98
It was found that men working with lethane sprays suffered from acute
irritation of conjuctivæ, of mucous membranes and of the hands. Though
apparently harmless the irritation does definitely occur.
Experiments have shown that ½ oz. of 1 in 75 Liq. Extract of Pyrethrum
or 1 in 33 Lethane freshly prepared in 3rd quality kerosene was required for
each 1,000 c.ft. of space for killing all mosquitoes. It was also shown that
the carbon tetrachloride, petrol and even citronella could be deleted from our
original mixture.
In all stations definite spraying programmes are carried through for
barracks, quarters, offices, followers-quarters and even trains. The demand
is great and entails heavy work by the anti-malarial and unit squads, but so
obvious are the results that units willingly co-operate.
The ordinary hand spray-gun and various types of portable sprayer have
been employed. A new robust hand sprayer devised by the Malaria Institute
of India has been manufactured, but has not yet reached complete success.
Six Phantomyst machines were purchased for various stations and reports
on their use through a season have been received. The reports indicate that
when they are working they are good ; but they are under-engined and mecha
-nically defective and therefore usually not working. For large, closely group
-ed barracks they . are useful ; but they are not really suited to our universal
needs.
Oily plate.—This is a method much in favour in many stations and pheno
- m i n a l c a t c h e s h a v e b e e n r e p o r t e d ,e
. g . ,a
t S i a l k o t t w o m i l l i o n m o s q u i t o e s
were caught by this method in 7 months ; 800,000 in September alone ; at
Multan some 90,000 in one month. The bulk, of course, are culicines but
many hundreds of anophelines are killed by this means.
The oily plate method is also of value in indicating the direction from
which mosquitoes are coming. At Razani camp, outside which no work could
be done, the arrival and spread of anophelines from certain villages into and
through the camp and the subsequent tide of malarial cases was clearly shown
by this oily plate method.
Traps.—The black cloth trap placed in a frame work is found to be most
effective and is much in use.
( b ) Methods of protection.
(i) The mosquito net .—This forms the safest protection provided it is
used whenever possible. Failure to use nets during the infective autumn
period after the declaration of war was reported on a number of occasions
and was undoubtedly the cause of a great many unnecessary admissions for
malaria.
The B. net (Bivi type) has been used successfully on the frontier and a
universal pattern has been evolved which will function either as the single
rectangular pattern or as a bivouac net.
A policy was laid down as to mosquito proofing of buildings namely that
this method of protection would not be considered except in very malarious
places where external measures could not be made effective.
From Wana it is reported that the warping of the woodwork used in
mosquito proofing had been so extensive as to render the proofing useless
until considerable repairs were carried out.
(ii) Anti-mosquito cream .—This, which was introduced by us for the 1937
Waziristan operations, has been taken into universal use throughout India.