What is the diagnostic technique used to detect the presence of microfilariae in blood?

The diagnostic technique that is most effective for detecting microfilariae in the blood is a blood smear. In this method, a drop of blood is spread thinly on a microscope slide, stained, and examined under a microscope. This allows for the direct visualization of the microfilariae, which are the larval stage of certain parasitic worms, such as those causing filariasis. Blood smears can also reveal the morphology and movement of the microfilariae, aiding in identification.

While techniques such as PCR tests are valuable for detecting specific genetic material and can confirm the presence of these parasites, they are generally more complex and not used as a first-line diagnostic method compared to the straightforward approach of a blood smear. ELISA tests are useful for detecting antibodies or antigens related to various infections but do not directly visualize the microfilariae themselves. A stool test is irrelevant in this context, as microfilariae are not found in feces but rather in the bloodstream. Hence, a blood smear remains the most direct and effective method for this specific detection.