environmental assay data sheet

Trichuris trichiura (whipworm) PCR test

Test code: X0053 - Ultrasensitive qualitative detection of Trichuris trichiura by real time PCR

Trichuris trichiura, commonly known as whipworm, is a species of parasitic roundworm that infects the intestine of humans and some non-human primates. It belongs to the phylum Nematoda and is one of the most common helminths that infect people. It is estimated that 600-800 million people, mostly in tropical and subtropical regions with poor sanitation, are infected with this parasite.

Adult worms are whip-like in shape, with a thin anterior end that embeds into the intestinal mucosa, and a thicker posterior end looking like a whip handle extending out into the intestinal lumen.  Females are typically 30-50 mm long, while males are 30-45 mm. Eggs of this worm are passed in feces and mature in warm, moist soil over 2-3 weeks. Infections occur by ingesting embryonated eggs through contaminated food, water, or soil. The eggs hatch into larvae in the small intestine and then migrate to the large intestine, where they mature into adults in about 1-3 months. The adult worms can live for 1-2 years within the large intestine. The female worms can produce up to 20,000 eggs per day.

Infection of humans causes trichuriasis. Light infections may not develop symptoms, but heavy infections can cause abdominal pain, diarrhea (sometimes bloody), nausea, and weight loss. Infected children may have growth retardation, anemia, cognitive delays, and rectal prolapse in severe cases. Chronic infections may lead to malnutrition and impaired nutrient absorption.

Diagnosis of the parasitic infection is often through stool examination for characteristic barrel-shaped eggs. The eggs are about 50-55 μm long with bipolar plugs under a microscope. However, polymerase chain reaction is increasingly being used to diagnose the disease or to perform environmental surveillance due to its high sensitivity and specificity (Matamoros et al., 2024; O'Connell et al., 2016).

Utilities:

• Check for Trichuris trichiura in water sources, soil, and other environmental samples
• Selection of appropriate remediation regimens
• Check for post-remediation absence of this agent
• Help confirm the presence of this agent in animals
• Help minimize human exposure to this agent

References:

Matamoros G, Sanchez A, Cimino R, Krolewiecki A, Mejia R. A comparison of the diagnostic capability of Kato-Katz and real-time PCR for the assessment of treatment efficacy of ivermectin and albendazole combination against T. trichiura infections. PLoS Negl Trop Dis. 2024 Nov 19;18(11):e0012677.

Specimen requirements: 2 ml of feces, or 10 ml of water, or used water filter media; or 10 ml of soil; or environmental swabs or swipes.

Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative real time polymerase chain reaction

Normal range: Nondetected