Brote epidémico de meningitis aséptica: experiencias en un hospital infantil privado / Epidemic of aseptic meningitis experience of private hospital

Se informa acerca de las experiencias obtenidas en 193 niños con meningitis aséptica, estudiados durante un brote epidémico registrado entre febrero y julio de 1992. Los cultivos de líquido cefalorraquídeo hechos en el Instituto de Referencia Epidemiológica permitieron identificar al virus Echo 30 como un agente a la meningitis en 48 niños

Infection by echoviruses 1 and 8 depends on the alpha 2 subunit of human VLA-2.

Anti-VLA-2 antibodies protected HeLa cells from infection by echoviruses 1 and 8 but not from infection by other echovirus serotypes. Echoviruses 1 and 8 bound to and infected nonpermissive hamster cells transfected with the alpha 2 subunit of human VLA-2. These results indicate that the human alpha 2 subunit is critical for infection by echoviruses 1 and 8 but that other echovirus serotypes must bind receptors other than VLA-2.

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.

[An outbreak of poliomyelitis in Tajikistan in 1991 caused by the poliomyelitis virus type 1 in concomitant echovirus 19 infection]. / Vspyshka poliomielita v Tadzhikistane v 1991 g., vyzvannaia virusom poliomielita tipa 1 pri soputstvuiushchei infektsii virusom ECHO 19.

In 1991 in Tajikistan 36 cases of acute poliomyelitis were recorded (spinal form 27, bulbospinal 3, pontospinal 6 cases) in children ranging in ages from 6 months to 6 years. The outcome of the disease was fatal in 4 cases and with crude residual effects in 32 children. Out of 23 children examined, poliomyelitis virus type I was isolated from 13, antibodies to poliovirus type I in titres 1:16 to 1:1024 were detected in 21 children, ECHO 19 virus was isolated from 5 children and antibodies to this virus in titres 1:16 to 1:8192 were demonstrated in 13 children. The fresh isolates of poliomyelitis virus type I had rct+, DS+ and N+ markers. The strains of ECHO 19 virus were highly pathogenic for monkeys causing deaths of the animals within 3-4 days. It is assumed that the main causative agent of the Tajikistan outbreak of poliomyelitis was a virulent "wild" variant of poliovirus type I. The preceding or concomitant infection with ECHO 19 virus (considering the data from the literature and the demonstrated high virulence of this agent for monkeys) could exert an aggravating effect on the course of poliomyelitis or, in some cases, be an independent cause of the disease and, possibly, death of the children.

[A survey on enteroviruses-carrying status among healthy population in Changle and Wucheng counties of Shandong Province. Shandong Collaborative Group of Poliomyelitis].

Four-hundred and fourty-six faecal specimens sampled from healthy carriers between 0 and more than 20 year-old age groups in Changle and Wucheng counties of Shandong Province were collected from June to Sept. of 1991. From them, 142 (31.84%) isolates of enteroviruses were obtained. There was no significant difference in the enteroviruses isolation rate between Changle and Wucheng. No poliovirus was isolated. Among other enterovirus isolates, 85 were echoviruses, 6 coxsackieviruses, 9 enterovirus type 70 and 2 enterovirus type 71. Other 40 isolates were positive for cytopathogenic effect (CPE) in cell culture, but they could not be identified by antisera to poliovirus and enteroviruses. The results showed that the infection by non-polio enteroviruses which could cause polio-like paralysis should be paid attention in the poliomyelitis eradication program.

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.

Epidemiological features of type 22 echovirus infection.

During a 25-year observation period, isolates of type 22 echovirus were obtained from 109 patients. 92% of the patients were < 2 years old. Echovirus type 22 was isolated with peaks both during late summer and autumn, as enterovirus infections, and during the winter months and early spring, as respiratory viruses. Diarrhea was the most common symptom, followed by obstructive bronchitis and, less often, CNS symptoms. Nosocomial infections were common. In a noticeable number of the children, maternal neutralizing antibodies were most probably present at the time of infection. The epidemiologic features of type 22 echovirus infections with regard to age and seasonal distribution, contagiousness and a relative lack of protection by neutralizing antibodies differed from most enterovirus infections.

A 44,000 glycoprotein is involved in the attachment of echovirus-11 onto susceptible cells.

Cellular receptors play an important role in viral pathogenesis. Until now little was known on echovirus (EV) receptor. Using detergent-treated KB cell extracts as immunogen, a mouse monoclonal antibody (Mab 143) was produced that selectively blocks the attachment of EV-11 to KB and other susceptible cells. By immunoblotting, Mab 143 detected a 44,000 protein on susceptible cell lines but not on cell lines from nonprimate origin. The receptor protein complex, purified from KB cell membranes by immunoaffinity using Mab 143 as ligand, was shown to contain a single glycoprotein with apparent molecular weight of 44,000 (gp44). The role of gp44 in the attachment of EV-11 onto KB cells was demonstrated by the ability (i) of affinity-purified gp44 to reduce the infectivity of EV-11 and (ii) of rabbit polyclonal antisera raised against gp44 to protect cells from the replication of various EV, as did Mab 143.

[Diagnosis of bacterial infections on vascular prosthesis. Histological and microbiological analysis]. / Diagnostic de l'infection des prothèses vasculaires. Analyse histologique et microbiologique.

A retrospective study of 212 vascular graft failures, using different criteria of infection evidenced a relatively high incidence of infectious complications. Vascular graft infection was assessed on one of the following criteria: clinical infection, positive bacteriological and/or virological examination of the graft, presence of characterized micro-organisms and of microstructures 0.1 to 0.5 micron in size at the blood/prosthesis surface at scanning electron microscopy, and presence of foci of persistent polymorphonuclear cells and lymphocytes at histological microscopy. In the absence of overlapping between these criteria, the present results raise the question of the adequacy of conventional bacteriological sampling on explanted artificial surfaces.

Use of non-neutralizing monoclonal antibodies in an ELISA for intratypic differentiation of 28 echovirus type 25 clinical isolates.

Three non-neutralizing monoclonal antibodies were produced and selected against echovirus type 25 JV-4 prototype strain. They were used in an ELISA to investigate the intratypic differentiation of 28 wild isolates. Clinical isolates fell into seven different groups according to their reactivity patterns in ELISA. Two of the non-neutralizing monoclonal antibodies, 9E4 and 6D3, were highly specific, while the third, 6C9, may recognize an epitope common to other types of echoviruses. In contrast, mouse polyclonal antiserum exhibited large cross-reactivities among echovirus serotypes. The reactivity patterns and the geographical origin of the isolates were generally not correlated and, in the same area, four major antigenic variants sometimes coexisted, especially in the south of France. Moreover, reactivity patterns found with ELISA were hardly ever correlated with those observed in a previous study when neutralization tests were used. These results again underline the non-correlation between structure and biological function in the Picornavirus family.

Enterovirus associated placental morphology: a light, virological, electron microscopic and immunohistologic study.

The purpose of this study was to identify the possible effect of enteroviruses on placental tissue. Seventy-eight pregnant women were studied throughout their pregnancy: enteroviral infection was detected by faecal viral isolation and seric neutralization of previously identified virus in cell culture. In 19 cases of confirmed maternal infection, placentae were examined grossly, by optical microscopy, immunohistochemical and electron microscopic methods. Ten term placentae from women included in the study, with no clinical, serological or virological evidence of enteroviral infection, were used as control, and examined by gross and optical microscopy. In 17 specimens (echovirus-coxsackievirus) an haematogenous placentitis was suspected on the basis of gross observation. Microscopic lesions were similar to those found in other viral infections, with specific features. The nature of the inflammatory reaction pointed to the presence of an acute type of haematogenous placentitis, not present in placentae of the control group. The authors (AA) comment on the results and present the hypotheses about the available data: (1) maternal enteroviremia and faecal virus shedding without placental invasion, placentary damage being an unspecific consequence of infection; (2) direct virus-induced injury is not the only possible cause for the lesions: (3) placental enteroviral infection occurred with placental pathology but the virus did not cross the organ as the newborn had no signs of infection.

Impact on routine diagnosis of echovirus infections of intratypic differentiation and antigenic variation in echovirus type 25 studied by using monoclonal antibodies.

We studied the biological and antigenic properties of wild strains of echovirus type 25 isolated in France between 1982 and 1987 and compared them with the JV-4 prototype strains isolated in 1957. The wild strains differed from the prototype strain in their cellular tropism. The prototype strain grew readily in five cell lines (MRC5, MA 104, Vero, BGM, and HT 29-18), while for wild strains MRC5 and HT 29-18 cells were the most sensitive and supported growth to high titres (between 4.5 and 7.4 50% tissue culture infective doses per 0.05 ml). Plaques produced by wild strains were larger (6.05 +/- 0.94 mm in diameter [mean +/- standard deviation]) than those of the prototype strain (2.3 +/- 0.97 mm in diameter) and heterogeneous, even after cloning by three terminal dilution passages, which suggested heterogeneous virus populations. Virus neutralization with polyclonal monovalent sera showed that wild strains were significantly less neutralized by two reference immune sera than the prototype strain was. Monoclonal antibodies were raised against the echovirus type 25 JV-4 prototype strain. Nine clones with neutralizing activity were identified. Heterologous neutralizations of 14 clinical isolates revealed highly conserved, moderately conserved, and poorly conserved epitopes. The natural isolates differed from the prototype strain in two to four epitopes and can be classified into four different groups. We concluded that echovirus type 25, like coxsackie- and polioviruses, consists of heterogeneous viral populations with respect to biological and antigenic properties. In term of viral diagnosis, it may become increasingly difficult to identify recently isolated strains because of their antigenic variation.