Showing posts with label hepatitis. Show all posts
Showing posts with label hepatitis. Show all posts

Saturday, February 7, 2009

Hepatitis C and Cardiovascular Risk

Conflicting results have been produced regarding the association between chronic hepatitis C virus (HCV) infection and coronary artery disease, including heart attacks and strokes. It was found in a study about the relationship between HCV infection and risk for incident (newly emerging) coronary artery disease. HCV-positive patients were less likely to have arterial hypertension, dyslipidemias, and diabetes than persons without HCV. HCV-positive patients were more likely to smoke cigarettes and abuse alcohol or drugs. Compared with participants without HCV, patients with HCV had lower mean plasma levels of total cholesterol , low-density lipoprotein (LDL) cholesterol, and triglycerides .
In a multivariate analysis, HCV infection was associated with a 25% higher risk for coronary artery disease. Classic risk factors (older age, hypertension, smoking, diabetes, dyslipidemias) were associated with a higher risk for coronary artery disease. In contrast, nonwhite ethnicity and female sex were associated with a lower risk. It was concluded that people infected with HCV are at increased risk for coronary artery disease despite having fewer other cardiovascular risk factors.
(Butt A, Xiaoqiang W, Budoff M, et al. Hepatitis C virus infection and the risk of coronary disease. Program and abstracts of the 48th ICAAC/46th IDSA; October 25-28, 2008; Washington, DC. Abstract V-4219)

Saturday, January 24, 2009

Hepatitis Vaccination Recommendations

Hepatitis A vaccination is indicated for persons with chronic liver disease, those who receive clotting factor concentrates, men who have sex with men, illegal drug users, laboratory workers exposed to hepatitis A virus–infected primates, persons traveling to or working in countries with high or intermediate endemicity of hepatitis A, and those seeking protection from hepatitis A virus infection. Single-antigen vaccine formulations should be given in 2 doses either at 0 and 6 to 12 months (Havrix, GlaxoSmithKline) or at 0 and 6 to 18 months (Vaqta, Merck). Combined hepatitis A and hepatitis B vaccine (Twinrix, GlaxoSmithKline) should be given in 3 doses at 0, 1, and 6 months or in 4 doses on days 0, 7, and 21 to 30, followed by a booster dose at month 12.
Hepatitis B vaccination is indicated for persons with end-stage renal disease, HIV infection, or chronic liver disease; for healthcare personnel and public-safety workers exposed to blood or other potentially infectious body fluids; for sexually active persons not in a long-term, mutually monogamous relationship; for persons seeking evaluation or treatment of a sexually transmitted infection; for current or recent injection-drug users; and for men who have sex with men. Other indications and settings are also listed, as well as special formulation indications.
(Morb Mortal Wkly Rep. 2009;57(53))

Thursday, January 22, 2009

The Difficulties of Acute HCV-Infection Diagnosis

Most individuals infected with hepatitis C virus (HCV) fail to clear virus at the acute stage, becoming chronically infected, with consequent significant risks of progressive liver disease, cirrhosis and hepatocellular carcinoma. Treatment of chronic HCV with combination pegylated-interferon (PEG-IFN) and ribavirin achieves sustained virological response (SVR) rates of 42-52% of patients infected with HCV genotype 1 and 76-82% of those with genotype 2/3. In contrast, much higher SVR rates (e.g. >97%) have been reported when treating acute HCV infection with PEG-IFN, irrespective of the infecting genotype. It would thus seem preferable to treat HCV infection at the acute stage rather than waiting for the infection to become chronic.
The problem is the diagnosis of acute HCV infection is not straightforward. Detection of anti-HCV IgM does not distinguish acute from chronic infection. Genome or antigen detection techniques provide information on the current infection status of an individual, but do not indicate when infection may have taken place. One possible laboratory approach to diagnosis of acute infection would be to demonstrate sero- or genoconversion in serial samples, but practically, it is difficult to obtain regular repeat samples in high-risk individuals such as injecting drug users (IDUs). Clinical approaches to diagnosis are also flawed. Only a small minority of acute infections are symptomatic. Even in patients presenting with acute hepatitis C, the majority of whom are already anti-HCV positive, one cannot be certain that illness is due to recent infection with HCV rather than another inter-current cause in a chronically infected patient.
(J Viral Hepat. 2008;15(12):871-877)