What type of sample is primarily analyzed for detecting parasitic infections?

Fecal samples are primarily analyzed for detecting parasitic infections because many parasitic organisms, particularly intestinal parasites, are shed in the feces of infected individuals. The examination of fecal samples allows for the identification of various parasitic eggs, larvae, or adult forms, which can indicate the presence of specific intestinal parasites such as helminths (worms) and protozoa (such as Giardia and Entamoeba histolytica).

When testing for parasitic infections, fecal samples offer a direct method to visualize or detect these organisms using techniques like microscopic examination, antigen testing, or molecular methods. This makes them the gold standard for diagnosing many gastrointestinal parasitic infections. Other sample types, such as blood, saliva, or urine, may sometimes be used for certain parasitic infections (e.g., malaria detection in blood tests or detecting Schistosoma in urine), but they are not the primary choice for the vast majority of common parasitic infections that originate in the gastrointestinal tract.