si^rvrARY 
Convinced from tlieoretical deductioiiH that liookworm disease (uncinariasis) must 
be more or less common in the South, a trij) was made from Washinj^ton, I), to 
Ocala, Fla., stoi)ping at i)enitentiaries, mines, farms, asylums, schools, and factories, 
and the fact was established that the chief anemia of the Southern rural sand dis- 
tricts is due to uncinariasis, while clay districts and cities are not favorable to the 
development of this disease. 
In the Old World, hookworm disease was i)robably known to the Egyptians nearly 
three thousand live hundred years ago, but its cause was not understood until about 
the middle of the nineteenth century, when it was shown to be dm* to an intestinal 
parasite, AgchyJontonm duodenaJe. Until 1898 no authentic cases of this disease were 
recognized as such in the United States, but between 1893 and 1902 about 35 ciises 
were diagnosed. In 1902 it was shown that a distinct ho(jkworm, Unrinnria amcri- 
cana, infests man in this country, and this indicated very strongly that the <lisea.<e 
must be present although not generally recognized. It is now established that in 
addition to the few cases of Old World hookworm disease imjajrted into the Fnited 
States we have in the South an endemi(t uncinariasis due to a distinct cause, (^nrina- 
ria (uncricana. This disease has been known for years in the South and can lu* traced 
in medical writings as far back as 1808, but its nature was not understood. Some 
cases have been confused with malaria, others have been attributed to dirt-eating. 
The hookworms are about half an inch long. They live in the small intestine, 
where they suck blood, produce minute hemorrhages, and in all i)robability also 
j)naluce a substance which acts as a poison. They lay eggs which can not develop 
to maturity in the intestine. These ova escape with the feces and hatch in about 
twenty-four hours; the young worm sheds its skin twice and then is reatly to infect 
man. Infection takes place through the mouth, either by the hands soiled with 
larva* or by infected food. Infection through the drinking water may possibly 
occur. Finally, the larvae may enter the l)ody through the skin and eventually 
reach the small intestine. 
Patients may be divided into light ca.ses, in which the symptoms are very obscure; 
medium cases, in which the anemia is more or less mark(*d, and severe cases, repre- 
sented by the dwarfed, edematous, anemic* dirt -eater. Infection occurs cliielly in 
rural sand districts. Above the frost line the symptoms are more sevt*re in summer 
than in winter, and whites appear to be more severely affected than negroes. Per- 
sons who come in contact with damp earth are more cc^mmonly infc*c*ted than others, 
so that the disease is found chiefly among farmers, miners, and brickmakei's. Severe 
cases are more common in women and children than in men ovc*r 25 yc*ars of age. 
Uncinariasis is a dis(*ase wliich occurs in grouj)s of cases, and if om* case is found in 
a family the chances are that other members of the same family are intc*ct(*d. 
The testimony of patients severely infected is unreliable. Kc*calling that any om* 
or more symptoms may be absent cu* subject to variation, it maybe notc*<l that the* 
period of incubation (at least before the malady can be diagnosc*d by linding the 
eggs) is from four to tc*n weeks. Stages are not necessarily distinctly «U*tinc*d, but arc* 
described as (1) stage of purely local symj)toms, corr(*sponding to tin* light ca.*^t*s; 
(2) stage of simple anemia, corresponding to the medium ca.*<c*s; and (3> dro|»sical 
stage, corresponding more or less to the .«c*vere case's. The* iluration ol the* disc*a.“c* 
after isolation from the source of infc*ction has 1m*c*u traced for six yc*ars and sc*vc*n 
