Hepatitis epidemiology

Lemon, S.M. Type A viral hepatitis epidemiology, diagnosis and prevention. Clin. Chemist. 1997 43 1494-1499... 

Halogenated compounds, found in high concentrations in seaweeds consumed in Japan and Hawaii, have been suspected of being carcinogenic, largely based on epidemiological extrapolation (high incidences of hepatic carcinoma). However, direct human causation has not been estabUshed (107). 

Shepard CW, Finelli L, Alter MJ (2005) Global epidemiology of hepatitis C virus infection. Lancet Infect Dis 5 558-567... 

Agarwal et al. 1978), the quantification of these specific enzymes may indicate that exposure to endosulfan has occurred. Blood tests, such as decay curves for aminopyrine in plasma, which are semiquantitative indices of liver enzyme induction, have been used successfully in the past to demonstrate enzyme induction in pesticide-exposed workers. Because numerous chemicals found at hazardous waste sites also induce these hepatic enzymes, these measurements are not specific for endosulfan exposure. However, measurements of enzyme activity, together with the detection of the parent compound or its metabolites in tissue or excreta, can be useful indicators of exposure. All of these potential biomarkers require further verification in epidemiological studies. Further studies with focus on the development of methods to separate and measure the estrogenicity of endosulfan in in vitro assays would be valuable since these assays are more sensitive and discriminative than other conventional biomarkers. Preliminary results have been presented by Sonnenschein et al. (1995). 

Malek B, Kremarova B, Rodova A. 1979. [An epidemiological study of hepatic tumor incidence in subjects working with trichloroethylene. II. Negative result of retrospective investigations in dry cleaners.] Prac Lek 31 124-126. (Czech)... 

Viral hepatitis can occur at any age and is the most common cause of liver disease in the world. The true prevalence and incidence may be underreported because most patients are asymptomatic. The epidemiology, etiology, and pathogenesis vary depending on the type of hepatitis and will be considered separately below. 

In an epidemiological study at a munitions plant where workers were exposed to 0.28 mg/m time-weighted average (TWA), there were no abnormalities of the hematologic, hepatic, or renal systems. ... 

An epidemiological study of 151 matched pairs of exposed textile workers revealed no evidence of cardiovascular, hepatic, renal, or other effects as a function of exposure for some workers, exposures exceeded 200 ppm, and duration of exposure ranged ftom several months to 6 years. ... 

Vinyl chloride has been associated with cancer in humans in a number of epidemiological studies. In four facilities engaged in the polymerization of vinyl chloride for at least 15 years, workers exposed for at least 5 years had a significant number of excess deaths due to malignant neoplasms (35 deaths observed, 23.5 expected). The excesses were found for four organ systems CNS (3 observed, 0.9 expected), respiratory system (12 observed, 7.7 expected) hepatic system (7 observed, 0.6 expected), and lymphatic and hematopoietic systems (4 observed, 2.5 expected). 

Talk H, Telles NC, Ishak KG. 1979. Epidemiology of Thorotrast induced hepatic angiosarcoma in the USA. Environ Res 18 67-73. 

Meyer, R.A., and S.C. Gordon, Epidemiology of hepatitis C virus infection in a suburban Detroit community. Am J Gastroenterol, 1991. 86 1224-6. 

Alter, MJ., Epidemiology of Hepatitis C American Liver Eoundation, http //www.liv-erfoundation.org /html/livheal./dir/livheal.htm. 2001. 

One major question is whether humans are at risk from these chemicals. Although they clearly have the receptor for the lipid-lowering drugs to work, there is no evidence of increased risk of hepatic cancer from epidemiological studies. However, fibrates are relatively weak PPARa agonists. 

Knowledge of tumor induction by sex steroids is largely based on interpretation of epidemiological data, with careful exclusion of possible confounding elements. Hepatic tumors have given rise to most concerns, but some evidence also indicates an increased incidence of various other malignancies, including carcinomas of the breast, endometrium, and prostate (71). 

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