminated with the virus of foot-and-mouth disease.
A Federal quarantine was declared by the Secretary of Agriculture on November 27, 1902, as soon as the nature of the disease was established, and steps for eradication were at once taken by the Bureau of Animal Industry of the United States Department of Agriculture in cooperation with authorities of the affected States. The methods followed consisted of inspection to trace and detect the disease, quarantine of infected premises and territory, slaughter and burial or burning of diseased and exposed animals, and disinfection of premises.
This outbreak involved Massachusetts, New Hampshire, Vermont, and Rhode Island, and was eradicated in about six months. Two hundred and forty-four herds, including 4,712 cattle, were found infected. Of these, 205 herds with 3,872 cattle, as well as 360 hogs and 220 sheep and goats, were slaughtered. The cattle infected but not slaughtered were those that either died or completely recovered before slaughtering could be carried out. The animals slaughtered were valued at $184,155.10, and the Federal Government reimbursed owners to the extent of 70 per cent, or $128,908.57. It is understood that the States paid the remainder. The total cost to the Department of Agriculture of stamping out the disease was about $300,000.
The next appearance of the foot-and-mouth disease was early in November, 1908, when it was observed in cattle near Danville, Pa. A Federal quarantine was issued November 12. The infection was traced back to the stockyards at East Buffalo, N. Y., and to Detroit, Mich. The disease appeared in the States of Michigan, New York, Pennsylvania, and Maryland. A careful and thorough investigation made by Mohler of the Bureau of Animal Industry and Rosenau of the Public Health Service demonstrated that the outbreak started from calves used to propagate vaccine virus at an establishment near Detroit, and that the source of the infection was contaminated Japanese vaccine virus.
Vigorous measures of eradication similar to those employed in 1902-3 were at once put into effect and the disease was stamped out in about five months at an expense of about $300,000 to the Department of Agriculture, and of about $113,000 to the States. The inspectors made 108,683 visits to farms, stockyards, etc., and inspected more than 1,500,000 animals (including reinspections). One hundred and fifty-seven premises were found infected, and 3,636 animals (2,025 cattle, 1,329 hogs, and 282 sheep and goats), valued at $90,033.18, were slaughtered. Owners were reimbursed for the value of their animals and property destroyed, one-third being paid by the States and two-thirds by the Federal Government.