Necator americanus (hookworm)

Test code: X0055 - Ultrasensitive qualitative detection of Necator americanus by real time PCR

Necator americanus causes hookworm disease (ancylostomiasis or necatoriasis) in humans. Dogs, pigs and non-human primates are not primary hosts but can act as transport hosts. Necator americanus is called hookworm because of its distinctive head, which features a pronounced hook-like bend and specialized mouthparts equipped with cutting plates or teeth. These structures allow the parasite to adhere to the intestinal wall of its host, burrow into the mucosa, and feed on blood and tissue.

Adult worms are small and thread-like, with females about 9-11 mm long and males 7-9 mm long. Eggs are laid in the host's feces, hatch into larvae in soil, and penetrate another host’s skin (often via barefoot feet) or via ingestion. Larvae migrate through the bloodstream to the lungs, then to the intestines, where they mature.

Eggs can survive in warm and moist environments for extended periods. Infected persons can develop iron-deficiency anemia due to blood loss from the worm feeding on intestinal blood, leading to fatigue, weakness, malnutrition, and in severe cases (especially children), stunted growth or cognitive issues. This parasite can be differentiated from another common hookworm, Ancylostoma duodenale, which causes similar disease. A large number of people in underdeveloped countries and regions where sanitation is poor are infected with this parasite. Prevention relies on sanitation and wearing shoes in endemic areas. Deworming programs to remove the eggs from contaminated soil and water are helpful.

Traditional detection by microscopic examination of feces has low sensitivity. This method is also not suitable for environmental surveillance because the concentration of eggs in a sample is usually very low and non-homogeneous. Polymerase chain reaction can outperform traditional methods such as flotation or centrifugation followed by microscopy, because PCR provides species-specific detection with minimal sample volume, even in complex matrices where viable eggs might be scarce or degraded (Manuel et al., 2024; Nguemnang Kamdem et al., 2023).

Utilities:

• Help confirm the disease causing agent
• Shorten the time required to confirm a clinical diagnosis of Necator americanus infection
• Help ensure that herds are free of Necator americanus
• Early prevention of spread of Necator americanus between animal species
• Minimize human exposure to Necator americanus

References:

Manuel M, Amato HK, Pilotte N, Chieng B, Araka SB, Siko JEE, Harris M, Nadimpalli ML, Janagaraj V, Houngbegnon P, Rajendiran R, Thamburaj J, Kaliappan SP, Sirois AR, Walch G, Oswald WE, Asbjornsdottir KH, Galagan SR, Walson JL, Williams SA, Luty AJF, Njenga SM, Ibikounlé M, Ajjampur SSR, Pickering AJ. Soil surveillance for monitoring soil-transmitted helminths: Method development and field testing in three countries. PLoS Negl Trop Dis. 2024 Sep 6;18(9):e0012416.

Specimen requirement: 2 ml of feces; or rectal swab; or 10 ml of soil; or 10 ml of water, or used water filter media; or environmental swabs or swipes; or 0.2 ml EDTA whole blood.

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 PCR

Normal range: Nondetected