Healthcare Reveal » hepatitis c

How is hepatitis C virus spread and how can transmission be prevented?

admin — Thu, 15 Jul 2010 11:58:27 +0000

HCV is spread (transmitted) most efficiently through inadvertent exposure to infected blood.

The most common route of transmission is needles shared among users of illicit drugs.
Accidental needle-sticks in healthcare workers also have transmitted the virus.
The average risk of getting HCV from a stick with a contaminated needle is 1.8% (range 0% to 10%).
Prior to 1992, some people acquired the infection from transfusions of blood or blood products. Since 1992, all blood products are screened for HCV, and cases of HCV due to blood transfusionnow are extremely rare.
HCV also can be passed from mother to unborn child. Approximately 4 of every 100 infants born to HCV-infected mothers become infected with the virus.
A small number of cases are transmitted through sexual intercourse. The risk of transmission of HCV from an infected individual to a non-infected spouse or partner without the use ofcondoms over a lifetime has been estimated to be 1% to 4%
Finally, there have been some outbreaks of HCV when instruments or sharp tool have been re-used without appropriate cleaning between patients.

Transmission of HCV can be prevented in several ways.

Programs have been aimed at avoiding needle sharing among drug addicts. Needle exchange programs and educational interventions have reduced high-risk behaviors. However, the population of drug addicts is a difficult population to reach, and rates of HCV remain high among addicts (30% of younger users).
Among healthcare workers, safe needle-usage techniques have been developed to reduce accidental needle-sticks. Newer syringes have self-capping needle systems that avoid the need to manually replace a cap after drawing blood and reduce the risk of needle-sticks.
There is no clear way to prevent transmission of the HCV from mother to child.
Persons with multiple sexual partners should use barrier precautions such as condoms to limit the risk of HCV as well as other sexually-transmitted diseases.
Monogamous couples should consider the low risk of transmission when deciding whether to use condoms during intercourse. Some couples may decide to use them and some may not.
Screening tests for blood products have almost eliminated the risk of transmission through transfusion, estimated by the CDC to be less than one in two million transfused blood products.
People with HCV should not share razors or toothbrushes with others.
It is critical that physicians and clinics follow manufacturer’s directions for sterilizing/cleaning instruments and that disposable sharp instruments be discarded properly.

It is important to realize that HCV is not spread by casual contact. Thus, shaking hands, kissing, and hugging are not behaviors that increase the risk of transmission. There is no need to use special isolation procedures when dealing with infected patients.

How does liver damage occur in hepatitis C infection?

admin — Thu, 15 Jul 2010 11:57:13 +0000

The presence of HCV in the liver triggers the human immune system, which leads to inflammation. Over time (usually decades), prolonged inflammation may cause scarring. Extensive scarring in the liver is calledcirrhosis. When the liver becomes cirrhotic, the liver fails to perform its normal functions, (liver failure), and this leads to serious complications and even [...] Related posts:

Hepatitis C

admin — Thu, 15 Jul 2010 11:50:40 +0000

What is hepatitis C?

Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). It is difficult for the human immune system to eliminate the virus from the body, and infection with HCV usually becomes chronic. Over decades, chronic infection with HCV damages the liver and can cause liver failure in some people. In the U.S., the number of new cases of infection with HCV has declined over the last 10 years from a peak of some 200,000 annually to about 19,000 in 2006. When the virus first enters the body, there usually are no symptoms, so these numbers are estimates. Up to 85% of newly infected people fail to clear the virus and become chronically infected. In the U.S., more than three million people are chronically infected with HCV. Infection is most common among people who are 40 to 60 years of age, reflecting the high rates of infection in the 1970s and 1980s. There are 8,000 to 10,000 deaths each year in the U.S. related to HCV. HCV is the leading cause of liver transplantation in the U.S and is a risk factor for liver cancer.

What is the nature (biology) of the hepatitis C virus?

‘Hepatitis’ means inflammation of the liver. HCV is one of several viruses that can cause hepatitis. It is unrelated to the other common hepatitis viruses (for example, hepatitis A or hepatitis B). HCV is a member of theFlaviviridae family of viruses. Other members of this family of viruses include those that cause yellow feverand dengue.

Viruses belonging to this family all have ribonucleic acid (RNA) as their genetic material. All hepatitis C viruses are made up of an outer coat (envelope) and contain enzymes andproteins that allow the virus to reproduce within the cells of the body, in particular, the cells of the liver. Although this basic structure is common to all hepatitis C viruses, there are at least six distinctly different strains of the virus which have different genetic profiles (genotypes). In the U. S., genotype 1 is the most common form of HCV. Even within a single genotype there may be some variations (genotype 1a and 1b, for example). Genotyping is important to guide treatment because some viral genotypes respond better to therapy than others. The genetic diversity of HCV is one reason that it has been difficult to develop an effective vaccine since the vaccine must generate viral proteins from each genotype.

Medical Author: Suresha Rajaguru, MD and Mary Nettleman, MD, MS, MACP

Link Between Hepatitis C And Insulin Resistance Surprises Scientists

admin — Wed, 10 Mar 2010 06:21:45 +0000

Scientists in Australia found that when they studied insulin resistance in people with Hepatitis C little or none of it was in the liver and nearly all the insulin resistance occured in muscle, which surprised them because Hepatitis C is a liver disease that not only leads to cirrhosis and cancer, but also makes people three to four times more likely to develop Type 2 diabetes.

You can read about the study that led to these findings in the March 2010 issue of the journal Gastroenterology, which is also available online.

Among the researchers were Dr Kerry Lee Milner and Professor Don Chisholm from Sydney’s Garvan Institute of Medical Research and Professor Jacob George from the Storr Liver Unit, University of Sydney at Westmead Hospital.

Hepatitis C is a virus that lives in the blood and can be passed from one drug user to another by sharing needles: in Australia this is the main route of transmission. However, unsterile tattooing or body piercing is another way the virus can spread.

Unlike Hepatitis A and B, there is no vaccine for Hepatitis C, of which there are 6 strains, the two most common in Australia being Genotype 1 and Genotype 3, which causes significant amounts of fat to deposit in the liver.

Insulin, a hormone that helps the body convert glucose into energy, is made in the pancreas, but the two most important organs that respond to it are the liver and muscle, each responding differently. When it detects insulin, the liver stops making glucose, while healthy muscle responds by using glucose.

A liver that has become insulin resistant overproduces glucose, while muscle that has become insulin resistant does not absorb glucose so well from the bloodstream. In both cases the result is too much circulating glucose.

When they studied the insulin resistance of 29 people with Hepatitis C (14 with Genotype 1 and 15 with Genotype 3) and confirmed they had high insulin resistance, they found to their surprise that nearly all the insulin resistance was in the muscle and hardly any in the liver.

Chisholm also told the media that contrary to expectations, not only did they find no significant insulin resistance in the liver of the study participants: “The fifteen people with very high levels of fat in the liver [the participants with Genotype 3] had the same degree of insulin resistance as the fourteen that didn’t have fatty livers.”

Chisolm said experts around the world have been arguing that fat in the liver is an important factor in the development of insulin resistance, perhaps the most important. But this study shows this may not be the case, he said.

“Before you get Type 2 diabetes, you must become insulin resistant and your insulin producing cells must also fail to compensate. Insulin resistance alone will not give you diabetes,” he explained.

For this study, Chisolm and colleagues gave intravenous glucose, which specifically stimulates insulin secretion, and showed that it was not impaired in the Hepatitis C patients compared to controls.

“This finding tells us that people with Hepatitis C who develop diabetes probably have susceptible insulin-producing cells, and would probably get it anyway — but much later in life,” said Chisolm.

The extra insulin resistance caused by Hepatitis C apparently brings on diabetes at 35 or 40, instead of 65 or 70,” he added.

The researchers suggest further research should now be done to find out why Hepatitis C causes insulin resistance in muscle.

“That will give us better insight into the behaviour of the disease,” said Chisolm.

For people with Hepatitis C, the message from this study is a deeper understanding of insulin resistance, and perhaps, if they have family members with Type 2 diabetes, they would be advised to manage their diets very carefully and take plenty of exercise, as this delays onset.

Estimates suggest there are currently around 212,000 Australians infected with Hepatitis C, with 10,000 new infections a year.

“Chronic Hepatitis C Is Associated With Peripheral Rather Than Hepatic Insulin Resistance.”
Kerry-Lee Milner, David van der Poorten, Michael Trenell, Arthur B. Jenkins, Aimin Xu, George Smythe, Gregory J. Dore, Amany Zekry, Martin Weltman, Vincent Fragomeli, Jacob George, Donald J. Chisholm.
Gastroenterology, March 2010 (Vol. 138, Issue 3, Pages 932-941.e3)

Source: GAVAN Institute.

Written by: Catharine Paddock, PhD
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today