Selective Intermittent Preventive Treatment of Vivax Malaria: Reduction of Malaria Incidence in an Open Cohort Study in Brazilian Amazon
Table 3
Plasmodium vivax incidence throughout the follow-up period.
Community
Cohort period
Persons-year
P. vivax incidence
RR* (CI 95%)
Cases/100 persons-year
São Sebastião
Jan–Jun/2008
139.5
21
15.1
—
—
Jul–Dec/2008
132.5
52
39.2
—
—
Jan–Jun/2009
128.0
32
25.0
—
—
Jul–Dec/2009
126.5
25
19.8
—
—
Jan–Jun/2010
124.5
26
20.9
—
—
Jul–Dec/2010
122.5
40
32.7
—
—
Jan–Jun/2011
125.5
20
15.9
—
—
Jul–Dec/2011
127.5
43
33.7
—
—
Jan–Jun/2012
129.5
25
19.3
—
—
Jul–Dec/2012
130.5
24
18.4
—
—
Vila Amazonas
Jan–Jun/2008
99.0
52
52.5
3.489 (2.121–5.901)
<0.0001
Jul–Dec/2008
114.5
34
29.7
0.757 (0.487–1.164)
0.2064
Jan–Jun/2009A
126.5
49
38.7
1.549 (0.994–2.440)
0.0530
Jul–Dec/2009
110.0
30
27.3
1.380 (0.810–2.367)
0.2367
Jan–Jun/2010
101.5
5
4.9
0.236 (0.081–0.582)
0.0009
Jul–Dec/2010
93.5
4
4.3
0.131 (0.040–0.338)
<0.0001
Jan–Jun/2011
77.0
2
2.6
0.163 (0.026–0.600)
0.0031
Jul–Dec/2011
56.5
1
1.8
0.052 (0.003–0.270)
<0.0001
Jan–Jun/2012
44.0
0
—
0.000 (0.000–0.391)
0.0009
Jul–Dec/2012
42.5
0
—
0.000 (0.000–0.408)
0.0052
Cachoeira do Teotônio
Jan–Jun/2008
196.0
49
25.0
1.661 (1.004–2.820)
0.0479
Jul–Dec/2008
234.0
64
27.4
1.217 (0.844–1.761)
0.2941
Jan–Jun/2009
261.0
48
18.4
0.736 (0.471–1.160)
0.1828
Jul–Dec/2009B
268.0
78
29.1
1.473 (0.948–2.349)
0.0867
Jan–Jun/2010
273.5
77
28.2
1.348 (0.872–2.136)
0.1850
Jul–Dec/2010C
305.5
76
24.9
0.762 (0.521–1.126)
0.1683
Jan–Jun/2011
348.0
39
11.2
0.703 (0.413–1.227)
0.2070
Jul–Dec/2011
359.5
27
7.5
0.223 (0.136–0.359)
<0.0001
Jan–Jun/2012
365.5
16
4.4
0.236 (0.123–0.444)
<0.0001
Jul–Dec/2012
374.0
12
3.2
0.175 (0.084–0.346)
<0.0001
: Incident cases. RR: relative risk. : value. *incidence density ratio, considering São Sebastião data as a control community. treatment and SIPT beginning (June/2009). treatment (July/2009). CSIPT beginning (August/2010).