The parasite diagnosed by tracheal wash is:

The parasite diagnosed by tracheal wash is:

• A. Anaplasma species
• B. Dictyocaulus species
• C. Tritrichomonas species
• D. Dioctophyma species

Answer: (B)

Sampling the lower airways with a tracheal wash directly targets parasites that inhabit the respiratory tract. Dictyocaulus species are lungworms that reside in the bronchi and trachea, so their presence can be detected in airway samples as larvae or characteristic inflammatory changes on cytology. This makes a tracheal wash the most appropriate test to diagnose a respiratory parasite like Dictyocaulus. The other organisms listed are not respiratory tract parasites and are typically diagnosed with different samples: Anaplasma is a red blood cell–associated bacterium diagnosed by blood tests; Tritrichomonas is a protozoan of the GI or reproductive tracts diagnosed from fecal or reproductive tract samples; and Dioctophyma is a kidney worm diagnosed via urine analysis or imaging, not airway sampling.

Sampling the lower airways with a tracheal wash directly targets parasites that inhabit the respiratory tract. Dictyocaulus species are lungworms that reside in the bronchi and trachea, so their presence can be detected in airway samples as larvae or characteristic inflammatory changes on cytology. This makes a tracheal wash the most appropriate test to diagnose a respiratory parasite like Dictyocaulus. The other organisms listed are not respiratory tract parasites and are typically diagnosed with different samples: Anaplasma is a red blood cell–associated bacterium diagnosed by blood tests; Tritrichomonas is a protozoan of the GI or reproductive tracts diagnosed from fecal or reproductive tract samples; and Dioctophyma is a kidney worm diagnosed via urine analysis or imaging, not airway sampling.