Category Archives: Hepatitis

Hepatitis C – HVC – Epidemiology

Epidemiology

It is estimated that Hepatitis C has infected nearly 200 million people worldwide, and infects 3-4 million more people per year. There are about 35,000 to 185,000 new cases a year in the United States. It is currently a leading cause of cirrhosis, a common cause of hepatocellular carcinoma, and as a result of these conditions it is the leading reason for liver transplantation in the United States. Co-infection with HIV is common and rates among HIV positive populations are higher. 10,000-20,000 deaths a year in the United States are from HCV; expectations are that this mortality rate will increase, as those who were infected by transfusion before HCV testing become apparent. A survey conducted in California showed prevalence of up to 34% among prison inmates;[34] 82% of subjects diagnosed with Hepatitis C have previously been in jail,[35] and transmission while in prison is well described.

Prevalence is higher in some countries in Africa and Asia. Egypt has the highest seroprevalence for HCV, up to 20% in some areas. There is a hypothesis that the high prevalence is linked to a now-discontinued mass-Treatment campaign for schistosomiasis, which is endemic in that country. Regardless of how the epidemic started, a high rate of HCV transmission continues in Egypt, both iatrogenically and within the community and household.

Co-infection with HIV

Approximately 350,000, or 35% of patients in the USA infected with HIV are also infected with the Hepatitis C virus, mainly because both viruses are blood-borne and present in similar populations. In other countries co-infection is less common, and this is possibly related to differing drug policies. HCV is the leading cause of chronic liver disease in the USA. It has been demonstrated in clinical studies that HIV infection causes a more rapid progression of chronic Hepatitis C to cirrhosis and liver failure. This is not to say Treatment is not an option for those living with co-infection.

Hepatitis C – HCV – Virology

Virology

The Hepatitis C virus (HCV) is a small (50 nm in size), enveloped, single-stranded, positive sense RNA virus. It is the only known member of the hepacivirus genus in the family Flaviviridae. There are six major genotypes of the Hepatitis C virus, which are indicated numerically (e.g., genotype 1, genotype 2, etc.).

The Hepatitis C virus (HCV) is transmitted by blood-to-blood contact. In developed countries, it is estimated that 90% of persons with chronic HCV infection were infected through transfusion of unscreened blood or blood products or via injecting drug use or sexual exposure. In developing countries, the primary sources of HCV infection are unsterilized injection equipment and infusion of inadequately screened blood and blood products. There has not been a documented transfusion-related case of Hepatitis C in the United States for over a decade as the blood supply is vigorously screened with both EIA and PCR technologies.

Symptoms Hepatitis C – HCV – Hepatitis C Treatment

Symptoms Hepatitis C

Hepatitis C is an infectious disease affecting the liver, caused by the Hepatitis C virus (HCV). The infection is often asymptomatic, but once established, chronic infection can progress to scarring of the liver (fibrosis), and advanced scarring (cirrhosis) which is generally apparent after many years. In some cases, those with cirrhosis will go on to develop liver failure or other complications of cirrhosis, including liver cancer.

The Hepatitis C virus (HCV) is spread by blood-to-blood contact. Most people have few, if any symptoms after the initial infection, yet the virus persists in the liver in about 85% of those infected. Persistent infection can be treated with medication, peginterferon and ribavirin being the standard-of-care therapy. Only 51% are cured overall. Those who develop cirrhosis or liver cancer may require a liver transplant, and the virus universally recurs after transplantation.

An estimated 270-300 million people worldwide are infected with Hepatitis C. Hepatitis C is a strictly human disease. It cannot be contracted from or given to any animal. Chimpanzees can be infected with the virus in the laboratory, but do not develop the disease, which has made research more difficult. No vaccine against Hepatitis C is available. The existence of Hepatitis C (originally “non-A non-B hepatitis“) was postulated in the 1970s and proved conclusively in 1989. It is one of five known hepatitis viruses: A, B, C, D, and E.

Hepatitis B – HBV- Prognosis

Prognosis

Hepatitis B virus infection may either be acute (self-limiting) or chronic (long-standing). Persons with self-limiting infection clear the infection spontaneously within weeks to months.


Children are less likely than adults to clear the infection. More than 95% of people who become infected as adults or older children will stage a full recovery and develop protective immunity to the virus. However, only 5% of newborns that acquire the infection from their mother at birth will clear the infection. This population has a 40% lifetime risk of death from cirrhosis or hepatocellular carcinoma. Of those infected between the age of one to six, 70% will clear the infection.

Hepatitis B – HBV- Diagnosis

Diagnosis

The tests, called assays, for detection of Hepatitis B virus infection involve serum or blood tests that detect either viral antigens (proteins produced by the virus) or antibodies produced by the host. Interpretation of these assays is complex.

Hepatitis B viral antigens and antibodies detectable in the blood following acute infection.

Hepatitis B viral antigens and antibodies detectable in the blood of a chronically infected person.

Hepatitis B – HBV- Epidemiology

Epidemiology

Prevalence

Prevalence of Hepatitis B virus as of 2005.

The primary method of transmission reflects the prevalence of chronic HBV infection in a given area. In low prevalence areas such as the continental United States and Western Europe, where less than 2% of the population is chronically infected, injection drug abuse and unprotected sex are the primary methods, although other factors may be important. In moderate prevalence areas, which include Eastern Europe, Russia, and Japan, where 2-7% of the population is chronically infected, the disease is predominantly spread among children. In high prevalence areas such as China and South East Asia, transmission during childbirth is most common, although in other areas of high endemicity such as Africa, transmission during childhood is a significant factor. The prevalence of chronic HBV infection in areas of high endemicity is at least 8%.

Hepatitis B – HBV- Virology

Virology

Structure

A simplified drawing of the HBV particle and surface antigen.

Hepatitis B virus (HBV) is a member of the HepaDNAvirus family. The virus particle, (virion) consists of an outer lipid envelope and an icosahedral nucleocapsid core composed of protein. The nucleocapsid encloses the viral DNA and a DNA polymerase that has reverse transcriptase activity. The outer envelope contains embedded proteins which are involved in viral binding of, and entry into, susceptible cells. The virus is one of the smallest enveloped animal viruses with a virion diameter of 42nm, but pleomorphic forms exist, including filamentous and spherical bodies lacking a core. These particles are not infectious and are composed of the lipid and protein that forms part of the surface of the virion, which is called the surface antigen (HBsAg), and is produced in excess during the life cycle of the virus.

Hepatitis A – HAV – Pathogenesis, Epidemiology, Caces and Diagnosis

Hepatitis A is an acute infectious disease of the liver caused by the hepatitis A virus (HAV), which is most commonly transmitted by the fecal-oral route via contaminated food or drinking water. Every year, approximately 10 million people worldwide are infected with the virus. The time between infection and the appearance of the symptoms, (the incubation period), is between two and six weeks and the average incubation period is 28 days.

In developing countries, and in regions with poor hygiene standards, the incidence of infection with this virus is high and the illness is usually contracted in early childhood. HAV has also been found in samples taken to study ocean water quality. Hepatitis A infection causes no clinical signs and symptoms in over 90% of these children and since the infection confers lifelong immunity, the disease is of no special significance to the indigenous population. In Europe, the United States and other industrialized countries, on the other hand, the infection is contracted primarily by susceptible young adults, most of whom are infected with the virus during trips to countries with a high incidence of the disease.

Hepatitis C – hepatitis treatment and symptoms

Symptoms

Jaundice in a man with hepatic failure.

Acute infection with Hepatitis B virus is associated with acute viral Hepatitis – an illness that begins with general ill-health, loss of appetite, nausea, vomiting, body aches, mild fever, dark urine, and then progresses to development of jaundice. It has been noted that itchy skin has been an indication as a possible symptom of all Hepatitis virus types. The illness lasts for a few weeks and then gradually improves in most affected people. A few patients may have more severe liver disease (fulminant hepatic failure), and may die as a result of it. The infection may be entirely asymptomatic and may go unrecognized.

Hepatitis B – HBV – Symptoms and Treatment

Hepatitis B

Hepatitis B is a disease caused by HBV Hepatitis B virus which infects the liver of hominoidae, including humans, and causes an inflammation called hepatitis. Originally known as “serum hepatitis”, the disease has caused epidemics in parts of Asia and Africa, and it is endemic in China. About a third of the world’s population, more than 2 billion people, have been infected with the Hepatitis B virus. This includes 350 million chronic carriers of the virus. Transmission of Hepatitis B virus results from exposure to infectious blood or body fluids containing blood.