38
SUPPLEMENT TO THE A NNUA 1, REPORT OP
E
3. Spleen and parasite rates were retaken in five areas to serve as samples of
the interior and outlying portions :—
Name of places.
Spleen rate.
Parasite rate.
Apr. 1927 .
PER CENT.
Sep. 1927.
PER CENT.
Apr. 1927.
PER CENT.
Sep. 1927.
PER CENT.
1. Dondaparti
...
...
22.2
26 0
19 5
24.0
2. Kancharapalem
..
. . .
. . .
23.5
. . .
23.5
3. Gnanapuram
...
. . .
0.0
12.5
6.7
20.8
4. Burujupeta
...
. . .
8.3
8.7
8.3
13.0
5. Gollaveedi
...
. . .
6.0
6.1
2.0
6.9
These show a slight increase in the spleen rate over the April figures in all
cases and a very distinct increase in the infection rate, particularly in the outlying
parts, Dondaparti, and Gnanapuram. Kancharapalem also an outlying area which
was visited for the first time agrees with these in the spleen and parasite rates.
4. Adult mosquitoes were more plentiful than in April and the following is
a record of the catch from houses and cow-sheds :—
A. rossi.
A. subpictus.
A. vagus.
A. culicifacies.
Culex. Stegomyia. Total.
♂
550
♀
1,721
♂
8
♀
64
♂
12
♀
210
464
249
Total anophelines ... 2,575
3,288
Culex and stegomyia mosquitoes were more numerous than anopheline in
the town wards, but in all other places Anophelines formed the majority of the
catch. Most of the A. culicifacies were caught from Dondaparti, Gnanapuram
and Kancharapalem. Thus apart from malaria carriers large numbers of other
species of mosquitoes are found some of which are vicious biters and a source of
great nuisance. Further A. rossi whose breeding places are so vast and numerous
is known to transmit filariasis.
186. A. culicifacies (0) and 50 A. vagus were dissected and examined for the
presence of sporozites and zygotes. Zygotes were present in 3 A. culicifacies.
It would seem, therefore, that A. culicifacies is the local malaria-carrier and
occurs in relatively greater numbers in close association with the inhabitants of
the abovementioned three hamlets, where the infection is greatest.
5. Mosquito breeding in the harbour area was being kept down by oiling.
But some of the borrow-pits opposite to Vizagapatam station (see photo. No. 1)
had been allowed to be overgrown with algæ and sheltered among the algal
threads I found numerous anopheline larvæ) and pupæ. Fortunately these were
all A. subpictus; the water was so saltish (1,200 parts chlorides per 100,000)
that no dangerous variety could breed in it. The condition was subsequently
remedied, all the algæ removed and there is no breeding now. Mosquito pro
- d u c t i o n i n t h e s t a t i o n a r e a w a s a l s o b e i n g c o n t r o l l e d b y t h e r a i l w a y a u t h o r i t i e s .
Several small pools have been filled with cinder or earth, large areas drained
and the drains themselves trained and kept clear of grass. A systematic oiling
programme has been adopted and there was no breeding at the time of my visit.
6. In the municipal area itself, breeding places were innumerable and some
very extensive. The breeding places noted during this survey with the species
of Anophelines occurring in each is represented in some detail in the accompany
- i n g p l a n . M a p I I .
Taking them in the order of our April list
—
(a) Wells. — Anopheline larvæ were present in 36 out of the 124 wells
examined. Of these 24 wells were breeding A. culicifacies, 8 A. stephensi and
2 A. vagus. It is interesting to note that A. culicifacies has displaced A. ste
- p h e n s i , t h e n a t u r a l w e l l - b r e e d e r f r o m m o s t o f t h e w e l l s w h e r e i t w a s f o u n d
breeding before. The reason for this is not obvious. Observations on the
conductivity of the water do not give any clue.
(b) The Votu gedda. —The harbour staff had just started oiling the stream
for the protection of their officers' bungalows which are very near. But as it is