What is the diagnostic approach for detecting Ancylostoma duodenale/Necator americanus eggs in stool?

• A. Serology for antibodies.
• B. Stool culture to grow parasites.
• C. Microscopic identification of eggs in stool and/or observation of rhabditiform larvae in fresh stool.
• D. Urine antigen testing.

Answer: (C)

Detecting eggs in stool by microscopy is the standard, practical way to diagnose hookworm infection. Ancylostoma duodenale and Necator americanus lay eggs that are excreted with feces, so examining stool under a microscope allows direct visualization of the characteristic eggs. In fresh stool, rhabditiform larvae may also be seen, which supports the diagnosis since larvae pass through the stool early in the infection. Serology would only show exposure and can cross-react with other parasites, so it isn’t reliable for diagnosing current infection. Culturing stool to grow parasites isn’t routine for diagnosis and takes more time, and urine antigen tests aren’t used for detecting hookworms. So, microscopic identification of eggs in stool and, when possible, observation of rhabditiform larvae in fresh stool is the correct approach.