The fecal flotation test requires a larger sample than the one needed for the direct smear.

• A. True
• B. False
• C. It depends on the parasite
• D. It varies with sample quality

Answer: (A)

The key idea is that detection sensitivity improves when you concentrate eggs from a larger amount of feces. In a fecal flotation, you mix feces with a dense flotation solution so eggs float to the surface for easy viewing. Because parasite eggs can be sparse and unevenly distributed, using more fecal material increases the likelihood that eggs are present in the suspension you examine. A direct smear, by contrast, uses only a tiny amount of feces with saline and has no concentration step, making it easier to miss eggs if the infection is light. So, to boost detection chances, the flotation method typically requires a larger sample than a direct smear.