Using infective mosquitoes to challenge monkeys with Plasmodium knowlesi in malaria vaccine studies

Malaria Journal

Table 3 Summary of exposure to P. knowlesi -infected mosquitoes vs. monkey infection

Exposure category	# Mosquitoes (+sporozoites/+blood)	# Mosquitoes (+sporozoites/no blood)	# Monkey exposures	% Monkeys infected
A	≥ 2	0 to 10	9	100
B	1	0 to 8	8	100
C	0	≥ 1	10	40
D	0	0	22	4

From 3-20 mosquitoes infected with P. knowlesi were exposed to a monkey for 15-30 minutes on 49 occasions. Mosquitoes were dissected to grade the sporozoites in the salivary glands, and identify ingested blood in the mosquito midgut. Monkeys were followed for 30 days to see if they developed parasites in the blood. Category A exposures had two or more mosquitoes containing both sporozoites and blood. Category B exposures had only one mosquito with both sporozoites and blood. Category C exposures had some mosquitoes with sporozoites but none of these had ingested blood. Category D exposures had no mosquitoes with any sporozoites in the salivary glands, nor any mosquitoes with ingested blood.

ISSN: 1475-2875