Ancylostomiasis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Kalpana Giri, MBBS[2]

Ancylostomiasis is a hookworm infection, soil-transmitted helminths (STH) occurs predominantly in countries with low socioeconomic status located in tropical and subtropical areas of the world. Common symptoms of ancylostomiasis include: anorexia, flatulence, diarrhea, weight loss, pallor, dyspnea, weakness, generalized edema, melena, hematemesis, dizziness, syncope, cough, sneezing, hemoptysis, nausea, vomiting, pharyngeal irritation, itchy, erythematous, serpiginous skin lesions. The mainstay of treatment for ancylostomiasis is anti-helminthic therapies are recommended among patients with ancylostomiasis.

Ancylostomiasis was first discovered by Dubini, an Italian physician, in 1838.

Ancylostomiasis may be classified according to the species into two groups: Human hookworm: Ancylostoma and Necator Americanus and Zoonotic hookworm: Ancylostoma braziliense, Ancylostoma caninum, Ancylostoma ceylanicum and Uncinaria stenocephala.

Ancylostomiasis is a hookworm infection, soil-transmitted helminths (STH) occurs predominantly in countries with low socioeconomic status located in tropical and subtropical areas of the world. The life cycle of hookworm include: human hookworm and zoonotic hookworm. Mature females released eggs in the host’s small intestine and these eggs are passed in the feces. Under appropriate conditions, each eggs hatch in soil, and develops into an infective filariform (L3) stage larva. It enter the body either through a skin or oral ingestion then enters the bloodstream, and reach the lungs and migrate across the alveoli. Then they ascend from the bronchial tree to the pharynx and reach the small intestine where they mount into fourth-stage larvae and mature into blood-feeding adults male or female.

Common causes of ancylostomiasis include: Ancylostoma duodenale, Necator americanus, Ancylostoma ceylanicum, and less common organisms include: Ancylostoma braziliense, Ancylostoma caninum, Ancylostoma ceylanicum, and Uncinaria stenocephala.

Ancylostomiasis must be differentiated from contact dermatitis, scabies infection, migratory myiasis, and cercarial dermatitis for cutaneous manifestations, and portal hypertension, meckel’s diverticulum, inflammatory bowel disease and nonsteroidal anti-inflammatory drug-induced small bowel disease, angiectasias, adenocarcinoma, leiomyoma, and lymphoma for GI bleeding.

The incidence rate of hookworm infection was 7.5/100 person-years. Prevalence of ancylostomiasis is approximately 1 billion people worldwide. People of all ages are susceptible to ancylostomiasis, commonly affects children and women of childbearing age. Mortality rate of hookworms in the tropics is approximately 50-60,000 deaths per year. Men are more commonly affected by ancylostomiasis than women.

Common risk factors of ancylostomiasis include: exposure to soil where filariform larvae, the infective stage, live in and penetrate human skin, poor sanitation, low socioeconomic status, low educational attainment.

The majority of the infected patients remain asymptomatic. The symptoms of ancylostomiasis typically develop by direct contact of the skin with contaminated soil and the fecal-oral route. The most common complications include: iron deficiency anemia, in child: intellectual and cognitive development, in pregnant women: severe anemia, impaired growth, severe anemia, premature birth, neonatal anemia. Prognosis is generally excellent with proper treatment.

The diagnostic test of ancylostomiasis is the microscopic detection of hookworms eggs in stool.

The majority of patients with ancylostomiasis are asymptomatic. Common symptoms of ancylostomiasis include: anorexia, flatulence, diarrhea, weight loss, pallor, dyspnea, weakness, generalized edema, melena, hematemesis, dizziness, syncope, cough, sneezing, hemoptysis, nausea, vomiting, pharyngeal irritation, itchy, erythematous, serpiginous skin lesions.

Physical examination include: pallor, fatigue, dizziness, serpiginous, erythematous, and palpable plaque associated with edema, abdominal distension.

Lab findings include: decreased hemoglobin, eosinophilia, presence of several live and motile worms in upper gastrointestinal endoscopy.

There are no x-ray findings associated with ancylostomiasis.

There are no CT findings associated with ancylostomiasis.

Other diagnostic studies for ancylostomiasis include upper gastrointestinal endoscopy, which demonstrates live and motile worms in GI tract.

Anti-helminthic therapies are recommended among patients with ancylostomiasis. Efficacy of treatment varies according to the severity of infection, geographical distribution, and age groups. Multiple blood transfusion, iron supplements are also be given in severe cases.

Surgical intervention is not recommended for the management of ancylostomiasis.

Effective measures for the primary prevention of ancylostomiasis include periodic mass anthelminthic treatment of at-risk populations, avoid gardening barefooted, patient education on proper hygiene and sanitation.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Kalpana Giri, MBBS[2]

Ancylostomiasis was first discovered by Dubini, an Italian physician, in 1838 who provided the first detailed description of hookworms during an autopsy on a woman who had died in Milan. Necator americanus and Ancylostoma duodenale were responsible for all human hookworm infections mentioned by Bethony et al ( 2006), de Silva et al.(2003), however Bradbury & Traub (2016) and Traub et al. (2008) mentioned Ancylostoma ceylanicum is also an important hookworm of humans, especially in Southeast Asia.

• Ancylostomiasis was first discovered by Dubini, an Italian physician, in 1838 who provided the first detailed description of hookworms during an autopsy on a woman who had died in Milan.^[1]

• Necator americanus and Ancylostoma duodenale were responsible for all human hookworm infections mentioned by Bethony et al ( 2006), de Silva et al.(2003), however Bradbury & Traub (2016) and Traub et al. (2008) mentioned Ancylostoma ceylanicum is also an important hookworm of humans, especially in Southeast Asia.^[2]

The following are a few famous cases of ancylostomiasis:

• In 1880, the anemia first appeared in Italy when the Saint Gothard railway tunnel was being bored. The epidemic of ancylostomiasis to which so many of the workmen fell victim and several workers died. This led to major advances in parasitology by research into the etiology, epidemiology, and treatment of ancylostomiasis. ^[3]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Kalpana Giri, MBBS[2]

Ancylostomiasis may be classified according to the species into two groups: Human hookworm: Ancylostoma and Necator americanus and Zoonotic hookworm: Ancylostoma braziliense, Ancylostoma caninum, Ancylostoma ceylanicum and Uncinaria stenocephala.

Ancylostomiasis may be classified according to the species into two groups:^{[1] [2]}

• Human hookworm: Ancylostoma and Necator Americanus
• Zoonotic hookworm (i.e., cat and dog hookworms): Ancylostoma braziliense, Ancylostoma caninum, Ancylostoma ceylanicum and Uncinaria stenocephala.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Kalpana Giri, MBBS[2]

Ancylostomiasis is a hookworm infection, soil-transmitted helminths (STH) occurs predominantly in countries with low socioeconomic status located in tropical and subtropical areas of the world. The life cycle of hookworm include: human hookworm and zoonotic hookworm. Mature females released eggs in the host’s small intestine and these eggs are passed in the feces. Under appropriate conditions, each eggs hatch in soil, and develops into an infective filariform (L3) stage larva. It enter the body either through a skin or oral ingestion then enters the bloodstream, and reach the lungs and migrate across the alveoli. Then they ascend from the bronchial tree to the pharynx and reach the small intestine where they mount into fourth-stage larvae and mature into blood-feeding adults male or female.

Ancylostomiasis is a hookworm infection, soil-transmitted helminths (STH) also known as miner’s anaemia, tunnel disease, brickmaker’s anaemia occurs predominantly in countries with low socioeconomic status located in tropical and subtropical areas of the world.^[1][2] The external surface of Helminth comprises key molecules excretory/secretory (ES) products. Hookworm ES products contain a large range of structurally and functionally distinct molecules, mostly proteins, and also lipids, and carbohydrates. They are secreted from the oral orifice or outer surfaces of the parasite representing the boundary between the helminth parasites and their hosts. These molecules react with host proteins and are essential for the penetration of the host, tissue migration, nourishment, reproduction, and evasion of host immunity. These molecules also have major functions in the development and survival of parasites. By inhibiting the inflammatory reaction, encouraging effector cells apoptosis, and skewing the immune reaction phenotype, these molecules help the parasite to survive and evade the host immunological response. The biological role and molecular nature of hookworm ES products are still unclear though the intensive study has been done for many years.^[3]

All species of hookworm have no intermediate host, they have a direct life cycle. Mature females released eggs in the host’s small intestine and these eggs are passed in the feces, where they hatch first stage rhabditiform larva (L1) within several days. The L1 feeds on soil microbes and molts to the L2 stage, and under appropriate conditions, each eggs hatch in warm, moist, sandy soil, or in feces and develops into an infective filariform (L3) stage larva. The infective-stage larvae (L3) enter the body either through a cutaneous route or by direct oral ingestion.

Some species of human hookworm such as Ancylostoma and Necator Americanus may cause a local pruritic dermatitis, also called ground itch at the site of penetration whereas the ancylostoma species can also enter the body orally.^[4] The infective larvae (L3) migrate through the dermis, enters the bloodstream, and reach the lungs within 10 days. Once they reach the lungs, they migrate across the alveoli and breaks into alveoli leads to mild and usually asymptomatic alveolitis with eosinophilia. Then they ascend from the bronchial tree to the pharynx, during which the host may develop a cough, sore throat, fever. They coughed up, swallowed, and reach the small intestine where they mount into fourth-stage larvae and mature into blood-feeding adults male or female.^[5] The adult worms attached to the mucosal layer of the small intestine, using their buccal capsule leads to arterioles and venules ruptures along with the luminal surface of the intestine. These adult worms release hyaluronidase and other hydrolytic enzymes result in blood extravasation by degrading the intestinal mucosa and erosion of blood vessels.^[6] Hookworms also secrete Ancylostoma ceylanicum anticoagulant peptide-1, which inhibits the blood coagulation in the attachment site and leads to blood loss from the intestine.^[7] The adult worms colonize the intestinal tract and in 3-5 weeks the adults becomes sexually mature and female worms begin to lay eggs in the intestine that pass in the stool.^[5]

Some species of zoonotic hookworm (i.e., cat and dog hookworms) include: Ancylostoma braziliense, Ancylostoma caninum, Ancylostoma ceylanicum and Uncinaria stenocephala. Among these most commonly encountered hookwormis Ancylostoma braziliense.^[8] It causes cutaneous larva migrans (creeping eruption) generated by the larva migrating through the epidermis. This lesion is self-limiting, characterized by the erythematous serpiginous lesions.^[9] Ancylostoma ceylanicum is the only species that develops to adult in humans, and causes enteric hookworm infection. Ancylostoma caninum occasionally reaches adulthood in humans, and causes eosinophilic enteritis.^[10][11]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Kalpana Giri, MBBS[2]

Common causes of Ancylostomiasis include: Ancylostoma duodenale, Necator americanus, Ancylostoma ceylanicum, and Less common organisms include: Ancylostoma braziliense, Ancylostoma caninum, Ancylostoma ceylanicum, and Uncinaria stenocephala

They commonly infect the skin, eyes, and viscera in humans.

• Ancylostoma brasiliensis causes cutaneous larva migrans.

• Toxocara causes visceral larva migrans.^[1]

• Common causes of ancylostomiasis include the following organism:^[2]
  • Necator americanus: reach maturity in the human intestine.
  • Ancylostoma duodenale: reach maturity in the human intestine.
  • Ancylostoma ceylanicum also occurs in humans as an intestine-inhabiting adult but it is usually a parasite of cats, dogs and other carnivores.
• Less common organism include:^[2][3]
  • Ancylostoma braziliense: responsible for creeping eruption or cutaneous larva migrans, which survive in extra-intestinal sites and rarely mature in human.
  • Ancylostoma caninum: occasionally reaches adulthood in humans, and causes eosinophilic enteritis
  • Ancylostoma ceylanicum: only species that develops to adult in humans, and causes enteric hookworm infection
  • Uncinaria stenocephala

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Kalpana Giri, MBBS[2]

Ancylostomiasis manifests in a variety of clinical forms, differentiation must be established in accordance with the particular sign and symptoms. Such as abdominal symptoms differentiated from ascariasis and trichuriasis, and parasites associated with pneumonitis and peripheral eosinophilia are Aascaris and Strongyloides species. Cutaneous manifestations are differentiated from contact dermatitis, scabies infection, migratory myiasis, and cercarial dermatitis. In infants gastrointestinal bleeding must be differentiated from other diseases that cause melena, pallor, anorexia, listlessness, and edema such as portal hypertension, Meckel’s diverticulum, or AV malformation. In adults gastrointestinal bleeding must be differentiated from other diseases such as Meckel’s diverticulum and Dieulafoy’s lesions, inflammatory bowel disease and nonsteroidal anti-inflammatory drug-induced small bowel disease. In older patient (>50 years old) are prone to gastrointestinal bleeding from angiectasias, adenocarcinoma, leiomyoma, and lymphoma.

• Ancylostomiasis must be differentiated from other diseases that cause, abdominal symptoms such as ascariasis and trichuriasis and parasites associated with pneumonitis and peripheral eosinophilia are Aascaris and Strongyloides species.^[1]
• Cutaneous manifestations of ancylostomiasis are differentiated from contact dermatitis, scabies infection, migratory myiasis, and cercarial dermatitis.^[2]

• As ancylostomiasis manifests in a variety of clinical forms, differentiation must be established in accordance with the particular sign and symptoms.
• In infants gastrointestinal bleeding due to hookworm disease must be differentiated from other diseases that cause bloody stools, melena, pallor, anorexia, listlessness, and edema such as portal hypertension, Meckel’s diverticulum, or AV malformation.^[3]
• Adult gastrointestinal bleeding must be differentiated from other diseases such as Meckel’s diverticulum and Dieulafoy’s lesions, inflammatory bowel disease and nonsteroidal anti-inflammatory drug-induced small bowel disease. In older patients (>50 years old) are prone to gastrointestinal bleeding from angiectasias, adenocarcinoma, leiomyoma, and lymphoma.^[4]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Kalpana Giri, MBBS[2]

The incidence rate of hookworm infection was 7.5/100 person-years. Prevalence of ancylostomiasis is approximately 1 billion people worldwide. People of all ages are susceptible to ancylostomiasis, commonly affects children and women of childbearing age. Mortality rate of hookworms in the tropics is approximately 50-60,000 deaths per year. Men are more commonly affected by ancylostomiasis than women. Ancylostomiasis is a common disease that tends to affect cooler, drier regions.

• The incidence rate of hookworm infection was 7.5/100 person-years.^[1]
• Incidence of ancylostomiasis are more common with occupational risk (farmers, miners, workers in clay, etc.) and certain geographic areas where inadequate hygienic behavior has been persists among the rural population.^[2]

• Prevalence of Ancylostomiasis is approximately 1 billion people worldwide.^[3]
• The prevalence of ancylostomiasis in children increases with age, and typically reaches a plateau in late adolescence, whereas the intensity may continue to increase throughout adulthood.
• Ancylostoma duodenale and Necator americanus are common species, which are prevalent in tropical and subtropical countries. (Pawlowski, Schad & Scott, 1991).^[4]
• Also the current study showed, the prevalence of Ancylostoma ceylanicum infection in human is higher than N. americanus (Inpankaew et al., 2014; Ngui et al., 2012a) particularly in Asia.^[5]

• People of all ages are susceptible to ancylostomiasis.
• Ancylostomiasis commonly affects children and women of childbearing age because of their particular need for micronutrients.^[6]
• The overall prevalence of ancylostomiasis in Zhongzhou was 33.2% with a greater prevalence among males.^[7]

• Mortality rate of hookworms in the tropics is approximately 50-60,000 deaths per year.^[8]

• Men are more commonly affected by ancylostomiasis than women, and this is because most likely related to exposure to contaminated soil.^[3]

• Ancylostomiasis is a common disease that tends to affect cooler, drier regions, such as Europe, the Middle East, the Mediterranean, North Africa, Pakistan, and northern India as Ancylostoma duodenale is usually found in these regions. Necator americanus predominates in America, Central Africa, eastern and southern India, Indonesia, and the South Pacific. But in many areas of the world mixed infections are found, including parts of Latin America.^[3]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Kalpana Giri, MBBS[2]

Common risk factors of ancylostomiasis include: exposure to soil where filariform larvae, the infective stage, live in and penetrate human skin, poor sanitation, low socioeconomic status, low educational attainment.

Common risk factors in the development of ancylostomiasis include:^[1][2]

• Exposure to soil where filariform larvae, the infective stage, live in and penetrate human skin.
• Poor sanitation
• Low socioeconomic status
• Low educational attainment

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Kalpana Giri, MBBS[2]

The majority of the infected patients remain asymptomatic. The symptoms of ancylostomiasis typically develop by direct contact of the skin with contaminated soil and the fecal-oral route. The most common complications include: iron deficiency anemia, in child: intellectual and cognitive development, in pregnant women: severe anemia, impaired growth, severe anemia, premature birth, neonatal anemia. Prognosis is generally excellent with proper treatment.

The symptoms of ancylostomiasis typically develop by direct contact of the skin with contaminated soil and the fecal-oral route.^[1]

The majority of the infected patients remain asymptomatic.^[1] The most common complications include:

• Iron deficiency anemia due to chronic blood loss

Children with moderate and heavy intensity hookworm infections include:^[2]

• Impaired growth
• deficits in intellectual and cognitive development.

Women especially pregnant infected with hookworms include:

• Severe anemia
• Increased maternal morbidity and mortality
• Premature birth
• Neonatal anemia

Prognosis is generally excellent with proper treatment and mortality rate in the tropics is approximately 50-60,000 deaths per year. It causes significant morbidity in the form of chronic anemia and protein malnutrition.^[3][4]

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