Schistosomiasis

70M p/w abd pain.
Has 5cm mass at hepatic flexure on cscope. Requires ex-lap (due to iatrogenic perf), colonic resection. Path images with incidental finding of eggs 👇

Emigrated fr China. Only travel: US, China, Philippines
Not sure about prior infections but has been tx’d for “worms” prev

What is the treatment of choice for this organism?

Eventually ID’d as Schistosoma japonicum! Found incidentally. This is a good time to review Schistosoma egg morphology and geography, since case photos are not always classic!

Check out this prior @BIDMC_IDFellows chart + CDC life cycle (🔑2 distinct types of reproduction)

Schistosomiasis clinical presentations:
🔹Asx
🔹Acute: cercarcial dermatitis (self-limited, pruritic rash), Katayama synd(fever, HA, myalgia, diarrhea, urticaria, angioedema, eosinophilia)
🔹Chronic: granulomatous inflam response to eggs in vessels of liver, intestine-cont’d👇

continue? final fight GIF


🔹For S.japonicum, adult worms are tropic for mesenteric venous plexus
▪️Chronic inflam can lead to➡️bowel wall ulceration, hyperplasia, polyposis, intestinal bleeding. Can also cause liver fibrosis, portal HTN

🔹S.haematobium egg in GU tract ➡️LUTS, hematuria

Tx:
🔸Cercarcial: self-limited
🔸Acute schisto: steroids➡️praziquantel (PZQ)
🔸Chronic: PZQ

💊Adult dead worms can release eggs as destroyed- PZQ kills🪱 but not eggs/larval stage
💊Confirm cure w/surveill 2-6mo later, can repeat tx if persistent egg excretion

is it over yet? end of the world GIF by Michelle Porucznik


So what is the relationship between malignancy and Schistosoma?
✳️WHO Intl Agency for Research on Cancer (IARC) monographs on carcinogenic hazards notes few schistostoma spp

💫Most know the classic risk of bladder cancer (usu squamous cell) with S.haematobium (IARC group 1)

🔖Data on relation S.japonicum to CRC, liver ca = case control and epi studies, case series, case reports

📰A recent @AJTMH review of S.japonicum assoc'd CRC noted:
Young age
Male predominance
Predilection sigmoid colon, rectum
Multifocal distribution

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6402928/


https://pubmed.ncbi.nlm.nih.gov/15701255/
🔹A 🇨🇳 case control study, reported pts with chronic S.japonicum + ⬆️risk of cancer vs those with no prior exposure (OR 3.7 with liver ca, OR 3.3 with CRC)
🔹Authors attributed 24% CRC cases, 27% liver ca to long-standing schistosomal infection

A good case to remember to the association between some chronic infections and malignancy!

Here's one other paper thinking about GI malignancy and bowel parasitosis with summary chart below

https://www.hindawi.com/journals/jtm/2011/234254/

Originally tweeted by BIDMC Infectious Diseases Fellowship (@BIDMC_IDFellows) on 17 August, 2020.

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