Postmortem manifestations of echovirus 11 sepsis in five newborn infants

An Overview of the Characteristics, Pathogenesis, Epidemiology, and Detection of Human Enterovirus in the Arabian Gulf Region

Enteroviruses are RNA viruses that initiate infections through the gastrointestinal (GI) tract and are associated with enteric illness in individuals of all ages. Most serious infections of enteroviruses are in infants and young children where it is the common cause of aseptic meningitis and other systemic diseases, leading to a high mortality rate. Enteroviruses belong to the small non-enveloped family of the Picornaviridae family. The virus can spread mainly through fecal-oral and respiratory routes. In the Arabian Gulf countries, the incidence of enteroviral infections is only restricted to a few reports, and thus, knowledge of the epidemiology, characteristics, and pathogenesis of the virus in the gulf countries remains scarce. In this minireview, we sought to provide an overview of the characteristics of enterovirus and its pathogenesis, in addition to gathering the reports of enterovirus infection prevalence in Gulf Cooperation Council (GCC) countries. We also present a summary of the common methods used in its detection.

Congenital Echovirus 11 Infection in a Neonate

Neonates infected with enterovirus in utero would be fulminant at birth or develop symptoms within a few days. Echovirus 11 causes life-threatening hepatic necrosis with coagulopathy and adrenal hemorrhagic necrosis. The prognosis depends on the enterovirus serotype and the absence of serotype-specific maternal antibodies at the time of delivery. We describe a fatal neonatal case of congenital echovirus 11 infection.

Therapeutics for fulminant hepatitis caused by enteroviruses in neonates

Neonatal infection with nonpolio enteroviruses (EVs) causes nonspecific febrile illnesses and even life-threatening multiorgan failure. Hepatitis, which often results in hepatic necrosis followed by disseminated intravascular coagulopathy, is one of the most severe and frequent fatal neonatal EV infection complications. Coxsackievirus B (CVB) 1–5 and many echoviruses have been most commonly identified. Neonatal EV infection treatment has usually involved initial supportive care. Studies for CVB and echovirus infection treatments were developed for more than thirty years. Intravenous immunoglobulin and pleconaril therapy was performed in some clinical trials. Additionally, other studies demonstrated antiviral and/or anti-inflammatory pathogenesis mechanisms of neonatal EV hepatitis in in vitro or in vivo models. These treatments represented promising options for the clinical practice of neonatal EV hepatitis. However, further investigation is needed to elucidate the whole therapeutic potential and safety problems.

Echovirus 11 infection induces pyroptotic cell death by facilitating NLRP3 inflammasome activation

Echovirus 11 (ECHO 11) is a positive-strand RNA virus belonging to the genus Enterovirus of the family Picornaviridae. ECHO 11 infections can cause severe inflammatory illnesses in neonates, including severe acute hepatitis with coagulopathy. The activation of NLRP3 inflammasome is important for host defense against invading viruses, which also contributes to viral pathogenicity. However, whether and how ECHO 11 induces NLRP3 inflammasome activation remains unclear. In this study, we isolated a clinical strain of ECHO 11 from stools of an ECHO 11-infected newborn patient with necrotizing hepatitis. This virus shared 99.95% sequence identity with the previously published ECHO 11 sequence. The clinically isolated ECHO 11 can efficiently infect liver cells and strongly induces inflammation. Moreover, we showed that ECHO 11 induced IL-1β secretion and pyroptosis in cells and mouse bone marrow-derived macrophages (BMDMs). Furthermore, ECHO 11 infection triggered NLRP3 inflammasome activation, as evidenced by cleavages of GSDMD, pro-IL-1β and pro-caspase-1, and the release of LDH. ECHO 11 2B protein was required for NLRP3 inflammasome activation via interacting with NLRP3 to facilitate the inflammasome complex assembly. In vivo, expression of ECHO 11 2B also activated NLRP3 inflammasome in the murine liver. Besides, 2Bs of multiple EVs can also interact with NLRP3 and induce NLRP3 inflammasome activation. Together, our findings demonstrate a mechanism by which ECHO 11 induces inflammatory responses by activating NLRP3 inflammasome, providing novel insights into the pathogenesis of ECHO 11 infection.

NLRP3 inflammasome is important for host defense against invading viruses, and contributes to viral pathogenicity. Human echovirus 11 (ECHO 11) belongs to the Enterovirus genus from the family Picornavirida, and it can cause severe acute hepatitis in newborns with high morbidity and mortality. However, the knowledge about the pathogenesis of ECHO 11 infection is limited. Whether and how ECHO 11 induces NLRP3 inflammasome activation remains unclear. This work provides the first demonstration that ECHO 11 can induce inflammatory responses via activating NLRP3 inflammasome and pyroptosis. More importantly, ECHO 11-encoded 2B protein was found to activate NLRP3 inflammasome in cells and in vivo, and the interaction between 2B and NLRP3 was required for inflammasome complex assembly. Furthermore, we uncovered that 2Bs of other enteroviruses, including enterovirus 71, coxsackievirus A16 (CVA16) and CVB3 could induce NLRP3 inflammasome and interact with NLRP3. Our findings uncover a mechanism by which ECHO 11 induces inflammatory responses and demonstrate a novel function of ECHO 11 2B.

Antiviral Peptides Targeting the Helicase Activity of Enterovirus Nonstructural Protein 2C

Enteroviruses belong to the genus Enterovirus of the family Picornaviridae and include four human enterovirus groups (EV-A to -D): the epidemic of enteroviruses such as human enterovirus A71 (EV-A71) and coxsackievirus A16 (CVA16) is a threat to global public health. Enteroviral protein 2C is the most conserved nonstructural protein among all enteroviruses and possesses RNA helicase activity that plays pivotal roles during enteroviral life cycles, which makes 2C an attractive target for developing antienterovirus drugs. In this study, we designed a peptide, named 2CL, based on the structure of EV-A71 2C. This peptide effectively impaired the oligomerization of EV-A71 2C protein and inhibited the RNA helicase activities of 2C proteins encoded by EV-A71 and CVA16, both of which belong to EV-A, and showed potent antiviral efficacy against EV-A71 and CVA16 in cells. Moreover, the 2CL treatment elicited a strong in vivo protective efficacy against lethal EV-A71 challenge. In addition, the antiviral strategy of targeting the 2C helicase activity can be applied to inhibit the replication of EV-B. Either 2CL or B-2CL, the peptide redesigned based on the 2CL-corresponding sequence of EV-Bs, could exert effective antiviral activity against two important EV-Bs, coxsackievirus B3 and echovirus 11. Together, our findings demonstrated that targeting the helicase activity of 2C with a rationally designed peptide is an efficient antiviral strategy against enteroviruses, and 2CL and B-2CL show promising clinical potential to be further developed as broad-spectrum antienterovirus drugs.IMPORTANCE Enteroviruses are a large group of positive-sense single-stranded RNA viruses and include numerous human pathogens, such as enterovirus A71 (EV-A71), coxsackieviruses, and echoviruses. However, no approved EV antiviral drugs are available. Enteroviral 2C is the most conserved nonstructural protein among all enteroviruses and contains the RNA helicase activity critical for the viral life cycle. Herein, according to the structure of EV-A71 2C, we designed a peptide that effectively inhibited the RNA helicase activities of EV-A71- and coxsackievirus A16 (CVA16)-encoded 2C proteins. Moreover, this peptide exerted potent antiviral effects against EV-A71 and CVA16 in cells and elicited therapeutic efficacy against lethal EV-A71 challenge in vivo Furthermore, we demonstrate that the strategy of targeting the 2C helicase activity can be used for other relevant enteroviruses, including coxsackievirus B3 and echovirus 11. In summary, our findings provide compelling evidence that the designed peptides targeting the helicase activity of 2C could be broad-spectrum antivirals for enteroviruses.

Enteroviruses in gastrointestinal diseases

Gastrointestinal diseases including diarrhoea constitute a major cause of morbidity and mortality in infants and young children especially in developing countries. Worldwide deaths among all ages due to diarrhoea during 2015 were estimated to be about 1.31 million, diarrhoeal deaths in children below 5 years of age being 499 000. Rotavirus accounted for about 200 000 deaths. Although diarrhoeal deaths decreased significantly during the last two decades, they still represent the third largest cause of infantile deaths. Several bacterial, viral, parasitic, fungal and non-infectious diarrhoea causing agents have been identified, but 30% to 40% of diarrhoeal cases remain undiagnosed. Enteroviruses transmit by the faecal-oral route and replicate first in intestinal cells before spreading to the target organ. They have been associated with diarrhoea in a few studies, but their causative role in diarrhoea in humans has not been systematically demonstrated. In view of the recent demonstration that enteroviruses cause diarrhoea in newborn mice pups, thus validating Koch's postulates, the purpose of this review is to emphasise the importance of recognising enteroviruses as major gastrointestinal pathogens associated with acute and persistent diarrhoea and non-diarrhoeal increased frequency of bowel movements in infants, young children and adults. Our studies and several other subsequent studies reported from different countries should stimulate strategies to reduce the burden of infantile gastrointestinal disease, which has hitherto remained unaddressed.

Hand, foot, and mouth disease in pregnancy: 7 years Tuscan experience and literature review

OBJECTIVE

Evaluation of hand, foot, and mouth disease (HFMD) diagnostic strategies in pregnancy and the risk of HFMD-related fetopathy.

STUDY DESIGN

Pregnant women consecutively evaluated between 2010 and 2016 at the Tuscany Reference Center for Infectious Diseases in Pregnancy for HFMD were enrolled. A descriptive analysis of infected patients/newborns data and literature review were carried out.

RESULT

Of the 128 women evaluated, 52 (41%) were symptomatic: 32 (61.5%) developed HFM vesicles, 12 (23%) palmoplantar vesicles, and 8 (15.5%) oral aphthae. Serological positivity and direct Enterovirus detection on blood and vesicle were obtained in 1.9% (1/52), 9.1% (1/11), and 68.7% (11/16), respectively. Three miscarriage and few cases of fetal/neonatal anomalies were reported.

CONCLUSION

HFMD diagnosis is primarily a clinical diagnosis. Direct viral detection is more sensitive than serology. Considering our series and literature review, data on embryo-fetal-neonatal outcomes are not conclusive. Although the role of EV as causative agents of congenital defects remains uncertain, the described cases of unfavorable outcome impose prudence and monitoring of pregnant women with HFMD throughout the gestation.

Extrahepatic Nonreticuloendothelial Siderosis Is Not Specific to Gestational Alloimmune Liver Disease

Autopsy reports of 78 stillbirths and early infant deaths (up to age 8 weeks) were reviewed to investigate the prevalence of extrahepatic nonreticuloendothelial siderosis (EHNRS) in the context of neonatal liver failure. Of these, 10 liveborns (12.8%), M:F 3:2, with mean gestational age 37.6 weeks (range: 35-39) and mean age at the time of demise 19.1 days (range: 7-42), showed significant liver injury: infection (n = 7, viral > fungal), congenital malformations (n = 2), and ischemia (n = 1). None had maternal history of gestational alloimmune liver disease (GALD) or previous fetal/neonatal death due to liver failure. Seven of 10 cases (70%) showed EHNRS: pancreas (n = 6), kidneys (n = 4), thyroid and adrenal glands (n = 3), and bronchial glands and heart (n = 2). Iron deposition was most frequent in the pancreas (60%), most diffuse in the kidneys, and seen in at least 2 organs, with pancreas and kidney being the most frequent combination. Hepatic C5b-9 expression was variable (1+ to 4+) except 1 case (100% necrosis). The duration of illness and the mean age at the time of demise tended to be higher in those with EHNRS. In summary, hepatic and EHNRS, with or without C5b-9 expression, are not specific for GALD. Other causes of liver failure should be investigated as clinically and pathologically appropriate.

Adverse effects of maternal enterovirus infection on the pregnancy outcome: a prospective and retrospective pilot study

Background

Enteroviruses account for about one billion infections worldwide each year, the majority remain asymptomatic. Data on enterovirus infections during pregnancy appear to be very rare. Several cases have been reported in the literature of fetal and neonatal complications attributed to these viruses, but prospective data on these infections during pregnancy are not available.

Objective

To estimate the prevalence of enterovirus infections in febrile syndromes in pregnant women, and in case of in utero fetal death (IUFD).

Methods

Ttri-centric observational cohort study. We performed prospective inclusion for patients with fever during a four-month period. We also analyzed the amniotic fluid in patients with unexplained IUFD retrospectively during a five-year period. Investigations of enteroviruses are made by RT-PCR from routine biological samples (amniocentesis, RT-PCR in maternal blood or CSF).

Results

Prospectively, 33 patients were included during the study period. We have identified 4 cases of confirmed enterovirus infection (12.4%). We have recorded a severe form of perinatal enterovirus infection involving the vital prognosis of the newborn.

In the retrospective cohort of 75 IUFD cases, we had only one case of enterovirus-positive RT-PCR in amniotic fluid during 5 years, meaning a frequency of 1.3%. We did not had any positive EV case in case of early miscarriage, but the limited number of inclusions cannot help us to conclude.

Conclusion

Enteroviruses are probably an underestimated cause of obstetric and neonatal complications. Investigation of enterovirus by PCR should be discussed during pregnancy and peripartum in case of febrile syndrome with no obvious bacterial cause, and unexplained IUFD.

[Enterovirus infection during pregnancy: Underestimated cause of fetal and neonatal complications?]

Enteroviruses are responsible for about one billion infections every year in the world. The clinical expression is in the vast majority asymptomatic cases (90%). Its consequences during pregnancy are rarely described. From the Medline database, we selected and analyzed 34 articles ranging from 1965 to 2015, to analyse the current knowledge of enterovirus infection consequences during pregnancy. We found that enterovirus infections may be the cause of fetal loss. The enterovirus infections during the 2nd and 3rd trimester may also lead to in utero fetal anomalies and death, but also to severe neonatal infections. PCR enterovirus detection should be performed during pregnancy and the peripartum in case of unexplained fever, specific fetal anomalies or unexplained fetal demise.

Non-polio enteroviruses and their association with acute diarrhea in children in India

A causative agent in approximately 40% of diarrheal cases still remains unidentified. Though many enteroviruses (EVs) are transmitted through fecal-oral route and replicate in the intestinal cells, their association with acute diarrhea has not so far been recognized due to lack of detailed epidemiological investigations. This long-term, detailed molecular epidemiological study aims to conclusively determine the association of non-polio enteroviruses (NPEVs) with acute diarrhea in comparison with rotavirus (RV) in children. Diarrheal stool specimens from 2161 children aged 0-2 years and 169 children between 2 and 9 years, and 1800 normal stool samples from age-matched healthy children between 0 and 9 years were examined during 2008-2012 for enterovirus (oral polio vaccine strains (OPVs) and NPEVs). Enterovirus serotypes were identified by complete VP1 gene sequence analysis. Enterovirus and rotavirus were detected in 19.01% (380/2330) and 13.82% (322/2330) diarrheal stools. During the study period, annual prevalence of EV- and RV-associated diarrhea ranged between 8% and 22%, but with contrasting seasonal prevalence with RV predominating during winter months and NPEV prevailing in other seasons. NPEVs are associated with epidemics-like outbreaks during which they are detected in up to 50% of diarrheic children, and in non-epidemic seasons in 0-10% of the patients. After subtraction of OPV-positive diarrheal cases (1.81%), while NPEVs are associated with about 17% of acute diarrhea, about 6% of healthy children showed asymptomatic NPEV excretion. Of 37 NPEV serotypes detected in diarrheal children, seven echovirus types 1, 7, 11, 13, 14, 30 and 33 are frequently observed, with E11 being more prevalent followed by E30. In conclusion, NPEVs are significantly associated with acute diarrhea, and NPEVs and rotavirus exhibit contrasting seasonal predominance. This study signifies the need for a new direction of research on enteroviruses involving systematic analysis of their contribution to diarrheal burden.

Detection of echovirus 18 in human breast milk

We detected enteroviral RNA and cultured infectious virus from a series of banked breast milk samples from the mother of an infant with neonatal sepsis; sequencing of the enterovirus isolate identified it as echovirus type 18. In this case, it is possible that enterovirus transmission occurred through the breast milk.

Adrenal infections

Adrenal infections are an important but under-recognized clinical entity. The adrenal gland can be infected by a myriad of pathogens including fungi, viruses, parasites, and bacteria. Infection can directly or indirectly cause tissue damage and alteration in endocrine function. Direct damage occurs via microbial replication and local production of toxic compounds, such as endotoxins. Indirect damage results from alterations in the regulation of a host's immunologic and endocrine mediators in response to damage by a microbe at a distant site. Variations in pathogen tropism, adrenal anatomy, and host immune integrity contribute to the progression of active disease and discernable adrenal dysfunction. Early recognition and intervention in the case of adrenal infection can significantly improve outcome, demonstrating the need for increased clinical suspicion in the appropriate clinical setting.

Placental inflammation

Placental inflammatory disorders represent a diverse and important category of pathological processes leading to fetal and neonatal morbidity and mortality. These processes can be divided into two broad subcategories, those caused by micro-organisms and those caused by host immune responses to non-replicating antigens. The mechanisms by which these inflammatory processes cause death and disability are diverse and can be separated into four distinct classes: placental damage with loss of function, induction of premature labour and subsequent preterm birth, release of inflammatory mediators leading to fetal organ damage and transplacental infection of the fetus. Each specific inflammatory process can be modulated by properties of the specific organism, the route and timing of infection and variations in the host's genetic background and immune responsiveness. All of these factors combine to produce specific patterns of placental pathology that can be used to guide treatment, predict complications and explain adverse outcome.

Management of coagulopathy with recombinant factor VIIa in a neonate with echovirus type 7

A 5-day-old newborn presented with neonatal enteroviral infection. The patient's hospital course was complicated by acute liver dysfunction, renal insufficiency, fluid overload, respiratory failure, hypertension, catheter related thrombosis, Klebsiella pneumoniae sepsis, intracerebral and intraventricular hemorrhage, and disseminated intravascular coagulation (DIC). Administration of fresh frozen plasma (FFP) and cryoprecipitate failed to control the patient's hemostasis and led to significant fluid overload. Recombinant activated factor VII (rFVIIa, Novoseven NovoNordisk, Bagsvaerd, Denmark) was given to the neonate as a bolus (rFVIIa at 60-80 microg/kg body weight), followed by a continuous infusion (2.5-16 microg/kg/hr). Recombinant activated factor VII controlled hemostasis, until the patient's liver function recovered. The patient's blood product requirement significantly decreased and his fluid overload resolved. Administration of rFVIIa appears to have stabilized the coagulation process. The patient appears to have fully recovered from the infection's complications.

Hepatic failure with neonatal tissue siderosis of hemochromatotic type in an infant presenting with meconium ileus. Case report and differential diagnosis of the perinatal iron storage disorders

We report on a female preterm infant with hepatic failure and neonatal tissue siderosis of hemochromatotic type diagnosed by using both histochemistry and atomic absorption spectroscopy. The infant presented with meconium ileus, signs of rapidly progressive hepatic failure, and hyperferritinemia (7132 ng/ml). Despite surgery and intensive care the infant died 32 days after birth. Postmortem examination showed a wrinkled liver with extensive collapse of the hepatic architecture and regenerating nodules as well as hepatic and extrahepatic iron accumulation of hemochromatotic type, sparing the reticuloendothelial system. Atomic absorption spectroscopy confirmed an increase in the iron content of various organs: liver, heart, pancreas, oral salivary gland, kidney, and adrenal gland. The increase in the iron content of various organs was determined by comparing the analysis of the propositus with those of 5 gestationally age-related preterm infants who had died in the intensive care unit: 2 died of meconium aspiration syndrome, the other 3 of hyaline membrane disease, bronchopulmonary dysplasia, and immaturity, respectively. We also compared the analysis of 15 fetuses having a a condition predisposing to iron accumulation (trisomy 21, trisomy 18, cytomegalovirus, amnion infection syndrome, Rhesus- and ABO-incompatibility, congenital hemolysis, anti-phospholipid syndrome, congenital heart disease). Delta F508, the most frequent mutation seen in cystic fibrosis patients, was excluded by gene sequencing. Different noxae causing iron accumulation in the neonatal period have led to the statement that neonatal hemochromatosis may collect different etiologies, such as metabolic disorders, infections, chromosomal aberrations, and immunological disorders. In this study, we report the singular evidence of neonatal iron accumulation of hemochromatotic type in an infant presenting with meconium ileus and propose a classification of the neonatal disorders associated with iron accumulation.

Prognosis for neonates with enterovirus hepatitis and coagulopathy

BACKGROUND

Neonatal enterovirus hepatitis and coagulopathy (EHC) can be a severe, life-threatening infection. However, the case-fatality rate of EHC and the prognosis for survivors are not well-defined.

METHODS

A search of a hospital medical records database and the investigator's files for the period 1983 to 2000 was performed. Patients with onset of enterovirus-associated illness at age < or = 30 days and either (1) aspartate aminotransferase or alanine aminotransferase > 3 times the upper limit of normal or (2) platelet count < 100 000 plus an abnormal coagulation profile were included.

RESULTS

Sixteen cases were identified. Symptoms began at a mean of 3.8 days (range, 1 to 7 days). Frequent clinical and laboratory findings included jaundice, lethargy, anorexia, hepatomegaly, thrombocytopenia, clotting time prolongation, elevated transaminase and bilirubin values and decreased fibrinogen and albumin concentrations. Five patients had myocarditis and 4 had encephalitis. Hemorrhagic complications occurred in 10 (intracranial hemorrhage in 5). Five (31%) patients died. Features discriminating patients who died from survivors were concomitant myocarditis (5 of 5 vs. 0 of 11, P < 0.001), encephalitis (3 of 5 vs. 1 of 11, P = 0.06), prothrombin time > 30 s (4 of 5 vs. 1 of 9, P = 0.02) and intracranial hemorrhage (4 of 5 vs. 1 of 8, P = 0.03). Follow-up of 6 survivors revealed normalization of liver function and platelet counts, satisfactory growth and absence of significant medical problems.

CONCLUSIONS

The case-fatality rate of 31% is evidence of the potentially devastating nature of EHC. Concomitant EHC and myocarditis are especially serious, but the prognosis for children who survive neonatal EHC is generally excellent.

Fatal neonatal echovirus 6 infection: autopsy case report and review of the literature

A full-term, healthy male neonate was delivered by caesarian section to a 26-year-old primigravida woman who had a history of fever and upper respiratory tract infection. On the fourth day of life, the neonate developed a sepsis-like syndrome, acute respiratory and renal failure, and disseminated intravascular coagulopathy. He died 13 days after birth. Postmortem examination revealed jaundice, anasarca, massive hepatic necrosis, adrenal hemorrhagic necrosis, renal medullary hemorrhage, hemorrhagic noninflammatory pneumonia, and severe encephalomalacia. Echovirus type 6 was isolated from blood, liver, and lungs. Although uncommon, echovirus type 6 infection may produce a spectrum of pathologic findings similar to those seen with the more commonly virulent echovirus type 11.

Exogenous iron overload in perinatal hemochromatosis: a case report

We report an infant with fatal neonatal liver disease in whom efforts to correct an associated unremitting anemia resulted in massive exogenous iron overload that was expressed as perinatal hemochromatosis (PH). Levels of iron and copper were elevated in multiple tissues. Echovirus subtype 9, recovered from the urine at age 3 weeks, may have been etiologic in the liver failure. PH is best viewed as a definable phenotype with an undefined genetic and/or environmental basis that emerges only in the context of severe perinatal liver disease. The absence of hemosiderin in splenic and bone marrow reticuloendothelial (RE) cells of our patient suggests an important role for RE cell dysfunction.

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.