Hepatitis C is a viral infection caused by a virus that affects the liver causing severe swelling. It is caused by the Hepatitis C virus (HCV) whose infection is more likely to be asymptomatic showing no symptoms for several years after the infection has occurred. As a matter of fact, a great number of people infected by HCV do not realize it until several years later when the liver gets damaged to the point of recognition through medical checkups.
Among the various hepatitis viruses, HCV is considered to be one of the most serious and dangerous ones (WHO 2012, p 1). Since hepatitis C infection is mostly discovered late, cases of chronic infections are likely to result leading to failure of the liver or liver cancer. Life-threatening implications such as the esophagus and gastric varices may as well result. With no knowledge of hepatitis C infection on other animals, it has been estimated to infect 150 million people worldwide.
Etiology and pathophysiology
Cause and risk factors
Hepatitis C is caused by a virus, the Hepatitis C Virus (HCV), a small single-stranded RNA virus consisting of seven genotypes all of which cause hepatitis C but at different percentages. However, most infections occur as a result of the transmission of the virus from infected persons to healthy ones. The most common means through which the virus is transmitted is through the use of intravenous drugs, especially in developing nations.
Blood transfusion is another common means of transmitting HCV and it is common in developed countries which have technological advances in transfusing blood. The use of intravenous drugs is a major risk factor in the transmission of HCV. A study carried out in 77 countries indicated that 25 of them, the US included, had a prevalence of hepatitis C in populations exposed to intravenous drug use of up to 80% (Liang, 2012, p 1). Ten million users of intravenous drugs are believed to be infected with hepatitis C with the highest rates occurring in the United States of America, Russia, and China.
Exposure to healthcare has as well-posed a great risk in the infection of hepatitis C. healthcare procedures causing such risks to include transfusion of blood and other blood products and organ transplantation especially when these procedures are done without carrying out HCV screening. Other healthcare risks include needle stick injuries, exposure of mucosa to blood in case of an open wound.
Hospital and medical equipment have as well been listed as risk factors for hepatitis C infections. Improperly sterilized surgical tools, reuse of syringes and infusion bags are some of the contributing factors to hospital equipment causing hepatitis C infections/transmission. Sexual activities are as well among the risk factors for hepatitis C infection although there have been controversies concerning its involvement in the same. Sexual practices involving concurrent sexually transmitted diseases pose the greatest risks. Sharing personal items such as toothbrushes and razors also poses a great risk (Rajaguru, 2012, p 1). Transmission from mother to child is also a possible cause of hepatitis C infection.
Even though HCV is found in body parts such as the liver, epithelium, and monocular cells among others, the virus replicates in the hepatocytes. The replication process involves an RNA-dependent polymerase chain reaction. However, the virus does not directly cause hepatotoxic in persons with strong immune systems as the infected cells are quickly recognized by lymphocytes initiating an immediate immune response against the virus. Progression of inflammation is mediated by cytokinesis which eventually leads to damage of the parenchyma of the liver (CDC 2011, p 1). Progressive activation of stellate cells in the liver parenchyma by specific inflammatory mediators leads to hepatic fibrosis which occurs at different degrees. This may eventually lead to cirrhosis in some patients
Not all hepatitis C patients develop chronic infections. Similarly, not all chronic hepatitis C patients develop cirrhosis. Hepatitis Chas has been reported to be the major cause of chronic hepatitis in the United States with an estimate of 20% of all acute hepatitis. A study by Alter et al reported that approximately 30, 000 infections are made every year with a yearly death rate of up to 10, 000. Out of all the new hepatitis C infections, 60% of them are a result of intravenous drug use with 20% resulting from sexual exposure. Genotype 1a of the Hepatitis C Virus has been reported to be the common cause of hepatitis C occurring in 57% of hepatitis patients. Between the period of 1989 and 1993, the prevalence of hepatitis C infections decreased by 80% from a high number of new cases of infections of 100, 000 to approximately 28, 000 in a year (New York State 2008, p 1).
In the United States, the number of deaths resulting from hepatitis infection complications increased from 10, 000 to 15, 000 per year with this number expected to rise shortly due to the rising number of patients with chronic hepatitis infections.
Reports on hepatitis C infections in the United States indicate that minority populations are more susceptible to HCV than other populations. Such groups include blacks, persons with low economic statuses, Hispanic groups, and uneducated people. Studies have also indicated that 65% of hepatitis C infections in the United States are among people aged between 30 and 49 years with those infected at younger ages having possibilities of better prognosis than those infected at a later age.
HCV has been reported to be less common among people aged 20 years and below but more prevalent in older persons probably from the age of 40 years (PubMed 2010, p 1). Age has also been implicated in the transmission of HCV with variations in the mode of transmission. However, studies have not associated sex and ethnic-racial groups with HCV preponderance.
Clinical manifestation and diagnosis
HCV infection is mostly asymptomatic especially in its early stages with possibilities of general symptoms such as mild nausea and fatigue. However, after 60 days of incubation, some patients approximately 25% experience icteric illness. When symptoms occur, they tend to be milder than those of other hepatitis infections. Other mild manifestations include fever, headaches, abdominal discomfort, and lack of concentration among others. As the infection transits from acute to chronic stages, liver enzymes may arise and persist for several years but with possibilities of fluctuating to normal levels at times (Mayo Clinic 2011, p 1). In other cases, symptoms appear only with the onset of an advanced liver-related illness.
Hepatitis C Virus is detected through serological assays which are based on the detection of HCV antibodies or HCV RNA. The Enzyme-Linked ImmunoSorbent Assay (ELISA) is the most commonly used serological test for detection of HCV having a high rate of specificity and sensitivity of 95%. To eliminate false-positive ELSA tests on HCV, positive ELISA results are confirmed using Recombinant Immunoblot Assay (RIBA) as a supplement.
Even in individuals who clear the virus naturally, their antibody test results are always positive and this prevents them from being used to ratify infections. Due to possible false-negative results during infections, confirmations are made on HCV RNA using quantitative/qualitative methods such as PCR (Polymerase Chain Reaction) (Fox, 2012, p 1). This is required for ongoing infections to determine the viral load which is significant in determining the effectiveness of anti-HCV therapies. The level of the liver hormone, alanine aminotransferase has also been used as an indirect indicator of necrosis of the liver cells. However, this has been discredited by the finding that many infected people have normal levels of the hormone.
As discussed earlier, HCV affects the hepatocytes and the consequent liver damage may be as a result of a direct cytopathic effect of the virus and/or due to the effects of cytolytic response by the host’s immune system. Chronic hepatitis C is categorized by inflammation of the hepatocytes resulting in fibrosis and necrosis. The normal progression of hepatitis C is however affected by other factors especially the pre-existence of Hepatitis B Virus (HCV) and alcohol intake. Co-infected patients run a higher risk of developing carcinoma of hepatocytes than patients who are infected by only one of the viruses (Heller, and Liang, 2004, p 1).
The course of the disease is sometimes determined by the size of the inoculum where cases of post-transfusion are more likely to progress more aggressively than infections resulting from injection of drugs. The expression of this disease is generally related to the expression of the virus evidenced by the presence of HCV RNA in asymptomatic patients exhibiting normal levels of ALT hormone levels.
Treatment of hepatitis C depends on the stage of infection although acute infection is rarely treated as it is hardly recognized due to its associated flu-like symptoms. However, the intervention of a therapy containing interferon does prevent the progression of the disease to chronic levels when administered early enough. However, treatment of the disease with interferon has several contraindications which patients need to consider before deciding to get therapy for HCV (Mukherjee, 2012, p 1). Deep depression, autoimmune hepatitis, organ transplantation implications, and concurrent diseases among others are the possible complications associated with the use of interferon in hepatitis C patients. Interferon has been reported to be effective with a response of 14% – 73% with variations depending on the patient’s genome. With these reports, interferon has been considered to be more effective than other previous treatments.
Hepatitis C is a very serious viral infection being the most common and deadly hepatitis infection. Hepatitis C is caused by HCV which infects hepatocytes causing inflammation of the cells which develop into cirrhosis in chronic stages of infection. Acute infection is hardly detected since it is asymptomatic with general symptoms resembling those of flu. Hepatitis C has been reported all over the world with no racial and sex inclination prevalence. With the transmission of HCV through intravenous drugs and improperly sterilized equipment, many people are susceptible to infection. Although intravenous is effective in treating the disease, factors like body mass, iron load in the hepatocytes, genotype, and HCV RNA from previous treatments do affect the therapeutic response of interferon.
CDC. (2011). Hepatitis C information for health professionals. Center for Disease Control and Prevention. Web.
Fox, R. (2012). Hepatitis C medications: A review and update for patients. United States Department of Veterans Affairs. Web.
Heller, T. and Liang, J. (2004). Pathogenesis of hepatitis C-associated hepatocellular carcinoma. National center for biotechnology information, U.S. national library. Web.
Liang, J. (2012). Pathogenesis, natural history, treatment and prevention of hepatitis C. Annals of internal medicine: American college of physicians. Web.
Mayo Clinic. (2011). Hepatitis C: symptoms. Mayo Foundation for Medical Education and Research. Web.
Mukherjee, S. (2012). Hepatitis C. Medscape reference: drugs, diseases and procedures. Web.
New York State. (2008). Hepatitis C. Department of health: Information for a healthy New York. Web.
PubMed. (2010). Hepatitis. National Center for Biotechnology Information: U.S. library of medicine. Web.
Rajaguru, S. (2012). Hepatitis C infection. MedicineNet.com: Bringing doctors’ knowledge to you. Web.
WHO. (2012). Hepatitis C: Global alert and response. World Health Organization. Web.