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

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

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

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

Schistosomiasis  Trematode infecting over 200 million worldwide 1  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

Life Cycle of Schistosomes

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

Transmission

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 years 2

Acute Schistosomiasis (Katayama fever)  Usually occurs 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. mansoni 3  A clinical diagnosis  antibody titers can take 3 months to be positive 5

Acute schistosomiasis: case report 4  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

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

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 women 7

Genitourinary Schistosomiasis: a study at KCMC  Retrospective analysis of pathologic specimens from at KCMC in Moshi, Tanzania 8  Schistosomiasis diagnosed histo- pathologically in 423 specimens  125 of these specimens were found in female genitourinary tract (cervix in 71 cases)

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

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

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. mekongi 9  Steroids often used w/ praziquantel in acute schisto

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

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:  7 Ghoneim MA, Radical cystectomy for carcinoma of the bladder: critical evaluation of the results in 1,026 cases. J Urol Aug;158(2):  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: 36 th Edition,  10 Garba, A et al. Implementation of national schistosomiasis control programmes in West Africa. Trends in Parasitology July; Volume 22, Issue 7,  11 Weekly Epidemiological Record, No.16; 2006, 81,