Implications of population-level immunity for the emergence of artemisinin-resistant malaria: a mathematical model

Table 1 For various P. falciparum prevalence settings in the Greater Mekong Subregion, estimates of the time between artemisinin-based combination therapy (ACT) introduction and the setting being classified by the WHO as having confirmed partial resistance

Country	Year ACT introduced (estimated uncertainty)^a	P. falciparum prevalence in year ACT introduced (95% confidence interval)^b	Year when classified as area of confirmed partial resistance	Observed time to confirmed partial resistance (estimated uncertainty)^a	Average number of ACTs administered per person per year^c
Vietnam	1995 (1994–1996) [32, 33]	4% (3–5%) [29]	2009 [34]	14 years (13–15 years)	0.192
Thailand	1994 (1993–1995) [30, 32, 35]	7% (5–9%) [29]	2008 [34]	14 years (13–15 years)	0.031
Cambodia	2000 1999–2001) [30, 36]	6% (5–7%) [29]	2006 [34]	6 years (5–7 years)	0.996
Myanmar	2002 (2001–2003) [37]^d	9% (8–10%) [29]	2008 [34]	6 years (5–7 years)	0.681
Lao PDR	2002 (2001–2003) [37]^d	20% (17–22%) [29]	2013 [34]	11 years (10–12 years)	1.588

Lao PDR Lao People’s Democratic Republic
^a The precise year that ACT was introduced at scale is unclear, and so a ±1 year margin was used to capture this uncertainty
^b Prevalence was estimated by calculating the average of the results of all studies from the Malaria Atlas Project in the relevant years, with 95% confidence intervals estimated as two standard errors of the mean. Details are provided in Additional file 1: Table S4
^c Calculated from World Malaria Reports (treatment numbers) and UN Population Division data (population sizes). Details in Additional file 1: Table S3
^d The year the World Health Organization recommended the use of ACT in these settings

ISSN: 1475-2875