. inactivated by the sun's rays, thus explaining a fewer occurrences 
 @f feot and south disease in animale during these periods of the 
yeary #8 compared to the autumn and winter months. 
SOURCES OF INFECTION AND MEANS OF FROPAGATION. 
) fhe main sources of the disease are sick animals and those 
_ that have recovered from an attack of the foot-and-mouth virus, 
 @8 well as, the products and raw materials obtained from such 
 gnimals, and the contaminated sedia of their environment (such 
as barns, farm lands, pasture grounds, water, etceje The carri- 
ers of footeand-mouth infection can be humana, transport, infected 
house pets, wild animals and birds, which have visited a foot-and- 
mouth disease center. 
while studying the epizcotic flare-ups of foot-and-mouth 
disease in fresh ferms and settlements, which had no previous 
record of such epizootic areas at crest distances from disease 
¢eenters (sometimes as much as hundreds of kilometers), we did 
_ mot find even one case where an animal affected by the foot-and- 
mouth disease, had passed-on the disease directly. in the greater 
_ mumberrof cases (70%), the infection was transported by humans, 
who were present in the foot-and-mouth disease center and assumed 
the role of csrriers of the virus te far away regionae. Thus, the 
feot-and-mouth virus was introduced into the VINITSKAYA region 
from the foot-and-mouth center in Rastov, Kiev region, and from 
the Sums'kaya region such an infection was carried to the thitomi- 
re'kij regions. in most cases in fact it was because timely 
measures had not been undertaken in the foot-and-mouth center, 
namely, veterinary, hygiene check posts had not been set upto: 
Carry out the required checking of persons who had been present 
in the region of the foot-and-mouth center, formalin-steem cham- 
bers had not been set up to disinfect peronnel and upper clothing, 
Special uniforme, shoes, etc. The second reason for the spread 
ef the foot~and-wouth infection. (14%) was, according to our data, 
transport vehicles, mainly of the autocar types, which were not 
¢hecked by veterinary theck posts, because of non-availability of 
‘Buch check posts at the time, these vehicles were net aiways 
properly disinfected while leaving the farma where the foot-and- 
mouth center, waa located. 
"2 
Very often (in 4% of the cases) the foot-and-mouth infec~ 
tion was caused by milk products which were not properly treated 
at the dairies and were products of animals which developed foot- 
andemouth disease later. Thia milk wae used to feed the calves ~~ 
and young pigs in farms which had remained unaffected by the virus. 
The infected milk and other milk products were specially haraful 
because the very young calves and young pigs generally had very 
Ww resistance to the foot-and-mouth virus, which in such cases, 
ur in @ non-aphthous (septic) condition, resulting in a large 
er of deaths among the young ones. That is usually the reason 
(3) 
