Evening star., 1940-10-15
Of Stors, Men
And Atoms
Notebook Of Science Progress
In Field, Laboratory
And Study \
By Thomas r. Henru.

belt Of poison night where death
strikes with dusk now is being studied
| by DR.. Marshall Hertig, Harvard ento-
| mologist in the service of the Peruvian
government.
The weird story of DR.. Hertig's work
Is contained in reports to the Pan-Amer-
| lean Sanitary Bureau mere. He has
| already gone far toward solving a mys-
terry which has baffled medicine since
1t first was reported by Spanish doctor
In $780,
| The death belt consists of a few
narrow valleys on the western slope of
the Andes from an elevation of 1000
| to approximately 1900 meters over an
arid, very desolate and sparsely inhab-
tied country. This is the verruga zone.
Nearly every one who spends a night
| there is afflicted few days later with
severe anemia which often proves
fatal. The red blood cell count may
drop at the rate of a million a day. 1t
is not known whether the cells actually
are destroyed by the disease, or whether
1t inhibits the forming of new ones
from the bone marrow. The effect in
either case Is the same. The blood
loses its capacity to carry oxygen and
the victim is slowly smothered.
The malady is known as Cartons
disease. In 1885 Carrion, a Peruvian
medical student, inoculated himself with
| it to prove its identity. He succeeded,
but the experiment was fatal. He had
been inspired to the foolhardy act by
an extreme patriotism. The Peru-Cilile
war was just over. Most work on the
disease had been done by Chileans and
| Carrion desired that the credit for medi-
| cal research should come back to Peru.
If one RECEIVERS from this anemia a
second stage starts in which the body
is covered with wart-like. growths, pre-
| sumably due to some alteration in the
blood supply to the skin. These give
the name "verrugaf to the disease It
is the Spanish for "wart" The growths
have no relation to real warts One
attack gives immunity for life, but the
death rate during the first stage is
very high.
During the day the death belt is
perfectly safe This long has been rec
ognized by natives who move through
| it freely between sunrise and sunset.
| The borders Of the area are sharply
| defined within a few yards of altitude.
The only permanent inhabitants of the
| region are persons who have recovered
from the disease.
! For some years it has been recognized
that verruga infection comes from the
bite of a sandfy whose habitat appears
strictly confined to this area. There are
| three such flies-smaller than mosquitoes
| and vicious biters Protection against
| them is afforded only by special screens
| and ordinary mosquito netting is worth
less. DR.. Hertig's work has consisted
of an exhaustive study of the habits
| of these insects.
Up to the present he has found that
the disease is transmitted only by one
species. The other two, specifically
indistinguishable from the deadly little
bitter, are harmless. The insect cannot
endure light. The belt is place
Of bright sunshine nearly every day.
| The flies remain secluded while the sun
| is out and it is difficult to secure speci-
mems, even when hiding places are well
known. AS soon as darkness falls they
appear in great abundance.
The disease organism carried by the
fly is known. DR.. Hertig has been able
| to infect monkeys with insects brought
to his laboratory from the infected
region, and also by inoculations. Curl
ously, however, efforts to infect sand
flies Matched in the laboratory by having
them feed on these monkeys have all
| failed. The indication is, public health
service officers believe, that the contin-
uation of the dreaded malady depends
on some very delicate balance of nature
in this particular region. There must
be some intermediate host of the dis
| ease which transmits it to the flies who
transmit it to man. Presumably it
would not be transmitted from man to
man. Infection bearing insects have
been found hundreds of miles from any
| human habitation. They could not
| possibly have had any contact with q
| human being.
Another fact found by DR.. Hertig is
| for the infection. Two of his work.
ers spent a night in the area Their
| sleeping quarters presumably were
| adequately screened. The sandf1ies bit
them through the screens, however, and
| one of them came down with the disease.
| There were marks of so bites on his
| body. The other was bitten five times
| and showed no bad effects. Thus, DR..
| Hertig concludes, the threshold lies
somewhere between these figures and
| for the present anything over five bites
must be considered dangerous.
The Harvard entomologist himself sell
| dom ventured into the area at night
| but he is about to 60 there with two
assistants, both of whom have recovered
| from the disease. He will be confined
| from sunset to sunrise in an especially
screened railroad car. A few minutes
outside it might easily prove fatal. The
immune assistants will study the habits
| of the insects In the field.
The extent Of the area along the
Andean slopes is unknown. A few cases
have been reported from Ecuador and
Columbia, but the apparent extreme
specificity of the sandfy to its sur
roundings renders remote any likelihood
Of spread of the disease 1t is credited,
however, with 1000 deaths in Peru in
few years.