39 
But milk epidemics necessarily follow the milkman, and often his 
route can be plotted by the incidence of the disease. The outbreak 
may be limited to a certain section of the city if the route is small 
and circumscribed in extent. This will usually eliminate water as 
a cause of typhoid where a public supply is in use. Or where various 
water supplies are used the cases may occur among the users of the 
different sources. If the dairy is a large one, delivering to all parts 
of the city, the cases may be widely separated and much scattered, 
having nothing in common but the milk supply. The children may 
go to different schools, the families be of varied social status. These 
points will usually eliminate schools and contact as sources. 
At times where the area covered by the milk route and therefore the 
district involved in the outbreak is circumscribed, occasional isolated 
cases will be found at a distance, and upon careful investigation it will 
be found that they had friends or relatives on the involved route and 
used the suspected milk while on a visit. 
Very interesting cases have been reported where the evidence seemed 
quite convincing of persons drinking a single glass of the suspected 
milk and falling ill after a due period allowed for incubation. 
Milk outbreaks are as a rule more typical in small towns where the 
organization is less complicated and fewer extraneous factors occur 
to conceal the true picture. An example of this is the outbreak at Elk- 
ton, Md., in 1900. 
Elkton epidemic .^ — Elkton had a population of 2,542. The town 
Avater supply was obtained from the Elk River about miles above 
the toAvn. Part of the families drank the town water, the rest used 
private wells. The inhabitants were supplied with milk from 4 dairy 
farms having routes in the town. Dairyman B on his way to town 
each day with his own milk obtained an additional amount from 2 
other farmers, C and D, both of whose farms remained free from 
typhoid. In September, 1900, a case of typhoid fever occurred on 
farm A (see diagram IV) adjoining farm B. Mrs. B, wife of the 
dairyman, assisted in nursing the case at A for tAvo or three weeks up 
to October 5. For some days before this Mrs. B and one of her sons 
had been ailing, but the boy continued milking and the mother han- 
dling the milk up to October 8, when both became too ill to work. 
(Later another son fell ill.) Previous to this time there had been in 
Elkton only 3 cases of typhoid and they were all in one family, oc- 
curring August 12, September 12 and September 19. On October 11, 
3 cases of typhoid fever were reported; 12, 1 case; 13, 2 cases; 14, 
3 cases; 15, 3 cases; 16, 3 cases; 18, 6 cases. By October 28, 32 fam- 
ilies had been invaded. All used milk, supplied by B, 18 used the 
« Fulton (John S.) Jour. Hyg., Camb., 1901, 1, p. 422. 
