Effectiveness of piperonyl butoxide and pyrethroid-treated long-lasting insecticidal nets (LLINs) versus pyrethroid-only LLINs with and without indoor residual spray against malaria infection: third year results of a cluster, randomised controlled, two-by-two factorial design trial in Tanzania

Table 3 Entomological outcomes comparing the two main interventions (PBO-Pyrethroid LLIN vs standard LLIN groups and IRS vs No IRS groups) in the 3rd year follow up in 2017

	Vector density per night per household					Sporozoite rate					EIR per nights per household
	N	Mean	DR	95%CI	P-value	n/N	%	OR	95%CI	P-value	N	Mean^e	DR^f	95%CI	P-value
Standard LLIN^a	1575	5.24	1			108/2070	5.2	1			1540	0.15	1
PBO-Pyrethroid LLIN^b	1575	5.48	1.59	0.80–3.16	0.1832	67/1788	3.8	0.88	0.55–1.42	0.5992	1536	0.11	0.63	0.25–1.61	0.3296
No IRS^c	1567	5.00	1			103/1962	5.3	1			1524	0.14	1
IRS^d	1583	5.71	1.06	0.48–2.37	0.8807	72/1896	3.8	0.87	0.52–1.47	0.609	1552	0.12	0.97	0.41–2.28	0.9426
Interaction coefficient			0.47	0.16–1.40	0.1699			0.63	0.31–1.28	0.195			0.88	0.24–3.21	0.8489

Density ratio (DR) for vector density and EIR and odds ratio (OR) for sporozoite rate are adjusted for their respective baseline value
^aStandard LLIN and standard LLIN & IRS groups
^bPBO-Pyrethroid LLIN and PBO-Pyrethroid LLIN & IRS groups
^cStandard LLIN and PBO-Pyrethroid LLIN groups
^dStandard LLIN & IRS and PBO-Pyrethroid LLIN & IRS groups
^e,fArithmetic mean and DR of the EIR are weighted to account the proportion of mosquitoes sampled to be tested for sporozoites

ISSN: 1475-2875