Table 3

Univariate analysis of gametocytaemia at enrolment


% (N) with gametocytes at enrolment
OR [95% CI]
P-value



All
(N = 10,920)
Thailand
(N = 7,502)
The Gambia
(N = 2,018)
Tanzania
(N = 1400)

Total1
6 (680)
< 0.0011
4 (318)

12 (250)

8 (112)


Age (years)2




     0–5
8 (270)
2 (31)
13 (151)
11 (88)
     5–15
5 (203)
3(90)
13 (99)
5 (14)
     > 15
6 (207)
6 (197)
0 (0)
4 (10)

0.980 [0.971–0.988]
0.986 [0.975–0.997]
0.962 [0.917–1.009]
0.966 [0.950–0.983]

< 0.001
< 0.013
0.114
< 0.001

Symptoms




     Yes
3 (195)
2 (103)
No Data
10 (92)
     No
5 (17)
4 (7)

8 (10)

0.962 [0.576–1.608]
0.510 [0.228–1.142]

1.330 [0.673–2.627]

0.883
0.095

0.410

History of illness




     = 3 days
6 (64)
4 (28)
No Data
11 (36)
     < 3 days
3 (147)
2 (79)

8 (68)

1.659 [1.214–2.267]
1.978 [1.250–3.130]

1.445 [0.943–2.216]

0.001
0.003

0.089

Sex




     Male
5 (223)
2 (59)
19 (114)
10 (50)
     Female
5 (190)
2 (51)
16 (85)
8 (54)

1.129 [0.918–1.389]
0.912 [0.623–1.336]
1.213 [0.888–1.657]
1.271 [0.848–1.905]

0.250
0.637
0.225
0.244

Severe Anaemia




     Yes
33 (36)
17 (7)
43 (27)
40 (2)
     No
5 (304)
2 (83)
13 (200)
34 (21)

4.475 [2.856–7.011]4
10.331 [4.459–23.462]4
4.322 [2.494–7.491]
1.238 [0.189–8.126]

< 0.001
< 0.001
< 0.001
0.834

Anaemia




     Yes
14 (204)
6 (47)
21 (144)
50 (13)
     No
3 (136)
1 (43)
9 (83)
26 (10)

2.921 [2.305–3.703]4
4.346 [2.902–6.510]4
2.477 [1.830–3. 354]
2.900 [0.970–8.671]

< 0.001
< 0.001
< 0.001
0.050

Haematocrit2
0.877 [0.860–0.895]4
0.819 [0.789–0.850]4
0.897 [0.874–0.920]
0.942 [0.882–1.007]

< 0.001
< 0.001
< 0.001
0.080

Palpable liver




     Yes
7 (72)
3 (28)
20 (44)
No Data
     No
4 (227)
2 (75)
17 (152)


1.613 [1.178–2.209]
1.978 [1.269–3.084]
1.355 [0.868–2.116]


0.003
0.002
0.179


Palpable spleen




     Yes
8 (137)
3 (38)
19 (99)
No Data
     No
3 (164)
2 (64)
16 (100)


1.552 [1.296–1.998]4
2.183 [1.464–3.254]4
1.288 [0.928–1.786]


< 0.001
< 0.001
0.129


Axillary Temperature




     > = 37.5C
3 (133)
1 (41)
13 (92)
No Data
     < 37.5C
7 (176)
3 (68)
24 (107)


0.494 [0.404–0.604]
0.660 [0.554–0.786]
0.502 [0.367–0.687]


< 0.001
< 0.001
< 0.001


Mixed infection on admission




     Yes
-
1 (6)
No Data
No Data
     No

5 (312)




0.354 [0.152–0.821]




0.011



Parasitaemia2,3(/μL)




     ≤ 1,600
7 (170)
5 (88)
22(26)
14(56)
     1,600–4,000
6 (101)
5 (54)
14(20)
6 (27)
     4,000–20,000
8 (224)
5 (195)
20(100)
7 (19)
     > 20,000
5 (185)
3 (71)
8(104)
3 (10)

0.688 [0.632–0.749]4
0.517 [0.443–0.604]
0.600 [0.495–0.728]
0.681 [0.543–0.853]

< 0.001
< 0.001
< 0.001
0.001

1 p-value from chi-square test

2 OR and test for the continuous representation;

3 The Gambia, Thailand: OR calculated for log10 parasitaemia; Tanzania, All : OR for ordered categories, p-value is for test for trend.

4 p-value for homogeneity < 0.05

Stepniewska et al. Malaria Journal 2008 7:249   doi:10.1186/1475-2875-7-249