Recently we have been using Barber’s technique. Emulsify the faeces in equal parts of glycerine and saturated salt solution on a slide. The eggs rise to the surface and are easily discovered with the ⅔-inch objective. As a centrifuge method, Barber emulsifies faeces in this same mixture which brings the eggs to the surface. A wisp of cotton is placed on the surface and 3 or 4 drops of melted agar dropped on the cotton. The disc of agar is removed with the cotton, deposited on a slide and examined for entangled eggs. With operculated eggs this method does not seem to be satisfactory as the salt solution loosens the operculum and floods the contents of the shell,—thus altering the specific gravity of the egg and preventing flotation.
Lane Levitation Method.—Clayton Lane recommends a technique which he designates as the levitation method. In this procedure the concentrated sediment of a centrifuged specimen is transferred to a glass slide, where it is mixed with one cc. of water. The slide is allowed to stand for five minutes and is then immersed in water and manipulated until all coarse matter has floated free. The hookworm ova stick firmly to the slide and are not washed away. Lane reports that on an average this method results in a ten-fold concentration of ova.
In certain cases, where a microscope is not available, the diagnosis may be made by finding the worms in the stool following a thymol treatment.
Whyte has recommended the phenolphthalein test for occult blood as of value in determining the cure of ancylostomiasis. This test is so delicate that the least trace of blood from the mucosal lesion will be detected.
The presence of eosinophilia is of great assistance in diagnosis but it should be remembered that not rarely severe cases of the disease fail to show any excess of eosinophiles.
Charcot-Leyden crystals are often present in hookworm stools.
Prognosis
The disease is more serious in children than in adults, on account of its interfering with physical and mental development. The dark races do not seem to suffer as much as the white ones. Treatment is usually most successful, but in those who are debilitated by other diseases or, in those in whom the disease has assumed a pernicious anaemia tendency, the outlook is not good.
The presence of eosinophilia is of good prognostic significance as the absence of eosinophiles indicates an exhaustion of the haemopoietic system.