Etiology of community-acquired pneumonia in 254 hospitalized children

BACKGROUND: Childhood community-acquired pneumonia is a common illness, but there have been relatively few comprehensive studies of the viral and bacterial etiology in developed countries. The aim of the present investigation was to determine the etiology of community-acquired pneumonia in hospitalized children by several laboratory methods. METHODS: In a 3-year prospective study a nasopharyngeal aspirate for viral studies and acute and convalescent serum samples for viral and bacterial serology were taken from 254 children with symptoms of acute infection and infiltrates compatible with pneumonia in the chest radiograph. The role of 17 microbes was investigated. RESULTS: A potential causative agent was detected in 215 (85%) of the 254 patients. Sixty-two percent of the patients had viral infection, 53% had bacterial infection and 30% had evidence of concomitant viral-bacterial infection. Streptococcus pneumoniae (37%), respiratory syncytial virus (29%) and rhinovirus (24%) were the most common agents associated with community-acquired pneumonia. Only one patient had a positive blood culture (S. pneumoniae) of 125 cultured. A dual viral infection was detected in 35 patients, and a dual bacterial infection was detected in 19 patients. CONCLUSIONS: The possible causative agent of childhood community-acquired pneumonia can be detected in most cases. Further studies are warranted to determine what etiologic investigations would aid in the management of pneumonia. With effective immunization for S. pneumoniae and respiratory syncytial virus infections, more than one-half of the pneumonia cases in this study could have been prevented.     

Ambulatory care of febrile infants younger than 2 months of age classified as being at low risk for having serious bacterial infections

We prospectively examined whether febrile infants younger than 2 months of age who were defined as being at low risk for having bacterial infection could be observed as outpatients without the usual complete evaluation for sepsis and without antibiotic treatment. A total of 237 previously healthy febrile infants were seen at the Pediatric Emergency Room over 17 1/2 months. One hundred forty-eight infants (63%) fulfilled the criteria for being at low risk: no physical findings consisting of soft tissue or skeletal infections, no purulent otitis media, normal urinalysis, less than 25 white blood cells per high-power field on microsopic stool examination, peripheral leukocyte count 5000 to 15,000/mm3 with less than 1500 band cells/mm3. One infant appeared too ill to be included, and had sepsis and meningitis. None of the 148 infants at low risk had bacterial infections, versus 21 of 88 (24%) of those at high risk (P less than 0.0001); eight of 88 (9%) had bacteremia. Of the 148 infants classified as being at low risk for having bacterial infection, 62 (42%) were discharged to home, and 72 (49%) were initially observed for less than or equal to 24 hours and then discharged. Seventeen infants (11%) were hospitalized: in six, low risk became high risk; six had indications other than fever; and five because the study physicians could not be found. The 137 nontreated infants were closely observed as outpatients. The duration of fever was less than 48 hours in 42%, and less than 96 hours in 91%. All infants were observed for at least 10 days after the last examination. The fever resolved spontaneously in all infants but two, with otitis media, who were treated as outpatients. Our data suggest that management of fever in selected young infants as outpatients is feasible if meticulous follow-up is provided.     

Concurrent serious bacterial infections in 2396 infants and children hospitalized with respiratory syncytial virus lower respiratory tract infections

BACKGROUND: At Driscoll Children's Hospital (Corpus Christi, Tex), we observed that most infants and children hospitalized for treatment of respiratory syncytial virus (RSV) bronchiolitis and/or pneumonia received broad-spectrum intravenous antibiotics despite having typical RSV signs and symptoms and positive RSV-rapid-antigen tests on admission. Physicians were concerned about the possibility of concurrent serious bacterial infections, especially in infants younger than 3 months and in those with infiltrates present on the chest x-ray films. OBJECTIVE: To report the frequency of concurrent serious bacterial infections in infants and children hospitalized for treatment of RSV lower respiratory tract infections. METHODS: The medical records of 2396 infants and children admitted to Driscoll Children's Hospital with RSV bronchiolitis and/or pneumonia during 7 RSV seasons from July 1, 1991, through June 30, 1998, were reviewed. RESULTS: There were positive cultures obtained from initial sepsis/meningitis workups on admission in 39 infants and children (1.6%). Of these, 12 (31%) were positive blood cultures and 27 (69%) were positive urine cultures. There were no positive cerebrospinal fluid cultures. All of the positive blood cultures contained either Staphylococcus epidermidis, Staphylococcus warneri, or Bacillus species, which are common contaminants. None of the patients received a standard 10-day course of intravenous antibiotic therapy. All of the positive urine cultures were typical urinary tract pathogens. All of the patients were treated. CONCLUSIONS: Concurrent serious bacterial infections are rare in infants and children hospitalized with RSV lower respiratory tract infections and the empiric use of broad-spectrum intravenous antibiotics is unnecessary in children with typical signs and symptoms of RSV bronchiolitis.     

Otitis media in the neonatal intensive care unit.

Thirty-eight of 125 premature infants who were hospitalized in a neonatal intensive care unit (NICU) had abnormal tympanic membrane mobility compatible with otitis media. Twenty-five of these 38 had received antibiotics within one week of otoscopic examination and were considered to have either serous otitis or partially treated bacterial otitis media; tympanocentesis was not performed in them. Tympanocentesis was performed in the remaining 13 infants who had not received antibiotics. Bacterial otitis media was confirmed in ten of the 13. Either staphylococcal (six cases) or Gram-negative enteric organisms (four cases) were isolated in cultures obtained by tympanocentesis in these cases. The four cases of Gram-negative infections occurred in infants within six weeks of birth. Nasotracheal intubation for more than seven days was significantly correlated with impaired tympanic membrane mobility compatible with otitis media. Otitis media occurs frequently among premature infants who are hospitalized in an NICU, and it should be looked for in any infant in whom sepsis is clinically suspected.     

Detection of new respiratory viruses in hospitalized infants with bronchiolitis: a three‐year prospective study

Aim: We have designed a study with the objective of describing the clinical impact of other viruses different from the respiratory syncytial virus (RSV) in hospitalized infants with bronchiolitis. Methods: A 3 year prospective study was conducted on infants admitted to the Paediatrics Department of the Severo Ochoa Hospital (Spain). We studied the frequency of 16 respiratory viruses. Clinical characteristics of RSV‐only infections were compared with other single agent viral infections. Results: Positive results were confirmed in 275 (86.5%) of the 318 children studied. A single virus was detected in 196 patients and 79 were dual or multiple viral infections. RSV was detected in 61.3% of total bronchiolitis. Rhinovirus (RV) was 17.4% of the identified virus, followed by human bocavirus (HBoV), adenovirus and metapneumovirus (hMPV). Only RV, HBoV and hMPV were significant as single infections. RSV patients were younger than HBoV (p > 0.0001) and hMPV (p = 0.025). Seasonality was clearly different between them. Children with RSV infection needed treatment in the intensive care unit more frequently than others. Conclusions: In hospitalized infants, RSV was the most frequent agent in bronchiolitis in winter, but other viruses were present in 47% of the patients. RV, HBoV and hMPV had a significant proportion of single infections. Clinical characteristics were similar amongst them, but seasonality was clearly different.     

Viral infection in the neonatal period: diagnostic difficulties, the role of interferon alpha levels]

Serum and/or cerebrospinal fluid (CSF) alpha interferon (aIFN) levels were determined in 31 neonates hospitalized for suspected sepsis. Final diagnosis was bacterial sepsis in 15, viral infection in 13 and no infection in 3. Among the 13 neonates with viral infection, enterovirus was isolated 5 times and coxsackievirus 4 times. No aIFN was found in cerebro-spinal fluid and/or serum among the neonates with bacterial sepsis or without infection. By contrast, in neonates with viral infection, CSF and/or serum aIFN levels were always elevated except in one case in which serum aIFN determination was not available. We conclude that in neonates, elevated levels of CSF and serum aIFN appear to be specific of viral infection, and that this might be helpful in the differential diagnosis of suspected sepsis.     

One-Year Prospective Study of Community Acquired Influenza and Parainfluenza Viral Infections in Hospitalized Egyptian Children with Malignancy: Single Center Experience

Background: Respiratory viruses are widespread in the community and easily transmitted to immunocompromised patients. Aims: Assess the prevalence of community-acquired respiratory viral infections among children with cancer presenting with clinical picture suggestive of lower respiratory tract infections (LRTIs), and evaluate its risk factors and prognosis. Methods: Over a year, 90 hospitalized children with malignancy and LRTIs recruited, subjected to clinical assessment, investigated through hematology panel, blood culture, chest x-ray, CT chest and PCR for influenza A and B, parainfluenza (PIV) types 1 and 3 viruses, and respiratory syncytial virus (RSV), and prospectively followed up for the clinical outcome. Results: Viral pathogens were identified in 34 patients (37.7%), with a seasonal peak from April to May. The most frequently detected virus was influenza virus [type A (16 cases; 47%), type B (4 cases; 12%)] followed by parainfluenza virus [PIV1 (9 cases; 26%), PIV3 (3 cases; 15%)], and none had RSV. Bacteria were identified in 26 patients, fungi in four, mixed infections [bacterial/viral and bacterial/fungal] in 13, and 36 cases had unidentified etiology. The majority of patients with influenza and parainfluenza infections had hematological malignancy, presented with fever, and had mild self-limited respiratory illness. Five patients with mixed viral and bacterial infection had severe symptoms necessitating ICU admission. Six patients died from infection-related sequelae; two had mixed PIV and Staphylococcal infections. Conclusions: Community acquired influenza and parainfluenza infections are common in pediatrics patients with malignancy, either as isolated or mixed viral/bacterial infections. Clinical suspicion is essential as hematological and radiological manifestations are nonspecific. Rapid diagnosis and management are mandatory to improve patients’ outcome.     

Comparison of broad range 16S rDNA PCR and conventional blood culture for diagnosis of sepsis in the newborn: a case control study

Background  

Early onset bacterial sepsis is a feared complication of the newborn. A large proportion of infants admitted to the Neonatal Intensive Care Unit (NICU) for suspected sepsis receive treatment with potent systemic antibiotics while a diagnostic workup is in progress. The gold standard for detecting bacterial sepsis is blood culture. However, as pathogens in blood cultures are only detected in approximately 25% of patients, the sensitivity of blood culture is suspected to be low. Therefore, the diagnosis of sepsis is often based on the development of clinical signs, in combination with laboratory tests such as a rise in C – reactive protein (CRP). Molecular assays for the detection of bacterial DNA in the blood represent possible new diagnostic tools for early identification of a bacterial cause.     

Risk of secondary bacterial infection in infants hospitalized with respiratory syncytial viral infection

Because infants hospitalized with respiratory syncytial virus (RSV) infection frequently receive antibiotics, our study was undertaken to determine what the actual risk of secondary bacterial infections in patients with RSV infection is and what effect antibiotic treatment might have on the course of illness. In a 9-year prospective study of 1706 children hospitalized with acute respiratory illnesses, 565 children had documented RSV infections. A subsequent bacterial infection rarely developed in those with RSV lower respiratory tract disease. The rate of subsequent bacterial infection was 1.2% in the total group of children infected with RSV, and 0.6% in the 352 children who received no antibiotics. A significantly greater proportion (4.5%) of subsequent bacterial infections occurred in infants who received parenteral antibiotics (p = 0.01), and especially in a subgroup who received parenteral antibiotics for 5 or more days (11%, p less than 0.001). We conclude that the risk of secondary bacterial infection appears to be low for most infants with RSV infection. In a few infants given parenteral broad-spectrum antibiotics the risk may be greater, but whether this is related to the antibiotic therapy or to other risk factors is not clear.     

Clinical and epidemiologic characteristics of viral infections in a neonatal intensive care unit during a 12-year period

BACKGROUND: The incidence of viral infections in patients treated in the neonatal intensive care unit (NICU) is not well-known. We summarized the data of all patients with laboratory-confirmed viral infections admitted at the NICU of our hospital during the period of 1992-2003. OBJECTIVES: To determine the incidence of viral infections among infants hospitalized in a NICU, the associated clinical manifestations and their outcome. METHODS: Retrospective analysis of epidemiologic, virologic and clinical data from infants with proven viral infection. The diagnosis viral infection was confirmed by positive viral culture and/or polymerase chain reaction from clinical samples. RESULTS: Viral infection was confirmed in 51 of 5396 infants (1%) admitted to the NICU; 20 (39%) had an enterovirus and parechovirus (EV/PEV) infection, 15 (29%) a respiratory syncytial virus (RSV) infection, 5 (10%) a rotavirus infection, 3 (6%) a cytomegalovirus (CMV) infection, 2 (4%) an adenovirus infection, 2 (4%) a parainfluenza virus infection, 2 (4%) a herpes simplex virus infection, 1 (2%) a rhinovirus infection and 1 (2%) a rubella virus infection. Three of the infants presented at birth with symptomatic rubella virus, CMV or herpes simplex virus infection. RSV infection developed mostly in hospitalized infants (60%), and 93% of infections occurred during the winter (November-March). The clinical presentations of EV/PEV disease were sepsis-like illness, prolonged seizures in term infants and gastrointestinal disease in preterm infants. RSV, parainfluenza virus, rhinovirus and CMV caused respiratory disease, predominantly in preterm infants. Gastrointestinal disease was seen only in preterm infants with adenovirus, rotavirus or EV/PEV infection. Mortality and serious sequelae were high in patients infected with EV/PEV (10 and 15%, respectively). CONCLUSIONS: The incidence of viral infection in the NICU was 1%. Enteroviral infections were the most frequently diagnosed infections, occurred often in term infants born at home and presented with sepsis-like illness or seizures. Preterm infants hospitalized from birth mainly developed gastrointestinal disease caused by rotavirus and adenovirus infection or respiratory disease caused by RSV, parainfluenza and CMV infection. Enteroviruses were responsible for the highest mortality and development of serious sequelae.     

Human neutrophil lipocalin (HNL) as a diagnostic tool in children with acute infections: a study of the kinetics

AIM: To study the changes in blood of human neutrophil lipocalin (HNL) and C-reactive protein (CRP) during the course of an acute infection in children. METHODS: Children (n=92) hospitalized with symptoms and signs of acute infections were included and categorized into five groups, i.e. bacterial infection, suspected bacterial infection, viral infection, suspected viral infection and others. Blood was taken at admittance and the following 3-4 d for the measurement of CRP and HNL. RESULTS: Both CRP and HNL were significantly raised at admittance in bacterial infection as compared to viral infection (p<0.001). After 25-48 h, 83% of the children with bacterial infections still had raised CRP levels in contrast to 11% having raised HNL levels. The levels of CRP, but not those of HNL, were significantly correlated to days of symptoms before admission. CONCLUSIONS: HNL is a promising diagnostic tool in the distinction of acute infections caused by bacteria or virus. The differences in the kinetics of CRP and HNL make HNL a better marker for monitoring antibacterial treatment, since HNL is probably elevated only when an active bacterial infection is at hand.     

Lumbar puncture in infants with urinary tract infection: Assessment of infant management in the emergency department

BackgroundNeonatal bacterial infections must be bacteriologically confirmed from laboratory samples to best adjust antibiotic therapy. Lumbar puncture (LP) has been recommended for infants younger than 1 month with suspected serious bacterial infection (SBI) to manage possible meningitis. However, the incidence of bacterial meningitis associated with other infections and particularly with urinary tract infections (UTIs) is low. Recourse to systematic LP may be less essential if infants have a UTI. We aimed (a) to determine the management and frequency of bacterial meningitis coexisting with a documented diagnosis of UTI in infants aged < 1 month who had an LP, and (b) to evaluate the management of infants in emergency admissions with suspected SBI while assessing antibiotic treatment. Methods: We conducted a retrospective single-center study from January 2010 to April 2019 including all cases of neonatal bacterial infections, and collected data on the clinical, laboratory, and radiological features.ResultsIn all, 409 infants were included in the study. Of these, 162 (39.6%) presented with a UTI and eight (2%) had bacterial meningitis. Of the infants diagnosed with UTI, 74.7% had an LP, of whom 34.7% experienced LP complications. No coexistence of UTI and bacterial meningitis was found among infants who had an LP and a documented UTI.ConclusionAlthough not all infants had an LP and a urine culture at the same time, these results show that bacterial meningitis coexisting with a confirmed UTI diagnosis in infants is rare. Furthermore, LP can be traumatic in some cases and therefore its utility should be assessed according to the clinical context.     

Comparison of conventional viral cultures with direct fluorescent antibody stains for diagnosis of community-acquired respiratory virus infections in hospitalized children

OBJECTIVE: Because of the widespread availability of rapid viral antigen testing, many institutions never adopted a routine practice of ordering viral cultures to detect community-acquired respiratory viruses (CRVs). The ease of performing complete viral studies in our on site laboratory allowed us to assess the clinical implications of the absence of conventional culture results in previously healthy hospitalized children with CRV infections. METHODS: From June 1997 through May 2000, the results of direct immunofluorescence assay (DFA) of 1069 nasopharyngeal swab (NP) specimens were compared with simultaneously inoculated conventional tube cell cultures for detection of CRVs. In addition the medical records of 140 previously healthy infants and children hospitalized for management of lower respiratory tract infections caused by culture-proved CRVs were reviewed. RESULTS: Viruses were isolated or detected by DFA or viral culture or both in 468 (30%) of the 1557 NP samples evaluated. The most common CRV isolated was respiratory syncytial virus (49%), followed by parainfluenza viruses (15%), influenza A viruses (14%), rhinoviruses (8%), adenoviruses (4%), enteroviruses (4%) and influenza B viruses (1%). Of the 1069 NP specimens for which both viral culture and rapid antigen testing were performed, 190 specimens were DFA-positive and culture-positive, 7 specimens were DFA-positive and culture-negative, 35 specimens were DFA-negative and culture-positive and 837 specimens were DFA-negative and culture-negative. The overall sensitivity, specificity, positive predictive value and negative predictive value of DFA were 84, 99, 96 and 96%, respectively. Of the 140 hospitalized patients with culture-proved viral cultures (89 respiratory syncytial virus, 22 influenza A, 20 parainfluenza virus and 9 adenovirus), the mean duration of hospital stay was 3.6 days, and the mean time for viral cultures to become positive was 7.7 days (P < 0.001, signed rank test). One hundred twenty (86%) viral cultures did not become positive until after the patient had been discharged from the hospital. In no case was the clinical decision regarding the patient's treatment or discharge from the hospital based on the results of viral culture. CONCLUSIONS: We conclude that positive viral cultures have no impact on clinical decision making and management of healthy children during hospitalization for illness attributable to community-acquired respiratory viruses.     

Diagnosis and outcomes of enterovirus infections in young infants

BACKGROUND: Enterovirus (EV) infections commonly cause fever in infants younger than 90 days of age. The polymerase chain reaction (PCR) has improved our ability to diagnose EV infections. OBJECTIVE: To evaluate the utility of blood and cerebrospinal fluid (CSF) specimens for the diagnosis of EV infections by PCR and to describe a large cohort of EV-infected infants. DESIGN/METHODS: Febrile infants younger than 90 days of age evaluated for sepsis at Primary Children's Medical Center in Salt Lake City, UT, were enrolled in a prospective study designed to identify viral infections from December 1996 to June 2002. All patients had bacterial cultures of blood, urine and CSF. Testing for EV was performed by PCR and/or viral cultures. Patients who were positive for EV were identified for this study. RESULTS: Of 1779 febrile infants enrolled, 1061 had EV testing and 214 (20%) were EV-positive. EV infections were diagnosed by PCR of blood, CSF or both in 93% of infants. PCR testing was positive in blood in 57%, and blood was the only positive specimen for 22% of EV infected infants. PCR of CSF was positive in 74%. The mean age of infants with EV infection was 33 days, with 18% younger than 14 days and 5% younger than 7 days. Fifty percent of EV-positive infants had CSF pleocytosis. Of EV PCR-positive infants, 91% were admitted, and 2% required intensive care. Possible serious EV disease was diagnosed in <1%, and there were no deaths. Twelve infants (5.6%) had concomitant urinary tract infection, and 3 (1%) had bacteremia. CONCLUSIONS: EV infections are common in febrile infants younger than 90 days. Blood and CSF are equally likely to yield positive results by PCR, but the combination of both specimens improved the diagnostic yield.     

Aseptic meningitis in infants younger than six months of age hospitalized with urinary tract infections

BACKGROUND: Aseptic meningitis associated with urinary tract infection (UTI) in young infants has not been described in detail in the literature. We performed a retrospective study to determine the incidence and clinical features of aseptic meningitis accompanying UTI. METHODS: We retrospectively reviewed the medical records of all infants younger than 6 months of age hospitalized with a UTI at Miller Children's Hospital from March 1995 through March 2000. UTI was defined as a urine culture growing > or =10,000 colony-forming units/ml of a single organism from a catheterized specimen or > or =100,000 colony-forming units/ml of a single organism from a bagged urine specimen. Meningitis was defined as a positive cerebrospinal fluid culture or cerebrospinal fluid with >35 white blood cells/mm3 in infants < or =30 days of age or with >10 white blood cells/mm3 in infants >30 days of age. RESULTS: Of 386 infants with UTI, a lumbar puncture was performed in 260, and 31 (11.9%) had aseptic meningitis. One infant had bacterial meningitis. None of the 26 infants with UTI and bacteremia had aseptic meningitis. Two infants with meningitis had confirmed enteroviral infections, but aseptic meningitis did not occur more frequently in any particular month or during times of peak enteroviral activity. CONCLUSIONS: A cerebrospinal fluid pleocytosis is relatively common in hospitalized infants <6 months of age who have a UTI and usually does not reflect bacterial meningitis. Knowledge of this may prevent unnecessary courses of antibiotics for presumed bacterial meningitis and lead to evaluation for other possible causes of aseptic meningitis including viral or congenital infections.     

Comparison of procalcitonin with C-reactive protein, interleukin 6 and interferon-alpha for differentiation of bacterial vs. viral infections.

BACKGROUND: Procalcitonin (PCT) concentration increases in bacterial infections but remains low in viral infections and inflammatory diseases. The change is rapid and the molecule is stable, making it a potentially useful marker for distinguishing between bacterial and viral infections. METHODS: PCT concentration was determined with an immunoluminometric assay on plasma collected at admission in 360 infants and children hospitalized for bacterial or viral infection. It was compared with C-reactive protein (CRP), interleukin 6 and interferon-alpha measured on the same sample. RESULTS: The mean PCT concentration was 46 microg/l (median, 17.8) in 46 children with septicemia or bacterial meningitis. PCT concentration was > 1 microg/l in 44 of 46 in this group and in 59 of 78 children with a localized bacterial infection who had a negative blood culture (sensitivity, 83%). PCT concentration was > 1 microg/l in 16 of 236 children with a viral infection (specificity, 93%). PCT concentration was low in 9 of 10 patients with inflammatory disease and fever. A CRP value > or =20 mg/l was observed in 61 of 236 patients (26%) with viral infection and in 105 of 124 patients (86%) with bacterial infection. IL-6 was > 100 pg/ml in 14% of patients infected with virus and in 53% with bacteria. A secretion of interferon-alpha was found in serum in 77% of viral infected patients and in 8.6% of bacterial infected patients. CONCLUSIONS: In this study a PCT value of 1 microg/l or greater had better specificity, sensitivity and predictive value than CRP, interleukin 6 and interferon-alpha in children for distinguishing between viral and bacterial infections. PCT values are higher in invasive bacterial infections, but the cutoff value of 1 microg/l indicates the severity of the disease in localized bacterial infection and helps to decide antibiotic treatment in emergency room. PCT may be useful in an emergency room for differentiation of bacterial vs. viral infections in children and for making decisions about antibiotic treatments.     

Acute deteriorations in neonatal chronic lung disease

Preterm infants with chronic lung disease (CLD) have frequent respiratory relapses. The aim of this study was to assess the aetiology of such deteriorations and in particular the proportion due to viral infections. During the study period 118 preterm infants with birth weight <1500g were consecutively admitted to the neonatal intensive care unit; 22 (18.6%) developed CLD. At the onset of all respiratory deteriorations, infants were examined for the presence of patent ductus arteriosus, apnoea or aspiration; they were also carefully screened for both viral and bacterial infection. The 22 infants had a total of 74 episodes of respiratory deterioration; median 3 per baby (range 1–8). Two episodes were associated with patent ductus arteriosus, 18 with apnoea and 5 with aspiration. Infection was suspected or proven in association with all other episodes. On ten occasions the infants had positive blood cultures and on a further eight, bacteria were isolated only from the endotracheal or nasopharyngeal secretions. On the remaining 31 occasions, 27 associated with chest X-ray film abnormalities, infection was suspected, but no bacteria isolated. Viral infections were identified in association with 8 (11%) of these episodes. We conclude viral infection should be considered as a cause of otherwise unexplained respiratory deteriorations in infants with neonatal CLD.     

The impact of dual viral infection in infants admitted to a pediatric intensive care unit associated with severe bronchiolitis

INTRODUCTION: Bronchiolitis is a major cause of morbidity and mortality in early childhood worldwide. The presence of more than one pathogen may influence the natural history of acute bronchiolitis in infants. OBJECTIVE: To investigate the relevance of dual viral infection in infants with severe bronchiolitis hospitalized in a short-term unit compared with those in a pediatric intensive care unit (PICU). STUDY DESIGN: One hundred eighty infants <1 year old hospitalized with bronchiolitis in a short-term unit (n = 92) or admitted to the PICU (n = 88) during 2 consecutive winter seasons 2003/2004 and 2004/2005 were evaluated. Molecular biology and standard methods were used to diagnose human respiratory viruses in nasal/throat swabs and nasal aspirates. Clinical data related to host factors and viral prevalence were compared among infants requiring or not PICU support. RESULTS: A viral agent was identified in 96.1% of infants with bronchiolitis. Respiratory syncytial virus (70.6% and 73.6%, respectively in the short-term unit and PICU) and rhinovirus (18.5% and 25.3%, respectively in the short-term unit and PICU) were the main detected respiratory viruses in infants hospitalized in both units. No significant difference in viral prevalence was observed between the populations studied. From multivariate analysis, infants with coinfections were 2.7 times (95% CI: 1.2-6.2) more at risk for PICU admission than those with a single infection. Respiratory syncytial virus and rhinovirus were the viruses most frequently identified in mixed infections in infants hospitalized with bronchiolitis. CONCLUSIONS: Dual viral infection is a relevant risk factor for the admission of infants with severe bronchiolitis to the PICU.     

Role of genital mycoplasmas in young infants with suspected sepsis

To establish the prevalence of Mycoplasma hominis and Ureaplasma urealyticum in infants up to 3 months of age with suspected sepsis, blood, cerebrospinal fluid, and urine specimens from 203 patients with clinical signs and symptoms of sepsis were cultured for Mycoplasma in addition to routine bacterial cultures. Proved bacterial infections were identified in 24 patients, four of whom had bacteremia. M. hominis and U. urealyticum were not isolated from any of the 191 blood and 199 CSF specimens tested. Of 170 specimens of urine cultured for Mycoplasma, M. hominis was isolated in six patients, U. urealyticum in nine patients, and both organisms in one patient. Twelve of the positive cultures were voided urine specimens, and four were suprapubic bladder aspiration specimens. Genital mycoplasmas appear to be uncommon causes of sepsis or meningitis in young infants. Further studies are required to assess their role in abnormal conditions of the urinary tract in childhood.     

Which febrile infants younger than two weeks of age are likely to have sepsis? A pilot study

During a 7-year period we prospectively studied 46 infants younger than 2 weeks of age with rectal temperatures of 100.6 degrees F or higher. Before performing a full laboratory evaluation for sepsis, house officers recorded their impressions of whether the infants were likely to have sepsis. Using the combination of impression of sepsis, white blood cell count and erythrocyte sedimentation rate, infants were assigned to one of two sepsis risk groups (high or low). All patients were hospitalized and treated with parenteral antibiotics. Sepsis or meningitis was diagnosed in 8.7% of the patients. Thirty-five of the 46 infants had sufficient data for risk group assignment. Sepsis or meningitis was diagnosed in 3 of 11 high risk infants vs. 0 of 24 low risk patients (P = 0.025). Of the 21 infants initially admitted without an identified bacterial source, 4 subsequently developed a bacterial complication, i.e. a bacterial focus that, although present at the time of admission, became apparent only after hospitalization. A bacterial complication was identified during the hospital course in 3 of 4 high risk infants vs. 1 of 17 low risk patients (P = 0.012).