Background of Hepatitis B infection
Hepatitis B virus infection is caused by a DNA virus belonging to the hepadnaviridae family of viruses. Approximately 2.2 million people in the United States of America are infected with Hepatitis B virus. Many of these patients, though they appear healthy, continue to spread the virus to others. Hepatitis B virus infection can be transmitted in the following ways: contact with contaminated blood (shared needles), sexual contact, and from mother to child. Unlike Hepatitis A, Hepatitis B is not spread through food, water, or causal contact. 95% of adults who get Hepatitis B can clear the virus through their system. However the remainder of the adults go on to develop chronic hepatitis B infection. This can
…show more content…
We need to understand the structure of the virus, the viral genome, and how it causes the disease, and also to better understand the body’s immune response to the infection. Hepatitis B is a hepadnavirus, (slectron emicroscopy image), with a 42 nm virion. The virion is a double shelled spherical particle and consists of smaller rods and spheres each with an average 22 nm diameter. Not surprisingly the virus is very resistant and survives in high temperatures and is known to have been sequenced from 400 year old mummified …show more content…
The vaccine is a recombinant vaccine, totally devoid of human blood or blood products. The vaccine is obtained by cloning a portion of the hepatitis B virus gene that codes for the s antigen into yeast cells. The recombinant yeast strains are cultured. The antigen is then harvested and purified and suspended in sterile solutions, ready for immunization. The vaccine does not cause hepatitis B virus infection. It in fact prevents infection by hepatitis B virus. It works on the immune system and causes the outpouring of antibodies that will protect against the infection, in the event the patient is exposed to the
The Hepatitis B virus is a disease that affects the liver and results in swelling and loss of normal function in the liver. It is estimated that 350 million people are infected with Hepatitis B worldwide, with 50 million new cases diagnosed every year.(1) In the Unit...
Hepatitis B Virus (HBV) is a virus that leads to infection of the liver. Infection of the HBV can be acute or lifelong (chronic). Humans are the only known host for HBV (CSC, 2017). This virus can survive on environmental surfaces for up to seven days (WHO, 2017).
The virus is primarily spherical shaped and roughly 200nm in size, surrounded by a host-cell derived membrane. Its genome is minus-sense single-stranded RNA 16-18 kb in length. It contains matrix protein inside the envelope, hemagglutinin and neuraminidase, fusion protein, nucleocapsid protein, and L and P proteins to form the RNA polymerase. The host-cell receptors on the outside are hemagglutinin and neuraminidase. The virus is allowed to enter the cell when the hemagglutinin/ neuraminidase glycoproteins fuse with the sialic acid on the surface of the host cell, and the capsid enters the cytoplasm. The infected cells express the fusion protein from the virus, and this links the host cells together to create syncitia.
HAV is known to be an infectious disease that usually occurs in children and young adults .The disease is usually transmitted from person to person through contaminated food, liquids or oral fecal route. An example would be when someone is carrying the virus and doesn’t wash their hands after using the restroom and then puts food in their mouth. HAV is most common in developing countries because of the living conditions and inadequate water, poor sewage facilities and sanitary conditions. The highest HAV levels in the world are from India,” Earlier reports suggest that India is hyperendemic for HAV infection2,4-6 with very high infection rates,” (Sowmyanarayanan). Most HAV are without severe complications, “Virus HAV infection rarely causes fulminant hepatic failure in people…,” (Vento,p.1) . The symptoms for HAV are high fever, nausea, vomiting and jaundice...
There are four phases of Hepatitis B: infection, inflammation, fibrosis, and cirrhosis. In the first phase, HBV invades the liver and goes for the nucleus, where it releases contents of DNA and polymerase into the surroundings. It then maneuvers its way to the cell’s components and enzymes. The polymerase sways the liver cells to make segments of the HBV DNA from RNA. The virus makes liver cells create spare parts for other HBV viruses. Replicas are released from liver cell into the bloodstream, destroying host cell and infecting other healthy liver cells. This entire process can take a few hours to occur, but must continue multiple times for serious damage to occur. The second phase is inflammation. Inflammation is caused by lymphocytes trying to get rid of the virus, but they also release harmful chemicals that damage the cells and take part in damaging the liver. The third phase is fibrosis. Fibrosis is scar tissue caused by inflammation and chronic infection. According to Everson and Weinburg, (2002, pg. 64) “Only 5/10% of people develop chronic Hepatitis B from acute Hepa...
The idea behind vaccines is to provide the body with just enough of the disease-causing substance to trick the body into producing antibodies against it. By injecting weak or dead infectious agents through the skin, it’s believed that the body will create the appropriate immune defense. Infants come into the world with antibodies they have gotten from their mother through the placenta. Infants who are breastfed continue to receive many important antibodies in the colostrum (the thick, yellowish premilk that is secreted during the first few days after a woman gives birth) and breast milk. During the first year of life, the immunity an infant gets from its mother at birth wears off. To help boost the fading ability to fight certain diseases, vaccines are given. Once the antibodies are produced, they stay around, protecting the child against the disease they were designed to fight.
Pathogens are a type of microorganism that spreads viral and bacterial diseases. These diseases when present in human blood and body fluids are known as blood borne pathogens, and can spread from one person to another. (Worcester polytechnic institute) The most serious types of blood borne diseases are the hepatitis B virus (HBV) and hepatitis C virus (HCV), which can cause liver damage; and HIV (human immunodeficiency virus), which is responsible for causing AIDS (acquired immune deficiency syndrome). The blood borne pathogens can be spread when the blood or body fluids (semen, vaginal fluid, breast milk, and amniotic fluid) of an infected individual comes into contact with mucous membranes or an open sore or cut on the skin of another person. Mucus membranes are located in the eyes, nose, mouth, and other areas as well. ("Bloodborne pathogens: MedlinePlus Medical Encyclopedia") Two of the most common ways that pathogens are transmitted is through the exchange of fluids during sexual intercourse or by sharing infected IV needles. (Worcester polytechnic institute)
natural history of hepatitis B and profnostic factors of Disease Progression. Giovanna Fattovich, Irene Zagni, Chiara Scattolini. Paris 2004
Hepatitis A is a usually short-acting virus that occurs in humans and monkeys. It is caused by the Hepatovirus and the species is Hepatitis A Virus. There are two major ways in which hepatitis A can be transmitted. One way is from person to person. This transmission occurs when the fecal matter of an infected person gets ingested by another person.
Hepatitis A being spread can be prevented by properly washing your hands with soap and water before and after preparing food and drinks. Washing hands thoroughly, after using the bathroom and changing diapers. Disinfecting kitchen counters, cutting boards and cooking utensils after use (5). It is recommended that if you feel you may have been contaminated with the virus that you see a healthcare provider promptly and ask about the Hepatitis A vaccine that is available. If you receive the vaccine within fourteen days of exposure illness can be prevented, it is unlikely you will contract Hepatitis A if you've been vaccinated prior.
Recent research shows that, there are three major means by which infections can be transmitted and they include direct transmission, indirect transmission and airborne transmission (Hinman,Wasserheit and Kamb,1995). Direct transmission occurs when the physical contact between an infected person and s susceptible person takes place (division of public health, 2011). An example is a health care worker who attends to an Ebola patient, without gloves, gown and mask plus forget to wash his or her hand with soap and hot water and or a person having flu without the use of mask or washes his hand after sneezing easily passes the infection to the other through hand shake or surface touch, living the bacteria there for another vulnerable person to also touch if the surface is not disinfected with bleach. Studies makes it clear that, the spreads takes effect when disease-causing microorganisms pass from the infected person to the healthy person through direct physical contact such as touching of blood, body fluids, contact with oral secretion, bites kissing, contact with body lesions and even sexual contact. However, measles and chicken pox are said to be conditions spread by direct
There is a disease spreading out in the world called Hepatitis C. It affects the liver and may cause the liver to fail. This disease is caused by a virus called Hepatitis C virus which is also known as HCV. About 32,000 people are affected with this disease per year only in the United States area. Some It’s a disease with many symptoms and many causes. of these symptoms are easy bruising, upset stomach and fever. These are just some of the many symptoms that come from the virus. Hepatitis Cs nature of the causative agent is determined by many things. The biological data of this disease is filled so much information. It is estimated that over 180 million people have gotten Hepatitis C and it is growing.
Hepatitis B, an infectious disease caused by the Hepatitis B virus (HBV, a DNA virus), was formerly called serum hepatitis, inoculation hepatitis and post-transfusion hepatitis. Infection with HBV may result in acute, fulminant or chronic hepatitis, sometimes even resulting in a chronic asymptomatic carrier state, apart from hepatocellular carcinoma and liver cirrhosis (Davis 179). The disease is transmitted when an individual comes in contact with infected blood or objects. It may also be transferred from an infected mother to her infant either during or after birth (Zuckerman et al. 211). Transmission may also occur by accidental inoculation from infected needles and hospital equipment, intravenous drug abuse, body piercing, tattooing, and mouth-mouth kissing (Zuckerman et al. 210). The risk of Hepatitis B is particularly high in individuals with multiple sex partners, and in homosexuals. The HBV virus occurs in morphologically different forms in the serum of infected individuals. HBV infection has an incubation period of about 75 days. Systemic symptoms of the disease include fatigue, fever, dyspepsia, arthralgia, malaise, and rash, while local symptoms include hepatomegaly, jaundice, dark urine, and pale stools (Davis 179; Zuckerman et al. 210).
Viruses can be transmitted in many ways. Being in contact with an infected person will most likely transfer the virus. One can also obtain the virus through swallowing, inhaling, and unsafe sex. Poor hygiene and eating habits usually increase the risk of catching a viral infection. Contracting a viral infection is followed by adverse s...
Sexually Transmitted Diseases Sexually Transmitted Diseases STDs, a.k.a venereal diseases, infectious diseases passed from one person to another during sexual contact. STDs are the most common infections known. More than 12 million people in the United States, including 3 million teenagers, are infected with STDs every year. The United States has the highest STD rate in the world about one in ten Americans will contract an STD during his or her lifetime. People who do not know they are infected risk infecting their sexual partners and, in some cases, their unborn children. If left untreated, these diseases may cause pain or may destroy a woman's ability to have children. Some STDs can be cured with a single dose of antibiotics, but AIDS cannot be cured. Those most at risk for contracting STDs are people who have unprotected sex—without using a condom, people who have multiple partners, and people whose sex partners are drug users who share needles. Static’s show that Americans between the ages of 16 and 24 are most likely of catching STDs than older adults, because younger people usually have multiple sexual partners than an older person in a long-term relationship. Teenagers may be embarrassed to tell their sexual partners they are infected Teenagers may also be embarrassed or unable to seek medical attention for STDs. This means that they only more likely to pass the disease to other young people and have a greater risk of suffering the long-term consequences of untreated STDs. STDs are transmitted by infectious bacteria, viruses, parasites, fungi, and single-celled organisms called protozoa that live in warm, moist parts of the body, like the genital area, mouth, and throat. Most STDs are spread while having sex, but oral sex can also spread disease. Some STDs are passed from a mother to her child while pregnant, when the disease enters the baby's bloodstream, during childbirth as the baby passes through the birth canal, or after birth, when the baby drinks infected breast milk. AIDS can be transmitted by blood contact such as open wounds, between people who share infected needles or received through an injection of infected blood. Some people believe that STDs can be transmitted through shaking hands or other casual contact, or through contact with inanimate objects such as clothing or toilet seats, but they can’t. Chlamydeous, is from trachoma is bacterium, is the most commonly transmitted STD in the United States.