Studies with Brugia pahangi. II. The effect of repeated infection on parasite levels in cats

Denham D. A., Ponnudurai T., Nelson G. S., Rogers Rosemary and Guy Frances 1972. Studies with Brugia pahangi—II. The effect of repeated infection on parasite levels in cats. International Journal for Parasitology2: 401–407. 21 cats were given a primary infection of 100–200 infective larvae of Brugia pahangi followed, some time later, by repeated challenge with 50 larvae per time at 10-day intervals. In most cats the microfilarial levels increased considerably but in a minority the levels remained the same as those seen in cats given only one infection. Adult worm recoveries were very much higher than after a single infection but after about 20 challenges there was no further increase in the number of worms establishing an infection. After a long series of challenge infections, the microfilarial counts of some cats suddenly fell and the blood became free of microfilariae.