Herpes Viruses May Lead To Memory Loss Cognitive Declines
The virus that causes common cold sores may be behind cognitive problems and memory loss later in life.
New research published in Neurology on March 25, found people who had higher levels of the herpes simplex type 1 virus circulating in their blood were more likely to have cognitive deficits than those who had lower levels of the virus in their blood.
“While this association needs to be further studied, the results could lead to ways to identify people at risk of cognitive impairment and eventually lower that risk,” study author Dr. Mira Katan, a neurologist with the Northern Manhattan Study at Columbia University Medical Center in New York City, said in a statement.
Cold sores are caused by one of two types of herpes simplex virus. The other typically affects the genital area. People with the herpes simplex 1 virus may not show any symptoms, but some develop painful cold sores that are often unsightly can last a week or more. There is no cure for the virus.
Researchers conducted tests that measured memory, thinking and processing abilities in 1,625 people who were on average 69 years old and lived in northern Manhattan in New York. Tests were given annually for eight years on average. Participants were also given blood tests that looked for five common infections the researchers considered low-grade: herpes simplex type 1, herpes simplex type 2, cytomegalovirus , chlamydia pneumoniae and Helicobacter pylori .
Does Alzheimer’s Make The Brain More Susceptible To Infection
The blood-brain barrier protects the brain by controlling what substances can pass from the blood into brain tissue. In Alzheimer’s disease, the blood-brain barrier is damaged, particularly in the brain region affected by Alzheimer’s.
Evidence suggests that inflammation, the Alzheimer’s hallmark amyloid protein and the ApoE4 gene, which are all linked to Alzheimer’s disease, can contribute to the breakdown of the blood-brain barrier. Once it has been weakened, bacteria, viruses, and other harmful substances can get through into the brain more easily. This may explain why certain viruses and bacteria, such as herpes and spirochetes, are more common in the brains of people with Alzheimer’s.
Untreated Stds And Health Risk Associated With Them
In the year 2016, more than 2 million people in America were reported to be suffering from a Sexually Transmitted Disease. And as per the US Centers for Disease Control and Prevention. Chlamydia, Gonorrhea, and Syphilis were the three most common and untreated STDs among them. That was in 2016, but the numbers of such cases have been increasing at an alarming rate.
With so many cases, it is very important to look for solutions to prevent these from happening in the first place rather than looking for treatment later on. The most common types of Sexually Transmitted Diseases include genital herpes and human papillomavirus , Chlamydia, and Gonorrhea, other than these the cases of HIV are on the rise as well.
When it comes to preventing Sexually Transmitted Diseases, there is no better method like the one that involves total abstinence. But since that might not be practical for some, what people can do instead is to get themselves and their partners checked for any infections before starting a sexual relationship with them. Another way to prevent Sexually Transmitted Diseases is the use of condoms when engaging in a sexual act. Condoms are the number one way to prevent infections from spreading from an infected person to a healthy one.
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Can Herpesvirus Increase Your Risk For Alzheimers Disease
In the wake of several recent failures of Alzheimers therapies targeting beta-amyloid there is a growing interest in novel ideas on what may cause or accelerate the progression of Alzheimers disease. Since the 1980s, growing evidence has suggested that infection with herpes simplex virus -1 may play a role.
HSV-1 is a member of the herpesvirus family, which includes HSV-1 and HSV-2 , varicella zoster virus , cytomegalovirus, and Epstein-Barr virus. Although herpesvirus is very common in the general population, many who are infected never develop symptoms. After infection, HSV-1 can evade the immune system and remain latent by hiding in the nervous system. However, in certain conditions, such as stress or when the immune system is suppressed, HSV-1 can reactivate that is replicate, spread, and possibly cause another cold sore. In fact, a high proportion of cognitively healthy elderly individuals and Alzheimers patients have HSV-1 viral DNA in brain tissue after death .
The 11th International Conference on HHV-6 and HHV-7 last month brought together researchers studying human herpesvirus with researchers studying Alzheimers disease to discuss a possible link between the two. The consensus of the meeting was that herpesviruses do not cause Alzheimers disease but may accelerate its progression. However, more work is needed to uncover this connection. Here we review some of the evidence.
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Hsv1 Enters The Brains Of Elderly People As Their Immune System Declines With Age
We discovered in 1991 that in many elderly people HSV1 is also present in the brain. And in 1997 we showed that it confers a strong risk of Alzheimers disease when present in the brain of people who have a specific gene known as APOE4.
The virus can become active in the brain, perhaps repeatedly, and this probably causes cumulative damage. The likelihood of developing Alzheimers disease is 12 times greater for APOE4 carriers who have HSV1 in the brain than for those with neither factor.
Later, we and others found that HSV1 infection of cell cultures causes beta-amyloid and abnormal tau proteins to accumulate. An accumulation of these proteins in the brain is characteristic of Alzheimers disease.
Times of stress may reactivate the herpes virus, and this may eventually lead to long-term brain damage
We believe that HSV1 is a major contributory factor for Alzheimers disease and that it enters the brains of elderly people as their immune system declines with age. It then establishes a latent infection, from which it is reactivated by events such as stress, a reduced immune system and brain inflammation induced by infection by other microbes.
Reactivation leads to direct viral damage in infected cells and to viral-induced inflammation. We suggest that repeated activation causes cumulative damage, leading eventually to Alzheimers disease in people with the APOE4 gene.
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When Should I Call My Healthcare Provider
Treating herpes meningoencephalitis as soon as possible is essential. If youre feeling neck stiffness, having any neurological problems , are sensitive to light, or are running a fever along with a bad headache, call your healthcare provider and have the problem treated promptly.
If you have already been diagnosed with herpes meningoencephalitis and are being treated, it’s very important to let your healthcare providers know if any of your symptoms get worse or if you develop any new symptoms, as these could be signs that the infection is getting worse despite treatment.
Spreading It To Other People
Sexually Transmitted Diseases like human papillomavirus can be passed on from one person to another, even after using a condom. Being asymptomatic does not always mean that a person does not have an STD, which is why testing is important.
Some Sexually Transmitted Diseases like HIV, Genital herpes, hepatitis B, and human papillomavirus are not completely curable, but being tested for these can help the medical health experts to provide certain medications to help manage it easily, and it also reduces the chances of transmitting it to others. For instance, in the case of HIV, antiretroviral medications help manage it and bring the concentration of the virus in the body to very low levels, which means that the chances of that person infecting others is close to zero.
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Interpretation In Light Of Literature
Different studies have previously explored the question of an effect of AHDs on the risk of dementia with various methodologies: a comparison of methods used and the results obtained are available in Supplemental Table .
Using a Taiwanese medico-administrative database, Tzeng et al. first studied the question in a very particular population: subjects over 50 and defined as with newly diagnosed HSV infection if they had at least three outpatient visits related to HSV-1 or HSV-2 infections in the inclusion year and no visit related to HSV previously. Among them, subjects treated with AHDs had a very marked decrease in the risk of dementia , suggesting that 90% of dementia cases in this population could be prevented by AHDs. Notably, the association remained significant regardless of the duration of treatment considered . The discrepancy between Tzengs results and ours regarding the magnitude of the association may be partially due to the selection of subjects: Tzeng et al. included subjects with potentially more severe infections as reflected by the high prevalence of subjects treated and the use in some cases of intravenous treatments . In addition, the majority of incident dementias in this study were neither Alzheimers diseases nor vascular dementias. It questions the proportion of purely infectious dementias in this study which could explain a significant part of the protective association found.
Interpretation of our results
Viral Infections Linked To Dementia
Infection With Common Viruses May Increase Dementia Risk
A new study shows that elderly people with evidence of infection with three common viruses — viruses that cause cold sores, genital herpes, and a mono-like illness — were more than twice as likely to suffer from dementia.
Researchers say the study adds new evidence to the theory that inflammation, which is part of the body’s natural response to infection, plays an important role in the development of several health problems, such as heart disease, stroke, and dementia.
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What Are The Symptoms Of Herpes Meningoencephalitis
If you have viral meningitis, symptoms may include fever, light sensitivity, headache, and a stiff neck. If you have other symptoms, such as confusion, seizures, sleepiness, or a focal neurologic deficita nerve function problem that affects a specific area these may suggest that your brain is also affected, and your healthcare provider may diagnose it as meningoencephalitis.
These are possible symptoms of meningoencephalitis:
Characteristics Of The Included Subjects
The characteristics of the included subjects are shown in Table . The mean age was 76 ± 8 years, and there were 41% men.
Table 1 Characteristics of the study sample according to the intake of systemic antiherpetic drugs. Echantillon Généraliste des Bénéficiaires. 20092017
Results of the sensitivity analyses are shown in Table . First, the exclusion of subjects with cancer, immunocompromised subjects or subjects with at least one hospitalization related to herpesviruses did not profoundly change the results. Second, after the introduction of a lag time, the associations remained significant for dementia from any cause and AD but not for VaD. Third, the observed association did not seem to be solely based on a potential protective effect of a regular treatment in the few subjects with 2 deliveries of systemic AHDs per year of follow-up because, after their exclusion, the results were similar to those of the main analysis.
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Findings Justify Use Of Herpes Drugs
However, researchers need to conduct further studies to confirm that HSV1 causes Alzheimers. So far, these studies can only show that there is a relationship between the two conditions.Despite this, Itzhaki believes that the data so far supports the case of using antiviral drugs to deter Alzheimers.Considering that over 150 publications strongly support an HSV1 role in Alzheimers, she says, these Taiwan findings greatly justify usage of antiherpes antivirals which are safe and well-tolerated to treat Alzheimers disease.They also incentivize the development of an HSV1 vaccine, which would likely be the most effective treatment, the researcher adds.Itzhaki says she would like to now study dementia rates among people who have mild HSV1 or mild genital herpes because the findings from the studies based on the Taiwanese data only examine the link between dementia and severe HSV1 and chickenpox infections.
What Is Herpes Meningoencephalitis
The meninges are the layers of thin tissue that cover your brain. If these tissues become infected, its called meningitis. When your brain becomes inflamed or infected, the problem is called encephalitis. If both the meninges and the brain are infected, the condition is called meningoencephalitis.
Encephalitis involving herpes is a medical emergency. It needs to be promptly diagnosed and treated. This disease is often fatal when it is not treated. Many people who survive it have long-term problems afterward.
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Viruses May Trigger Dementia
“Inflammation has been implicated in dementia, and viral infections could be a triggering factor,” says researcher Timo E. Strandberg, MD, PhD, of the University of Helsinki in Finland, in a news release. “Our findings should be tested in other studies, but if these viruses are involved, there are existing therapies such as vaccination and antiviral drugs that could be used to prevent or treat dementia.”
In the study, which appears in Stroke: Journal of the American Heart Association, researchers tested 383 elderly men and women with heart disease for the antibodies that are produced in response to infection with three common viruses: herpes simplex 1 , herpes simplex type 2 and cytomegalovirus , and followed them for 12 months.
HSV1 causes cold sores, and HSV2 causes genital herpes. CMV is a virus that infects between 50% to 85% of American adults by age 40, but it causes few symptoms and no long-term health problems in most people.
The mental function of the participants was also assessed at the beginning and end of the study.
After testing for the viruses multiple times, researchers found that up to 60% of the participants tested positive for one or more or the viruses. And the more viral exposure, the higher the risk of dementia.
Those who had evidence of infection with all three viruses were 2.5 times more likely to have mental impairment than those with antibodies for less than three of the viruses.
Usage Of Gv971 To Treat Ad And The Case For Using A Related Compound Fucoidan
The study by Cairns et al. strongly supports the use of antiviral treatment for AD patients, and a clinical trial of VCV to treat AD patients is ongoing at Columbia university. Another clinical trial treating AD patients, described by Cummings et al. , is yielding encouraging results: a phase 2 trial of GV971, a compound derived from brown algae which consists of polysaccharideslinear sodium oligomannate moleculesof a range of sizes. This, they suggest, may reduce brain inflammation as well as systemic inflammation through effects on the gut microbiome, and very recently, the positive results of a phase 3 trial of GV971 have been reported by Xiao et al. . The latter authors stated that GV971 demonstrated significant efficacy in improving cognition, with sustained improvement across all observation periods of a 36-week trial, and it was safe and well-tolerated. However, an alternativeor perhaps additionalmechanism might operate via the drug acting as an antiviral agent against HSV1 . Marine-derived polysaccharides have been shown to have a variety of bioactivities, including antiviral effects , and anti-bacterial effects.
The next section deals with links between COVID-19. HSV1, and APOE.
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How An Outsider In Alzheimers Research Bucked The Prevailing Theory And Clawed For Validation
Neuropathologist Ruth Itzhaki of the University of Manchester in England, who has studied the role of microbes in causing Alzheimers, agreed, calling the research a really important development. She said the Tufts team, by showing that HSV-1 causes the formation of structures closely resembling the characteristic AD plaques and tangles, demonstrated directly what before now had been only inferred: that the human brains response to HSV-1 and other viruses might be what gets Alzheimers disease going years before symptoms, and that the plaques and other pathology that most people thought caused the disease are instead a defensive response to the true cause.
That might seem to suggest that antivirals will never be effective against Alzheimers: The damage is long since done. Thats what Devanands clinical trial is designed to find out. But the 3D quasi-brains offer reason for optimism. When the scientists added the herpes drug valacyclovir, which GlaxoSmithKline sells as Valtrex, the brain tissue became less inflamed, eliminated many of the plaque-like deposits, and functioned better.
Involvement Of Vzv In Ad/dementia
Apart from in the studies described in the preceding section, VZV has not so far been suggested as a prospective cause of dementia. A possible argument against its involvement is the fact that it usually reactivates only once, rarely a second time. Recurrent reactivations seem to be a prerequisite for the development of dementia, as progression of the disease occurs over many years. However, as mentioned above, it is unknown whether or not dementia might be caused by VZV if present in brain or via inflammation caused by peripheral VZV infection leading to HSV1 reactivation in brain. In the case of herpes zoster sufferers, both Chen et al. and Bae et al. found shingles was associated with a clear but small risk of AD/dementia, and a significantly lower risk in those treated with antivirals.
As to whether an allele of APOE confers a risk of shingles is uncertain: Pirtilla et al. examined the APOE genotypes of 41 patients with HZ and found no differences in allele frequency between the patients and controls. In contrast, my group , found that women homozygous for APOE-4 had a higher-than-normal risk of shingles . However, both studies had only a small number of participants, so they need to be repeated.
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