Host-parasite relations in cotton rat filariasis. I: The quantitative transmission and subsequent development of Litomosoides carinii infections in cotton rats and other laboratory animals.

This paper introduces the long-term and continuing studies of the authors and their colleagues on several aspects of the host-parasite relations in cotton rat filariasis. Five methods are described for the calculation of the number of infective larvae of Litomosoides carinii transmitted to cotton rats and other laboratory animals by groups of Liponyssus bacoti mites. The relation between the calculated transmission intensities and the number of worms recovered from individual infected animals has been determined by each of the five methods. The accuracy and relevance of each method is discussed and one (method B) has been found to give a better correlation with worm recovery than the others. Some effects of infection with filariasis on the mites are described. The role of heavily infected mites in transmission is questioned and their influence on the calculation of transmission is discussed.