Soil-Transmitted Helminths in the USA: a Review of Five Common Parasites and Future Directions for Avenues of Enhanced Epidemiologic Inquiry

Abstract

Purpose of Review The aim of this review is to present a comprehensive look at five intestinal soil-transmitted helminths (STHs) of global health importance that may continue to plague low-income and rural areas of the USA and argue the need for enhanced surveillance of these infections, which primarily affect the nation's most vulnerable groups. Recent Findings Human STH infections in middle-and high-income countries are at particular risk for being undiagnosed; as common symptoms are non-specific, differentials require a high index of clinical suspicion, and cases are concentrated in areas of poverty where access to care is limited. Although autochthonous STHs are thought to be rare in the USA, infections were once common in the American South and Appalachia and robust epidemiologic surveillance is limited post 1980s. However, recent community studies and case reports from small-scale farms and areas of high rural or inner-city poverty reveal the potential for persisting helminth infections in distinct populations of the country. Summary STHs are among the most common neglected tropical diseases globally causing significant morbidity in underserved communities and contributing to the continuation of cycles of poverty within vulnerable populations. Due to possible severe disease sequalae and their ability to perpetuate poverty and poverty-associated health outcomes within already vulnerable groups, it is vital that surveillance for these infections is enhanced to bolster health equity in the USA.

Symptomatic Anemia Due to Trichuriasis

“…Trichuriasis is the second most common geohelminth infection in humans (affecting an estimated 600–800 million people globally) endemic to parts of Asia, Africa, and Latin America . 1 , 2 In the United States, where infections are rare, most cases are diagnosed in immigrants or travelers returning from tropical areas with poor sanitation except for sporadic infections reported in the rural Southeast. 1 , 3 Trichuriasis is contracted through the fecal-oral route after ingesting embryonated eggs.…”

“… 1 , 2 In the United States, where infections are rare, most cases are diagnosed in immigrants or travelers returning from tropical areas with poor sanitation except for sporadic infections reported in the rural Southeast. 1 , 3 Trichuriasis is contracted through the fecal-oral route after ingesting embryonated eggs. 1 , 2 Eggs hatch in the small bowel and larvae migrate to the cecum where they burrow into the crypt epithelium until maturation.…”

“… 1 , 3 Trichuriasis is contracted through the fecal-oral route after ingesting embryonated eggs. 1 , 2 Eggs hatch in the small bowel and larvae migrate to the cecum where they burrow into the crypt epithelium until maturation. 2 , 5 The worm's whip-like anterior end attaches to the mucosa where it may live for up to 4 years.…”

Current Finding of Helminth Morphology Cause Infectious Disease

“…It is very difficult to distinguish them from the eggs of Taenia saginata worms, so without information on the origin of the inspection specimens, eggs are often only reported as Taenia sp. [12] Hymenolepis nana Adult worm populations have bodies that are elongated segments resembling ribbons like other tapeworms, but in relatively small sizes. Overall body length can reach a size of 25-40 mm, body width 1 mm.…”

Prevalence and Risk Factors of Soil-transmitted Helminth Infections in Cattle Breeders in Mlaten Village, East Java

“…In addition, the health of the breeders is also important. An earlier study [9], showed that the prevalence of helminth infection was 19.2%, and the majority of the cattle farmers also experienced helminth infections when their cows are positive for parasitic worm eggs [10].…”