39
Among 1,368 cases of infection examined -
621 or 461 per cent. were malignant tertian.
589 or 43.0 „ „ „ benign tertian.
148 or 10.8 „ „ „ quartan.
Powell during the examination of. a large number of malarial bloods in
Bombay in 1901-1903 found-
1,382 benign tertian infections or 52.9 per cent.
1,186 malignant „ „ or 45.4 „
41 quartan infections or 1.5 „
A comparison of these figures indicates that there has been an increase of
quartan malaria in recent years. Among 357 cases in which sexual forms of
the malaria parasite were observed during the recent enquiry-
142 or 39.7 per cent. were benign tertian.
121 or 33.6 „ „ „ crescent malignant tertian.
94 or 26.3 were quartan.
These figures indicate that a still further increase of quartan malaria may
occur in the future.
87. Seasonal Infection.-A series of observations conducted in one of the
most malarious localities throws some new light on the course of the seasonal
incidence of malaria. Blood specimens were collected at intervals from two
large chawls A and B, both containing many hundreds of people.
The observations upon chawl A are as follows :-
Infection indices in chawl A showing seasonal incidence and intensity.
Serial number.
Date of observation.
Blood specimens examined.
Number infected.
Percentage infected.
Average number of parasites per 150 fields.
1
10th June 1909
171
92
53 8
35.0
2
29th September 1909
100*
34
34.0
30.4
3
14th December 1909
165*
48
29.1
8.2
4
13th April 1910
55
11
20.0
2.8
5
19th ,, ,,
50
12
24.0
2.8
6
11th June ,,
61
15
24.5
21.0
7
11th July ,,
70
22
31.4
13 1
8
22nd August ,,
52
20
38.5
42.9
9
4th October ,,
54
28
51.9
13.8
10
6th December ,,
60
16
26.7
8.7
This table refers to blood from both children and adults.
The children taken by themselves gave the following series of indices :-
Serial number.
Month.
Number examined.
Number infected.
Percentage infected.
1
June
107
59
55.1
2
September
69*
20
29.0
3
December
104*
34
32.7
4
April
51
10
19.6
5 

29
5
17.2
6
June
55
14
25.4
7
July
68
21
30.9
8
August
44
19
43.2
9
October
42
22
52.4
10
December
50
12
24.0
Chawl B although situated very near chawl A did not show as high
an infection index and the infections met with were much more scanty than
those in chawl A.
* Many residents receiving quinine.