Helminths (Parasitic Worms)
Definition
Infections caused by parasitic worms including threadworm (Enterobius vermicularis), hookworm, roundworm, and others such as those causing cutaneous larva migrans, schistosomiasis, and filariasis
Transmitted via the faecal-oral route, skin penetration, or vector-borne methods depending on the species
Common in children, travellers, and endemic regions, with varying systemic and local manifestations
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Threadworm (Enterobius vermicularis)
Most common helminth infection in children, spread through close contact and contaminated surfaces
Presents with nocturnal perianal pruritus, disturbed sleep, irritability, and sometimes abdominal pain
Diagnosed using the adhesive tape test to detect eggs on the perianal skin
First-line treatment is Albendazole 400 mg PO as a single dose or Pyrantel pamoate 10 mg/kg PO (max 1 g) as a single dose
Mebendazole 100 mg PO as a single dose may be used for threadworm, with alternative regimens for other helminth infections
Treat all household contacts simultaneously to prevent reinfection
Emphasise strict hygiene measures including daily showers, trimming nails, frequent laundering of bedding on hot cycles, and thorough cleaning of living areas
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Hookworm and Roundworm
Cause gastrointestinal symptoms such as abdominal pain, diarrhoea, and malabsorption, with hookworm infection leading to iron-deficiency anaemia
Diagnosed by stool microscopy to detect ova or larvae
Managed with the same anthelmintic regimens as threadworm (e.g. Albendazole 400 mg PO stat), with possible additional courses if necessary
Dietary and iron supplementation may be required in cases with significant anaemia
Reinforce hygiene and sanitation to prevent recurrent infections
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Cutaneous Larva Migrans (CLM)
Caused by the penetration of hookworm larvae into the skin, typically acquired from walking barefoot in tropical or subtropical areas
Characterised by intensely pruritic, serpiginous, erythematous tracks on the skin
Diagnosis is clinical, supported by travel or exposure history
First-line treatment is Ivermectin 200 mcg/kg PO as a single dose
Alternative treatment is Albendazole 400 mg PO daily for 3 days if Ivermectin is contraindicated or ineffective
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Schistosomiasis (Bilharzia)
Infection by Schistosoma species transmitted through contact with contaminated freshwater
Acute phase may present with "swimmer’s itch" and Katayama fever (fever, myalgia, malaise, headache, cough)
Chronic infection can lead to hepatosplenomegaly, rectal bleeding, and urinary symptoms depending on the species
Diagnosed by detection of eggs in stool or urine, supported by serology when necessary
Treated with Praziquantel 20 mg/kg PO, two doses given 4 hours apart; repeat treatment may be required in high worm burden cases
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Filariasis
Caused by filarial worms transmitted by mosquitoes, resulting in lymphatic involvement
Presents with lymphoedema, elephantiasis, and scrotal or limb swelling
Diagnosis is via detection of microfilariae on blood smears or serological tests
Managed with a combination of Ivermectin and Albendazole, with Diethylcarbamazine added based on specialist advice
Supportive measures include management of lymphoedema through compression therapy and meticulous skin care to prevent secondary infections
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Prevention and General Notes
A detailed travel and exposure history is essential in suspected helminth infections
Preventive measures include wearing appropriate footwear, avoiding consumption of contaminated water and food, and maintaining good personal hygiene
Environmental sanitation and regular deworming programmes in endemic areas are critical to reducing infection rates
Educate patients and families on the importance of hygiene, proper food handling, and household cleaning to minimise reinfection risks
