Comparison of a counting chamber and thick smear methods of counting microfilariae

A glass chamber method of counting living microfilariae in 20–100 c.mm. samples of freshly haemolyzed blood proved to be substantially more sensitive than, and as reliable as, the use of standard wet or stained dry films. The method has the further advantages of simplicity and brevity. The results showed that with the “normal” thick smear technique between 30 and 40% of microfilariae are lost during processing of the slide. It is suggested that the chamber counting method has practical field and laboratory utility.