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Bilharziosis (Schistomiasis) (B65)
Contents
Definition
Tropic disease caused by parasites. There are several types of schistosoma parasites. Most often, a chronic condition develops. The parasites attack the skin, bladder and intestines, but can also cause arthritis (arthritis). Eggs left in tissues cause a granulomatous infection.
Disease Causes
1-2 cm long worms (Termatoder).
- Urinary Bladder bilharzinose: S. haematobium
- Perkutan infection by swimming in infected lakes
- Intestinal bilharzidose: S. mansoni, S. japonicum, S. intercalaticum, S. mekongi.
Occurrence
Troper, subtroper. Over 85% are infected in sub-Saharan Africa. Asylum seekers from Africa. Less common in the Caribbean, South America, the Middle East and Asia.
Contamination
Transferring via contaminated bathing water. The parasites originate from infected freshwater snails. In particularly, children (who are playing in water) are infected
Incubation
- 2-7 weeks to first symptoms (itchy skin on feet and other parts that have been exposed to contaminated freshwater)
- 4-12 weeks for symptoms of internal organs
Symptoms
Initially
- Itchy little lumps in the skin (especially on the feet) that have been in contact with contaminated fresh water, hives (urticaria)
Later
- Fever
- Abdominal (stomach) pain (intestinal manifestation)
- May cause chronic back pain and headaches
- Diagnosis by MRI (localized inflammation) and Serum Schistoma IF antigen, ELISA Egg titer, Serum Schistoma IF
- Diarrhea (bloody)
- Exhaustion
- Coughing (lung infection)
- Genital mucosal bleeding (genital affection)
- Blood in urine (urinary bladder infection)
Rheumatic symptoms
- Arthritis (arthritis) is described (reference: Rakotomala HN, 2017)
Medical examinations of blood and urine
- Extreme eosinophilia in blood (by differential counting of leukocytes)
- Effective screening of parasite antigen with ELISA blood test
- Serum Schistoma IF antigen, ELISA Egg titer, Serum Schistoma IF
- Antibody can be detected in blood test
- Microscopic examination of parasite eggs in faeces (possibly also in urine)
- Biopsy of rectal mucosa (or bladder) can detect eggs if they are not detected by microscopy
- Urinary bladder: Hematuria (blood in urine)
Complications
- Increased risk of cancer of the urinary bladder, colon and liver in the long term
- Portal hypertension
- Focal epilepsy (neuroschistosomiasis) in S. japonicum
Diagnosis
- Trope anamneses + Detection in urine, stool or tissue
- Antibody detection. Antibody is specific (> 95%), but lasts for up to several years after treatment and completion of infection.
Treatment
Praziquantel (Biltricide) (a single dose annually). More than 80% will be healthy
Prophylaxis
- Prohibition of swimming in infected lakes. Avoid infected drinking water.
- A vaccine is under trial
NOTE! Harmless bilharzia species cause bath dermatitis in Central Europe and North America (reference: Omar HN, 2016)
Literature
Tropic diseases, BINDEVEVSSYKDOMMER.no