By Dr. Bob Sears
TACA Physician Advisory member
Viruses have been implicated as a possible contributor to Autism Spectrum Disorders (ASD’s.) Solid research on this is lacking, and much of what autism biomedical practitioners do to diagnose and treat viruses is based on theory, experience, and consensus. In this article I will discuss how I approach viruses in my practice. I will also share what some of my colleagues do regarding viruses. Some may argue these therapies are still alternative. We need to keep in mind that patients also need answers now to help their day to day quality of life. We need to balance the two issues while additional research is performed.
How viruses may affect autism
When viruses infect the body, two things may happen that can influence the nervous system. First, the virus may harm nerve tissues directly as the infection begins. In some viruses, this effect may be temporary; the infection passes within several days, and may or may not leave behind some residual damage to the nervous system. With other viruses, particularly the herpes family, the infection can become permanent; the virus will live within the nerve tissues for the rest of a person’s life and potentially cause ongoing irritation and damage to the nervous system. The second way that viruses can cause harm is through the immune response that the body creates to try to eliminate the virus. This immune response involves white blood cells, antibodies, and various immune chemicals that, unfortunately, can also harm the body tissues around the virus and thus cause inflammation. If the viral infection is ongoing, so is the inflammation, and the nervous system can suffer damage and dysfunction from this inflammation.
Why don’t these viral infections cause noticeable harm to most children? Kids with properly-functioning immune systems handle viruses with little or no problems, and the inflammatory response is healthy and coordinated properly so that the body tissues aren’t harmed. Many children who develop autism have a dysfunctional immune system, so they seem less able to handle these viral infections properly. The immune response may be too weak to eliminate the virus effectively or quickly. The inflammatory response may also be improperly regulated so that it attacks the body tissues more than the virus.
Which viruses are implicated in autism?
Many viruses are suspected of playing a role in autism. These include Herpes Simplex Virus 1 and 2, Human Herpes Virus 6, Epstein-Barr Virus, Rubella virus, Measles virus, Cytomegalovirus, and others. The herpes family of viruses seems to be the most susceptible to anti-viral prescription medications, so these are the viruses than most people focus on. Here is a brief discussion of each virus:
HSV 1: Herpes Simplex Virus 1 causes canker sores in the mouth. It is transmitted via saliva. Most adults carry this virus within the nerves of the mouth. It is inevitably passed to almost all children or teens at some point in life. The initial infection can cause fevers and numerous painful canker sores in the mouth, with swollen and bleeding gums. But it can also be asymptomatic or just cause one canker sore. After the initial exposure, a person tends to get a canker sore a few times each year, without any obvious harm.
HSV 2: Herpes Simplex Virus 2 causes genital herpes. An infant can be exposed to this virus during the birth process if an active lesion is present at birth. Beyond that, infant or childhood infection would be extremely rare.
HHV 6: Human Herpes Virus 6 is commonly known as Roseola virus. Virtually every infant is exposed to this virus during the first few years of life. It is transmitted via the same routes as the flu. It typically causes about three days of high fever without any cold or flu symptoms, followed by a light red rash on the upper body that may spread to the extremities. It is a very common cause of febrile seizures. Any infant or toddler who had an unexplained high fever for about three days, without any apparent reason (like ear infection, throat infection, cough, cold, or flu), followed by a rash, likely had Roseola. This virus may be the one most commonly implicated in autism.
These three herpes viruses (1, 2, and 6) live within the nervous system (usually where nerves of the face or body enter the brain or spinal cord). This proximity to the brain makes these viruses particularly troublesome in autism.
EBV: Epstein-Barr Virus, causes the illness known as infectious mononucleosis, or mono. Most kids grow up without exposure to this virus, as it is far less common than HHV 6. Symptoms vary, but many include fever, sore throat, tonsillitis, and rash. If this virus persists in the body, it might cause chronic fatigue syndrome. Its role in autism is less clear than with the herpes viruses.
Measles: Natural infection with this virus has been found to slightly increase the risk of developing autism in some studies, but this isn’t certain. The live measles strain in the MMR vaccine has also been hypothesized to play a role in autism by causing intestinal and neurologic inflammation, but that has been a topic of much heated debate that I won’t expand on here.
Rubella: There is some research on the association between rubella and autism, but since this virus is now rare, it unlikely plays any significant role in autism.
CMV: Cytomegalovirus is an uncommon virus that is thought to be fairly harmless for most people. Its role in autism is unclear.
Testing for viruses
It is very difficult to physically identify viruses in test samples. The primary way we test for viruses is to look for antibodies to the viruses in blood work. We can test for antibodies that suggest if the infection is new and active (called IgM antibodies) and we can test for antibodies that show the infection occurred sometime in the past (called IgG antibodies). Since most testing in autism is done years after the symptoms have started, we mainly find IgG antibodies to viruses and not IgM. Having a positive test result does not actually tell us whether or not the infection is active. It also doesn’t tell us whether or not the infection had any negative or lasting effects on the brain. A higher level of antibodies doesn’t necessarily mean that the initial infection was worse or that the current status of the virus is more severe. It primarily tells us that at some time in the past, the child had that viral infection. Some doctors believe that a high antibody result does correlate with the severity of the virus and that the antibody level should decrease with effective treatment. They also believe that following such antibody levels can help guide treatment. But I’m not aware of any good research on this. It does make theoretical sense, but in practice I don’t keep checking antibody levels throughout treatment.
I commonly test for HSV 1 and 2 and HHV 6, as these viruses seem to be the most susceptible to treatment. I don’t routinely test for the other viruses, although I don’t find anything wrong with such testing.
I used to test measles viral titers to see if a child’s immune system is over-reacting to the live measles virus in the MMR vaccine. It was theorized that a higher than normal lab result might indicate that the measles vaccine virus has remained active in the body and may be contributing to the autism. There is very little research that has confirmed the accuracy and usefulness of this practice, however. I rarely test for this anymore, as it doesn’t provide any reliable information. I will often simply proceed with Vitamin A treatment, if warranted (see below).
There are three ways to treat viruses. There are natural treatments that may help kill viruses and/or boost the anti-viral capabilities of the immune system. There are also prescription anti-viral medications and anti-inflammatory treatments that may decrease the inflammation caused by the viruses. This third aspect of treatment won’t be covered here. (See other articles regarding anti-inflammatory treatments.)
There are many natural treatments for viruses. I will discuss the ones that I have experience with. There are numerous other treatments that I am not familiar with, but these may be just as helpful. There is very little published research on these natural treatments. The following are the ones that I have tried with some success, or have learned about from other practitioners:
Monolaurin: this is a fat found in coconut milk and breast milk. It has anti-viral properties. Numerous brands are available online.
Low dose naltrexone: this immune booster may help boost the body’s anti-viral defenses. It is available by prescription only.
Mushroom supplements: various brands of these supplements are available to boost the anti-viral part of the immune system.
Larch arabinogalactan: I don’t have much experience with this immune-boosting herbal compound, but some practitioners use it with success.
Olive leaf extract: this over the counter supplement has some anti-viral properties.
High dose vitamin A: at very high doses, vitamin A may have anti-viral effects against the measles virus. Since high doses can be toxic to the body, this practice should only be done under the guidance of a physician. Children who developed regressive autism between 12 and 18 months in relation to receiving the MMR vaccine may benefit from this treatment. However, there is very little research on the efficacy or the necessity of this treatment. Measles titer testing can be done (see above), but is considered by many doctors to be unnecessary as the accuracy of the results is uncertain.
I can’t specify dosing and directions with these supplements. Please seek the advice of your health care provider.
As for prescription anti-viral medications, there are three that are used primarily. None of these are FDA approved for treating viruses in autism:
Valtrex: This is the most commonly-used choice. It was originally designed for adults with genital herpes. It is given daily for several months or longer to suppress the virus and decrease the inflammation and neurological dysfunction caused by the virus. Many doctors will recommend taking it in cycles of 4 weeks on and 2 weeks off to give the body a break. There are no improvements that are specific to Valtrex treatments; kids may show improvements in any aspects of their autism. If no improvement is seen within the first two months, I generally discontinue therapy. There is no particular endpoint to treatment. I commonly will continue therapy for 6 to 12 months if it is helping. I do have patients that have stayed on therapy for longer than this. It also may help increase the production of glutathione is a subset of children with autism.
Famvir: This is in the same class as Valtrex. It will sometimes be tried when a patient doesn’t show any positive response to Valtrex. It is potentially more toxic than Valtrex.
Acyclovir: This is an older version of Valtrex. It has traditionally been used to treat chicken pox and shingles, and is also effective against herpes. It is a worthwhile option in place of Valtrex. It has to be dosed more frequently than Valtrex.
It is important to do periodic blood work while on Valtrex or any other prescription anti-viral med to make sure the child’s liver, kidneys, and blood cells are not being harmed by these medications. Such side effects are rare; I have not yet had a child show abnormal labs from these medications. But it is important to regularly check every two or three months while on therapy, or as you doctor directs.
We hope this offers an introduction to a complex topic. We look forward to more research and treatment options available for families living with autism.