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schistosomiasis (bilharziasis, Katayama fever)

Acute schistosomiasis is Katayama fever. Etiology: 1) Schistosoma haematobium (blood fluke) 2) Schistosoma japonicum (intestinal venules) 3) Schistosoma mansoni (intestinal venules) 4) Schistosoma mekongi Epidemiology: - infection is acquired through freshwater contact, from which larvae infect humans via skin penetration. - snails are intermediate hosts & release larvae into water - the larvae can penetrate human skin - adult worms may live in human body for years - sub-Saharan Africa Pathology: 1) Schistosoma haematobium infests plexus of bladder & pelvis 2) Schistosoma mansoni resides in mesenteric venules 3) eggs migrate to liver, lung, genitourinary tract, intestines & CNS 4) immunologic response to the antigens present during the maturation process of the schistosomal worm 5) trapped eggs can lead to granulomatous inflammation of periportal spaces progressing to fibrosis, occlusion of the portal veins with resulting esophageal varices Clinical manifestations: 1) most cases asymptomatic 3) acute manifestations 2-10 weeks after exposure (Katayama fever) - fever, dry cough, myalgias, headache, urticarial rash, fatigue, malaise, lassitude - image of rash [4] 3) painful urination (may or may not be present) - pedunculated papillomas in urethral orifice 4) perineal fibrous nodules 5) hepatomegaly, no ascites [6] 6) melena [6] 7) esophageal varices [6] Laboratory: 1) complete blood count a) leukocytosis b) eosinophilia c) microcytic anemia 2) urinalysis: a) hematuria b) ova occasionally found in urine - 3 separate sample on 3 separate days for Schistosoma haematobium 3) stool for ova & parasites: ova in stool 4) liver function tests normal 5) no stigmata of chronic liver disease 6) see ARUP consult [3] Special laboratory: - Cystoscopy: a) papillomas at trigone b) reduced bladder capacity c) urinary calculi in - ureter - renal pelvis - bladder d) rectovesical fistulas - colonoscopy with colonic biopsy Radiology: - chest X-ray - ill-defined nodular infiltrates (case report) [4] Differential diagnosis: - Ascaris, trichinellosis, filariasis, Hookworm - none are transmitted in fresh water Management: 1) praziquantel a) 40 mg/kg in 2 doses (same day) 1] S. mansoni 2] S. haematobium b) 60 mg/kg in 3 doses (same day) 1] S. japonicum 2] S. mekongi c) single oral dose of praziquantel, preferably given after acute stage (case report) [4] 2) oxamniquine (alternative agent) a) 15 mg/kg once b) 30 mg/kg once in East Africa c) 30 mg/kg once daily for 2 days in Egypt & South Africa 3) metrifonate* 7.5-10 mg/kg given every other week x 3 * Available from Centers for Disease Control, Parasitic disease division

Related

clinical manifestations of schistosomiasis by species Schistosoma

General

helminth infection

References

  1. DeGowin & DeGowin's Diagnostic Examination, 6th edition, RL DeGowin (ed), McGraw Hill, NY 1994, pg 932
  2. Harrison's Principles of Internal Medicine, 13th ed. Isselbacher et al (eds), McGraw-Hill Inc. NY, 1994, pg 927
  3. ARUP Consult: Schistosoma Species - Schistosomiasis The Physician's Guide to Laboratory Test Selection & Interpretation https://arupconsult.com/content/schistosoma-species
  4. Puylaert CAJ, van Thiel PP IMAGES IN CLINICAL MEDICINE. Katayama Fever N Engl J Med 2016; 374:469. February 4, 2016 PMID: 26840136 http://www.nejm.org/doi/full/10.1056/NEJMicm1504536
  5. Gleeson SE, Zhang X, Azar MM Recurrent Hematochezia in a Returning Traveler. JAMA. Published online March 5, 2021. PMID: 33666646 https://jamanetwork.com/journals/jama/fullarticle/2777393
  6. NEJM Knowledge+ Gastroenterology