The sun. [volume] (New York [N.Y.]) 1833-1916, 1905-08-11
THE YELLOW FEYER.
A Summary OF the Results Of tho Latest
Investigations Regarding IL.

A Summary or the Results OF tho Latest
Investigations Regarding IL.
To THE EDITOR or the suN-Sir: 30
little being known OF the yellow fever virus
or mlcrobe, and its distributor. the mosquito
known as Steoonvia fdsciotd. 1t VIII be oi
interest TO hear what Dr. Marchoux ana DR..
slSnond. connected with the Pasteur lnstl-
tute Of Paris. have TO say on the subject.
Messrs Marohoux and Simond, after having
spent nearly four years In the fever quarters
Of Rio de Janelro Brazil. have returned TO
Paris. and are now busily engaged investiga-
ting the possibilities Of fighting yellow fever
by means Of q serum taken from yellow FEVER
convalsscent and vaccination.
Stirred BY the yellow fever epidemic WHOM
ravaaed Senegal In 1900. NJ. Decrais. member
Of the Frsnch Chamber Of Deputies. In
troduced Q bill providing for means to carry
on an exhaustive research as to the causes.
prevention and cure Of yellow fever. the
bill passing. the matter was entrusted TO the
care Of the Pastsur Institute. and Messrs.
Marohoux and Simond. two scientlsts OF
the premier order. were commissioned 10
conduct the actual work. In this they we're
to be aided by NJ, sallmbeni. then chief OF
the laboratory Of the Pasteur Institute; how
ever. his services were but Of short duration
for shortly after arriving at Rio do Jansro NJ.
Salimbenl was taken Ill and had to return TO
France.
The yellow fever epidemic raging at Rio
do Janelro In 1901 gave the commission every
opportunity to study the disease thoroughly
and under the most favorable condition.
Tho Brazilian Government aided them all
It could. and NJ. OSWALD Cruz. chief OF the
sanitary service Of Brazil. deserves great
credit for the assistance he rendered.
Tho American commission combating the
yellow fever in Cuba had already arrived
at the conclusion that II was O species OF
MOSQUITO. known as the Steoomwa tdsctdfd.
which by means Of Its sting planted the virus
OF tho disease in the blood Of the healthy
man. OF the virus itself-the yellow fever
nicrobe-llttle was known. 1t was this part
OF the investigation which gave the most
trouble to Messrs. Marchoux and Simond. and
this chiefly because the yellow fever microbe
remains invisible to the human eye. even
| with the aid Of the most perfected microscopes.
| How great an obstacle this is to the bactert-
ologlst needs no reiteration here. However,
patient application to their task. coupled
| with unusual resourcefulness and intelligence.
| finally rewarded the two savants. and there
can be no doubt that the information they
were able to give to the world is quite inval-
liable. The results Of their labor briefly are
these:
I. They established hey ond all doubt that
| the yellow fever virus Is found In the blood
Of the patient.
,. That 1t Is carried there by the sting OF
| the Steoomyid fdsciatd, and that the females
Of the species are more dangerous than the
| males.
3. That the virus. or miorobe. is absolutely
| invisible to the human eye, though aided by
| tho very best of lenses.
| !. That its life Is short and that the In
| dlvidual mlcrobe colony dies on the fourth
day after its generation.
S. That it lives only four days In the
blood Of the patient. and that the patient
| does not die as direct result Of the presence
| Of the microbes In the blood: but that the
weakness caused by their ravages on the
| constitution Of the patient Is the cause Of
death. heart failure very often being the
| immediate agent OF dissolution.
o. That heat Of IS degrees Celsius Is gem
| orally sufficient to destroy the germ.
Z. That exposure OF the serum to the cir
| will render 1t inoffensve.
8. That tho micTobe can only be kept In
| defbrined blood covered with a layer OF
vasellne. and at 70 degrees to ~ degrees
| Celsius. Under these conditions the germ
remains active for five days.
0. That the Steoomyd fdscidtd receives
| the virus from q yellow fever case, and that
| the germ passes into the system Of the insect
| without harming 1t.
10. That tho sting Of the insect Is the only
means Of infection.
fasciasa has received the virus its sting still
| remains harmless for twelve days. and that
| only after this period the germ becomes SO
| active IN tho insect that q sting In most cases
| Is followed by infection.
| H. That the mosquito with the microbe
in its system remains dangerous until its
| death, and that the longer the insect lives the
more vrulent the yellow fever germ becomes.
IS. That worst Of all, the microbe is trans
mItted to the eggs and young OF the Steoornyia.
IA. That the insect only stings at night;
| that II cannot live in air devoid Of excessive
| humidity and at temperatures less than %
| degrees Celsius.
IS. That It attains its best development In
| temperatures ranging from 20 to IS degrees
| Celsius and that it cannot endure heat greater
| than 80 degrees Celsius.
10. That contact with yellow fever
| patient Is not contagious and that it Is i'm
possible to transmit the disease by means Of
| excretions.
This would suggest that to avoid infection
| a person should never be out at night, always
sleep under good mosquito netting. and.
| when possible. in the evening retire to a
locality where the nights are never warmer
than about 22 degrees Celsius.
1t has been positively established that
hilly regions in yellow fever stricken dis
| trict are absolutely safe. As an example,
Petropols, a place close to Rio de Janeiro.
| may be cited. Rio de Janeiro Is visited year
after year by the disease. and Petropolis. al
| though within the closest proximity OF the
fever ridden port has never had one single
case Of IL. The secret OF this is that Petropols
| is situated at an altitude Of 500 meters above
| the level OF the sea and most parts Of Rio de
| Janeiro, and that owing to lack OF humidity
| and cooler air the Steoomvid cannot live there.
Unfortunately Petropolls cannot be found
| in every fever district. However, careful
| closing OF the house. a general use Of vim
| dow screens and mosquito bars and incense
will make the chances of infection slight.
The total abstinence from alcohol Is also
recommended. though 1t is administered to
the patient Alcohol has detrimental effects
| on the mucous membrane OF the stomach.
| and the excessive use Of 1t will practically
prepare the stomach and intestnes for the
awful work OF the yellow fever germ.
| Messrs. Marchoux and Simond now propose
to render persons immune by the injection OF
the serum OF a yellow fever convalescent,
| The immunity accorded, however, Is OF a
| limited nature: twenty-six days Is about
the time that the effects Of this serum are
felt, and the same must be said Of vaccination
although there Is great hope that before
long tho influence Of the latter will be rem
dered more lasting or even permanent.
L