John Snow and Hepatology Potpouri

If you mention the name “John Snow,” I bet most people would think about one of the characters from Game of Thrones.  However, a more important John Snow is referenced in a recent Hepatology review (Hepatology 2014; 60: 1124-25).  “In 1855, the physician and epidemiologist John Snow used the technique of medical geography to stem the cholera epidemic in London.  By mapping the number of choleras case and the local water supply, he found that the Broad Street pump station was responsible and after the pump handle was removed, incident cases declined.”

Hepatology 2014; 60: 1150-59, editorial 1124-25.  Using spatial (clustering) epidemiology, the authors show that parenteral antischistosomal therapy (PAT) alone cannot explain the high HCV prevalence in Egypt.  Other iatrogenic exposures and poor infection control are likely contributing factors.

Hepatology 2014; 60: 1222-30, editorial 1130.  In a prospective study (western Europe), the authors show that vitamin D (25-OH) levels were inversely associated with the risk of hepatocellular carcinoma (HCC).  What is remarkable about this study is the levels were obtained on average 6 years before HCC diagnosis.  Also, this study uses tertiles -comparing those in the top third to those in the lowest third.

Hepatology 2014; 60: 1399-1408.  More data showing injury from Herbals and dietary supplements.  Liver injury caused by bodybuilding herbal supplements (often anabolic steroids) were typically less severe than liver injury induced in non-bodybuilding herbals (predominantly middle-aged women). Table 3 identifies by name many of the herbal supplements/dietary supplements associated with death or liver transplantation.  “Contrary to popular belief, this study demonstrates that HDS products are not always safe.”