This is in reference to the paper by Kenney and Hewitt on “The Treatment of Bancroftain Filariasis with Hetrazan in British Guiana,” from the January 1949 issue of the Journal.
During the war, Drs. A. McG. Harvey, F. B. Bang, N. G. Hairston and myself tested the effectiveness of anthiomaline in microfilaria-positive Papuans in Lae, New Guinea. We found a consistent and striking reduction in microfilaria counts in all cases. However, we found by taking daytime smears in addition to the usual night-time smears, that there was actually not a disappearance of the microfilariae, but a complete reversal of periodicity, so that the night-time smears tended to become negative, while the daytime smears showed progressively higher microfilaria counts, reaching levels equal to the pre-treatment night-time smears.
It occurs to me that this phenomenon, which I have not seen described in the literature, should be taken into account in experiments assessing the effect of hetrazan.