Observations on the Rate of Growth and Maturity of Litomosoides carinii, a Filarial Worm of the Cotton Rat

Abstract

Uninfected cotton rats, Sigmodon hispidus texianus, were exposed for a period of 10 days to colonies of tropical rat mites, Liponyssus bacoti, some of which were infected with the filarial worm, Litomosoides carinii. Upon autopsy of the rats at various intervals thereafter, the largest worms of each sex were measured. On the basis of these and other observations, growth curves for this species have been plotted. It is tentatively concluded that the final length attained averages about 20 mm. for [male][male] and 80 mm. for [female][female]. The max. size is reached in some cases as early as 21/2 months after infection. Microfilariae have been found in the blood as early as the 50th day, at which time the [male][male] have attained only 1/2 their ultimate size, while the [female][female] at this time have completed 85% of their growth.