Schistosomiasis: A Common Diagnosis in Tanzania

1. Schistosomiasis: A Common Diagnosis in Tanzania Anna Person, MD PGY-3

2. 43 year old male presents to Kilimanjaro Christian Medical Centre in Moshi, Tanzania… • One week of melena • Progressive abdominal distension • One day of hemetemesis • No hx of fever, cough, diarrhea • Works as a farmer in the rice paddies • No past medical history • No medications

3. Exam • BP 86/50, HR 121, Temp 36.5 C, RR 21 • Thin male in mild distress • HEENT- pale conjunctiva • CV- regular rate and rhythm, no murmurs • Pulm- clear to ascultation bilaterally • Ab- distended, dullness to percussion, palpable, enlarged liver and spleen • Ext- no edema

4. Studies • Hb- 5, Hct- 15 • Abdominal US- markedly enlarged spleen, somewhat enlarged liver, heterogenous in appearance • Endoscopy (available at KCMC)- bleeding esophageal varices identified

5. Schistosomiasis • Trematode infecting over 200 million worldwide1 • Transmitted through skin while wading in freshwater • S. hematobium (Africa and Middle East) kidney and bladder • S. mansoni (Africa, ME, Carribean, S. America), japonicum (Asia), mekongi (Asia) liver

6. Life Cycle of Schistosomes

7. Life Cycle • Females produce eggs which release larvae into water • Larvae seek out snails and become sporocyts and then cercarial larvae • Cercarial larvae leave the snail and penetrate intact skin of humans

8. Transmission • www.humanillnesses.com/.../Schistosomiasis.html

9. Transmission, cont. • Once in humans they become schistosomulae • These migrate into the arterial circulation • Then they reach the liver and mature into adults (within 4 weeks) • Worms can live up to 30 years2

10. Acute Schistosomiasis (Katayama fever) • Usually occurs 14-84 days from initial contact • Fever, headache, myalgias, bloody diarrhea, abdominal pain, hives • Respiratory symptoms can occur in up to 70% of those infected with S. mansoni3 • A clinical diagnosis antibody titers can take 3 months to be positive5

11. Acute schistosomiasis: case report4 • 16 patients between ’94-’95 • All had been in sub-Saharan Africa • Dominant symptoms were fever, lethargy • Symptoms began on average 36 days after exposure • 14/16 had eosinophilia, 12/16 had negative stool microscopy • All were treated with praziquantel, 8 required further courses of tx

12. Chronic Schistosomiasis • Long-term sequelae caused by granuloma formation (immune response to antigens from schistosome)6 • Small subset with high burden of organisms (S. mansoni and S. japonicum) develop periportal fibrosis causes portal hypertension, esophageal varices, etc

13. Chronic Schistosomiasis, cont. • S. hematobium infections hematuria, fibrosis of bladder and ureters, effects on kidneys (protenuria) • Causes many types of bladder cancer 75% are squamous, 20% are transitional cell, 5% are adenocarcinoma, more common in men than women7

14. Genitourinary Schistosomiasis: a study at KCMC • Retrospective analysis of pathologic specimens from 1999-2005 at KCMC in Moshi, Tanzania8 • Schistosomiasis diagnosed histo-pathologically in 423 specimens • 125 of these specimens were found in female genitourinary tract (cervix in 71 cases)

15. Burden of genitourinary schistosomiasis • Main symptoms reported were bleeding (48%), ulcer (17%), tumor (20%), lower abdominal pain (11%), and infertility (7%). • Authors conclude that genitourinary schisto is underrecognized cause of disease burden in women in Moshi, Tanzania

16. Diagnosis • Sometimes a clinical diagnosis if other tests not available • Peripheral eosinophilia can be suggestive • Microscopic examination of feces and urine for eggs sensitivity unknown • Serologic tests for antischistosomal antibodies, ELISA tests reported to be >90% sensitive and >95% specific • PCR not widespread

17. Treatment • Praziquantel. • 20mg/kg po bid for 1 day (two total doses) for S. hematobium, intercalatum, and mansoni • 20mg/kg po tid for 1 day (three total doses) for S. japonicum and S. mekongi9 • Steroids often used w/ praziquantel in acute schisto

18. Reducing Morbidity • Burkina Faso, Mali and Niger annual mass-treatments of schoolchildren w/ praziquantel. In Burkina Faso, prevalence went from 90% to <5% after one year.10 • WHO has adopted a Resolution 54.19, which aims to treat 75% of all school-age children at risk for morbidity due to schistosomiasis by 201011.

19. References • 1,3 Ross, A et al: Current Concepts: Schistosomiasis. N Engl J Med 346:1212, 2002 • 2 Arnon, R. Life span of parasite in schistosomiasis patients. Isr J Med Sci 1990; 26:404. • 4,5 Doherty, JF et al. Lesson of the Week: Katayama fever: an acute manifestation of schistosomiasis. BMJ 1996;313(7064):1071. • 6 Boros DL, et al. Delayed hypersensitivity-type granuloma formation and dermal reaction induced and elicited by a soluble factor isolated from Schistosoma mansoni eggs. J Exp Med 1970;132:488-507. • 7 Ghoneim MA, Radical cystectomy for carcinoma of the bladder: critical evaluation of the results in 1,026 cases. J Urol. 1997 Aug;158(2):393-9. • 8 Swai, B et al. Female genital schistosomiasis as an evidence of a neglected cause for reproductive ill-health: a retrospective histopathological study from Tanzania. BMC Infectious Disease 2006, 6:134. • 9 Gilbert et al. The Sanford Guide to Antimicrobial Therapy: 36th Edition, 2006. • 10 Garba, A et al. Implementation of national schistosomiasis control programmes in West Africa. Trends in Parasitology. 2006 July; Volume 22, Issue 7, 322-326. • 11http://www.who.int/wer. Weekly Epidemiological Record, No.16; 2006, 81, 145-164.