Impact of Insecticide Resistance on Vector Control

Impact of Insecticide Resistance in Anopheles Arabiensis on the Effectiveness of Malaria Vector Control in Sudan

The purpose of the study is to determine whether long lasting insecticidal nets and indoor residual insecticide spraying, alone or in combination, are effective for controlling insecticide resistant anopheles mosquitoes for malaria prevention.

The study will assess the impact that insecticide resistance has on the effectiveness of malaria vector control tools LLIN and IRS. This is done by a cluster randomised trials of universal coverage LLINs versus universal coverage LLINs in combination with IRS, with levels of baseline insecticide resistance in the main vector balanced between the two study arms. In each cluster resistance to the insecticide used on LLINs is monitored, and malaria incidence is estimated from cluster specific cohorts of children followed up over the duration of the study. Resistance impact will be assessed from the ratio of incidence rates in clusters with high compared to those with low resistance and from a continuous measure of resistance expressed as percentage loss of mosquito mortality when exposed to insecticide in standardised WHO tests. Resistance mechanisms will be studied in subsets of study clusters.

Inclusion Criteria:

• Children older than 6 months and younger than 10 years in approximately 100 randomly selected households in all 140 study clusters selected in the four study areas

Exclusion Criteria:

• Children living in households within 1 km from the edge of a neighbouring cluster (the buffer zone)