Diagnosis of Ankylostomiasis

THE community percentages of hookworm infection for Egypt of 48 to 97 obtained by the use of Howard's, the least efficient concentrative diagnostic technique, emerge from analysis of Khalil's tables. A percentage of 16.6 for his floatation method indicates then either an unluckily chosen experimental site or an undependable technique. It was held that the evidence suggested that the latter factor was involved. This conclusion would indeed seem to be Khalil's also, since he writes: ``It is probable that some of my negative results were due to the very few ova which escaped the attention of the examiner'' (p. 82). Put otherwise, his first requisite for a trustworthy diagnosis-namely, that the technique must be ``delicate enough to detect infection with one couple of worms of which one is a normally ovipositing female''-is an ideal which he seemingly holds unattained by his own technique.