Massage & Bodywork

MARCH | APRIL 2015

Issue link: https://www.massageandbodyworkdigital.com/i/465652

Contents of this Issue

Navigation

Page 41 of 132

F r e e m u s i c d o w n l o a d s f o r C e r t i f i e d m e m b e r s : w w w. a b m p . c o m / g o / c e r t i f i e d c e n t r a l 39 than 90 percent of viral infections involve hepatitis A, B, C, or some combination. Hepatitis C is a retrovirus. It mutates relatively easily; to date, six different genotypes and 50 subtypes of hepatitis C have been identified. This tendency to change—called antigenic drift—means that unlike versions A and B, no vaccine has yet been developed against hepatitis C. Further, it is possible (but rare) to be super-infected with more than one version of hepatitis C. Estimates about the incidence of hepatitis C vary, but most agree it affects between 4 and 4.5 million people in the United States (that's more than 1 in 100), and up to 200 million people worldwide. It causes some 15,000 deaths each year in the United States, and up to 350,000 deaths each year around the globe. COMMUNICABILITY Hepatitis C is the most common blood-borne infection in the United States, but exactly how it gets from one person to another is still not fully understood. We do know that the most efficient way for the virus to spread is through direct or indirect blood-to- blood contact. Intravenous drug users, people who get tattoos or piercings with contaminated equipment, and people who received blood products or transplant organs before 1993 are among the highest-risk populations. It seems that this virus can also be transferred through sexual activity, but that mechanism is not particularly efficient for spreading the infection. And some research suggests that sharing personal items that might have blood on them—razors, toothbrushes, tweezers—may also allow hepatitis C to move within households; the virus can be active for anywhere from 16 hours to four days outside a host. Again, this is not the most efficient or common mechanism. In up to 10 percent of all diagnoses, the method of transmission is never identified. How It Works Like many viruses, hepatitis C starts with a core of genetic material that is housed inside a protein coat. This capsid has an outside protective lipid membrane. The blood-borne virus is quickly carried to the liver, and its lipid covering allows it to attach to receptor sites on liver cells: the lipids merge with the cell membrane of the hepatocyte. Then, the protein coat dissolves, and the ribonucleic acid (RNA) enters the cell. Once inside a hepatocyte, the viral RNA changes the activity of normal ribosomes (the organelles that produce cellular secretions). In this process, all normal cell function is halted, and the ribosomes are instructed to produce an enzyme called transcriptase, which allows the RNA molecules to replicate—thousands of times in each infected cell. Next, the co-opted ribosomes produce protein coats to cover the new RNA molecules, making new capsids. As the capsids are completed, they migrate to the cell membrane and bud into new viruses, taking some of the lipid cell membrane with them as they escape to find new cells to attack. Ultimately, the infected cell is destroyed, either by viral overload or an immune system response. Hepatitis C usually incubates for two weeks to six months. During this time, it is slowly progressing, but not aggressively enough to stimulate an immune system response. When that happens, some patients experience a period called acute hepatitis C. During this time, signs include about 2–12 weeks of fever, fatigue, abdominal pain, nausea, and vomiting. However, up to 80 percent of all patients don't go through this stage. For this reason, hepatitis C is seldom diagnosed until extensive liver damage has accrued. Hepatitis C is the most common blood-borne infection in the United States.

Articles in this issue

Links on this page

Archives of this issue

view archives of Massage & Bodywork - MARCH | APRIL 2015