Evening star. [volume] (Washington, D.C.) 1854-1972, 1908-07-13
STUDY RAT LEPROSY
Officers of Marine Hospital
Service Investigate.
DOCTOR SUBMITS REPORT
Rodents May Transmit Disease to
Human Beings.
WHAT STUDY SHOWS TO DATE
incubation Of Animals From Typ
ical Cases-Wait of Several
Months for Developments.
DOCTOR SUBMITS REPORT
WHAT STUDY SHOWS TO DATE

! DR.. George Mccoy, passed assistant
surgeon Of the marine hospital service,
has reported to Surgeon General Wyman
OF the marine hospital service the dis
covery of a leprosy-like disease among
the rats Of San Francisco, and the serious
question arises whether the disease may
be transmitted to human beings. Since
the discovery of the plague In San Fran
cisco surgeons of the marine hospital
service have been hard at work trying to
exterminate rats, it being positively
known to science that rats do more to
scatter plague than any other known
agency.
When plague broke out afresh at San
Francisco more than a year ago and ex-
tended to Oakland and other cities not
only did the marine hospital service use
every effort against rats but the city and
state authorities gave bounties for their
bodies. Now comes the new disease
among the rodents.
Reports of DR.. Mccoy.
The reports of DR.. Mccoy are regarded
as of great interest Portions of them are
as follows:
Shortly after being assigned to the ex-
animation of rats at San Francisco I was
informed by the city bacteriologist that
he had observed the leprosy-like disease In
one or two instances. He also showed me
gross and microscopic specimens of the
| LESSONS.
Il therefore began to look for the con-
dition and to keep notes on its occurrence.
| During the period covered by this re-
port 1850 rats were examined and
twenty-five cases of the disease observed.
tC 1.ait I4rr hat
dition is more frequent than these figures
indicate, as all of the cases observed have
BEEN made in full-grown, large rats and
the LESSONS very we'll marked. l think 1t
quite probable that l have failed to de-
tect cases in young rats and early cases
In general. though number of LESSONS
that suggested an early state of rat lep-
rosy were submitted to microscopic ex-
animation, but always with negative re-
suits. All of the cases have'b been in rats
Of the species Mus decumanus. Where
note was made of the sex the records
show that three males and eleven females
were observed.
The cases have come from widely
Iseparated points in the city, but 1t is
noteworthy that four Of them came from
Butchertown. three of these being from
one establishment. Two others came
from places only a few doors apart on
Market street.
As to Essential Lesion.
THE essential lesion. or at any rate
the one invariably found, has been a
more or less general inf1ltration Of the
simultaneous tissues and the peripheral
lymph glands. with an enormous num-
Der Of fine white or slightly yellowish
! granules. At times this. infiltration
forms general layer. covering the
whole surface of the body between the
skin and muscular tissues. At other
times it is more or less patchy in dis
tributiOn. This layer of tissue is usually
mistaken for fat. The peripheral lymph
glands are invariably enlarged, pale,
Succulent looking, and upon section are
seen to contain a large number Of the
| whitish points corresponding In appear
ance to the granules found in the sub
cutaneous tissues In two of the rats
examined the enlargement Of individual
| lymph glands was remarkable.
| "Alopecia, more or less extensive, was
i present in $50 per cent of the cases;
| liberation in 63.6 per cent. The dis
| charge from the ulcers was usually Of
a mealy, dryish character. and consisted
| of enormous numbers of the bacilli and
a few remnants of cell debris. In Ave
cases rather large nOdules were noted
| in the subcutaneous tissue, apparently
| caused by fus1ng of large number
| Of the granules above mentioned.
| IN one rat only were LESSONS found
| in the internal organs.
In Advanced Stage.
This rat was evidently In a very an
vanced stage of the disease In addition
to the usual findings granules were found
in the retro-peritQneal tissues, on the
surface of the peritoneum, on the parie-
tai pericardium. and a few In the liver;
| in the spleen about a half dozen LESSONS
| were found varying in size from a pin
head UP to about 2 nm. In diameter.
These LESSONS were made up almost en-
| 49,
| found in this disease. Many bacfili were
| found In the contents of the bladder;
| none were found In the intestinal con-
| tents. In number of cases 1t has been
attempted to demonstrate the organism
| in the nasal mucus; thus far. without
| success. Beyond these LESSONS peculiar to
| the disease, the organs of the animals
| have appeared to be normal with the
exception of the kidneys, which were al
most always yellowish or of slate color,
| enlarged, ffiable and often showed small
| cysts upon the surface and upon sec
ton. This condition of the kidneys is
not however peculiar to the disease, as
it was found In nAmber of rats other
| wise healthy. 1t is believed that this
frequency of nephritis in rats in general
| here may be due in some measure to the
| vigorous crusade of poisoning by arsenic
and other toxic agents which has been
| carried on
Dr. Mccoy says the skin of the animal
| shows micro organisms In large numbers,
as in the case Of human beings with
| leprosy. The kidneys showed nephritis.
Relation to Human Leprosy.
| DIR. Mccoy concludes his report as fol-
| lows:
LAS to the relation of the disease to
| leprosy in man, DIR. w. r. Brinckerhoff
director of the leprosy investigation sta
| ton at Molokai, T. H., stated in an
| article which appeared In the Transactions
of the Fifteenth Annual Meeting of the
Hawaiian Territorial Medical Society as
follows: The question Immediately
arises as to whether this disease of the
rat may not be human leprosy occurring
in that animal OF course. with the data
now available it Is impossible to give a
| categorical answer to this question, but
| the geographical distribution Of the dis
| ease speaks against an Affirmative reply.
| 1t seems more probable that rat leprosy
| is to human leprOsy as Ia bovine or avian
Tuberculosis to the human disease. rather
than that 1t Is like plague or CHAMBERS,
| a disease common to and transmits sible
between two Species
| "A number of rats have been inoculated
! from typical cases Of this interesting dis
| ease with the view Of making q further
| study of it, but as a number of months
| are necessary for the development of the
disease in inoculated animals. considera-
| BILE time will elapse before 1t Will be
possible to ascertain whether the inocu-
| lations have been successful"
|