Lower anti-echovirus antibody responses in children presenting to hospital with asthma exacerbations.

BACKGROUND: Rhinoviruses from the Enterovirus genus cause frequent infections and induce remarkably high titres of anticapsid antigen antibodies in asthmatics, while the prevalence of neutralising antibodies to the gut-trophic echoviruses from the same genus is diminished. OBJECTIVE: To assess the absolute and specific antibody titres to VP1 antigens of the gut-trophic enteroviruses, echovirus 30 and Sabin 1 poliovirus, in asthmatic and non-asthmatic children. METHODS: Recombinant polypeptides representing the VP1 capsid antigens of echovirus 30 and Sabin poliovirus 1 were produced. Their ability to bind IgG1 antibodies from the plasma of asthmatic (n = 45) and non-asthmatic (n = 29) children were quantitated by immunoassays that incorporated immunoabsorptions to remove cross-reactivity. RESULTS: The IgG1 antibody titres and prevalence of antibody binding to echovirus 30 were significantly lower for asthmatic children compared to controls (P < 0.05) and inversely correlated with total IgE levels for the whole study population (r = -0.262; P < 0.05). There was no difference in the prevalence and titre between groups to the VP1 antigen of Sabin poliovirus. Anti-tetanus toxoid titres measured for comparison did not correlate with anti-echovirus or poliovirus, but correlated with anti-rhinovirus titres in controls but not asthmatics, where the titres were higher for the asthmatic group. CONCLUSIONS AND CLINICAL RELEVANCE: The associations of lower antibody titres of asthmatic children to echovirus reported here and those of our previous findings of a heightened response to rhinovirus suggest a dichotomy where respiratory enterovirus infection/immunity increases the probability of developing asthma and enteric infections lower the risk. This provides further support for the concept of intestinal infection playing a key role in the development of allergic respiratory disease.

[Acute enterovirus uveitis in infants].

Enterovirus uveitis (EU) is a new infant eye disease that was first detected and identified in Russia in 1980-1981. Three subtypes of human echoviruses (EV19K, EV11A, and EV11/B) caused 5 nosocomial outbreaks of EU in different Siberian cities and towns in 1980-1989, by affecting more than 750 children mainly below one year of age. Sporadic and focal EU cases (more than 200) were also retrospectively diagnosed in other regions of Russia and in different countries of the former Soviet Union. There were following clinical manifestations: common symptoms of the infection; acute uveitis (rapid focal iridic destruction, pupillary deformities, formation of membranes in the anterior chamber of the eye); and in 15-30% of cases severe complications, cataract, glaucoma, vision impairments. Uveitis strains EV19 and EV11 caused significant uveitis in primates after inoculation into the anterior chamber of the eye, as well as sepsis-like fatal disease with liver necrosis after venous infection. The uveitis strains are phylogenetically and pathogenetically close for primates to strains EV19 and EV11 isolated from young children with sepsis-like disease. The contents of this review have been published in the Reviews in Medical Virology, 2004, vol. 14, p. 241-254.

Re-emergence of echovirus type 13 infections in 2002 in Yamagata, Japan.

OBJECTIVES: To analyze the prevalence of echovirus type 13 (Echo13) in Yamagata, Japan. METHODS: Virus isolation was performed from 6514 clinical specimens using six cell lines between January 1999 and December 2002. We also carried out a seroepidemiological study against Echo13, using 234 serum samples collected in 2001. RESULTS: In 2002, we isolated a total of 50 Echo13 strains, which had not been detected from 1981 until 2001 in Japan. The antibody positive rate was higher (57.2-62.0%) in subjects 50 years or over than in those under 50 years (0-14.4%). CONCLUSIONS: Serological study suggested that Echo13 had been present in Yamagata until around 1960, at which time the antibody positive persons were exposed to Echo13 in their childhood. Furthermore, results of virus isolation demonstrated that Echo13 re-emerged in around 2002 after a hiatus of several decades.

[Detection of nonpoliomyelitic enteroviruses in central nervous system infections in Poland in 1995-2000; viral isolation data]. / Badania wirusologiczne udzialu enterowirusów niepoliomyelitycznych w zakazeniach osrodkowego ukladu nerwowego w Polsce w latach 1995-2000.

The aim of this study was evaluation of enterovirus diagnosis based on isolation of the virus in cell culture from subjects with aseptic neuroinfection conducted in six Provincial Sanitary-Epidemiological Stations in 1995-2000 years. Available data from six Sanitary-Epidemiological Stations indicated that 1429 isolation of enteroviruses from fecal samples of those patients were performed. The most frequently isolated enterovirus serotype was echovirus type 30: 138/203 isolated enteroviruses, but also others enterovirus serotypes were isolated in a study period. In the years 1995 and 1996 the percentage of positive results of isolation was highest with the numbers of 31% and 28.27% respectively. The decrease in positive isolation results has been observed from 1997 year. Negative results of isolation come up to 90% of investigated cases. Only 1.5% of enterovirus isolation attempts finished successfully in 2002 year. The situation when percentage of positive results of isolation is on so low level, the natural alterations in a profile of enterovirus serotype infected population cannot be observed, and serological investigations can be conducted for enterovirus serotypes others than really circulating and causing infections in population.

[Pseudo-poliomyelitis paralysis caused by Echovirus 7]. / Paralysie pseudo-poliomyélitique associée à échovirus 7.

The authors describe one case of acute flaccid paralytic of lower limbs in a 10-year-old boy with Echovirus 7 isolated in the stool and a high titer of homologous antibodies (> or = 1,024). At the final stage of poliomyelitis program eradication, paralysis associated with non polio enterovirus may replace cases of paralytic poliomyelitis. In the present study, the authors highlight the needs to confirm virologically all suspect cases of acute flaccid paralytic. Aetiological function of the virus isolated and interpretation of the diagnostic methods are discussed.

A novel serological technique: polymerase chain reaction enhanced immunoassay. Application to enterovirus IgM diagnosis.

The polymerase chain reaction (PCR) method is a sensitive, specific and rapid technique for virus detection. The principles of a PCR enhanced immunoassay (PIA) are described. The method combines solid phase serological techniques with the PCR, providing a versatile and sensitive method for antibody detection. By linking the antigenicity of virus particles with their content of nucleic acid, the method provides new possibilities for virus serology: for example, antibody specificity can be coupled to viral sequence in patients with chronic infections caused by highly variable viruses such as HIV and HCV. An application of the PIA technique is described for the detection of anti-enterovirus IgM. IgM is captured to anti-human IgM-coated microwell plates. The anti-enterovirus IgM is allowed to bind crude enterovirus antigen. Bound virus is heat denatured and the released RNA is used as a template for reverse transcription PCR (RT-PCR) amplification. Amplicons are detected by hybridisation to an affinity labelled probe in a microwell colorimetric assay. In a pilot study, 18 serum specimens from patients with enterovirus infections were examined. Using a mixture of ten crude enterovirus antigens, the frequency of IgM positivity was 6/18 (33%). Titres between 1/500 and 1/100,000 were recorded. Predominantly type-specific antibodies were detected. The results were compared with a procapsid enterovirus radioimmunoassay (RIA). After further optimisation, the PIA has the potential to be a clinically useful assay for the detection of antiviral antibodies.

An outbreak due to echovirus type 30 in a neonatal unit in France in 1997: usefulness of PCR diagnosis.

Between February and August 1997, 53 patients with enterovirus meningitis were hospitalized in Clermont-Ferrand, France. All but one were children. Echovirus type 30 was involved in 70% of cases with identified serotype. The outbreak ceased on August 8. Two months later, a neonate was admitted to the neonatal unit with an echovirus type 30 meningitis thought to be acquired at delivery. Twenty days later a nosocomial outbreak of echovirus type 30 involving five neonates occurred. Two of them presented with meningitis and two with febrile seizure; One was asymptomatic. The retrospective examination of the maternal sera in a neutralization test, using the index case strain as a source of antigen, showed that none of the neonates was passively immunized before hospitalization. The use of genome detection in cerebrospinal fluid allowed rapid diagnosis and infection was contained by re-inforcing hygiene measures. Prospective examination of stools in the neonatal and paediatric units showed no further occurrences of the disease. No sporadic case was observed in the general population. Hence, nosocomial infections can occur a long time after an outbreak in the general population; rapid diagnosis with molecular tools is useful both for a definite diagnosis in patients already hospitalized, and to act as a rapid alert, even in intervals between seasonal outbreaks.

Septic shock in an elderly patient: unusual presentation of echovirus infection.

We have described a case of fulminant echovirus infection that progressed rapidly to purpura and septic shock. To our knowledge, this is a previously unreported presentation of acute echovirus infection in an immunocompetent adult.

Transient erythroblastopenia of childhood presenting with echovirus 11 infection.

We report a case of transient erythroblastopenia in a three-year-old girl presenting with echovirus 11 infection. Viral infection was demonstrated by isolation of echovirus 11 in stool cultures and the presence of echovirus 11-specific IgM antibody in serum. We suggest that echovirus may have played a role in the pathogenesis of transient erythroblastopenia of childhood in this patient.

[Epidemic outbreak of viral meningitis caused by type 30 ECHO virus]. / Brote epidémico de meningitis viral causado por virus ECHO tipo 30.

The clinical records of 15 children admitted to Hospital Infantile de México Federico Gómez with diagnosis of viral meningitis were reviewed. They were part of 19 patients admitted with this diagnosis during a 5 week period (March 22 to April 30, 1992) and represent a significant increase of aseptic meningitis compared with the same periods of previous years at Hospital Infantile de Mexico and in Mexico City where there is an ongoing epidemic outbreak of this entity. All the patients studied had spinal fluid findings consistent with viral meningitis and in 4 of them on ECHO virus type 30 was isolated at the Enterovirus Section of the CDC, Atlanta Georgia USA.

Severe encephalitis associated with disseminated echovirus 22 infection.

Severe encephalitis associated with disseminated echovirus 22 infection occurred in a previously healthy 5-month-old boy. Echovirus 22 was diagnosed by a seroconversion both in serum and cerebrospinal fluid and by isolation of the virus from several stool samples. The child damaged severely and at the age of 8 1/2 months infantile spasms developed.

Prolonged echoviral meningitis in a cancer patient with normal serum immunoglobulins.

This is a report of prolonged meningitis caused by echovirus type 20 in a patient with rhabdomyosarcoma. It represents one of the few documented cases of delayed clearance of echovirus in the cerebrospinal fluid in a patient with normal serum immunoglobulins. The case illustrates the prolonged clinical course of echoviral meningitis in a patient receiving cytotoxic drug therapy, and it suggests that factor(s) other than humoral antibodies may be involved in the elimination of echovirus from the central nervous system.

Neutralizing antibody and interferon-alpha in cerebrospinal fluids and sera of acute aseptic meningitis.

Cerebrospinal fluids (CSFs) and sera from 20 patients with echovirus 30 (E 30) meningitis, 4 patients with enterovirus 71 (EV 71) meningitis, and 5 patients with acute aseptic meningitis (AM) of unknown etiology were investigated at the acute and the convalescent phases of the disease to elucidate the roles of neutralizing antibody (NT) and interferon-alpha (IFN-alpha) in the central nervous system (CNS) in cases of AM in humans. Viruses were isolated from the CSFs at the acute phase of AM, but not at the convalescent phase. There was a fourfold or greater rise in NT titer between paired sera to E 30 or EV 71 but only a slight rise between paired CSFs. IFN-alpha was detected in the CSFs ranging from less than 10 to 25.5 IU/ml but not in the sera, and the IFN-alpha level in the CSF was significantly higher in the acute phase than in the convalescent phase. These results suggest that in cases of acute enteroviral infections in the CNS, NT plays only a small role in the recovery from AM, and IFN-alpha plays a direct or indirect role in curbing the local spread of the virus and eliminating the virus from the CNS at the acute phase of AM.

Myositis, myoglobinemia, and myoglobinuria associated with enterovirus echo 9 infection.

A 30-year-old man had a "flu-like" syndrome followed by clinical and laboratory evidence of myositis localized in both thighs. Serum neutralization test results were compatible with enterovirus echo 9 infection. Severe myoglobinuria dominated the clinical picture. We discuss other possible manifestations of enterovirus echo 9 infections. To our knowledge, this report is the first describing myositis caused by enterovirus echo 9.