Table 1

Comparison of studies during which a rebound effect was observed upon termination of drug treatment. Studies are in the order they are cited in the text.
Drug used (country)	Ages of study group	Duration of treatment	Duration of post-intervention follow-up	Effect on malaria morbidity	Rebound effect	Reference

P-D¹(Tanzania)	2 mo. at start of study	Weekly for one year	One year after termination of treatment	Reduced incidence of clinical malaria by 40% during treatment period	80% higher incidence of clinical episodes in treated group during the year following termination of treatment	[17]
P-D (The Gambia)	3 mo. at start of study	Every 2 weeks for maximum of 5 years	5 years	65% reduction in malaria episodes after 3 years of chemoprophylaxis	52% more cases in treated group during the year following termination of treatment	[18, 22]
SP²+ artesunate (The Gambia)	Entire villages, all ages	MDA³1 dose	20 weeks	Reduced rate of malaria attacks in children <11 yr by 60%	Rate of clinical malaria was 69% higher in treated groups 3 months after treatment	[25]
SP (Mali)	3 mo. to 20 years	MDA 1 dose	24 weeks	Reduced incidence of first malaria episode from 26% to 3% during first month	Incidence of first malaria episodes in treated group rose to 42% compared to 17% (untreated group) during the third month after treatment	[26]

¹P-D: pyrimethamine-dapsone ²SP: sulfadoxine-pyrimethamine ³MDA: mass drug administration
O'Meara et al. Malaria Journal 2005 4:33 doi:10.1186/1475-2875-4-33