Mark J. Abzug

A cluster of acute flaccid paralysis and cranial nerve dysfunction temporally associated with an outbreak of enterovirus D68 in children in Colorado, USA

BACKGROUND Clusters of acute flaccid paralysis or cranial nerve dysfunction in children are uncommon. We aimed to assess a cluster of children with acute flaccid paralysis and cranial nerve dysfunction geographically and temporally associated with an outbreak of enterovirus-D68 respiratory disease. METHODS We defined a case of neurological disease as any child admitted to Childrens Hospital Colorado (Aurora, CO, USA) with acute flaccid paralysis with spinal-cord lesions involving mainly grey matter on imaging, or acute cranial nerve dysfunction with brainstem lesions on imaging, who had onset of neurological symptoms between Aug 1, 2014, and Oct 31, 2014. We used Poisson regression to assess whether the numbers of cases during the outbreak period were significantly greater than baseline case numbers from a historical control period (July 31, 2010, to July 31, 2014). FINDINGS 12 children met the case definition (median age 11·5 years [IQR 6·75-15]). All had a prodromal febrile illness preceding neurological symptoms by a median of 7 days (IQR 5·75-8). Neurological deficits included flaccid limb weakness (n=10; asymmetric n=7), bulbar weakness (n=6), and cranial nerve VI (n=3) and VII (n=2) dysfunction. Ten (83%) children had confluent, longitudinally extensive spinal-cord lesions of the central grey matter, with predominant anterior horn-cell involvement, and nine (75%) children had brainstem lesions. Ten (91%) of 11 children had cerebrospinal fluid pleocytosis. Nasopharyngeal specimens from eight (73%) of 11 children were positive for rhinovirus or enterovirus. Viruses from five (45%) of 11 children were typed as enterovirus D68. Enterovirus PCR of cerebrospinal fluid, blood, and rectal swabs, and tests for other causes, were negative. Improvement of cranial nerve dysfunction has been noted in three (30%) of ten children. All ten children with limb weakness have residual deficits. INTERPRETATION We report the first geographically and temporally defined cluster of acute flaccid paralysis and cranial nerve dysfunction in children associated with an outbreak of enterovirus-D68 respiratory illness. Our findings suggest the possibility of an association between enterovirus D68 and neurological disease in children. If enterovirus-D68 infections continue to happen in an endemic or epidemic pattern, development of effective antiviral or immunomodulatory therapies and vaccines should become scientific priorities. FUNDING National Center for Advancing Translational Sciences, National Institutes of Health.

Profile of enterovirus disease in the first two weeks of life

We studied 57 infants < or = 14 days of age referred for possible enterovirus (EV) infection to assess the accuracy of that clinical diagnosis and describe the natural history of neonatal EV infection. Twenty-nine neonates proved to have EV infection, 23 had illnesses compatible with (but not proven to be) EV infection, and 5 had alternative diagnoses: bacterial infections (2); herpes simplex virus infection (1); and metabolic disorders (2). Neonates with proved EV infection were generally full term and had uncomplicated immediate postnatal periods but high percentages of ill contacts. Neonatal symptoms and signs included fever, irritability, anorexia, lethargy, hypoperfusion, rash, jaundice and respiratory findings. Laboratory abnormalities included cerebrospinal fluid (CSF) pleocytosis, chest radiograph infiltrates, abnormal urinalyses and elevated transaminases. EVs were most commonly isolated from CSF and rectum/stool but also frequently from serum and urine. Five EV-infected patients had severe multisystem disease (pneumonitis, hepatitis, thrombocytopenia, bleeding and meningitis), requiring supportive care and lengthy hospitalizations. All survived, 2 with residual hepatic dysfunction. Markers of severe disease included: early age of illness onset (especially Day 1 of life); maternal viral symptoms at delivery; absence of fever and irritability; tachypnea; lethargy; abdominal distension; hepatomegaly; and positive serum viral culture. These data support conservative management of ill infants < or = 2 weeks of age and suggest that antiviral therapy for neonatal EV infection would be optimally targeted at infants with early onset illness, multisystem disease and/or viremia.

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.

In utero nucleoside reverse transcriptase inhibitor exposure and signs of possible mitochondrial dysfunction in HIV-uninfected children.

Background:There is equivocal evidence of in utero nucleoside reverse transcriptase inhibitor (NRTI) exposure and the occurrence of mitochondrial dysfunction (MD) in HIV-uninfected children born of HIV-infected women. Methods:The primary analysis included 1037 HIV-uninfected children born in 1991–2002 and enrolled in Pediatric AIDS Clinical Trials Group protocols 219/219C. Possible cases with unexplained signs of MD according to the Enquête Périnatale Française criteria were identified through retrospective review. Associations between overall in utero NRTI exposure, and trimester of first in utero NRTI exposure and possible MD were estimated with exact logistic regression. Results:Cases (n = 20) were significantly more likely to be male and to be born in earlier years than non-cases (n = 1017). There was no association between overall in utero NRTI exposure and MD. In unadjusted models there were higher odds of first in utero exposure in the third trimester to lamivudine (3TC) [odds ratio (OR), 3.76 versus 3TC unexposed; 95% confidence interval (CI), 1.09–11.78] and to zidovudine (ZDV) and 3TC in combination (ZDV/3TC) (OR, 3.29 vs. ZDV/3TC unexposed; 95% CI, 0.96–10.25) among cases than noncases. When adjusted for year of birth the odds of first exposure in the third trimester to 3TC (OR, 10.57; 95% CI, 1.93–75.61) and ZDV/3TC (OR, 9.84; 95% CI, 1.77–71.68) were significantly higher among cases than non-cases. Incomplete data precluded control of possible confounding by maternal viral load and psychoactive drug use. Conclusions:Our study suggests that first exposure to 3TC or ZDV/3TC in the third trimester may be associated with the occurrence of possible MD. Further studies that rigorously assess MD and better control confounding are needed.

Double blind placebo-controlled trial of pleconaril in infants with enterovirus meningitis

Background. Enterovirus (EV) meningitis is common in infants and may have neurologic complications. Treatment of older children and adults with pleconaril has been associated with reduced severity and duration of symptoms. This study evaluated the pharmacokinetics, safety and efficacy of pleconaril in infants with EV meningitis. Methods. Infants ≤12 months old with suspected EV meningitis were randomized 2:1 to receive pleconaril, 5 mg/kg/dose orally three times a day or placebo for 7 days. Evaluations included pharmacokinetic determinations, safety laboratory testing, serial culture and PCR assays and clinical evaluations. Results. Of 21 evaluable subjects 20 were confirmed with EV infection (12 pleconaril, 8 placebo). Among pleconaril-treated subjects 26 of 29 peak and trough pleconaril levels exceeded the 90% inhibitory concentration for EVs. A median 3.5-fold drug accumulation occurred between Days 2 and 7. Pleconaril was well-tolerated, although twice as many adverse events occurred per subject in the pleconaril group. Serial cultures from the oropharynx, rectum and serum had low yield (≤50%) and positivity generally persisted for <4 days in both groups. Serial PCR assays of culture-negative oropharyngeal and rectal specimens had high positivity rates (generally ≥50%) persisting through Day 14. No significant differences in duration of positivity by culture or PCR, hospitalization or symptoms were detected between groups. Conclusions. The dose of pleconaril studied provided sufficient plasma levels and was well-tolerated; however, drug accumulation was evident. The low yields of serial viral cultures, relatively short and benign clinical courses and the small number of subjects enrolled precluded demonstration of efficacy. If this medication is to be prescribed in infants, surveillance for toxicity related to drug accumulation will be necessary.

Results from a Prospective, International, Epidemiologic Study of Invasive Candidiasis in Children and Neonates

Background: Candida species are the third most common cause of pediatric health care–associated bloodstream infection in the United States and Europe. To our knowledge, this report from the International Pediatric Fungal Network is the largest prospective, multicenter observational study dedicated to pediatric and neonatal invasive candidiasis. Methods: From 2007 to 2011, we enrolled 196 pediatric and 25 neonatal patients with invasive candidiasis. Results: Non-albicans Candida species predominated in pediatric (56%) and neonatal (52%) age groups, yet Candida albicans was the most common species in both groups. Successful treatment responses were observed in pediatric (76%) and neonatal patients (92%). Infection with Candida parapsilosis led to successful responses in pediatric (92%) and neonatal (100%) patients, whereas infection with Candida glabrata was associated with a lower successful outcome in pediatric patients (55%). The most commonly used primary antifungal therapies for pediatric invasive candidiasis were fluconazole (21%), liposomal amphotericin B (20%) and micafungin (18%). Outcome of pediatric invasive candidiasis was similar in response to polyenes (73%), triazoles (67%) and echinocandins (73%). The most commonly used primary antifungal therapies for neonatal invasive candidiasis were fluconazole (32%), caspofungin (24%) and liposomal amphotericin B (16%) and micafungin (8%). Outcomes of neonatal candidiasis by antifungal class again revealed similar response rates among the classes. Conclusions: We found a predominance of non-albicans Candida infection in children and similar outcomes based on antifungal class used. This international collaborative study sets the foundation for large epidemiologic studies focusing on the unique features of neonatal and pediatric candidiasis and comparative studies of therapeutic interventions in these populations.

Immunogenicity, safety, and predictors of response after a pneumococcal conjugate and pneumococcal polysaccharide vaccine series in human immunodeficiency virus-infected children receiving highly active antiretroviral therapy

Background: The immunogenicity and safety of 2 doses of pneumococcal conjugate vaccine (PCV) and 1 dose of pneumococcal polysaccharide vaccine (PPV) were evaluated in human immunodeficiency virus (HIV)-infected children receiving highly active antiretroviral therapy (HAART). Methods: Children 2 to <19 years, receiving stable HAART for ≥3–6 months, with HIV RNA PCR <30,000–60,000 copies/mL, received 2 doses of PCV and 1 dose of PPV at sequential 8-week intervals. Antibodies to pneumococcal serotypes (STs) 1 (PPV only) and 6B, 14, 19F, and 23F (PCV and PPV) were measured by ELISA. Results: Two hundred sixty-three subjects were enrolled, of whom 225 met criteria for inclusion in the primary dataset. Antibody concentrations were low at entry, despite previous PPV in 75%. After vaccination, 76%–96% had concentrations ≥0.5 &mgr;g/mL and 62–88% ≥1.0 &mgr;g/mL to the 5 STs (geometric mean concentrations [GMCs] = 1.44–4.25 &mgr;g/mL). Incremental gains in antibody concentration occurred with each vaccine dose. Predictors of response included higher antibody concentration at entry, higher immune stratum (based on nadir CD4% before HAART and CD4% at screening), lower entry viral RNA, longer duration of the entry HAART regimen, and age <7 years. Response was more consistently related to screening CD4% than nadir CD4%. Seven percent had vaccine-related grade 3 events, most of which were local reactions. Conclusions: Two PCVs and 1 PPV were immunogenic and safe in HIV-infected children 2 to <19 years who were receiving HAART. Responses were suggestive of functional immune reconstitution. Immunologic status based on nadir and, especially, current CD4% and control of HIV viremia were independent determinants of response.

Viral pneumonia in the first month of life.

We performed a 5-year review of 40 patients ≤30 days of age with viral pneumonia. Isolates included respiratory syncytial virus (55%), enteroviruses (15%), rhinoviruses (15%), adenoviruses (10%), parainfluenza virus (7.5%) and herpes simplex virus (5%). Most infants were previously healthy but had ill family members. Nine were born at <37 weeks of gestation. Symptoms and signs included tachypnea, decreased feeding, cough, cyanosis, lethargy, retractions, apnea, bradycardia, seizures and depressed consciousness. Seasonality and clinical features, but not radiographic patterns, suggested specific pathogens. Patients were moderately to severely ill. The median duration of hospitalization was 7 days; therapies administered included oxygen (90%), mechanical ventilation (45%), blood transfusions (25%) and supplemental oxygen after discharge (27%). The case fatality rate was 7.5%. Prematurity, ill appearance at presentation, lobar consolidation and adenovirus infection were risk factors for severe disease.

Diagnosis of neonatal enterovirus infection by polymerase chain reaction

A 5-hour colorimetric polymerase chain reaction (PCR) assay was more sensitive than viral culture in identifying viral infection in initial serum (13/16 vs 5/16; p = 0.008) and urine (10/16 vs 5/16; p = 0.2) specimens from 16 enterovirus-infected newborn infants, and remained more sensitive throughout their illnesses. Combined sensitivity of serum and urine PCR was 14 of 16 (88%). Results of all acute-phase PCR assays of serum and urine from four neonates with cultures negative for enterovirus were also negative. PCR assay of serum and urine facilitates rapid, accurate diagnosis of neonatal enterovirus infections.

The enteroviruses: Problems in need of treatments

Specific antiviral therapy is currently not available for enterovirus (EV) infections. Poliomyelitis, EV 71 neurologic disease, and neonatal EV disease are three manifestations of EV infections that exemplify the importance of developing antivirals for EV infections. Despite tremendous strides in the effort to eradicate polio through vaccination, challenges remain, including the potential for transmission of neurovirulent vaccine-derived polioviruses which have genetically reverted from live-attenuated, oral poliovirus vaccine virus. EV 71 emerged in the late 1990 s in eastern Asia as a neurovirulent virus that causes large outbreaks of hand-foot-mouth disease, herpangina, and fever, and, in some children, meningitis, acute flaccid paralysis, and brainstem encephalitis complicated by pulmonary edema and cardiopulmonary collapse. EV infections in neonates can cause severe disease characterized by meningoencephalitis, myocarditis, pneumonitis, and/or hepatitis and coagulopathy. Prototypic agents for specific therapy of EV infections that act upon numerous potential viral targets exist. Three candidate compounds are currently in development: pleconaril (active against many EVs), V-073 (anti-poliovirus), and BTA-798 (active against many rhinoviruses and EVs). The three conditions described illustrate why development of antiviral medications for EV infections is a medically important need.