Table 3.

Impact of mass drug administration on lymphatic filariasis infection parameters.

Treatment Zone	Timing of the survey	Number of participants (N)	CFA prevalence(95% CI)	Mf prevalence(95% CI)	Geometric mean Mf/mL	Community Mf load (CMFL)
Annual MDA	BaselineA	997	12.5 (10.5, 14.8)	1.6 (0.8, 2.5)	59.4 (27.3, 129.2)	3.9 (3.3, 4.7)
	Follow-up 1A	639	6.1 (4.4, 8.2)	0 (0.0, 0.6)	N/A	N/A
	Follow-up 2B	898	1.8 (1.0, 2.9)	0 (0.0, 0.4)	N/A	N/A
	Follow-up 3A,B	1066	1.2 (0.7, 2.1) B	0 (0.0, 0.3)	N/A	N/A
	Follow-up 4B,C	ND	ND	ND	ND	ND
Semiannual MDA	BaselineA	1169	13.6 (11.7, 15.7)	1.7 (0.7, 2.1)	65.8 (37.4, 116.0)	4.1(3.6, 4.6)
	Follow-up 1A	1174	10.1 (8.4, 11.9)	0.2 (0.003, 0.06)	N/A	N/A
	Follow-up 2B	1132	3.3 (2.3, 4.5)	0 (0.0, 0.3)	N/A	N/A
	Follow-up 3A,B	1209	4.2 (3.2, 5.5) B	0 (0.0, 0.3)	N/A	N/A
	Follow-up 4B,C	1748	2.6 (2.0, 3.5)	0 (0.0, 0.2)	N/A	N/A

ND, Not done. N/A, Not applicable.

Villages in the Center received annual MDA while villages in the North received semiannual MDA.

^ACirculating filarial antigenemia (CFA) was detected by ICT.

^BCFA was detected by FTS.

^CBoth treatment zones received once/year MDA from the Liberia Ministry of Health from months 36 to 60.