Which quick method is used to detect endoparasites but is not very accurate?

Which quick method is used to detect endoparasites but is not very accurate?

• A. Direct fecal smear
• B. Anal tape test
• C. Fecal sedimentation
• D. Skin scraping

Answer: (A)

Testing for endoparasites often relies on how much you concentrate the sample and how often parasites are shed. A direct fecal smear is a very quick way to look for parasites: you place a tiny amount of fresh feces on a slide with a drop of saline or iodine and scan it under a microscope. It gives fast, on‑the‑spot information, which is handy for a rapid yes/no screen. But that speed comes with a tradeoff in accuracy. Because the sample isn’t concentrated and the parasite material may be unevenly distributed or shed intermittently, many infections are missed with a direct smear. Small numbers of eggs, cysts, or trophozoites can easily slip by, making this method unreliable as the sole diagnostic test. To improve detection, laboratories use concentration techniques that gather more parasite material from a larger fecal sample, such as fecal flotation or sedimentation. Other options are more specific to particular situations: the anal tape test is used mainly to detect pinworm eggs around the perianal area, which is a targeted approach; fecal sedimentation is a concentration method that improves sensitivity; and skin scraping targets ectoparasites on the skin, not endoparasites. So the quick, general screening method that is not very accurate for detecting a broad range of endoparasites is the direct fecal smear.

Testing for endoparasites often relies on how much you concentrate the sample and how often parasites are shed. A direct fecal smear is a very quick way to look for parasites: you place a tiny amount of fresh feces on a slide with a drop of saline or iodine and scan it under a microscope. It gives fast, on‑the‑spot information, which is handy for a rapid yes/no screen.

But that speed comes with a tradeoff in accuracy. Because the sample isn’t concentrated and the parasite material may be unevenly distributed or shed intermittently, many infections are missed with a direct smear. Small numbers of eggs, cysts, or trophozoites can easily slip by, making this method unreliable as the sole diagnostic test. To improve detection, laboratories use concentration techniques that gather more parasite material from a larger fecal sample, such as fecal flotation or sedimentation.

Other options are more specific to particular situations: the anal tape test is used mainly to detect pinworm eggs around the perianal area, which is a targeted approach; fecal sedimentation is a concentration method that improves sensitivity; and skin scraping targets ectoparasites on the skin, not endoparasites. So the quick, general screening method that is not very accurate for detecting a broad range of endoparasites is the direct fecal smear.