Parasitic Infection

Helminthiasis

refers to infection caused by parasitic worms

nematodes (roundworms), trematodes (flukes), and cestodes (tapeworms).

Types of parasitic worms that causes infection. Transmission often occurs through ingestion of eggs, larvae, or skin penetration.

Ascaris lumbricoides

Causative agent of Ascariasis

Ascariasis (Roundworm Infection)

Eggs are ingested via contaminated soil or food → hatch in the intestine → larvae migrate through the bloodstream to lungs → coughed up and swallowed → mature in intestines causing obstruction or malnutrition.

Ascariasis manifestations

Early (migration): cough, wheezing, fever (Loeffler's syndrome)

Late (intestinal phase): abdominal pain, bloating, malnutrition, intestinal obstruction.

Loeffler's syndrome

a rare and self-limited lung disease characterized by transient, migratory pulmonary infiltrates (abnormalities on a chest X-ray) and peripheral eosinophilia (an elevated number of a specific type of white blood cell)

Ascariasis diagnostics

Stool examination for Ascaris eggs

CBC: eosinophilia

X-ray/ultrasound may show intestinal worms.

Ascariasis management

Medical: Albendazole 400 mg single dose or Mebendazole 100 mg BID × 3 days.

Nursing: Promote hygiene, sanitation, periodic deworming, monitor for obstruction.

Prevention: Handwashing, proper disposal of feces, washing vegetables.

Ancylostoma duodenale or Necator americanus

Causative agent of Ancylostomiasis

Ancylostomiasis (Hookworm Infection)

When an Infective larvae penetrate the skin (barefoot walking) → migrate to lungs → swallowed → attach to intestinal mucosa → suck blood → anemia.

Ancylostomiasis manifestations

Itching at entry site, cough, abdominal pain, pallor, fatigue, anemia, pica.

Ancylostomiasis diagnostics

Stool exam for ova, CBC (microcytic anemia, eosinophilia)

Ancylostomiasis management

Medical: Albendazole or Mebendazole; iron supplementation for anemia.

Nursing: Encourage footwear, treat anemia, improve hygiene.

Prevention: Sanitary toilets, deworming campaigns.

Enterobius vermicularis

Causative agent of Enterobiasis

Enterobiasis (Pinworm Infection)

Transmission via ingestion or inhalation of eggs → hatch in intestines → females migrate to perianal region at night to lay eggs → causes itching.

Enterobiasis manifestation

Perianal itching (especially at night), irritability, disturbed sleep.

Enterobiasis diagnostics

Scotch tape test (perianal swab under microscope showing eggs).

Enterobiasis management

Medical: Mebendazole or Pyrantel pamoate; repeat after 2 weeks.

Nursing: Wash hands and bedding, trim nails, treat all family members.

Paragonimus westermani

Causative agent of Paragonimiasis

Paragonimiasis (Lung Fluke Infection)

Caused by an Infection by eating undercooked crabs/crayfish → larvae migrate to lungs → form cysts → chronic inflammation and fibrosis.

Paragonimiasis manifestations

Chronic cough, blood-streaked sputum, chest pain, mimics tuberculosis.

Paragonimiasis diagnostics

Sputum/stool exam for eggs

Chest X-ray (cystic lesions)

Serologic tests.

Paragonimiasis management

Medical: Praziquantel 25 mg/kg TID × 3 days.

Nursing: Educate about safe food preparation; prevent misdiagnosis as TB.

Strongyloides stercoralis

Causative agent of Strongyloidiasis

Strongyloidiasis (Threadworm Infection)

Barefoot exposure on contaminated soil → Larvae penetrate skin → migrate via bloodstream → lungs → swallowed → mature in intestines → can cause autoinfection and hyperinfection in immunocompromised hosts. n.

Strongyloidiasis manifestation

Skin rash, diarrhea, abdominal pain, cough, in severe cases—sepsis.

Strongyloidiasis diagnostics

Stool exam for larvae, serologic tests (ELISA).

Serologic tests (ELISA) - ELISA (Enzyme-Linked Immunosorbent Assay)

common serological test that detects and measures antibodies or antigens in a blood sample to diagnose conditions like HIV, Lyme disease, and syphilis.

Strongyloidiasis management

Medical: Ivermectin (first-line) or Albendazole.

Nursing: Maintain hygiene, avoid barefoot walking.

Taenia saginata (beef) or T. solium (pork)

Causative agent of Taeniasis

Taeniasis (Tapeworm Infection)

Infection occurs via ingestion of cysts in undercooked meat → worms mature in intestines. T. solium can cause cysticercosis if eggs are ingested (larvae invade brain, muscles).

Taeniasis manifestations

Abdominal discomfort, nausea, passage of proglottids in stool; in cysticercosis—seizures, muscle nodules.

Taeniasis diagnostics

Stool exam for eggs or proglottids; imaging for cysticercosis.

Taeniasis management

Medical: Praziquantel or Niclosamide.

Nursing: Ensure meat is cooked thoroughly, promote sanitation

Fasciolopsis buski

Causative agent of Fasciolopsiasis

Fasciolopsiasis (Giant Intestinal Fluke Infection)

Infection from eating raw contaminated aquatic plants (water chestnut, lotus). Adult flukes attach to intestinal mucosa → irritation and malabsorption.

Fasciolopsiasis manifestation

Abdominal pain, diarrhea, edema, malnutrition.

Fasciolopsiasis diagnostics

Stool exam for eggs.

Fasciolopsiasis management

Medical: Praziquantel.

Nursing: Educate on safe food preparation, sanitation.

Trichinella spiralis

Causative agent of Trichinosis

Trichinosis (Trichinellosis)

Caused by larvae in undercooked pork enter intestines → invade muscles → cause inflammation and pain.

Trichinosis manifestation

Fever, myalgia, facial edema, eosinophilia, periorbital swelling.

Trichinosis diagnostics

Serologic tests, muscle biopsy for larvae.

Trichinosis management

Medical: Albendazole, corticosteroids for severe inflammation.

Nursing: Prevent infection through proper meat cooking and inspection.

Pediculus humanus species.

Causative agent of Pediculosis

Pediculosis Capitis (Head Lice)

Parasitic infestation of the hair. Transmitted through direct contact or sharing of combs/hats. Manifested as Itching scalp, visible nits/lice.

Pediculosis capitis management

Permethrin shampoo (1%), wash bedding and combs in hot water.

Pediculosis Corporis (Body Lice)

Parasitic infestation of the body. Caused by poor hygiene, and infested clothing. Manifested as Itchy body rash, lice in clothing seams

Pediculosis Corporis management

Bathe thoroughly, wash/discard clothing; treat with insecticide powder.

Phthirus pubis (Pubic Lice / "Crabs")

Parasitic infestation of the genitalia. Transmission through Sexual contact, shared clothing/bedding. Manifested by Itching in pubic area, visible lice attached to hair.

Phthirus pubis management

Permethrin cream, treat sexual partners, disinfect clothing.

Sarcoptes scabiei mite

Causative agent of Scabies

Scabies

caused by a mite mite which burrows into skin → hypersensitivity reaction → intense itching.

classic, crusted, nodular, bullous, scalp, incognito

Types of Scabies

Scabies manifestation

Intense pruritus (especially at night), burrows (finger webs, wrists, axilla, groin).

Scabies diagnostics

Skin scraping with microscopic confirmation of mites/eggs.

Scabies management

Medical: Permethrin 5% cream (apply overnight), Ivermectin (oral if severe).

Nursing: Treat all family members, wash clothing and linens in hot water, maintain hygiene.

Schistosoma species (e.g., S. haematobium, S. mansoni).

Causative agent of Schistosomiasis

Schistosomiasis (Bilharzia)

Caused by Infection via skin penetration by cercariae from bathing in contaminated freshwater (snails as intermediate hosts). Worms migrate to mesenteric or vesical veins → cause granulomatous inflammation and fibrosis.

Schistosomiasis manifestation

Acute: Rash, fever, eosinophilia (Katayama fever)

Chronic: Hepatosplenomegaly, portal hypertension, hematuria (urinary type).

Schistosomiasis diagnostics

Stool or urine exam for eggs; serology, ultrasound for organ damage.

Schistosomiasis

Medical: Praziquantel 40 mg/kg single dose.

Nursing: Educate to avoid contaminated water; snail control; health education on sanitation.

Strongyloidiasis manifestation