Enterovirus

71 type of enteroviruses have been discovered. Among these are Coxsackie A viruses, Coxsackie B viruses, echoviruses and polioviruses.

Enteroviruses, unlike herpesviruses, usually leave the body after an effective immune response. However, they can cause chronic or life-threatening conditions in certain populations, such as in patients with X-linked agammaglobulinemia (XLA).

Role in Myalgic Encephalomyelitis

Enterovirus infection has been posited as a key etiological factor in Myalgic encephalomyelitis (ME). The evidence for enteroviral persistence in ME patients has been mixed, due in part to different methods of testing and types of tissue samples (for example muscle biopsies, stool samples, stomach biopsies, cerebrospinal fluid).

Some studies have found evidence of Enteroviral infection in muscle biopsies in a subset of patients while others have failed to replicate those results.

Research by John Chia and his son, Andrew Chia has looked for enteroviruses in gut biopsies. 82% of samples were positive for viral capsid protein 1 (VP1) compared to 20% of controls. Enteroviral RNA was detected in 37% of biopsy samples 4.7% of controls. They posit that a subset of Chronic Fatigue Syndrome patients have a chronic enteroviral infection.

Treatment

There are no FDA-approved treatments for enteroviruses. The drug Pleconaril has been shown to have activity against a number of enteroviruses but has not been approved by the FDA.

Treatment usually involves supporting the immune response particularly in those with documented immune dysfunction. Dr. Chia treats his patients with enteroviral infection with Equilibrant, gammaglobulin and interferon.

Published Studies

• In one study, enterovirus-specific RNA three standard deviations greater than controls was found in muscle biopsies of 20% of ME patients studied..
• A Swedish study using the Fukuda criteria was unable to find evidence of any persistent enteroviral infection in fecal samples, muscle biopsies, or cerebrospinal fluid.
• A study on brain tissue samples from a deceased ME patient found evidence of enterovirus specific genomic sequences and enteroviral protein in the patient's cerebral cortex.
• A second postmortem tissue study found positive enterovirus PCR sequences in the muscle, heart, brain stem, and hypothalamus of a deceased ME patient.
• A study on stomach tissue samples from CFS patients found that 82% of patients have evidence of chronic enterovirus infection of the stomach.
• A longitudinal study found that a percentage of patients presenting to emergency care with acute enterovirus infection would go on to develop symptoms of ME and CFS and had demonstrable evidence of viral persistence.

See Also

• John Chia
• John Richardson
• James Mowbray

References

<references>

enterovirus A genus of RNA viruses which typically enter the body through the respiratory or gastrointestinal systems and sometimes spread to the central nervous system or other parts of the body, causing neurological, cardiac, and other damage. Since the first reports of myalgic encephalomyelitis (ME), enteroviruses have been suspected as a cause of ME. Enteroviruses have also been implicated as the cause of Type I diabetes, congestive heart failure, and other conditions. Enteroviruses include poliovirus, coxsackieviruses, and many others. New enteroviruses and new strains of existing enteroviruses are continuously being discovered. (Learn more: viralzone.expasy.org)

myalgic encephalomyelitis (M.E.) - A disease often marked by neurological symptoms, but fatigue is sometimes a symptom as well. Some diagnostic criteria distinguish it from chronic fatigue syndrome, while other diagnostic criteria consider it to be a synonym for chronic fatigue syndrome. A defining characteristic of ME is post-exertional malaise (PEM), or post-exertional neuroimmune exhaustion (PENE), which is a notable exacerbation of symptoms brought on by small exertions. PEM can last for days or weeks. Symptoms can include cognitive impairments, muscle pain (myalgia), trouble remaining upright (orthostatic intolerance), sleep abnormalities, and gastro-intestinal impairments, among others. An estimated 25% of those suffering from ME are housebound or bedbound. The World Health Organization (WHO) classifies ME as a neurological disease.

etiology The cause of origin, especially of a disease.

enterovirus A genus of RNA viruses which typically enter the body through the respiratory or gastrointestinal systems and sometimes spread to the central nervous system or other parts of the body, causing neurological, cardiac, and other damage. Since the first reports of myalgic encephalomyelitis (ME), enteroviruses have been suspected as a cause of ME. Enteroviruses have also been implicated as the cause of Type I diabetes, congestive heart failure, and other conditions. Enteroviruses include poliovirus, coxsackieviruses, and many others. New enteroviruses and new strains of existing enteroviruses are continuously being discovered. (Learn more: viralzone.expasy.org)

enterovirus A genus of RNA viruses which typically enter the body through the respiratory or gastrointestinal systems and sometimes spread to the central nervous system or other parts of the body, causing neurological, cardiac, and other damage. Since the first reports of myalgic encephalomyelitis (ME), enteroviruses have been suspected as a cause of ME. Enteroviruses have also been implicated as the cause of Type I diabetes, congestive heart failure, and other conditions. Enteroviruses include poliovirus, coxsackieviruses, and many others. New enteroviruses and new strains of existing enteroviruses are continuously being discovered. (Learn more: viralzone.expasy.org)

enterovirus A genus of RNA viruses which typically enter the body through the respiratory or gastrointestinal systems and sometimes spread to the central nervous system or other parts of the body, causing neurological, cardiac, and other damage. Since the first reports of myalgic encephalomyelitis (ME), enteroviruses have been suspected as a cause of ME. Enteroviruses have also been implicated as the cause of Type I diabetes, congestive heart failure, and other conditions. Enteroviruses include poliovirus, coxsackieviruses, and many others. New enteroviruses and new strains of existing enteroviruses are continuously being discovered. (Learn more: viralzone.expasy.org)

enterovirus A genus of RNA viruses which typically enter the body through the respiratory or gastrointestinal systems and sometimes spread to the central nervous system or other parts of the body, causing neurological, cardiac, and other damage. Since the first reports of myalgic encephalomyelitis (ME), enteroviruses have been suspected as a cause of ME. Enteroviruses have also been implicated as the cause of Type I diabetes, congestive heart failure, and other conditions. Enteroviruses include poliovirus, coxsackieviruses, and many others. New enteroviruses and new strains of existing enteroviruses are continuously being discovered. (Learn more: viralzone.expasy.org)

cerebral 1. of or relating to the brain or the intellect 2. of, relating to, affecting, or being the cerebrum.

brainstem Region of the midbrain in adults, includes midbrain, pons, and medulla oblongata and develops.