Twenty-one studies were included: two randomised controlled trials (RCTs); three cluster RCTs; 14 non-randomised controlled trials (CTs); and two interrupted time series designs (ITS).
Five studies of behavioural or educational interventions resulted in an average reduction of 41.6% (range 4% to 87.6%). Monitoring duration ranged from 18 weeks to 15 months, where reported.
Five controlled trials of biological interventions resulted in reduction of mosquito larvae with a mean reduction of 96.3% (range 75.1% to 100%). Use of chemical sprays resulted in an average reduction of 27.2% (range 73.8% to 13.9%; one RCT, two cluster RCTs and three CTs). The range of monitoring durations for biological interventions was two months to three years and for chemical interventions was seven days to five months, where reported.