Herpes Simplex Virus Essay - 3306 Words
Herpes Simplex Virus
Herpes Simplex Virus
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Herpes Simplex Virus Type 1 Infection at the Molecular Level
Research Paper
24 November 2008
Herpes simplex virus type 1 (HSV-1) infection is widespread and causes significant disease in humans. The structure, epidemiology, pathogensis and immune response are examined in this review, as well as specific ways to reduce and eliminate pathology and related diseases. The virus naturally infects mucosal areas and begins the search for its target host cell. Upon binding to the host cell membrane via teams of glycoproteins, the virion is then phagocytosed. Soon the nucleus is seized and all regular host cell mechanisms are shut off. Replication of HSV-1 is specific encoding immediate early, early and late genes. Once the virus replication process is complete the virus exits epithelial cells near the site of infection through a process known as cell lysis. Sensory neurons are the specific target of HSV-1, where it can then travel to the trigeminal ganglia (TG) stoma via neuronal microtubular networks. Both innate and adaptive immune systems respond to the infection with various antibodies, interleukins and interferons. Once the virion reaches the nervous system, the immune responses are unable to detect it although they try to contain it as best they can. HSV-1 enters a latent stage, usually via latent associated transcripts, not causing pathogenesis but unable to fight off by means of the host immune system.
Following a stressful situation or similarly UV activation, HSV-1 travels back down nerve fibers to re-infect cells near the original site of infection. This process is known to continue throughout the lifespan of the infected individual, normally without fatalities. When the host immune response is unable to contain the virus in the TG, several associated diseases such as encephalitis and keratits result. Genes involved with virus replication and host genes, to eliminate the virus, have been maneuvered to cause reverse effects and are currently used as antivirals. Although no vaccine has been approved for use against HSV-1, various attempts have been made. This research paper defines the virus infection at a molecular level as well as demonstrates modifications of the virus genes to cause reverse effects and investigates just a few of the diseases connected with HSV-1.
Introduction
Herpes simplex viruses type 1 and 2 are well known members of the family Herpesviridae, subfamily Alphaherpesvirinae, which cause lifelong, latent infection in humans. Herpes simplex virus type 1 (HSV-1) typically remains the cause of cold sores, gingivostomatitis, and skin lesions in the orofacial area, as well as many rare but fatal conditions (1). Herpes simplex virus type 2 (HSV-2) is primarily associated with genital area infection. Worldwide, approximately one third of people display clinical manifestations of HSV-1 infection (2). HSV-1 is neurotropic, infecting multiple cell types but establishing latency in the trigeminal ganglia (TG). HSV-1 reactivates, in response to certain stimuli such as emotional or physical stress or UV light, and is transported along nerve fibers to mucosal or cutaneous regions (1). Infected cells show signs of the nucleus changing shape and nucleolus displacement with a formation of multinucleated giant cells. Cells degenerate, lyse and vesicles of fluid containing the virus locate between the epidermis and dermal layer of the skin forming a lesion (2). Although HSV-1 infects a large percentage of the population, few actually show symptoms of disease. HSV Structure and Genome
HSV-1 is an enveloped double stranded DNA (dsDNA) virus consisting of four elements. First, an outer envelope with glycoprotein spikes on its surface. Second, a tegument layer including several viral proteins important during HSV-1 infection. Third, an iscosahedral capsid surrounding the last compartment, the electron opaque core containing the dsDNA genome wrapped as a spool. The envelope is made up of 13...
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...This baby’s mother had genital herpes and he soon died a few hours later with organ failure.
Herpes simplex viruses are categorized into two types. Herpes type 1 is known as oral herpes, which is the most common, and then there’s herpes type 2 which is genital herpes. Herpes type 1 may cause sores in or around the mouth and lips. Herpes type 2 causes sores in or
around the genitals or rectum, usually below the waist.
HSV-2 is usually transmitted by sexual contact or by fluids from sore. It can also be spread through pregnancy. Neonatal HSV infections are acquired from maternal strains and 75-85% is caused by HSV-2.
Genital herpes increases the transmission of HIV infection. It’s more common in low income areas but it still happens everywhere, so therefore it’s worldwide. This disease is definitely endemic because it’s around all the time and it’s a stage 4 because there’s no animal host. Once a person has the virus, it remains in the body.
During puberty and early adulthood the prevalence of HSV-2 increases and 20-35% of the adults are seropostive meaning it shows a significant level of serum antibodies. The primary cause of Genital herpes is the result of transmission of an infectious agent by another person by one or more of the following: saliva, air, cough, fecal-oral route, surfaces, blood,...
...The herpes virus is one of the most prevalent viral diseases known to man. As much as eighty percent of all people, worldwide, have herpes simplex virus type 1 (HSV1), and twenty percent have herpes simplex virus type 2 (HSV2). This may sound like scary statistics, but most infected people suffer only mild discomfort. The more common form, HSV1, usually causes the occasional
blister-like sores on or around the mouth. These blisters are called cold sores or fever blisters and, as most sufferers know, they are annoying and mildly painful but rarely dangerous. If the sores are left alone, they will generally heal up in five to twenty days. The less common version, HSV2, has the same symptoms except that the sores are usually found on or around the genitals. However, either type can be found in other places on the body and, in rare cases, the virus can cause serious problems. Ocular herpes (an infection of the eye) can cause blindness, and herpes encephalitis (an infection of the brain) can cause brain damage or death. We have no cure for the herpes virus once you have the virus, you have it for life. After the virus invades a new host, it incubates for two to twenty days. Then blister-like sores start to form, and in the initial breakout there can be...
...Living with a Virus
When most people think about the Herpes Simplex Virus, most believe that is categorized only as a sexually transmitted disease that affects areas of the male and female genitalia.
In that case it would be a sexually transmitted disease however, Herpes Simplex Virus can be transmitted in several ways and affect millions of people all around the world.
Herpes is a disease caused by the Herpes Simplex Viruses types 1 (HSV-1) and 2 (HSV-2).
According to the location of the herpes, the virus can be categorized as oral herpes, genital herpes, ocular herpes, and so on.
Since herpes is an incurable virus, infected individuals will endure the annoying and contagious virus for the rest of their life with recurring “outbreaks”.
The virus is incurable because during the latent phase of the disease, the virus hides itself and becomes invisible to the immune system.
The immune system was designed to fight off
but cannot do its job if a pathogen has hidden itself. The only time the immune system fights off the herpes virus is when an outbreak occurs.
At this time the virus infects the epithelial cells causing...
...I have infected 45 million Americans and will infect 1 million more Americans each year. Who am I?
Herpes, from the ancient Greek meaning to creep or crawl, is the name of a family of viruses of which herpes simplex virus 1 and herpes simplex virus 2 (HSV-1 and HSV-2) are the most serious human pathogens. HSV-1 is normally associated with orofacial infections and encephalitis, whereas HSV-2
usually causes genital infections and can be transmitted from infected mothers to neonates. Both viruses establish latent infections in sensory neurons and, upon reactivation, cause lesions at or near point of entry into the body.
While HSV-1 and HSV-2 are different viruses, under a microscope, HSV-1 and 2 are virtually identical, sharing approximately 50% of their DNA and are treated similarly.
HSV-1 and HSV-2 contain a large double-stranded DNA molecule. HSV is gram negative, consists of 162 capsomers and replication takes place within the nuclei of eukaryotic cells. The HSV virion has four parts: an electrondense core containing viral DNA; an ico a tegument-an amorphous layer of proteins that and an envelope. HSV-1 and HSV-2 encode at least 84 different polypeptides. Each protein does many things, hence HSV genes can encode several hundred different functions. To initiate infection, HSV attaches to at least three different classes of...
...Genital Herpes
The history of herpes begins as early as ancient Greek times. Hippocrates speaks of the condition in his writings. Even the word “herpes” is a Greek word that means “to creep or crawl” which is the way that the Greeks described the way that skin lesions spread. In Roman times, the emperor Tiberius tried to stop an outbreak of mouth herpes by prohibiting kissing at public events and ceremonies. Soon after Tiberius, a
physician named Celsus suggested that herpes be treated by cauterizing the sores with a hot iron. It is unknown how long Tiberius’ ban on kissing lasted or how long Celsus’ treatment was used, but both seem to have ended pretty quickly.
Later in history, Shakespeare is believed to have had knowledge of the virus. In his play Romeo and Juliet he talks about “blisters plagues” which scholars believe refers to the herpes virus. There are also medical journals from the seventeen and early eighteen hundreds that discuss this disease. During this time there was also a lot of speculation as to what caused herpes – one of the most notable was the suggestion that herpes was caused by insect bites. Obviously, the history of herpes contains a lot of misconceptions.
However, this information doesn’t really tell us when or where the history of herpes started. The origin of...
Herpes is a highly contagious sexually transmitted disease that affects millions of people around the world. In the United States alone, statistics can reveal that more than 40 million people are diagnosed positive of this disease, although a little over 10 percent of them are aware of this malady. One of the reasons why herpes is not among the concerns of people is because it is a
relatively obscure condition. With the advent of the 21st century, however, and the increase in the rate of its victims, herpes have eventually become the center of scientific and medical research. This research attempts to provide a concise and comprehensive overview of the occurrence of herpes, its causes and symptoms, as well as treatment and prevention. Furthermore, this research aims to spread the awareness that preventing herpes is always better than finding ways to eliminate it from the system.
Keywords: herpes, sexually transmitted disease
Herpes is one of the most dreaded sexually infectious diseases that continues to afflict millions of people around the world. Despite causing misery to more than 45 million people in the U.S. alone, little is still known about this malady. In fact, 90 percent of those who have herpes do not know that they actually have it....
...Herpes establishes many manifestations in symptomology as well as several strains of this virus.
The following document will establish the many facets correlated with the virall infection of herpes to include, syptoms, treatment, and possible medical advancements in curing the herpes viral infections.
The first type of
herpes is HSV1 when you get a cold sore on the top of your lip. Which is also known as Oral
Herpes. It can be transmitted just like HSV2. HSV1 is an estimated 80 percent of adults are infected with it. Having HSV1 is not as bad as people think but it is still contagious, so you want to refrain from kissing and touching. Symptoms for HSV1 can last up to a few weeks than go disappear.
The second type of herpes is HSV2 is when you get blisters on your genital area. Which is also actually know that they have Genital Herpes. When you have an outbreak they usually happen on the vagina which is the most common one. Genital herpes symptoms can last up to several weeks than go away but than again they can always come back.
There are different ways you can treat your herepes. For HSV1 ask your doctor for an antiviral drug that will help minimize your outbreaks so you can live life and not feel embarrassed or uncomfortable. Now granted HSV1 is not as bad as HSV2 but you are still going to feel embarrassed when you get your first intial...
...having sex with someone who is carrying the infection. STDs are caused by bacteria, parasites and viruses. One of the STDs is Genital Herpes.
Genital Herpes is a common Sexually Transmitted Disease. It affects both male and female. Genital Herpes is caused by herpes simplex virus (HSV). There are two types of herpes simplex virus: HSV-1 and HVS-2. HSV-1 usually
causes cold sores beside the mouth. It can be spread to genital area during the oral sex. HSV-2 is highly contagious. It is the virus that causes genital herpes. This virus is able to spread through sexual contact or skin-to-skin contact. The virus can be suspended in the body and it might be reactivate several times a year. Unfortunately, the virus stays in the body for life.
The risk of getting genital herpes will increase if you are a woman. The virus is sexually transmitted more easily from men to women than it is from women to men. Having more than 1 sexual partners also increase the rate of getting genital herpes. Each additional sexual partner raises your risk of being exposed to the virus that causes genital herpes. Complications are developed when infected by sexually transmitted disease. You will get bladder problem, newborn infection and other...
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More great study tools:The Herpes simplex virus infection (common names: herpes, cold sores) is a common, contagious, incurable, and in some cases sexually transmitted disease caused by a double-stranded DNA virus. This website has the mission to bring you the most comprehensive and current information about the herpes virus and available treatments.《Herpes Simplex Virus》 Adrian Mindel【摘要 书评 试读】图书
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Updated January 2017
The herpes simplex virus, or herpes, is categorized into 2 types: herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2).
HSV-1 is mainly transmitted by oral-to-oral contact to cause oral herpes (which can include symptoms known as “cold sores”), but can also cause genital herpes.
HSV-2 is a sexually transmitted infection that causes genital herpes.
Both HSV-1 and HSV-2 infections are lifelong.
An estimated 3.7 billion people under age 50 (67%) have HSV-1 infection globally.
An estimated 417 million people aged 15-49 (11%) worldwide have HSV-2 infection.
Most oral and genital herpes infections are asymptomatic.
Symptoms of herpes include painful blisters or ulcers at the site of infection.
Herpes infections are most contagious when symptoms are present but can still be transmitted to others in the absence of symptoms.
Infection with HSV-2 increases the risk of acquiring and transmitting HIV infection.
Infection with the herpes simplex virus, commonly known as herpes, can be due to either herpes simplex virus type 1 (HSV-1) or herpes simplex virus type 2 (HSV-2). HSV-1 is mainly transmitted by oral to oral contact to cause infection in or around the mouth (oral herpes). HSV-2 is almost exclusively sexually transmitted, causing infection in the genital or anal area (genital herpes). However, HSV-1 can also be transmitted to the genital area through oral-genital contact to cause genital herpes.
Both oral herpes infections and genital herpes infections are mostly asymptomatic but can cause mild symptoms or painful blisters or ulcers at the site of infection.
HSV-1 is a highly contagious infection, which is common and endemic throughout the world. Most HSV-1 infections are acquired during childhood, and infection is lifelong. The vast majority of HSV-1 infections are oral herpes (infections in or around the mouth, sometimes called orolabial, oral-labial or oral-facial herpes), but a proportion of HSV-1 infections are genital herpes (infections in the genital or anal area).
In 2012, an estimated 3.7 billion people under the age of 50, or 67% of the population, had HSV-1 infection. Estimated prevalence of the infection was highest in Africa (87%) and lowest in the Americas (40-50%).
With respect to genital HSV-1 infection, 140 million people aged 15-49-years were estimated to have genital HSV-1 infection worldwide in 2012, but prevalence varied substantially by region. Most genital HSV-1 infections are estimated to occur in the Americas, Europe and Western Pacific, where HSV-1 continues to be acquired well into adulthood. In other regions, for example in Africa, most HSV-1 infections are acquired in childhood, before the age of sexual debut.
Oral herpes infection is mostly asymptomatic, and the majority of people with HSV-1 infection are unaware they are infected. Symptoms of oral herpes include painful blisters or open sores called ulcers in or around the mouth. Sores on the lips are commonly referred to as “cold sores.” Infected persons will often experience a tingling, itching or burning sensation around their mouth, before the appearance of sores. After initial infection, the blisters or ulcers can periodically recur. The frequency of recurrences varies from person to person.
Genital herpes caused by HSV-1 can be asymptomatic or can have mild symptoms that go unrecognized. When symptoms do occur, genital herpes is characterised by 1 or more genital or anal blisters or ulcers. After an initial genital herpes episode, which may be severe, symptoms may recur, but genital herpes caused by HSV-1 often does not recur frequently.
HSV-1 is mainly transmitted by oral-to-oral contact to cause oral herpes infection, via contact with the HSV-1 virus in sores, saliva, and surfaces in or around the mouth. However, HSV-1 can also be transmitted to the genital area through oral-genital contact to cause genital herpes.
HSV-1 can be transmitted from oral or skin surfaces that appear normal and when there are no symptoms present. However, the greatest risk of transmission is when there are active sores.
Individuals who already have HSV-1 oral herpes infection are unlikely to be subsequently infected with HSV-1 in the genital area.
In rare circumstances, HSV-1 infection can be transmitted from a mother with genital HSV-1 infection to her infant during delivery.
In immunocompromised people, such as those with advanced HIV infection, HSV-1 can have more severe symptoms and more frequent recurrences. Rarely, HSV-1 infection can also lead to more severe complications such as encephalitis or keratitis (eye infection).
Neonatal herpes can occur when an infant is exposed to HSV in the genital tract during delivery. This is a rare condition, occurring in an estimated 10 out of every 100,000 births globally, but can lead to lasting neurologic disability or death. The risk for neonatal herpes is greatest when a mother acquires HSV infection for the first time in late pregnancy. Women who have genital herpes before they become pregnant are at very low risk of transmitting HSV to their infants.
Recurrent symptoms of oral herpes may be uncomfortable and can lead to some social stigma and psychological distress. With genital herpes, these factors can have an important impact on quality of life and sexual relationships. However, in time, most people with either kind of herpes adjust to living with the infection.
Antiviral medications, such as acyclovir, famciclovir, and valacyclovir, are the most effective medications available for people infected with HSV. These can help to reduce the severity and frequency of symptoms, but cannot cure the infection.
HSV-1 is most contagious during an outbreak of symptomatic oral herpes, but can also be transmitted when no symptoms are felt or visible. People with active symptoms of oral herpes should avoid oral contact with others and sharing objects that have contact with saliva. They should also abstain from oral sex, to avoid transmitting herpes to the genitals of a sexual partner. Individuals with symptoms of genital herpes should abstain from sexual activity whilst experiencing any of the symptoms.
People who already have HSV-1 infection are not at risk of getting it again, but they are still at risk of acquiring herpes simplex virus type 2 (HSV-2) genital infection (see below).
The consistent and correct use of condoms can help to prevent the spread of genital herpes. However, condoms can only reduce the risk of infection, as outbreaks of genital herpes can occur in areas not covered by a condom.
Pregnant women with symptoms of genital herpes should inform their health care providers. Preventing acquisition of a new genital herpes infection is particularly important for women in late pregnancy, as this is when the risk for neonatal herpes is greatest.
Additional research is underway to develop more effective prevention methods against HSV infection, such as vaccines. Several candidate HSV vaccines are currently being studied.
HSV-2 infection is widespread throughout the world and is almost exclusively sexually transmitted, causing genital herpes. HSV-2 is the main cause of genital herpes, which can also be caused by herpes simplex virus type 1 (HSV-1). Infection with HSV-2 is lifelong and incurable.
Genital herpes caused by HSV-2 is a global issue, and an estimated 417 million people worldwide were living with the infection in 2012. Prevalence of HSV-2 infection was estimated to be highest in Africa (31.5%), followed by the Americas (14.4%). It was also shown to increase with age, though the highest numbers of people newly-infected were adolescents.
More women are infected with HSV-2 in 2012 it was estimated that 267 million women and 150 million men were living with the infection. This is because sexual transmission of HSV is more efficient from men to women than from women to men.
Genital herpes infections often have no symptoms, or mild symptoms that go unrecognised. Most infected people are unaware that they have the infection. Typically, about 10-20% of people with HSV-2 infection report a prior diagnosis of genital herpes.
When symptoms do occur, genital herpes is characterised by one or more genital or anal blisters or open sores called ulcers. In addition to genital ulcers, symptoms of new genital herpes infections often include fever, body aches, and swollen lymph nodes.
After an initial genital herpes infection with HSV-2, recurrent symptoms are common but often less severe than the first outbreak. The frequency of outbreaks tends to decrease over time. People infected with HSV-2 may experience sensations of mild tingling or shooting pain in the legs, hips, and buttocks before the occurrence of genital ulcers.
HSV-2 is mainly transmitted during sex, through contact with genital surfaces, skin, sores or fluids of someone infected with the virus. HSV-2 can be transmitted from skin in the genital or anal area that looks normal and is often transmitted in the absence of symptoms.
In rare circumstances, HSV-2 infection can be transmitted from a mother to her infant during delivery.
HSV-2 and HIV have been shown to influence each other. HSV-2 infection increases the risk of acquiring a new HIV infection by approximately three-fold. In addition, people with both HIV and HSV-2 infection are more likely to spread HIV to others. HSV-2 is amongst the most common infections in people living with HIV, occurring in 60-90% of HIV-infected persons.
Infection with HSV-2 in people living with HIV (and other immunocompromised individuals) often has a more severe presentation and more frequent recurrences. In advanced HIV disease, HSV-2 can lead to more serious, but rare, complications such as meningoencephalitis, esophagitis, hepatitis, pneumonitis, retinal necrosis, or disseminated infection.
Neonatal herpes can occur when an infant is exposed to HSV in the genital tract during delivery. This is a rare condition, occurring in an estimated 10 out of every 100,000 births globally, but can lead to lasting neurologic disability or death. The risk for neonatal herpes is greatest when a mother acquires HSV infection for the first time in late pregnancy. Women who have genital herpes before they become pregnant are at very low risk of transmitting HSV to their infants.
Recurrent symptoms of genital herpes may be painful and the infection can lead to social stigma and psychological distress. These factors can have an important impact on quality of life and sexual relationships. However, in time, most people with herpes adjust to living with the infection.
Antivirals, such as acyclovir, famciclovir, and valacyclovir are the most effective medications available for people infected with HSV. These can help to reduce the severity and frequency of symptoms, but cannot cure the infection.
Individuals with genital HSV infection should abstain from sexual activity whilst experiencing symptoms of genital herpes. HSV-2 is most contagious during an outbreak of sores, but can also be transmitted when no symptoms are felt or visible.
The consistent and correct use of condoms can help reduce the risk of spreading genital herpes. However, condoms only provide partial protection, as HSV can be found in areas not covered by a condom. Medical male circumcision can provide men life-long partial protection against HSV-2, in addition to HIV and human papillomavirus (HPV).
Pregnant women with symptoms of genital herpes should inform their health care providers. Preventing acquisition of a new genital herpes infection is particularly important for women in late pregnancy, as this is when the risk for neonatal herpes is greatest.
Additional research is underway to develop more effective prevention methods against HSV infection, such as vaccines or topical microbicides (compounds which can be applied inside the vagina or rectum to protect against sexually transmitted infections).
WHO and partners are working to accelerate research to develop new strategies for prevention and control of genital and neonatal HSV-1 and HSV-2 infections. Such research includes the development of HSV vaccines and topical microbicides. Several candidate vaccines and microbicides are currently being studied.
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