Etiology And Mechanisms Of Hbv Infection
Etiology
Hepatitis B virus
HBV is classified in the family Hepadnaviridae. It is a very small, partially double-stranded DNA virus. Humans are known to be the only natural host. HBV reaches the liver through the systemic circulation and can only replicate in hepatocytes . Since HBV is a hepatotropic virus, injury to the liver results from the immune-mediated destruction of infected hepatocytes .
The infectious HB virion has a diameter of 42-47 nm and is a double-shelled particle in serum. Its concentration can be as high as 108 virions per mL . The infectious HB virion consists of an outer lipoprotein coat containing hepatitis B surface antigen . HBsAg surrounds an inner nucleocapsid composed of hepatitis B core antigen that encapsidates the HBV genome and DNA polymerase .
Genome structure and proteins
FIGURE 1: Structure and organization of the HBV genome . The four protein-coding regions are shown by semicircular arrows. They include the precore and core gene the polymerase gene the X gene and the envelope genes pre-S1, pre-S2, and S . The positions of the direct repeats are indicated. Genome positions may change, depending on the HBV genotype . Abbreviations: HBV, hepatitis B virus P gene, the polymerase gene C gene, the core gene S gene, the surface gene.
Natural history of HBV infection
The natural history of chronic HBV infection can be separated into five stages, which are not necessarily sequential . These stages are summarized in Table 1 .
Hiv And Hepatitis B And Hepatitis C Coinfection
Hepatitis B and hepatitis C are liver infections caused by a virus. Because these infections can be spread in the same ways as HIV, people with HIV in the United States are often also affected by chronic viral hepatitis.
Viral hepatitis progresses faster and causes more liver-related health problems among people with HIV than among those who do not have HIV. Liver disease, much of which is related to HBV or HCV, is a major cause of non-AIDS-related deaths among people with HIV.
Given the risks of hepatitis B or hepatitis C coinfection to the health of people living with HIV, it is important to understand these risks, take steps to prevent infection, know your status, and, if necessary, get medical care from someone who is experienced in treating people who are coinfected with HIV and HBV, or HIV and HCV.
Is Hepatitis A Sexually Transmitted Disease
Robert Burakoff, MD, MPH, is board-certified in gastroentrology. He is the vice chair for ambulatory services for the department of medicine at Weill Cornell Medical College in New York, where he is also a professor. He was the founding editor and co-editor in chief of Inflammatory Bowel Diseases.
Some types of viral hepatitis can be transmitted through sexual contact, in addition to being transmitted via other routes. Each type of hepatitis virus has a different risk of being transmitted through sex.
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How Is Hepatitis B Treated
Treatment for hepatitis B depends on how long you have had the virus.
There is no specific treatment for acute hepatitis B, and most people recover within one to two months. Usually, you can manage symptoms at home with plenty of rest and painkillers if necessary. Most people make a full recovery from acute hepatitis B.
If you develop chronic hepatitis B, you will be given treatment to help some of the symptoms. This will also reduce the risk of liver damage and liver cancer. Treatment keeps the virus under control but cannot cure chronic hepatitis B. Some people will need lifelong treatment.
Hiv And Hbv Coinfection
About 2% of people with HIV in the United States are coinfected with HBV both infections have similar routes of transmission. People with HIV are at greater risk for complications and death from HBV infection. All people with HIV are recommended to be tested for HBV, and if susceptible, are further recommended to receive the hepatitis B vaccination or, if chronically infected, evaluated for treatment to prevent liver disease and liver cancer. For more information about HIV and HBV coinfection, visit HIV.govâs pages about hepatitis B and HIV coinfection.
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Can Viral Hepatitis Be Prevented
Hepatitis A and B can be prevented through vaccinations. Experts recommend that all gay and bisexual men be vaccinated for Hepatitis A and B. The Hepatitis A and B vaccines can be given separately or as a combination vaccine. The vaccines are safe, effective, and require 2-3 shots within a six month period depending on the type of vaccine. A person should complete all shots in the series for long-term protection. There is no vaccine for Hepatitis C.
Giving Blood And Organ Donation
If you have hepatitis C, you cannot give blood.
In a recent research study in America kidneys from people with hepatitis C who had died were transplanted into patients who did not have the virus.
All of the recipients subsequently contracted hepatitis C but were treated for it and all were cured. The benefit of receiving a kidney outweighed the risk of not clearing hepatitis C.
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How Is It Spread
Hepatitis B virus is spread by contact with body fluidsthat carry the virus, such as:
Hepatitis B is spread by contact with infected body fluids, mostly by:
- Sexual contact:
- Sharing unclean sex toys
- During illegal drug or drug equipment use
- Open sores of an infected person
- Sharing items such as razors or toothbrushes with an infected person
- Being tattooed or pierced with tools that were not properly cleaned
- Hepatitis B can spread to babies during pregnancy and birth.
Infected motherscan pass hepatitisB to their babiesduring childbirth.
Hepatitis B is rarely spread from a blood transfusion because:
- Hepatitis B tests are done on all donated blood.
- Blood and blood products that test positive for hepatitis B are safely destroyed. None are used for transfusions.
- There is no risk of getting hepatitis B when donating or giving blood.
Hepatitis B Symptoms And Treatment
Hepatitis B is part of a group of hepatitis viruses that attack the liver. It is spread through blood and bodily fluids. It is most commonly passed on via unprotected sex , from a mother to her child during birth, or through contaminated needles.
In adults, it often causes no obvious symptoms and can pass in a few months without treatment. Children are more likely to develop a long-lasting infection. Without appropriate treatment and care, children and adults with a chronic infection can become seriously ill and be at risk of liver damage or death.
Vaccines for hepatitis B are offered to infants and are available for people at high risk of the condition.
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How Is Hepatitis C Spread
Hepatitis C is spread through contact with the blood of someone who has Hepatitis C, mainly through sharing needles, syringes, or other injection drug equipment. Hepatitis C can also be spread when getting tattoos and body piercings in casual places or with non-sterile instruments. Although uncommon, Hepatitis C can also be spread through sexual contact. Having a sexually transmitted disease or HIV, sex with multiple partners, or rough sex can raise a persons chance of getting Hepatitis C.
What Are Signs Of Hepatitis B
When you first get hepatitis B, it is called acutehepatitis B. Most adults who have hepatitis B willrecover on their own. However, children and someadults can develop chronic hepatitis B.
Acute hepatitis B: Signs of acute hepatitis B canappear within 3 months after you get the virus.These signs may last from several weeks to 6 months.Up to 50% of adults have signs of acute hepatitis Bvirus infection. Many young children do not show anysigns. Signs include:
- Yellow skin or eyes
- A longer than normal amount of time for bleedingto stop
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What Is Hepatitis B
Hepatitis B, sometimes called Hep B or HBV, is part of a group of hepatitis viruses that attack the liver. For some people the infection becomes chronic, meaning it lasts more than six months. People with chronic hepatitis B have a higher chance of liver damage.
Most adults with hepatitis B make a full recovery, even if their symptoms are severe. Babies and children are more likely to develop a long-lasting hepatitis B infection.
How Can I Protect Myself And Others
You can protect yourself by getting vaccinated. This is especially important if you belong to one of the high-risk groups. You’re high risk if you:
- have close contact with someone with the infection
- are a gay man or have sex with men who have sex with men
- travel to parts of the world where the infection is common.
There is a vaccine which can protect you against both hepatitis A and B.
If you’re in a high-risk group for hepatitis B you can usually get vaccinated for free by your GP or at your sexual health clinic.
You may need a booster injection of the vaccination after five years.
If you have hepatitis B, tell people you live with or recently had sex with to urgently ask their doctor about vaccination. Avoid sex until told you’re no longer infectious.
Although not as effective as being vaccinated, you can also cut the risk by:
- using condoms for penetrative sex
- a latex barrier for rimming.
If you’re a carrier, you may want to tell a partner and explain that you’re infectious. That allows them to decide if they want to take precautions or are happy to take any risk.
That way they cannot accuse you of infecting them without them knowing the risk was there.
If you’re not vaccinated against hepatitis B and are exposed to the virus, theres a treatment which may stop you being infected. Hepatitis B immunoglobulin is an injection of antibodies. It’s best to get it within 48 hours of exposure you’ll be vaccinated at the same time.
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How Is Hepatitis A Treated
Unlike other types of viral hepatitis, hepatitis A rarely causes long-term liver damage and doesnt become a long-term illness. There isnt a specific treatment for hepatitis A, and most people will recover fully within one to two months. Usually, symptoms are managed at home with plenty of rest and painkillers and/or medication to help with itchiness, nausea or vomiting may be prescribed.
Occasionally hepatitis A can last longer and, in rare cases, it can be life-threatening if it causes the liver to stop working properly .
Whether youve got symptoms or not, dont prepare food for others or have sex until a healthcare professional tells you that youre no longer infectious.
Once youve recovered from hepatitis A youre immune this means you cant get it again. But you can get other types of hepatitis.
Health Services For Screening And Treatment Of Stis Remain Weak
People seeking screening and treatment for STIs face numerous problems. These include limited resources, stigmatization, poor quality of services and often out-of-pocket expenses.
In many settings, STI services in low- and middle-income countries are often neglected and underfunded. These problems lead to difficulties in providing screening for asymptomatic infections, insufficient number of trained personnel, limited laboratory capacity and inadequate supplies of appropriate medicines.
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Sexual Transmission And Viral Hepatitis
Certain adults who are sexually active should be vaccinated against hepatitis B.
CDC and the Advisory Committee on Immunization Practices recommend hepatitis B vaccination for
- sexually active people with more than one sex partner during the previous 6 months
- people seeking evaluation or treatment for a sexually transmitted disease
- sex partners of people with hepatitis B and
- men who have sex with men .
CDC recommends one-time hepatitis C testing of all adults and regular testing for people with risk factors.
How Many People Have Hepatitis B
In the United States, an estimated 862,000 people were chronically infected with HBV in 2016. New cases of HBV infection in the United States had been decreasing until 2012. Since that time, reported cases of acute hepatitis B have been fluctuating around 3,000 cases per year. In 2019, 3,192 cases of acute hepatitis B were reported however, because of low case detection and reporting, the Centers for Disease Control and Prevention estimates that there were 20,700 acute hepatitis B infections. New HBV infections are likely linked to the ongoing opioid crisis in the United States.
Globally, HBV is the most common blood-borne infection with an estimated 296 million people infected according to the World Health Organization .
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Epidemiology: Incidence And Prevalence
Incidence: worldwide view and HIV/HBV coinfection
More than one third of the worlds population are estimated to be infected with HBV. About 5% of the worlds population are chronic carriers of HBV, and HBV infection causes more than one million deaths every year . The HBsAg carrier rate varies from 0.1% to 20% of different populations worldwide. In low-risk regions, the highest incidence of infection is seen in teenagers and young adults.
Based on the data from Western cohorts, HIV/HBV coinfection has a profound impact on almost every aspect of the natural history of HBV infection . The consequences include higher rates of chronicity after acute HBV infection, higher levels of HBV replication and rates of reactivation, less spontaneous clearance, higher rates of occult HBV infection , more rapid progression to cirrhosis and HCC, higher rates of liver-related mortality, and decreased treatment response compared with individuals without HIV coinfection . Recent longitudinal cohort studies have found that coinfection with HBV also can lead to increased rates of progression to acquired immune deficiency syndrome -related outcomes and all-cause mortality . An estimated 5% to 15% of the 34 million HIV-infected individuals worldwide are coinfected with HBV, as a chronic infection . The burden of coinfection is greatest in Southeast Asia and sub-Saharan Africa .
Prevalence: international statistics
HBV serotypes and genotypes
The Types Of Sexually Transmitted Diseases And Hepatitis Infections
STD is a sexually transmitted disease that is a severe condition that passes through sexual contact. Anyone can contract STD through unprotected sexual relationships. STD is also a sexual infection that is known as venereal disease. There are other ways through which this infection can pass, such as sharing used needles or breastfeeding. Different types of STDs can be transmitted through one person to another. In this article, you can know more about the types of it and diseases like hepatitis.
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Hbv Serotypes And Genotypes
Based on some of the antigenic determinants of HBsAg, nine serological types -referred to as subtypesadw2, adw4,adrq+, adrq, ayw1,ayw2, ayw3, ayw4 andayr – have been identified 50. Ten genotypes of HBV have been identified, and thesecorrespond to specific geographic distributions 51. Genotype A is more frequently found in North America,northwestern Europe, India, and Africa. Genotypes B and C are endemic to Asia,and genotype D predominates in eastern Europe and the Mediterranean 52. Type E is found in western Africa typeF, in South America and type G, in France, Germany, Central America, Mexico,and the United States. Type H is prevalent in Central America 48 type I, in Vietnam and type J, in Japan 53.
HIV-seropositive MSM populations predominantly coinfected with HBV genotype Ahave been reported in European countries and Japan 54,55,56. The prevalence of HBV genotype A issignificantly higher in the MSM population than in the rest of the population56. In addition, Araujo etal. speculated in their review that HBV subgenotypes A2 and C arelikely to predominate in populations at high risk of infection via sexualtransmission 57. Additionally, HBVgenotype A develops into a persistent infection more often than genotype C 58,59.
Hepatitis B And Safe Sex
“All three forms of viral hepatitis may be transmitted sexually, although hepatitis B is most commonly transmitted sexually,” explains Michael B. Fallon, MD, professor of medicine at The University of Texas Medical School in Houston. Once you have been diagnosed with hepatitis B, you should tell your partner so he or she can be tested. If your partner does not have hepatitis B, and is not already immune to hepatitis B, a vaccine is recommended.
“Sexual partners of individuals with hepatitis B should consider vaccination to prevent acquiring infections,” says Fallon. Hepatitis B immune globulin which works like an antibody, quickly fighting infection can also be given to a partner who has been exposed to your body fluids within two weeks after exposure to prevent infection. Even after your partner has been vaccinated, you should always use a condom.
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Hepatitis C And Safe Sex
As with hepatitis B, the time to tell any sexual partner about your diagnosis is before you have sex or if you have already had sex, before you have sex again. Again, if you are having sex you need to use condoms and avoid risky sexual activity.
“In patients with hepatitis C in stable monogamous relationships, the rate of transmission appears to be in the range of 2 to 4 percent per year,” says Fallon.
Even though the chance of transmitting hepatitis C is lower if you are having sex with only one partner, you still need to be responsible and cautious. “Since there is no effective vaccine prevention is of particular importance in this group,” warns Fallon. Using condoms will decrease the risk of transmitting your hepatitis C infection to your partner.