Human herpesviruses types 6 and 7 and febrile seizures

The frequency was studied with which human herpesviruses types 6 and 7 (HHV-6 and HHV-7) occur in the cerebrospinal fluid (CSF) of patients with febrile seizures and matched control patients. CSF samples were prospectively collected from a case series of patients with febrile seizures and from age-, sex-, and race-matched control patients without febrile seizures, all of whom were evaluated in the emergency department of an urban, tertiary care, pediatric medical center. Using polymerase chain reaction, the samples were examined for the presence of viral DNA from HHV-6, HHV-7, herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2), and cytomegalovirus (CMV). CSF from a subset of both groups was also examined for RNA from enteroviruses. During the 7-month, 2-week collection period, a total of 174 patients were evaluated for fever and seizures. Of these, 23 (13.2%) met the study criteria. Their mean age was 1.4 +/- 0.7 years. Sixteen (70%) of the 23 were male. The 23 patients were matched to 21 control subjects. None of the samples from the patients or control subjects had polymerase chain reaction evidence of HHV-6, HHV-7, HSV-1, or HSV-2. All samples from the patients were negative for CMV. One control subject was positive for CMV. The 10 patients and seven control subjects tested for enteroviral RNA were negative. Neither HHV-6 nor HHV-7 appears to be present in the CSF of patients with febrile seizures. What role, if any, they have in the pathogenesis of febrile seizures merits further study.

The microbial ecology and immunology of the adenoid: implications for otitis media

The nasopharyngeal tonsil, or adenoid, is a major inductive site for the synthesis of J-chain-positive B cells that may migrate to other areas of the upper respiratory tract, such as the nasal mucosa, the parotid gland, the lacrimal gland, and the middle ear during inflammation. The production of secretory IgA by both the nasopharyngeal tonsil and the nasal mucosa plays a major role in local immune protection against bacteria and viruses. The release of cytokines from Th1 and Th2 lymphocytes must be appropriate for B cells to produce IgA. The factors or mechanisms responsible for this are not, at present, known, but it appears that there is a difference in the profiles of cytokine secretion by Th1 and Th2 lymphocytes in the adenoids in both otitis-prone, as well as nonotitis-prone children. We have suggested that if this specific immune system does not protect the host from invasion by potential pathogens, there are other modalities of therapy to protect the nasopharynx from colonization with pathogenic bacteria or viruses. These include the production of specific antibodies against bacterial surface proteins that have been identified as mucin-binding proteins. Alteration of the microbial flora with commensal organisms such as viridans streptococci can be utilized. These alpha-hemolytic streptococci probably function by producing an acid environment that prevents colonization of organisms such as nontypeable H. influenzae. Finally, the induction of specific SIgA by conserved outer membrane protein antigens of potential pathogens may be another strategy in the prevention of colonization of potential bacterial pathogens in the nasopharynx.

Middle ear mucin glycoprotein: purification and interaction with nontypable Haemophilus influenzae and Moraxella catarrhalis

Nontypable Haemophilus influenzae and Moraxella catarrhalis are important pathogens in children and adults. The mechanisms of their adherence to the epithelial cell surface and colonization are not clear. For the pathogen to adhere to the epithelial cell, it must first attach to and penetrate the mucus barrier. Mucin glycoproteins of the mucus layer generally are thought to be involved in bacterial attachment. To understand the precise mechanisms of middle ear mucin-bacterial interactions, we used an overlay binding assay with a highly purified middle ear mucin and outer membrane proteins of both nontypable H. influenzae and M. catarrhalis. Outer membrane proteins P2 and P5 were identified as the major components that medicate the binding between nontypable H. influenzae and human middle ear mucin. Moreover, the 57 kDa protein, CD, of the outer membrane protein of M. catarrhalis was found to be the only protein binding human middle ear mucin. Finally, it appears that a protein-oligosaccharide interaction is responsible for binding because asialo-mucin does not bind to either of the bacteria. Knowledge of the specific bacterial-mucin interaction may provide an understanding of the bacterial-epithelial cell colonization. Conversely, comprehension of this interaction between bacteria and purified mucin may be a strategy to prevent colonization of potential pathogens that cause otitis media and sinusitis in children.

Middle Ear Mucin Glycoprotein: Purification and Interaction with Nontypable Haemophilus Influenzae and Moraxella Catarrhalis

Nontypable Haemophilus influenzae and Moraxella catarrhalis are important pathogens in children and adults. The mechanisms of their adherence to the epithelial cell surface and colonization are not clear. For the pathogen to adhere to the epithelial cell, it must first attach to and penetrate the mucus barrier. Mucin glycoproteins of the mucus layer generally are thought to be involved in bacterial attachment. To understand the precise mechanisms of middle ear mucin-bacterial interactions, we used an overlay binding assay with a highly purified middle ear mucin and outer membrane proteins of both nontypable H. influenzae and M. catarrhalis. Outer membrane proteins P2 and P5 were identified as the major components that mediate the binding between nontypable H. influenzae and human middle ear mucin. Moreover, the 57 kDa protein, CD, of the outer membrane protein of M. catarrhalis was found to be the only protein binding human middle ear mucin. Finally, it appears that a protein-oligosaccharide interaction is responsible for binding because asialo-mucin does not bind to either of the bacteria. Knowledge of the specific bacterial-mucin interaction may provide an understanding of the bacterial-epithelial cell colonization. Conversely, comprehension of this interaction between bacteria and purified mucin may be a strategy to prevent colonization of potential pathogens that cause otitis media and sinusitis in children.

Binding between outer membrane proteins of nontypeable Haemophilus influenzae and human nasopharyngeal mucin

Bacterial colonization of the epithelial cells precedes infection. Mucins of the epithelial cell secretions modulate bacterial colonization. This study was designed to understand the mechanism of mucin-bacterial interactions and in particular binding between nontypeable Haemophilus influenzae and nasopharyngeal mucin(s). In an overlay assay, binding appears to be mediated by outer membrane proteins P2 and P5 of bacteria and sialic acid-containing oligosaccharides of mucin.

Recurrent otitis media with non-typable Haemophilus influenzae: the role of serum bactericidal antibody

The effect of serum bactericidal antibody on colonization with non-typable Haemophilus influenzae (NTHI) was studied in 26 children. Serum bactericidal antibody did not prevent colonization with NTHI in the nasopharynx. Antibody was present in 53% before, 91% during and 100% after documented colonization of the nasopharynx with NTHI. In addition, 5 children with recurrent otitis media with effusion (OME) due to NTHI were observed for bactericidal serum antibody during a 4-year period. Bactericidal antibody against the causative NTHI strain was not detected in the acute sera of any patient during each episode, but was observed in the convalescent sera of all of the patients. The bactericidal antibody in the convalescent serum did not appear to be protective against colonization and recurrence of disease by a different heterologous strain of NTHI. However, bactericidal antibody was augmented in some cases by a heterologous infection with NTHI. We confirmed the emergence of new strains of NTHI with DNA fingerprinting and outer membrane protein (OMP) analysis. The data suggest that the immune response to NTHI in OME is usually strain-specific, and furthermore, the results demonstrate that strain-specific bactericidal antibody does not prevent colonization in the nasopharynx with the homologous or heterologous bacterial strains. In general, bactericidal antibody is not cross-protective against heterologous strains of NTHI causing a second or third episode of otitis media with NTHI.

Nasopharyngeal colonization by nontypeable Hemophilus influenzae in children: the effect of serum bactericidal antibody

The effect of serum bactericidal antibody on colonization with NTHI was studied in 26 children. Serum bactericidal antibody did not prevent colonization with NTHI in the nasopharynx. Antibody was detected in 53% before, 91% during, and 100% after documented colonization. The log titer of antibody was significantly higher during (1.18 +/- 0.56), p less than 0.002; and after (1.31 +/- 0.29), p greater than 0.001 compared to before colonization (0.49 +/- 0.51). The roles of secretory IgA and normal nasopharyngeal flora in inhibiting pathogenic bacteria are discussed.

Effect of prior immunity on the shedding of virulent revertant virus in feces after oral immunization with live attenuated poliovirus vaccines

Groups of infants were immunized with one or two doses of orally inoculated live attenuated Sabin poliovirus vaccine (OPV group) or with one or two doses of enhanced-potency inactivated poliovirus vaccine (EIPV) administered parenterally followed by one or two doses of OPV (EIPV-OPV group). The fecal specimens from both groups were tested for poliovirus shedding 1-2 months after OPV. The virus isolates were examined for nucleic acid sequences in the 5' noncoding regions (bases 480, 481, and 472 for serotypes 1, 2, and 3, respectively) to determine whether the viruses shed represented nonattenuated revertants, attenuated parent vaccine strains (nonrevertants), or both. In the OPV group, 4 of the 6 virus isolates recovered 30-60 days after the first immunization dose and 1 of the 3 isolates obtained after the second dose were found to be nonrevertants (parent vaccine strain). In contrast, 11 of the 12 isolates in the EIPV-OPV group were of the nonvaccine revertant virus types. The frequency for reversion appeared to differ for different poliovirus serotypes. However, all revertant type 3 isolates were recovered from subjects previously immunized with EIPV.

Nasopharyngeal secretory antibody response to poliovirus type 3 virion proteins exhibit different specificities after immunization with live or inactivated poliovirus vaccines

By using immunoblotting, neutralization, and ELISA, the development of secretory antibody responses to poliovirus type 3 virion proteins (VP1, VP2, VP3) and to intact or trypsin-treated poliovirus type 3 was studied in the nasopharyngeal secretions in groups of infants after immunization with live attenuated poliovirus vaccine (OPV), enhanced potency inactivated poliovirus vaccine (IPV-EP), or after combined vaccination with IPV-EP followed by OPV. After three doses of vaccine, infants in all vaccine groups developed similar secretory IgA response to VP1 and VP2. The antibody response to VP3 was observed in 76.5% of subjects immunized with OPV alone and approximately 60% of those immunized with IPV-EP followed by OPV. However, only 13% of those immunized with IPV-EP alone exhibited VP3-specific antibody response. Significant differences in poliovirus type 3 specific antibody activity were observed between OPV and IPV-EP immunized subjects when trypsin-treated poliovirus was used as the antigen for neutralization or for ELISA in vitro. The neutralizing antibody activity against cleaved virus was significantly higher than against whole virus in the OPV vaccinated subjects. Both neutralizing and ELISA antibody activity against cleaved virus was significantly lower than against the whole virus in IPV-EP immunized subjects.

Mechanism of lung injury in cotton rats immunized with formalin-inactivated respiratory syncytial virus

Respiratory syncytial virus (RSV) seronegative cotton rats were immunized intramuscularly at four and eight weeks of age with either formalin-inactivated, alum-precipitated RSV grown in HEp-2 cell tissue cultures or virus-free HEp-2 cell tissue cultures similarly prepared. Sham-immunized animals served as controls. At 12 weeks of age, all animals were challenged with 6 x 10(5) plaque forming units of live RSV via the intranasal route. Animals were killed at predetermined days and evaluated for RSV antibody, virus replication and pulmonary histopathology. Of animals immunized with inactivated-RSV, 88% developed neutralizing antibody to RSV. Virus replication in the lungs of such animals was significantly reduced compared with tissue-culture-immunized animals. Surprisingly, however, both groups exhibited pulmonary histopathology, characterized by polymorphonuclear and mononuclear interstitial infiltrates. The virus-immunized animals manifested a more severe inflammatory reaction that reached a peak earlier than the virus-free, tissue-culture-immunized control group. In contrast, sham-immunized animals, when infected with live RSV for the first time, developed little or no pulmonary histopathology. The data suggest that the pathogenesis of pulmonary injury during natural RSV infection in the immunized host is due primarily to prior sensitization to the virus. In the animal model, sensitization to non-viral tissue culture components also contributes to lung injury.

Urinary tract infections in childhood: an update

Although controversies remain regarding the definition, diagnosis, and management of urinary tract infections, such infections can pose a major risk to a child's well-being. Bacteriuria or recurrent urinary tract infections often pose difficult management problems. Symptomatic and asymptomatic bacteriuria during infancy are generally characterized by a benign outcome. In some children repeated episodes and, possibly, renal scarring result. The prognosis in young boys may be guarded if neonatal bacteriuria, with or without symptoms, occurs in the presence of anatomic defects. Although a variety of pathogens have been identified as causing urinary tract infections, Enterobacteriaceae are usually the cause of initial uncomplicated lower tract infections. Accepted therapy for such infections is reviewed, as are the combination therapies used for hospitalized patients with upper tract infections. An investigation of piperacillin, a new, extended-spectrum acylaminopenicillin, raises the hope that it may provide effective monotherapy for upper tract infections. The criteria for selecting patients who require radiologic evaluation in the management of urinary tract infections are reviewed.

The development of respiratory syncytial virus-specific immune complexes in nasopharyngeal secretions following natural infection

Sequential samples of nasopharyngeal secretions (NPS) from 61 infants and children with respiratory syncytial virus (RSV) infection were examined for the presence of RSV-specific immune complexes in order to determine their possible role in recovery from or pathogenesis of RSV infection. Immune complexes in NPS were identified by the Raji cell assay using indirect immunofluorescence and RSV antigen in these complexes was also detected by indirect immunofluorescence. RSV-specific immune complexes were detected in 56% of subjects tested, being present as early as 3-6 days after the onset of illness and persisting for up to 36 days after the onset of illness. The appearance of immune complexes was temporally associated with the disappearance of RSV antigen from airway epithelial cells, suggesting a role for immune complexes in eradication of infection. RSV-specific immune complexes were identified with approximately equal frequency in patients with all forms of illness due to RSV, an observation which tends to rule out a role for immune complexes in the pathogenesis of RSV disease.

Interaction of mucosal immune system and infections in infancy: implications in allergy

The immune responses to viral antigens and other environmental agents to which the mucosal surfaces of the neonate are exposed during the perinatal period and early infancy are intimately related to the mechanism of innate immunologic reactivity of the mother-and, possibly, to the immunologic elements in the products of lactation for a breast-feeding infant-and the nutritional homeostasis of the neonate. The role of these factors in protecting against pathogenicity of viral infections in the respiratory and intestinal tract, and their impact on the development of allergic disease state in childhood will be reviewed.

Chlamydia trachomatis infection in infants delivered by cesarean section

This report describes a well documented case of Chlamydia trachomatis pneumonia in a child delivered by cesarean section. The case indicates that infants delivered by cesarean section are still at risk of developing chlamydial infection. Various routes of infection are discussed, with a review of chlamydial disease in infants born by cesarean section.

Efficacy of amikacin and ticarcillin as empiric therapy in febrile neutropenic children with cancer

Amikacin (600 mg/M2/day IV) and ticarcillin (12 gm/m2/day IV) were administered to 38 children with cancer, neutropenia (less than 1,000 PMN/mm3), and fever (greater than or equal to 38 degrees C) during 46 febrile episodes. Sixty-one percent of the children were severely neutropenic (less than 200 PMN/mm3). Febrile episodes consisted of 15 documented (E coli 5, K pneumoniae and P aeruginosa 1, P. Aeruginosa 1, S marcescens 1, S aureus 4, S epidermidis 1, S viridans 1, adenovirus 1), 13 clinically apparent, nine possible, and nine doubtful infections. Efficacy of amikacin and ticarcillin was not determined in persons with gram-positive, viral, and doubtful infections. Amikacin and ticarcillin were administered from 3 to 13 days (mean 7.3 days). Peak serum concentrations of amikacin on days two and five of treatment ranged between 13 and 35 microgram/ml; trough levels remained below 2 microgram/ml in 92% of the samples. Eighty-six percent of evaluable febrile episodes improved and 14% were unchanged. Among eight infections due to gram-negative enteric bacilli, six were cured (75%), and two (25%) improved temporarily. The excellent results observed in this study may be attributed, in part, to the predictably high serum concentrations of amikacin which exceeded the MICs of seven of eight gram-negative pathogens. Renal toxicity was not observed. Two children (9.5%) developed mild, transient, unilateral hearing losses. These data suggest that the combination of amikacin and ticarcillin is an effective and safe empiric regimen in febrile children with cancer.

Reovirus type 3 infection in a suckling mouse: the effects on pancreatic structure and enzyme content

Alterations in pancreatic function and structure were examined in suckling mice infected intraperitoneally with reovirus type 3. The results were compared to pancreatic zymogen enzyme activities and histology in adult mice infected with the same virus. No effect of the rovirus type 3 on the adult mice could be elicited. In contrast, the suckling mice infected by the reovirus type 3 revealed a definite change in pancreatic zymogen enzymes. However, the zymogen enzymes were affected in a nonparallel fashion and three groups of enzymes with different responses were noted. Amylase and lipase activities were significantly diminished (P less than 0.001) at 6 days of viral infection. The endopeptidases, trypsin (P less than 0.025) and cymotrypsin (P less than 0.001) activities were increased significantly in the infected group. The exopeptidases, carboxypeptidase A and B in the infected animals were not changed significantly compared to the control. It seems reasonable that the reovirus type 3 infection in the suckling mouse causes diminished lipase and amylase activities that might contribute to the pathogenesis of viral enteritis.

Treatment of Haemophilus influenzae type B epiglottitis

During 1969-1977, 48 children with blood cultures proved positive for Haemophilus influenzae type B epiglottitis were evaluated and treated. The fatality rate was 2%; one child died and another developed irreversible hypoxic brain damage. Ninety-five percent of the children were intubated and none required tracheostomy. The endotracheal tubes remained in place for 3.3 +/- 1.5 days. Short-term parenteral antimicrobial therapy, 4.0 +/- 1.4 days, was sufficient to eradicate bacteremia and prevent metastatic infectious foci. This report demonstrates the excellent results achieved in the treatment of epiglottitis with brief intubation and parenteral antimicrobial therapy.

Early diagnosis of neonatal bacteremia by buffy-coat examination

This study demonstrates the value of the buffy-coat smear examination in the early diagnosis of neonatal bacteremia. It is inexpensive, easy to perform, and relatively efficient. In most situations large numbers of bacteria could be seen in each positive smear. Unfortunately, the presence of a positive buffy-coat smear was often associated with a poor prognosis; more than one half (four of seven) of infants with positive smears died.

Nursery outbreak of scalded-skin syndrome. Scarlatiniform rash due to phage group I Staphylococcus aureus

From Aug 6 to 14, 1973, scariatiniform eruptions that were considered to be mild forms of the staphylococcal scalded-skin syndrome developed in four neonates. One infant had mild epidermal peeling. All had generalized, finely papular erythema that cleared rapidly after treatment with antibiotics. Cultures from the umbilical stumps or anterior nares of three of the infants yielded colonies of group I Staphylococcus aureus, phage type 29/52/79/86/D11/81, that were able to produce epidermal exfoliation in suckling mice. These data indicate that the nursery outbreak was caused by phage group I staphylococci rather than group II organisms previously associated with staphylococcal scalded-skin syndrome. The demonstration that a group I Staphylococcus can produce exfoliative toxin suggests that the same mechanism for toxin production may exist for phage groups I and II staphylococci.