Researchers have found that the virus that causes cold sores, along with other viral or bacterial infections, might be associated with memory loss, and if further studies establish such a link, it could eventually prove helpful in preventing strokes or Alzheimer’s disease.

A long-term study of a group of people in one neighborhood of New York City found that those with higher levels of infection in their blood -- meaning they had been exposed to various pathogens such as the herpes simplex type 1 virus that causes cold sores -- were more likely to have cognitive problems than people with lower levels of infection in the blood. The results, released Monday, are published in the March 26 issue of Neurology, the medical journal of the American Academy of Neurology.

"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," said Dr. Mira Katan, author of the study. "For example, exercise and childhood vaccinations against viruses could decrease the risk for memory problems later in life.”

Katan, who conducted the Northern Manhattan Study at Columbia University Medical Center in New York, is a member of the American Academy of Neurology . The study was performed in collaboration with the Miller School of Medicine at the University of Miami. She said she found the link between infections and memory loss was greater among women, people with lower levels of education and most prominently, in people who do not exercise.

 The study, performed in collaboration with the Miller School of Medicine at the University of Miami, tested thinking and memory in 1,625 people from northern Manhattan who had an average age of 69. Participants gave blood samples that were tested for five common low grade infections: three viruses (herpes simplex type 1, which is oral; herpes simplex type 2, which is genital; and cytomegalovirus), chlamydia pneumoniae (a common respiratory infection) and Helicobacter pylori (a bacteria found in the stomach).

The results showed that the people who had higher levels of infection had a 25 percent increase in the risk of a low score on a common test of cognition called the Mini-Mental State Examination.

The memory and thinking skills were tested every year for an average of eight years, but infection was not associated with changes in memory and thinking abilities over time.

"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," said Katan. "For example, exercise and childhood vaccinations against viruses could decrease the risk for memory problems later in life."

Katan, who is currently working at the University of Zurich, in Switzerland, said the study grew out of a previous clinical study of stroke victims that found an association between inflammation in the brain and chronic infections.

“We cannot make any conclusions that infections will lead to cognitive problems, but we think there is a connection,” she said. The issue will require further interactive studies. “If a causal effect is established, it could help in the treatment of dementia and strokes,” she said in a telephone interview with NBC News.com from Switzerland.

William Schaffner, chairman of the department of preventive medicine at Vanderbilt University’s School of Medicine in Nashville, Tennessee, said although the study did not definitively establish a causal association between infections and memory loss, it was “nevertheless provocative and would be worth pursuing fully.

“This will stimulate further research by the neurological and infectious disease communities,” said Schaffner, who was not affiliated with the study.

He noted that already researchers suspected a connection between chlamydia and heart attacks and between the pylori bacteria and stomach cancer. Solid evidence of a connection between infectious diseases and non-communicable illness would be very significant, he said.

“The whole area of connecting infectious diseases to diseases we have not considered infectious is on the cutting edge of research.

“I am intrigued and stimulated by it and it could have very positive implications in preventing diseases,” said Schaffner.

Dr. Alireza Atri, a cognitive neurologist at Massachusetts General Hospital and Harvard Medical School, cautioned the results of the study should be considered preliminary. “There is some plausibility but I would also say that these things (cold sore and herpes viruses) are very common. So it would be rare if older people did not develop antibodies to them.”

He also pointed out the study group was about 80 percent non-white and he would like to see it extended to a larger cross-section of the population. “Can the results be attributed to the general population? Maybe, maybe not,” said Atri.

In an editorial accompanying the study in Neurology, Dr.  Timo Strandberg and Dr. Allison Aiello noted there was still much work to be done.

“Undoubtedly, demonstrating that old-age cognitive diseases, including AD, are slowly progressing diseases of viral etiology would revolutionize the dementia research field and be Nobel Prize-worthy,” they wrote. “However, great challenges remain. Such a study is nevertheless worth doing and the editorialists hope that the study… will stimulate this endeavor.”

The study was supported by the National Institutes of Neurological Disorders and Stroke (NINDS), the Swiss National Science Foundation and the Leducq Foundation.

By Rachael Rettner
MyHealthNewsDaily

As the herpes virus spreads and produces cold sores on the skin, it goes through a "bottleneck" of sorts — which could mean the virus is vulnerable to treatments at this stage, a new study suggests.

The researchers looked at the herpes simplex virus type 1 (HSV-1), which many people become infected with during childhood. HSV-1 hides inside nerve cells, and can remain dormant for years, before making its way into skin cells and producing a cold sore.

The researchers found that although hundreds of virus particles may be lying dormant inside the nerve cells, just one or two make the trip to spread to a skin cell, said study researcher Lynn Enquist, a professor of molecular biology at Princeton University in New Jersey. Once inside a skin cell, the virus then multiplies and spreads to other skin cells, creating a cold sore.

This bottleneck could be "a point where the infection is more susceptible to drug treatments, if we had them," Enquist said. However, the study was conducted using cells in lab dishes, so more research is needed to confirm the same thing happens in animals and people. It's too early to say how it could translate to treatments, he said.

Currently, there is no way to cure an HSV-1 infection. While anti-inflammatory drugs can temporarily relieve symptoms, they don't target the virus itself. (HSV-1 can also cause genital herpes, though most cases are caused by the related virus, herpes simplex virus type 2.)

The findings also shed light on why herpes virus is such an efficient pathogen — only the fittest viruses spread from the nerve cells to the skin surface, which can then spread to other people. Flawed virus particles would be unlikely to survive this journey, Enquist said.

The researchers suspect their findings may apply to viruses that are similar to HSV-1, such as chickenpox, but more research is needed to confirm this. 

The study was published Oct. 16 in the journal Proceedings of the National Academy of Sciences.

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An ultra-Orthodox Jewish circumcision practice in which the circumciser places his mouth on a newborn's newly circumcised penis and sucks blood away from the wound carries a risk of transmitting the herpes virus to the baby, sometimes fatally, according to a new report from the Centers for Disease Control and Prevention.

The report is based on researchers' investigation into the cases of 11 infants in New York City who were infected with the herpes virus after this procedure, known as metzitzah b’peh ("direct orogenital suction"), between November 2000 and December 2011. Ten of these infants were hospitalized, and two died.

Some of the infants’ parents were not aware this technique would be a part of their child’s circumcision, the researchers found. Parents should be aware of the risk of herpes in metzitzah b’peh, and should inquire in advance whether direct orogenital suction will be performed so the practice can be avoided, the CDC researchers said.

"Oral contact with a newborn’s open wound risks transmission of [ herpes simplex virus ] and other pathogens," the researches wrote in their report. "Circumcision is a surgical procedure that should be performed under sterile conditions."

The virus that was found in most of the infants, called herpes simplex virus type 1 (HSV-1) — which is typically associated with cold sores, but does not always cause any symptoms — is highly prevalent in the general adult population, the report said. A 2004 study showed that 73 percent of adults ages 20 and older in New York City carried the virus.

At least three of the infants, including one who died, were circumcised by the same person, the report said. The New York City Commissioner of Health has issued a directive ordering that person to stop performing direct orogenital suction during circumcisions.

At least three mohliem (circumcisers) performed the circumcisions of the 11 infected infants, and there may have been as many as eight mohliem, the CDC said. In some cases, parents refused to identify their child's circumciser to CDC officials.

The rate of newborn boys who undergo direct orogenital suction and contract herpes infections is 24.4 per 100,000, the report said. That's 3.4 times higher than the rate of herpes infections seen in the general newborn male population, which is 8 per 100,000. Other cases of herpes are typically transmitted from mother to infant during delivery.

Neonatal herpes infections is a potentially disabling, life-threatening infection, the report said.  

Physicians should counsel parents considering out-of-hospital circumcisions about the risks of direct orogenital suction, and should consider herpes infection when evaluating a newborn male infant with a fever following Jewish ritual circumcision, and inquire about direct orogenital suction, the CDC said.

Mohelim should inform parents about whether they perform direct orogenital suction, and explain the risk of virus transmission, so that parents can choose not to have their newborns exposed, the report said.

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An experimental herpes vaccine protected young women against only one of the two types of the sexually transmitted virus, dashing hopes for widespread use of the treatment, researchers reported in the latest issue of the New England Journal of Medicine.

For reasons that aren’t clear, the vaccine protected against herpes simplex virus type 1, known as HSV1, but not type 2, known as HSV2, the study of more than 8,000 women aged 18 to 30 found.

“I think this is the end of the vaccine,” said coauthor Dr. Peter A. Leone, an infectious disease specialist at the University of North Carolina, Chapel Hill. “It would be difficult to imagine marketing a vaccine that would only work against HSV1.”

According to the Centers for Disease Control and Prevention, one in six Americans ages 14 to 49 is infected with HSV2. Nearly 60 percent of adults in the U.S. are infected with HSV1, federal health figures show.

Still, Leone and his fellow investigators called the vaccine against type 1 “a substantial step forward” in the quest for a future vaccine to protect against both types of herpes.

That's important because many people still think that the type 1 herpes virus causes only cold sores. “It used to be we’d think HSV1 above the waist, HSV2 below the waist,” Leone said.

In his study, though, HSV1 was a more common cause of genital disease in the women who didn’t get the herpes vaccine than HSV2. Scientists have assumed that people have to engage in oral sex to get genital HSV1 disease, Leone says, but his study didn’t find an association.

Women who weren’t infected with herpes at the beginning of the study were randomly assigned to receive either three shots of the herpes vaccine or three shots of the hepatitis A vaccine.

Two previous studies of the vaccine involved heterosexual couples in which either the man or woman was infected with herpes. Those found that the vaccine protected against both types of herpes in women, but neither of the types in men.

Perhaps having regular sex with an infected man primed the women’s immune systems to fight HSV1 and HSV2, or maybe they were naturally resistant, Leone and his coauthors theorized. Leone said it might not have worked for men because the skin covering the penis is different from the membranes lining the vagina and cervix.

So what’s next?

“We’re going to need a different approach,” Leone said. His trial used a vaccine containing an HSV protein designed to trigger an immune response against the virus. Maybe, he said, a vaccine that uses weakened live virus -- like the chickenpox vaccine -- would work better.

Meanwhile, Leone said, many Americans live in fear of contracting herpes. “The idea that you can transmit this and not know it terrifies people.”

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