Research Article

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.

CommunityCohort periodPersons-yearP. vivax incidenceRR* (CI 95%)
Cases/100 persons-year

São SebastiãoJan–Jun/2008139.52115.1
Jul–Dec/2008132.55239.2
Jan–Jun/2009128.03225.0
Jul–Dec/2009126.52519.8
Jan–Jun/2010124.52620.9
Jul–Dec/2010122.54032.7
Jan–Jun/2011125.52015.9
Jul–Dec/2011127.54333.7
Jan–Jun/2012129.52519.3
Jul–Dec/2012130.52418.4

Vila AmazonasJan–Jun/200899.05252.53.489 (2.121–5.901)<0.0001
Jul–Dec/2008114.53429.70.757 (0.487–1.164)0.2064
Jan–Jun/2009A126.54938.71.549 (0.994–2.440)0.0530
Jul–Dec/2009110.03027.31.380 (0.810–2.367)0.2367
Jan–Jun/2010101.554.90.236 (0.081–0.582)0.0009
Jul–Dec/201093.544.30.131 (0.040–0.338)<0.0001
Jan–Jun/201177.022.60.163 (0.026–0.600)0.0031
Jul–Dec/201156.511.80.052 (0.003–0.270)<0.0001
Jan–Jun/201244.000.000 (0.000–0.391)0.0009
Jul–Dec/201242.500.000 (0.000–0.408)0.0052

Cachoeira do TeotônioJan–Jun/2008196.04925.01.661 (1.004–2.820)0.0479
Jul–Dec/2008234.06427.41.217 (0.844–1.761)0.2941
Jan–Jun/2009261.04818.40.736 (0.471–1.160)0.1828
Jul–Dec/2009B268.07829.11.473 (0.948–2.349)0.0867
Jan–Jun/2010273.57728.21.348 (0.872–2.136)0.1850
Jul–Dec/2010C305.57624.90.762 (0.521–1.126)0.1683
Jan–Jun/2011348.03911.20.703 (0.413–1.227)0.2070
Jul–Dec/2011359.5277.50.223 (0.136–0.359)<0.0001
Jan–Jun/2012365.5164.40.236 (0.123–0.444)<0.0001
Jul–Dec/2012374.0123.20.175 (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).