Fatal echovirus 11 infections in outbreak in special-care baby unit

Diversity of Human Enterovirus Co-Circulations in Five Kindergartens in Bangkok between July 2019 and January 2020

Human enterovirus causes various clinical manifestations in the form of rashes, febrile illness, flu-like illness, uveitis, hand-foot-mouth disease (HFMD), herpangina, meningitis, and encephalitis. Enterovirus A71 and coxsackievirus are significant causes of epidemic HFMD worldwide, especially in children aged from birth to five years old. The enterovirus genotype variants causing HFMD epidemics have been reported increasingly worldwide in the last decade. We aim to use simple and robust molecular tools to investigate human enteroviruses circulating among kindergarten students at genotype and subgenotype levels. With the partial 5'-UTR sequencing analysis as a low-resolution preliminary grouping tool, ten enterovirus A71 (EV-A71) and coxsackievirus clusters were identified among 18 symptomatic cases and 14 asymptomatic cases in five kindergartens in Bangkok, Thailand, between July 2019 and January 2020. Two occurrences of a single clone causing an infection cluster were identified (EV-A71 C1-like subgenotype and coxsackievirus A6). Random amplification-based sequencing using MinION (Oxford Nanopore Technology) helped identify viral transmission between two closely related clones. Diverse genotypes co-circulating among children in kindergartens are reservoirs for new genotype variants emerging, which might be more virulent or better at immune escape. Surveillance of highly contagious enterovirus in communities is essential for disease notifications and controls.

Risk factors and early markers for echovirus type 11 associated haemorrhage-hepatitis syndrome in neonates, a retrospective cohort study

Background

Echovirus type 11(E-11) can cause fatal haemorrhage-hepatitis syndrome in neonates. This study aims to investigate clinical risk factors and early markers of E-11 associated neonatal haemorrhage-hepatitis syndrome.

Methods

This is a multicentre retrospective cohort study of 105 neonates with E-11 infection in China. Patients with haemorrhage-hepatitis syndrome (the severe group) were compared with those with mild disease. Clinical risk factors and early markers of haemorrhage-hepatitis syndrome were analysed. In addition, cytokine analysis were performed in selective patients to explore the immune responses.

Results

In addition to prematurity, low birth weight, premature rupture of fetal membrane, total parenteral nutrition (PN) (OR, 28.7; 95% CI, 2.8-295.1) and partial PN (OR, 12.9; 95% CI, 2.2-77.5) prior to the onset of disease were identified as risk factors of developing haemorrhage-hepatitis syndrome. Progressive decrease in haemoglobin levels (per 10 g/L; OR, 1.5; 95% CI, 1.1-2.0) and platelet (PLT) < 140 × 10⁹/L at early stage of illness (OR, 17.7; 95% CI, 1.4-221.5) were associated with the development of haemorrhage-hepatitis syndrome. Immunological workup revealed significantly increased interferon-inducible protein-10(IP-10) (P < 0.0005) but decreased IFN-α (P < 0.05) in peripheral blood in severe patients compared with the mild cases.

Conclusions

PN may potentiate the development of E-11 associated haemorrhage-hepatitis syndrome. Early onset of thrombocytopenia and decreased haemoglobin could be helpful in early identification of neonates with the disease. The low level of IFN-α and elevated expression of IP-10 may promote the progression of haemorrhage-hepatitis syndrome.

Echovirus induces autophagy to promote viral replication via regulating mTOR/ULK1 signaling pathway

Among enteroviruses, echovirus can cause severe illnesses in neonates or infants, with high morbidity and mortality. Autophagy, a central component of host defense mechanisms, can function against diverse infections. In the present study, we investigated the interplay between echovirus and autophagy. We demonstrated that echovirus infection increases LC3-II expression dose-dependently, accompanied by an increased intracellular LC3 puncta level. In addition, echovirus infection induces the formation of autophagosome. These results suggest that echovirus infection induces autophagy machinery. Furthermore, phosphorylated mTOR and ULK1 were both decreased upon echovirus infection. In contrast, both levels of the vacuolar protein sorting 34 (VPS34) and Beclin-1, the downstream molecules which play essential roles in promoting the formation of autophagic vesicles, increased upon virus infection. These results imply that the signaling pathways involved in autophagosome formation were activated by echovirus infection. Moreover, induction of autophagy promotes echovirus replication and viral protein VP1 expression, while inhibition of autophagy impairs VP1 expression. Our findings suggest that autophagy can be induced by echovirus infection via regulating mTOR/ULK1 signaling pathway and exhibits a proviral function, revealing the potential role of autophagy in echovirus infection.

Multiple genotypes of Echovirus 11 circulated in mainland China between 1994 and 2017

Echovirus 11 (E-11) is one of the most frequently isolated enteroviruses causing meningitis and other diseases such as hand, foot, and mouth disease (HFMD) and acute flaccid paralysis (AFP). Fifty-nine newly determined E-11 VP1 sequences from the China AFP and HFMD surveillance network and 500 E-11 VP1 sequences obtained from the GenBank database, which were associated with 12 categories of diseases, were screened for phylogenetic analysis. Based on the standard method of genotype classification, E-11 strains circulated worldwide were reclassified into six genotypes as A, B, C, D, E, and F, in which genotype F is newly divided, and genotypes A and C are further divided into A1–5 and C1–4 by this research, whereas genotype D was still divided into D1–5 as in a previous study of Oberste et al. Sub-genotype A1 was the predominant sub-genotype in mainland China between 2008–2017, whereas sub-genotype D5 was the predominant sub-genotype circulated outside China from 1998–2014. However, genotype and sub-genotype spectra showed statistical significance among AFP and HFMD cases (χ² = 60.86, P < 0.001), suggesting that different genotypes might have a tendency to cause different diseases. Strengthening the surveillance of E-11 might provide further information about pathogenic evolution or specific nucleotide mutation associated with different clinical diseases.

Enterovirus infections in neonates

Enteroviruses, which include echoviruses, coxsackie A and B viruses, polioviruses and the 'numbered' enteroviruses, are among the most common viruses causing disease in humans. A large proportion of enteroviral infections occur in neonates and infants. There is a wide spectrum of clinical manifestations that can be caused by enterovirus infection with varying degrees of severity. In the neonatal age group, enteroviral infections are associated with significant morbidity and mortality, particularly when infection occurs antenatally. This review provides a detailed overview of the epidemiology and clinical features of enterovirus infections in the neonatal period. In addition, laboratory features and diagnostic investigations are discussed. A review of the currently available data for prophylactic and therapeutic interventions, including antiviral therapy, is also presented.

Pitfalls in the diagnosis of enteroviral infection in young children

BACKGROUND

Three infants with enteroviral infections were admitted to a neonatal intensive care unit (NICU). Investigation into the possible nosocomial spread of enterovirus identified 31 other infected infants. Only 1 of the 31 was truly positive; 30 were false-positive results.

METHODS

This was a retrospective observational study. Investigational laboratory studies were conducted to identify problems in diagnostic procedures.

RESULTS

Stool cultures were used to identify asymptomatic infections. Investigation identified several problems in the procedures in identification of enterovirus: (1) stool specimens were not properly filtered, (2) insufficient number of tissue culture cell types were used, (3) nonspecific toxicity due to stool and the presence of Clostridia difficile toxin was responsible for cytopathic effects in tissue culture, (4) the failure to block nonspecific fluorescent staining led to misidentification of enteroviruses.

CONCLUSIONS

The use of stool cultures to identify asymptomatic enteroviral infections in infants in an NICU can be fraught with problems because of high frequency of C. difficile toxin and the nonspecific toxic effects of stool on tissue culture cells. These problems can be rectified when proper procedures are followed.

Investigation of treatment failure in neonatal echovirus 7 infection

We describe a case of fatal neonatal enteroviral infection caused by echovirus 7. Multiple treatments, including specific antiviral therapy, were attempted and failed. Studies of the viral isolate, maternal plasma, intravenous immunoglobulin preparations and pleconaril were performed to identify potential causes for treatment failure.

Presentation, diagnosis, and management of enterovirus infections in neonates

The nonpoliovirus enteroviruses commonly infect newborns, with consequences ranging from asymptomatic infection and benign illness, to severe, life-threatening disease. Frequently occurring symptoms include fever, irritability, lethargy, anorexia, and rash. Although most illnesses are mild, severe disease develops in a subset of newborns infected in the first 2 weeks of life. Severe disease may consist of sepsis, meningoencephalitis, myocarditis, pneumonia, hepatitis, and/or coagulopathy. Substantial mortality rates have been reported, and long-term sequelae may occur among survivors. Risk factors and clinical features associated with severe disease include absence of neutralizing antibody to the infecting serotype, maternal illness prior to or at delivery, prematurity, illness onset within the first few days of life, multiorgan disease, severe hepatitis, positive serum viral culture, and specific infecting serotype (e.g. group B coxsackieviruses and echovirus 11). Whereas the mainstay of diagnosis has traditionally been viral isolation in tissue culture, the polymerase chain reaction has been demonstrated to be more sensitive than culture, highly specific, and rapid. Immunoglobulin has been used as a therapeutic agent for neonates with enterovirus disease; however, clinical efficacy has not been proven. Specific antiviral therapy for enteroviruses is in development. Pleconaril is an investigational agent that inhibits viral attachment to host cell receptors and uncoating of viral nucleic acid. It has broad and potent anti-enterovirus activity, excellent oral bioavailability, and is well tolerated. Some clinical trials have demonstrated benefit in children and adults with enterovirus meningitis, and in adults with upper respiratory tract infections caused by picornaviruses (rhinoviruses or enteroviruses). Data summarizing compassionate use for severe enterovirus diseases (including neonatal sepsis) also suggest possible benefit. Limited pharmacokinetic data are available in infants and neonates. A multicenter, placebo-controlled, randomized trial of pleconaril in neonates with severe hepatitis, coagulopathy, and/or myocarditis is currently being conducted.

Molecular epidemiology and type-specific detection of echovirus 11 isolates from the Americas, Europe, Africa, Australia, southern Asia and the Middle East

Echovirus 11 (E11) is among the most commonly isolated human enteroviruses. To examine the range of genetic variation within the E11 serotype, we determined the complete VP1 sequences for 53 geographically dispersed E11 strains isolated in 16 countries from 1953 to 2001. E11 sequences were monophyletic with respect to all other enterovirus serotypes. The sequences clustered into four monophyletic genogroups, A-D; members of each genogroup differed from one another by <20%. Isolates in different genogroups differed from one another by 19-28%. The E11 prototype strain, USA/CA53-Gregory, was the sole member of genogroup B. All recent US isolates were members of one of two discrete lineages within genogroup D. The well-characterized E11 antigenic variant, USA/CA63-Silva, was also a member of genogroup D. Members of genogroups A and C were antigenically similar to USA/CA53-Gregory, as measured by neutralization with anti-Gregory and anti-Silva antisera. Only USA/CA63-Silva was neutralized more efficiently by the anti-Silva antiserum; other genogroup D viruses were Gregory-like or intermediate in their neutralization phenotype. Recent non-US isolates were distributed in genogroups A, C and D. Sequence similarities among genogroup D isolates from North America, Europe, Asia, Australia and North Africa demonstrate that an E11 strain can spread rapidly over a wide geographic area. The aligned sequences were used to develop an E11-specific RT-PCR assay, using degenerate, inosine-containing primers, to amplify all members of all genogroups.

Clinical and epidemiological aspects of an enterovirus outbreak in a neonatal unit

An outbreak of enterovirus infection occurred among neonates in a maternity hospital between July 7 and 22, 1999. Twenty neonates became ill (18 confirmed and two probable), an attack rate of 33%. The incubation period ranged from three to six days (mean, 4.2). The male:female ratio was 11:9 and the mean age at the onset of illness was 5.5 days. All the babies had fever, eight, a maculopapular rash, and six had symptoms of gastroenteritis, 11 developed meningitis. Nineteen neonates required hospitalization for three to seven days, but all were discharged home without sequelae. Enteroviral RNA was detected in all of 18 urines, and 14 cerebrospinal fluid specimens tested. A case-control study was conducted to determine risk factors associated with the outbreak. Rooming in the nursery ward was a significant risk factor (odds ratio=33.35; 95% confidence interval, 3.79-800; P=0.00002). No association was found between illness and other possible risk factors. Appropriate control measures resulted in resolution of the outbreak. Our findings demonstrate the potential for enteroviruses to cause widespread illness among newborns, and emphasize the usefulness of polymerase chain reaction in the early diagnosis of infection, and underline the role of effective control measures in interrupting viral transmission.

Viral hazards to and from health care workers

Much attention has been directed towards nosocomial transmission of viruses as a result of clear evidence of patient-to-staff and staff-to-patient transmission of the blood-borne viruses HIV and hepatitis B virus. Although the relatively long incubation periods of these viruses, together with the frequency of asymptomatic infections, renders problems for surveillance it has been possible to study modes of transmission and levels of risk over a number of years. Information on trends of incidence of other nosocomial virus infections has been difficult to obtain for a number of reasons. Often, an outbreak in the health care setting parallels an epidemic in the community. Although it may be possible to define nosocomial transmission from recording dates of onset of illness relative to admission date and, at times, demonstrate circulation of a common strain by molecular techniques, the relative contributions of patient-to-staff and staff-to-patient transmission may be difficult to clarify. In this review, details are presented of the major viruses associated with nosocomial transmission with examples of infections to and from staff where these have occurred. The major defences against patient-to-staff and staff-to-patient transmission are awareness of potential risks, education and adherence to infection control policies, immunization of staff, effective decontamination and sterilization and the adoption of 'Universal Precautions' in patient care. In addition, there may be occasions when additional measures should be considered including isolation, cohorting and the use of specific chemo- and immunoprophylaxis.

Outbred mice infected by an encephalomyocarditis virus variant: a model for studying chronic viral heart disease

Male 8 to 20-week-old NMRI mice (an outbred strain) infected with the encephalomyocarditis virus (EMCV) plaque variant (PV) 7 consistently develop a distinct myocarditis with a relatively low mortality (21%). Myocarditis occurs in essence independent of the virus dose applied, and other internal organs are not affected. Nevertheless, 3.5-week-old NMRI mice perished within 5 days of virus inoculation and exhibited disseminated myofibrillar degeneration (MFD); this obviously virus-induced myocardial damage was accompanied by scanty inflammatory infiltrates. EMCV PV7 infection of adult male C57Bl/6 and DBA/2 mice causes myocarditis comparable to that seen in NMRI mice. In DBA/2 mice, however, the virus-induced myocardial necrosis is complicated by subtotal calcification. This strain has a genetically determined "spontaneous" calcification of the myocardium, as shown by the study of uninfected controls. EMCV PV7-infected NMRI mice appear a promising model for study of long-term effects of viral myocarditis, possibly including cardiomyopathy. Furthermore, this outbred mouse strain offers the possibility of examining the pathogenesis of direct viral cytolysis and its relation to MFD as well as immunologically mediated cell damage.

Isolation and preliminary characterization of antigenic variant of echovirus type 11

Nosocomial infection with echovirus type 11 resulting in aseptic meningitis occurred among newborn babies in a hospital neonatal room at Fukui city. The virus was identified as a variant of echovirus type 11 by cross-neutralization tests with antisera against the prototype Gregory strain and the current Fukui isolate. Fukui isolates expressed strain specific antigen(s) in addition to type specific common antigen(s), but lacked a certain antigen(s) which was present in the prototype strain. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of virus polypeptides revealed that the capsid proteins VP2 and VP3 of Fukui strain migrated more rapidly than the Gregory strain, while both strains had the same migration pattern of VP1 protein on which the antigenic determinants responsible for virus neutralization were present. The current strain produced large plaques and was more thermoresistant, suggesting some alterations in the structural proteins of the virus.

Congenital echo virus infection--morphological and virological study of fetal and placental tissue

A prospective study of 78 pregnant women was undertaken to detect maternal enterovirus infection. Maternal faecal specimens and blood samples, placental and fetal tissue were taken for viral study, electron microscopy, histochemistry, and morphological examination. We present the post-mortem findings in three fetuses whose maternal infection was detected before delivery by isolation of ECHO virus type 33 and type 27 from faecal specimens and/or placental and fetal tissues. The morphological aspects were similar in all cases and included an acute infection of the placenta and hypoxic/hypotensive injury to fetal organs. In one case, viral particles were detected by electron microscopy of the fetal liver. This series of cases of intrauterine ECHO virus infection confirms the potential gravity of such infection during pregnancy and the need to prevent enteroviral disease.

Fatal echovirus 7 infection during an outbreak in a special care baby unit

A case of fatal echovirus 7 infection in a neonate which was probably acquired from the symptomatic mother and an outbreak of infection in a neonatal unit are described. The baby who died had extensive haemorrhagic necrosis of the brain, liver, adrenal glands and kidneys as well as disseminated intravascular coagulation. Three other babies and one member of staff were found to be infected. No other babies died. Human normal immunoglobulin was administered to all babies on the unit.

Conservative management of an echovirus 11 outbreak in a neonatal unit

Two babies in a neonatal unit presented on the same day with meningitis due to echovirus 11, which was thought to have been introduced by staff. At this time echovirus 11 was also isolated from the stools of eight other babies; five of them did not have signs of infection. No intervention was made except to emphasise the importance of handwashing. There was evidence of secondary spread to two babies who were both clinically well. The attack rate was twelve (29%) of forty-one babies exposed. Seven of the twelve infected babies were born before 30 weeks' gestation and would have had little or no maternal antibody, yet only two of the seven babies had signs of infection. Despite lack of special measures, all babies recovered. Most cases of horizontally acquired neonatal echovirus infection are mild: extreme measures in the management of outbreaks are unnecessary.

Two concurrent epidemics of enteroviral meningitis in an obstetric neonatal unit

A small epidemic of viral infection occurred in a neonatal unit. It involved 11 infants, all of whom recovered. Echovirus 11 was the cause of illness in six infants, coxsackie B3 in four, and one infant had a biphasic illness, due first to echo 11, then to coxsackie B3. The epidemic coincided with a major outbreak of echovirus 11 and a smaller outbreak of coxsackie B3 in the community. Several staff became ill. Five infants were considered to have been infected by perinatal materno-infant spread, others by cross-infection. The epidemic ended when the nursery was closed.

An epidemic of acute diarrhoea in rural southern India associated with echovirus type 11 infection

An epidemic of diarrhoea with two distinct waves affected a village of 1375 people in southern India in 1983. The first wave of the epidemic, from the last week of December 1982, had a sharp peak in January 1983 and was over by March. Echovirus type 11 was isolated from patients, who also had a serum antibody response to the virus. During the second wave of the epidemic, from May to September 1983, the clinical features were different and Shigella flexneri was isolated without significant viral isolates. Infection during the first wave did not protect from the second wave. Virus isolation was in human intestinal tumour-derived differentiated epithelial cell lines; such cell lines may be useful for the isolation and identification of enteroviruses in clinical samples.

Aseptic meningitis in a neonate with an oral vesicular lesion

Enteroviruses may be responsible for severe, life-threatening diseases, such as meningitis, within the neonatal period. Differentiation of an enteroviral etiology from that of herpes simplex virus may be difficult initially. We describe a case of aseptic meningitis in which the use of a viral blood culture was helpful.

Fatal hepatoadrenal necrosis in the neonate associated with echovirus types 11 and 12 presenting as a surgical emergency

Two neonates presented to our service with suspected intraabdominal surgical emergencies. Both subsequently were found to have hepatoadrenal necrosis due to overwhelming echoviral infection. Echovirus types 11 and 12 were isolated postmortem. The latter virus has not been associated previously with fulminant neonatal illness.

Selected aspects of nosocomial infections in the 1980s

Unusual or rare pathogens and syndromes may become significant problems in nosocomial infection. Pathogens that usually produce community-onset disease, particularly respiratory viruses, Legionella, and atypical mycobacteria, also cause nosocomial infection. Conversely, nosocomial pathogens may also produce disease in the community, as has been seen with Clostridium difficile. Contamination of parenteral and antiseptic solutions continues to be a problem in hospitals. Hospital-acquired viral infections are receiving increasing recognition. Nosocomial gastrointestinal infections, although of low frequency, are of major import because of their epidemic potential. Airborne transmission of pathogens is becoming more apparent at the same time that recognition of the importance of hand transmission creates hope for infection control. Antibiotics influence the type of microorganisms that colonize patients, but the host determines superinfection.

Epidemiology of neonatal enterovirus infection

During a typical enterovirus season in Rochester, New York, none of 666 neonates or 629 mothers were found to be excreting nonpolio enteroviruses within 1 day of delivery. No enteroviruses were isolated from weekly cultures of the 23 infants who died or remained hospitalized during the first month of life. After discharge, culture specimens were obtained in 586 infants at one to four weekly home visits until 1 month of age. The incidence of acquisition of nonpolio enterovirus infection was 12.8%, and the overall prevalence of enterovirus excretion was 5.3%. Risk of virus infection was associated only with lower socioeconomic status (P less than 0.0001) and lack of breast-feeding (P less than 0.0001). Four percent of all infants and 21% of infants in whom cultures for enterovirus were positive were readmitted to the hospital in the first month of life; 79% of infants with positive enterovirus cultures were asymptomatic. We conclude that enterovirus infection during the first month of life is very common in the late summer and early fall. Most infants are asymptomatic, but the risk of hospitalization is high. Breast-feeding may be associated with protection from infection.

A prospective study of chlamydial, mycoplasmal, and viral infections in a neonatal intensive care unit

In a prospective study of non-bacterial infection in a neonatal intensive care unit in north west London, Chlamydia trachomatis infection was identified in 4 of 280 babies (1.4%) and was the most common cause of neonatal ophthalmia. One of the four developed pneumonitis. Ureaplasma urealyticum was found to colonise the nasopharynx in 53 of 235 babies (22.6%), with Mycoplasma hominis present in 6 of 235 babies (2.6%). There was a statistically significant association between U urealyticum colonisation and preterm birth or prolonged rupture of membranes. Colonisation occurred more commonly in babies with apnoea. Viral infection was detected in 16 of 280 babies (5.7%). Rotavirus was identified in 5 of 170 babies (2.9%) and was associated with necrotising enterocolitis in two infants and with bloody diarrhoea in another. Respiratory syncytial virus, which was identified in 4 of 280 babies (1.4%), was not associated with lower respiratory tract infection.

Postmortem manifestations of echovirus 11 sepsis in five newborn infants

Five cases of fatal neonatal echovirus type 11 infection were observed in the Boston area during the summer and fall of 1979. Four of the mothers experienced gastroenteritis with fever and abdominal cramps late in the third trimester of pregnancy. The clinical course of each case was characterized by jaundice, hepatosplenomegaly, and progressive hepatic failure; all five infants were severely hypotonic. At autopsy massive hepatic and adrenal hemorrhage and necrosis, with evidence of consumption coagulopathy, were found. Echovirus type 11 was isolated from various sites before and after death. The histopathologic features and epidemiologic aspects of these cases are briefly discussed.

Use of normal immunoglobulin in an echovirus 11 outbreak in a special-care baby unit

An epidemic of echovirus 11 infections occurred in the Cambridge special-care baby unit during August to October, 1982. There were 21 confirmed infections in babies; 1 died, 1 recovered after resection of a kidney, 5 had meningitis, and 6 had respiratory symptoms. Normal human immunoglobulin which contained antibody to echovirus 11 was administered intramuscularly (250 mg) to give protection. None of the children given immunoglobulin immediately after delivery (205 doses) developed symptoms or ill-effects. Serological studies reinforced earlier evidence for the protective action of antibody, and it is considered that immunoglobulin is a valuable safeguard for exposed newborn infants.

Action of commonly used disinfectants against enteroviruses

The virucidal effect of some of the most commonly used hospital disinfectants against Coxsackie B4, Echovirus 11, Poliovirus type 1 and Rotavirus have been evaluated. It was found that 'Chloros', 'Totacide 28' and methylated spirits were completely virucidal to all the viruses under study. 'Stericol' and 'Lysol' had a limited effect while 'Hibiscrub' and 'Savlon' had no effect at all.

Disseminated neonatal echovirus 11 disease following antenatal maternal infection with a virus-positive cervix and virus-negative gastrointestinal tract

An infant girl was born apparently well one week after her mother had had a mild illness with chills, fever, and diarrhea. On the third day of life, the infant became ill and died four days later with necrotizing hepatitis. On the same day, echovirus type 11 was recovered from the throat, rectum, and buffy coat of the infant and from the cervix of the mother. At this time, the mother had an IgM neutralizing antibody titer to echovirus type 11 and 1:128, but no IgG antibodies. The infant had no echovirus type 11 antibodies. The virus was also isolated from the baby's liver and adrenal at autopsy. These findings raise the possibility of enterovirus infection at delivery from a contaminated cervix.

A report of a spring-summer outbreak of echovirus II infection

A spring-summer epidemic of echovirus II in New South Wales, Australia, is reported. The symptomatology was found to be age dependent. Neonates and young infants tended to have a severe 'septicaemic' illness. Older infants had a variety of clinical presentations: aseptic meningitis, febrile convulsions, upper respiratory tract infections, and acute enteritis. Children over the age of two in this study uniformly presented with symptoms suggestive of aseptic meningitis--confirmed by cerebrospinal (CSF) cytology in the majority of cases. The clinical presentation of an acute febrile illness in the young child may not allow for distinction between bacterial and viral infection. The importance of the recognition and confirmation of a viral aetiology relates to the subsequent management: i.e. antibiotics may be withheld, hospitalisation may be shortened, and a more favourable prognosis can be made. Certain epidemiological clues and laboratory studies are helpful in suggesting a viral aetiology, but a definitive diagnosis of enteroviral infection may only be readily achieved by virus isolation in tissue culture.

A study of school children who had identified virus infections of the central nervous system during infancy

Forty-nine children who had a virus infection of the central nervous system (CNS) when under 1 year of age were studied. One child had died during the initial illness and three of the survivors were severely disabled. The other survivors, more than 5 years after the initial illness, were all attending normal schools. These 45 children, together with 45 matched controls, were examined. We confirm the findings of other studies that virus infections of the CNS in infancy may cause severe disabilities in some cases, and may depress intellectual abilities in others, even though they appear to have recovered fully. Many of the children who had a virus infection of the CNS in infancy had adverse birth and social histories and so were exceptionally vulnerable, but these factors did not account fully for the findings, and when their influence was included in the analysis, the index children still had a mean performance IQ (WISC) 6 points lower than the control children (P less than 0.05), whereas there was less than 1 point difference between the verbal IQs. Attention is drawn to the problem of virus infections in neonatal units.

Epidemiology of an outbreak in a maternity unit of infections with an antigenic variant of Echovirus 11

After an 8-day-old child had died with clinical signs of septicemia, 6 other newborns fell ill. Virus was isolated from various sites from all the 6 children (28 isolations). The agent was identified by cross neutralization tests as an antigenic variant of Echovirus 11. The agent could not be isolated from mothers or nursery staff (49 people). We therefore tried to trace the path of infection by isolating specific IgM and IgG antibodies. A laboratory infection by the agent isolated enabled the time pattern of the serologic immune response to be roughly determined. The data collected indicate that the infection spread through close contact between the affected newborns and nurses working in the newborn room. Rigorous hygienic and isolation measures, initiated immediately, appeared to interrupt the spread of infection.

Echovirus type 11 infection in Melbourne--1953 to 1980

Echovirus type 11 (echo 11) has been isolated at the virus laboratory of Fairfield Hospital, Melbourne, Australia, in 20 of the 28 years since the laboratory was established. During this time two major epidemics have occurred; the first, in 1971-2 involved 90 patients with aseptic meningitis or respiratory illness. The second began in June 1979 and lasted for 11 months, during which echo 11 was isolated from 174 patients admitted to Fairfield Hospital, other Victorian and Tasmanian hospitals and a children's reception centre. The patients' illnesses included viral meningitis (66%), fever (10%), respiratory infections (7%) and gastroenteritis (2%). One baby died. Echo 11 was recovered from nasopharyngeal swabs or aspirates, cerebrospinal fluid and faecal specimens and was isolated most frequently in the Borrie cell line. Isolates were readily identified by immune electron microscopy and/or neutralization tests.