This is a little different. Dr. Chia's histopathology test shows direct evidence of active viral expression and persistence associated with the formation of double stranded RNA. This is a big step above using antibody tests to try to link disease with herpes antibody titers. This isn't just Dr. Chia's pet theory either, it builds on the work of many British investigators from the past.
found this in Virus 101 for dummies
Coxsackie (Group B) of Enteroviruses Infection
Coxsackie And Echoviruses
Coxsackieviruses are distinguished from other enteroviruses by their pathogenicity for suckling rather than adult mice. They are divided into 2 groups on the basis of the lesions observed in suckling mice. Group A viruses produce a diffuse myositis with acute inflammation and necrosis of fibers of voluntary muscles. Group B viruses produce focal areas of degeneration in the brain, necrosis in the skeletal muscles, and inflammatory changes in the dorsal fat pads, the pancreas and occasionally the myocardium. Typically, group A viruses produce a flaccid paralysis whilst group B viruses produce a spastic paralysis. Each of the 23 group A and 6 group B coxsackieviruses have a type specific antigen. In addition, all from group B and one from group A (A9) share a group Ag. Cross-reactivities have also been demonstrated between several group A viruses but no common group antigen has been found. (NB. coxsackie A23 was found to be identical to echovirus 9 and the A23 has been dropped and the number is unused)
The first echoviruses were accidentally discovered in human faeces, unassociated with human disease during epidemiological studies of polioviruses. The viruses were named echoviruses (enteric, cytopathic, human, orphan viruses). These viruses were picornaviruses isolated from the GI tract, produced CPE in cell cultures, did not induce detectable pathological lesions in suckling mice. Altogether, 34 viruses were assigned echovirus serotype designations but echovirus 10 and 28 were reclassified as a reovirus and a rhinovirus respectively and the numbers are now unused. Of the 32 echoviruses, 10 show haemagglutinating activity with human group O erythrocytes, the haemagglutinin is thought to be an integral part of the virus particle. There is no group echovirus Ag but heterotypic cross-reactions occur between a few pairs. At least 14 of the known viruses produce disease in rhesus and cynomolgus monkeys if inoculated intracerebrally or intraspinally. As with polioviruses, the mouth is the portal of entry of the viruses. Although a few can probably infect through the respiratory route. They are excreted in the pharynx and faeces early in the course of infection and virus may be isolated from the faeces up to several weeks after recovery. The incubation period varies between 2 - 7 days which may be followed by one of several different disease manifestations. Recovery from infection is accompanied by the development of lifelong immunity. and
2. Serological Techniques
- Neutralization tests are generally the best serological tests available. However they are labour intensive and takes at least 3 days before the results are available. Antibody titres are compared in paired sera, the first collected within 5 days of onset of symptoms and the second some days later. A significant rise in titre is evidence for recent infection. Significant rise in antibody titres are rare in cardiac disease as cardiac disease is usually a late consequence of coxsackie B infection.
More recently, M-antibody capture assays have become available for various coxsackie A and B, and echovirus serotypes. However, cross-reactivity between the IgM responses to different enteroviruses, including hepatitis A virus occurs. The older the patient, the more likely such heterotypic responses will occur. Enterovirus IgM usually lasts 8 - 12 weeks but may persists longer in some patients, up to a few years. It has been suggested that such a prolonged response may indicate a persistent infection in cases of recurrent pericarditis. Approximately 30 - 40% of patients with myocarditis, 60 - 70% of patients with aseptic meningitis, and 30% of patients with postviral fatigue syndrome give positive results for coxsackie B IgM. However, 10% of normal adults will also give a positive result, perhaps having experienced a recent enterovirus infection.
3. Direct detection of viral genomes
- PCR assays are becoming increasingly used for the detection and identification of enteroviruses. They are particularly useful in cases of suspected enterovirus meningitis where CSF is used.
Vaccination is not available against coxsackie or echoviruses. The multiplicity of antigenic types and the usually mild manifestation of disease make the production of vaccine impractical. The only effective measures for their control are high standards of personal and community hygiene. Quarantine is not effective because of the high frequency of inapparent infections.
L. Postviral Fatigue Syndrome
- also known as myalgic encehalomyelitis (ME), it occurs as both sporadic and epidemic cases. It is a poorly characterized illness, the cardinal feature being excess fatiguability of the skeletal muscles. Other symptoms that may be present include muscle pain, headache, inability to concentrate, paraesthesiae, impairment of short term memory and poor visual accommodation. Focal neurological signs are rare. Evidence of myopericarditis may be present occasionally. There may be a history of a nonspecific viral illness and some lymphadenopathy may be present. Routine laboratory investigations are usually normal. Recovery usually takes place within a few weeks or months but the illness may persists in some patients with periods of remission and relapse.
The aetiology is uncertain but it is thought that there is a substantial functional component as well as a viral component in many cases. ME occasionally follows confirmed virus infections such as varicella/zoster, influenza A and IM. It may follow some bacterial infections such as toxoplasma gondii and leptospira. In the majority of cases though, the initiating infection cannot be diagnosed specifically. There is now substantial evidence for a persistent enterovirus infection, particularly coxsackie B viruses in many cases of ME. Patients with ME appears to have a higher prevalence of antibodies against coxsackie B viruses than matched controls. Furthermore, coxsackie B viruses may occasionally be isolated from the faeces as well as skeletal muscle biopsies in patients with ME.
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Enteroviruses Slide Set