Viridans group streptococci (VGS) are major pathogens among children with cancer or receiving hematopoietic stem cell transplantation and are associated with considerable morbidity and mortality rates. The incidence and severity of VGS infections have increased during the past 15 years and account for as many as one third of all bacteremic episodes. Risk factors include severe neutropenia, mucositis, gastrointestinal toxicity, pneumonia, younger age, and high-intensity chemotherapy (especially cytosine arabinoside). VGS no longer can be assumed to be susceptible to penicillin because as many as 37 percent of VGS isolates harbor high levels of resistance (minimum inhibitory concentration >4 microg/mL). Furthermore, resistance to multiple classes of antibiotics, including beta-lactams and fluoroquinolones, has now been documented and is increasing in prevalence. In this article, we present a brief overview of VGS, describe the clinical spectrum of VGS-related diseases in children with cancer, and review the recent data regarding the incidence, clinical significance, and management of emerging antibiotic resistance among VGS.
Rotavirus infections are the leading cause of severe gastroenteritis in young children worldwide. Recently two new rotavirus vaccines have entered the world market. This review provides a summary of the rationale, development, and evaluation of one of these vaccines, Rotarix*. Rotarix* is a live oral rotavirus vaccine developed from a single protective human strain following multiple passages in tissue culture to attenuate the strain. The vaccine is administered as two oral doses at approximately 2 and 4 months of age. Large safety and efficacy trials have shown the vaccine is safe, not associated with intussusception, and effective against the most common circulating human serotypes. Efficacy against severe rotavirus gastroenteritis and hospitalization have ranged from 85 to 100 percent.
Vaccination against rotavirus disease has been a global preventive health priority since rotaviruses were first discovered in the 1970s. The first licensed rotavirus vaccine, RRV-TV, was removed from the market shortly after licensure because of an unexpected serious adverse event, intussusception. A pentavalent rotavirus vaccine, PRV, is the second FDA-licensed rotavirus vaccine and does not signal the risk observed with RRV-TV. The properties and large safety study results of PRV are reviewed here.
Group A streptococci (GAS) are gram positive cocci that can be divided into more than 100 M-serotypes or emm types based on their M proteins. Their virulence is related directly to the M protein on the cell surface that inhibits phagocytosis. Although it is more commonly thought of in the context of causing clinical illness, Streptococcus pyogenes can colonize the pharynx and skin. Infections due to GAS include pharyngitis, impetigo, ecthyma, erysipelas, and cellulitis. These infections, as well as the manifestations of invasive disease including streptococcal toxic shock syndrome and necrotizing fasciitis, will be reviewed in this article. Also included will be the nonsuppurative complications of GAS infections, acute rheumatic fever and post streptococcal glomerular nephritis. GAS is an important cause of infections in children in both the ambulatory and hospital settings. Current efforts aimed at the development of a vaccine are warranted but remain in preliminary stages at this time.
We present briefly 2 newborns with Pasteurella multocida meningitis following incidental household exposure to domestic pets and review 36 additional cases from the literature. Of 38 reported cases of P. multocida meningitis during infancy, 18 were less than or equal to 1 month of age. All but one of the infants less than 1 month of age had documented exposure to household dogs and/or cats, most only incidentally.
Epilepsy surgery has proven to be very effective in treating refractory focal epilepsies in children, producing seizure freedom or partial seizure control well beyond any other medical or dietary therapies. While surgery is mostly utilized in certain clinical phenotypes, either based on the location such as temporal lobe epilepsy, or based on the presence of known epileptogenic lesions such as focal cortical dysplasia, tumors or hemimegalencephaly, there is a growing body of evidence to support the role of surgery in other patients’ cohorts that were classically not thought of as surgical candidates. These include patients with rare genetic disorders, electrical status epilepticus in sleep, status epilepticus and the very young patients. Furthermore, epilepsy surgery is not considered as a “last resort” as seizure and cognitive outcomes of surgery are considerably better when done earlier rather than later in relation to the time of onset of epilepsy and age of surgery especially in the context of known focal cortical dysplasia. This article examines the accumulating evidence of the utility of epilepsy surgery in these special circumstances.
To determine the frequency with which inflammatory bowel disease (IBD) is diagnosed in persons with Hirschsprung disease in population-based datasets from 3 Canadian provinces.In study I, Ontario data were used to assess the incidence of IBD in a birth cohort of children with Hirschsprung disease relative to children without Hirschsprung disease. In study II, a case-control design was used in Alberta and Manitoba to determine the frequency of previously diagnosed Hirschsprung disease in persons with IBD, compared with the frequency of Hirschsprung disease in matched controls. Validated algorithms for Hirschsprung disease and IBD were applied to each provincial health registry.In study I, of the 716 children diagnosed with Hirschsprung disease in Ontario since 1991, 18 (2.5%) ultimately developed IBD (168.8 per 100 000 person-years), compared with 7109 of 3 377 394 children without Hirschsprung disease (0.2%, 14.2 per 100 000 person-years). The percentage of males with post-Hirschsprung disease IBD was 77.8%. The incidence rate ratio was 11.9 (95% CI, 7.5-18.8). In study II, the OR of having had Hirschsprung disease before a diagnosis of IBD compared with controls was 74.9 (95% CI, 17.1-328.7) in Alberta and 23.8 (95% CI, 4.6-123) in Manitoba. Crohn's disease was more common after Hirschsprung disease than ulcerative colitis.IBD can emerge in more than 2% of patients with Hirschsprung disease and, like Hirschsprung disease itself, is more common in males. IBD is much more common after a diagnosis of Hirschsprung disease than in the general population.
Pediatric acute respiratory distress syndrome (ARDS) is a severe lung injury caused by pneumonia, sepsis, and trauma. ARDS results from inflammation and pulmonary capillary leak causing major changes in lung architecture and function. It has a low incidence, but its severity and duration cause major morbidity, mortality, and use of resources. Any organism can cause ARDS. Susceptible populations develop the syndrome more often and have worse outcomes. Aggressive diagnosis and intensive treatment are essential to good outcomes in ARDS caused by infection. The prognosis for survival is good, but morbidity after the syndrome is a major burden.
Despite the advances that have been achieved in supportive pediatric intensive care, tracheitis remains a significant cause of reversible upper-airway obstruction in pediatric patients. This discussion highlights the epidemiology and clinical presentation of tracheitis in the twenty-first century and reviews diagnostic and therapeutic modalities. The gold standard for therapy remains supportive airway management in conjunction with appropriate antibiotic therapy. Finally, the unique challenges of diagnosis and treatment of tracheitis in the technology dependent child with an existing artificial airway (endotracheal tube or tracheostomy) are addressed.
The Integrated Management of Childhood Illness (IMCI) strategy has helped strengthen the application and expand coverage of key child survival interventions aimed at preventing deaths from infectious disease, respiratory illness, and malnutrition, whether at the health services, in the community, or at home. IMCI covers the prevention, treatment, and follow-up of the leading causes of mortality, which are responsible for at least two-thirds of deaths of children younger than 5 years in the countries of the Americas. The IMCI clinical guidelines take an evidence-based, syndrome approach to case managment that supports the rational, effective, and affordable use of drugs and diagnostic tools. When clinical resources are limited, the syndrome approach is a more realistic and cost-effective way to manage patients. Careful and systematic assessment of common symptoms and well-selected clinical signs provide sufficient information to guide effective actions.
There are numerous causes of acquired acute upper airway obstructions in children but most are secondary to infections, foreign bodies, and trauma. Recognizing impending airway obstructions is important because cardiopulmonary arrest rarely is a sudden event but rather follows a progressive deterioration in respiratory function. From an anatomic perspective, acute obstructions may present in the pharyngeal or laryngeal regions. In the pharynx, fascial layers create several potential peritonsillar, parapharyngeal, and retropharyngeal spaces that may accommodate abscess formation. Within the larynx and lower airways, small changes in radius dramatically affect the resistance to flow as described by Poiseuille's law, allowing for small amounts of inflammation to cause significant obstruction. The clinical presentation of acute upper airway obstruction will depend on the degree and location of the obstruction. Therapy is aimed primarily at maintaining a patent airway and prescribing appropriate antimicrobials.
Coagulase-negative staphylococcus (CONS) infection is the most common bloodstream infection treated in neonatal and pediatric intensive care units and significantly impacts patient mortality and morbidity. Staphylococcus epidermidis is the most common CONS species isolated clinically and investigated for its pathogenicity and virulence. Difficulties exist in the differentiation of CONS infection from culture contamination in clinical specimens, as CONS is a common skin commensal. Most CONS isolates have the mecA gene and exhibit beta-lactam resistance. The glycopeptide antibiotics, such as vancomycin, are the mainstay in therapy, although resistance has been reported. Arbekacin, linezolid, and streptogramins are newer antibiotics being evaluated as alternatives to glycopeptides. Monoclonal and polyclonal antibodies have been developed against the cell-wall components of staphylococcus and may hold promise for immune prophylaxis and treatment of CONS infection.
Innate and adaptive immunity are required for effective control of infection. Numerous breakthroughs have been achieved in the last 15 years with regard to the functioning of the innate immune system. This article focuses on new paradigms of microorganism recognition, discusses recently described (or rediscovered) cytokines that provide further insight into the development of sepsis, and reviews both pro- and anti-inflammatory pathways for control of infection. Finally, it discusses what has and has not worked with regard to controlling inflammatory pathways in septic patients.
The legal profession depends on expert witnesses, and indeed the first time an English Court relied on an expert medical witness was in the 14th century. Asking a specialist to comment on the standard of professional practice expected in their own specialty was first introduced in a 1767 case [1]. This article draws on 20 years of experience in medicolegal work relating to paediatric respiratory medicine. It highlights some of the legal principles that lie behind an expert opinion and what constitutes clinical negligence. It aims to set out lessons for medicolegal experts and clinicians, but also offers some advice to lawyers and parents. Finally, it illustrates some issues that arise more commonly in paediatric respiratory practice.
The impact of influenza in the very young appears to be comparable to that in the elderly. Influenza vaccine strategy is changing to reflect that impact. Currently, the broader recommendations include vaccination with trivalent inactivated influenza vaccines (TIVs) for children aged 6 to 59 months. This article reviews TIV safety, immunogenicity, and efficacy in children, current vaccine recommendations, and vaccine administration and dosage.
Nitric oxide (NO) is a gas that is involved in many biologic processes. It is synthesized, by the NO synthases. The synthesis of NO by vascular endothelium is responsible for the vasodilator tone. In the central nervous system, it is a neurotransmitter, involved in the formation of memory; in the periphery, some nerves operate through NO-dependent mechanisms to mediate neurogenic vasodilatation in the respiratory, gastrointestinal, and genitourinary tracts. NO also contributes to control of platelet aggregation and regulation of cardiac contractility. In addition, NO is produced in large quantities during host defense and immunologic reactions. Because it has cytotoxic properties and is generated by activated macrophages, it is likely to have a role in nonspecific immunity. This review discusses the physiology, the mechanism of action, and the role of NO in inflammation and immune responses.
From relative obscurity, enterococci have become a leading cause of nosocomial infection. This has been attributed, in part, to the growth in susceptible host populations, increased use of intravascular devices, prolonged hospital stay, and widespread antibiotics use. Furthermore, the facility with which enterococci acquire resistance characteristics coupled with their capacity to survive in the environment renders them uniquely suited as nosocomial opportunists and have resulted in global dissemination of resistant strains. Debate continues as to whether most serious infections arise from a person's indigenous flora or dissemination of virulent clones. Enterococci are normal inhabitants of the human gastrointestinal tract. Classically associated with endocarditis and wound and urinary tract infections, increasingly they are a cause of nosocomial bacteremia. The rise in incidence of serious enterococcal infection has been particularly evident in neonatal, paediatric intensive care, and haematology/oncology units. Spread of resistant phenotypes has posed a difficult therapeutic challenge. We have been rescued, albeit perhaps only temporarily, by the addition of newer agents, such as linezolid, to the therapeutic armamentarium. However, there is no room for complacency. Linezolid resistance already has been reported. Efforts must continue to focus on prevention of the emergence and dissemination of resistance through policies of rational antibiotic use, infection control and education.
This case report presents a female infant whose chief complaint of choking episodes resulted in a diagnosis of Chiari malformation type I and subsequent neurosurgical decompression. Although feeding difficulties and irritability are common complaints in pediatric primary care, dysphagia requires a more significant workup to identify a cause. This case report highlights red flags in the history and diagnostic studies and provides details for managing an unusual presentation of Chiari malformation type I.
