Microscopic Examination

In the past, surveys for lymphatic filariasis depended on the examination of blood films, which, in most areas, had to be collected around midnight. The thick blood smear technique normally employed to detect microfilaria is intensive especially when the parasite is nocturnally periodic and a nocturnal specimen is required to increase the chance of detecting the infection. The need for a nocturnal blood sample has been obviated by the administration of 50 and 100 mg of DEC before blood examination. Furthermore, conventional microscopy is not suitable for large-scale microfilariae screening of populations in endemic areas because it is very time-consuming and labor-intensive.

Various concentration methods have been developed to increase the sensitivity for the direct demonstration of

Fig. 1 Distribution of lymphatic filariasis. (From Ref. [1].)

(View this art in color at www.dekker.com.)

Fig. 1 Distribution of lymphatic filariasis. (From Ref. [1].)

(View this art in color at www.dekker.com.)

microfilaria, and these include the Knott's concentration and membrane filtration techniques in which 1 mL or more heparinized blood can be processed and the microfilaria can be concentrated for easy detection.

The Knott's concentration technique, although simple and economical to perform, is rather tedious. The membrane filtration technique, which effectively concentrates microfilariae onto a membrane that can be stained with Giemsa and examined under a light microscope, is a rapid, sensitive, and easy technique to carry out. However, the membrane filter technique requires the large volume of blood collected when the carrier cases are investigated. These two techniques should nevertheless be used to detect low microfilaremic states and to monitor the effectiveness of chemotherapy where microfilaria counts may become very low.

A recent technique developed for the detection and identification of microfilaria in blood samples is the

http://w ww, dpd.cdc.gov/dpdx Fig. 2 Life cycle of W. bancrofti. (From Ref. [2].) (View this art in color at www.dekker.com.)"/>
http://w ww, dpd.cdc.gov/dpdx Fig. 2 Life cycle of W. bancrofti. (From Ref. [2].) (View this art in color at www.dekker.com.)

Table 1 Comparison of the methods used for detection of W. bancrofti

Methods

Advantage

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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