The relationship of meteorological conditions to the epidemic activity of respiratory syncytial virus.

Our aim was to obtain knowledge of how meteorological conditions affect community epidemics of respiratory syncytial virus (RSV) infection. To this end we recorded year-round RSV activity in nine cities that differ markedly in geographic location and climate. We correlated local weather conditions with weekly or monthly RSV cases. We reviewed similar reports from other areas varying in climate. Weekly RSV activity was related to temperature in a bimodal fashion, with peaks of activity at temperatures above 24-30 degrees C and at 2-6 degrees C. RSV activity was also greatest at 45-65% relative humidity. RSV activity was inversely related to UVB radiance at three sites where this could be tested. At sites with persistently warm temperatures and high humidity, RSV activity was continuous throughout the year, peaking in summer and early autumn. In temperate climates, RSV activity was maximal during winter, correlating with lower temperatures. In areas where temperatures remained colder throughout the year, RSV activity again became nearly continuous. Community activity of RSV is substantial when both ambient temperatures and absolute humidity are very high, perhaps reflecting greater stability of RSV in aerosols. Transmission of RSV in cooler climates is inversely related to temperature possibly as a result of increased stability of the virus in secretions in the colder environment. UVB radiation may inactivate virus in the environment, or influence susceptibility to RSV by altering host resistance.

Adenovirus infection rates in pediatric recipients of alternate donor allogeneic bone marrow transplants receiving either antithymocyte globulin (ATG) or alemtuzumab (Campath).

Infectious complications due to adenovirus are of increasing concern after allogeneic stem cell transplantation. Over the past 4 years, we have modified our conditioning regimens to use alemtuzumab in preference to anti-thymocyte globulin (ATG) for pediatric patients receiving stem cell transplants from alternate donors. Recent reports in adult studies implicate alemtuzumab as a risk factor for adenovirus infection. We therefore evaluated the incidence of adenovirus infection in pediatric patients receiving either ATG or alemtuzumab in their conditioning regimens. Of the 111 patients evaluated, a total of 54 patients received ATG and 57 patients received alemtuzumab. In total, 35/111 (32%) patients were infected by adenovirus, and 9/111 (8%) had adenovirus disease (AD). Adenovirus infection was greater in the alemtuzumab group than the ATG group (23/57 vs 12/54) (P=0.039) and disseminated AD was more frequent in the alemtuzumab group vs the ATG group (8/57 and 1/54 respectively) (P=0.032). The presence of Grade 3-4 graft-versus-host disease was a risk factor for adenovirus infection. Our findings highlight the fact that adenovirus infection is a frequent complication after stem cell transplantation from alternate donors in the pediatric population and that alemtuzumab increases the risk of infection compared to ATG. This work will help in identifying at-risk populations for our upcoming immunotherapy trial using adoptively transferred donor-derived adenovirus-specific cytotoxic T lymphocytes.

Epidemiology and molecular characterization of co-circulating influenza A/H3N2 virus variants in children: Houston, Texas, 1997-8.

Co-circulating variants of influenza A/H3N2 viruses in children were studied in Houston, Texas between October 1997 and March 1998 to assess the effects of a new variant strain on the severity of clinical illness. Influenza A virus was isolated from the nasal wash or nasal aspirate specimens collected from children at two tertiary care hospitals, and 271 isolates were available for variant-specific subtyping using RT-PCR and restriction fragment length polymorphism (RFLP) analysis. We classified 124 (46%) influenza viruses as A/H3N2/Wuhan/359/95-like and 137 (50%) as A/H3N2/Sydney/05/97-like. Ten (4%) virus isolates could not be classified. Ill contacts in the household were reported more frequently in patients infected with A/Sydney-like viruses than in those infected with A/Wuhan-like viruses (85% vs. 71%, respectively, P=0.02). There were no differences in other demographic variables among children infected with these strains. This study found no increase in illness severity in children infected with a newly emerging strain.

The body buried twice.

The authors report the case of an unusual reason for an "exhumation." A young person "exhumed" a child's body involved in a road accident because he wanted to test methods for preventing or slowing down the process of postmortem decay.

Human cytomegalovirus a sequence and UL144 variability in strains from infected children.

Human cytomegalovirus (HCMV) displays genetic polymorphisms. This variability may contribute to strain-specific tissue tropism and disease expression in HCMV-infected humans. To determine strain variability in a sequence and UL144 gene regions, 51 low-passage isolates from 44 HCMV-infected children were studied. Isolates were obtained from 28 healthy children attending child care centers in Iowa and from 16 congenitally infected infants born in Texas. Isolates demonstrated substantial nucleotide variation in each gene region. Phylogenetic analysis of a sequence variability allowed 39 isolates to be grouped into six clades. The largest clade contained 16 isolates with > or = 95% nucleotide homology. Forty-eight of the 49 HCMV isolates yielding UL144 amplicons was grouped according to the clades described a few years ago [Lurain et al. (1999) Journal of Virology 73:10040-10050]. No linkage was observed among a sequence, UL144, and glycoprotein B (gB; UL55) polymorphisms. Four Texas and 11 Iowa isolates displayed > or = 95% sequence homology for a sequence and UL144 regions and possessed identical gB genotypes. No relationship between UL144 polymorphisms and outcome of congenital HCMV infection was observed. These data indicate that HCMV strains circulating among young children have UL144 polymorphisms similar to those of HCMV strains excreted by immunocompromised adults. Identification of conserved nucleotide sequences among Iowa and Texas children suggests genetic stability and biologic importance of these gene regions.

Characterization of human cytomegalovirus strains by analysis of short tandem repeat polymorphisms.

Human cytomegalovirus (HCMV) strains display genetic polymorphisms, and these polymorphisms can be analyzed to study viral transmission and pathogenesis. Recently, short tandem repeat (STR) length polymorphisms have been identified in the HCMV genome. We assessed the utility of STRs in characterizing HCMV strains and found that a multiplexed PCR assay using primers based upon these STRs accurately maps HCMV strains. Using primers for 10 microsatellite regions, the STR profiles of 44 wild-type and 2 laboratory strains of HCMV were characterized. The results of STR analysis were compared with those for strain characterization using nucleotide sequencing and restriction fragment length polymorphism analysis. In each instance, STR analysis accurately and specifically identified strains that were indistinguishable or distinct by conventional molecular analysis. Analysis of short tandem repeats also detected polymorphisms that supported simultaneous excretion of two HCMV strains. These results indicate that STR analysis allows rapid, precise molecular characterization of HCMV strains.

Early predictors of neurodevelopmental outcome in symptomatic congenital cytomegalovirus infection.

OBJECTIVE: To determine the ability of neonatal clinical, audiologic, and computed tomography (CT) findings to predict long-term neurodevelopmental outcome in children with symptomatic congenital cytomegalovirus (CMV) infection. METHODS: Longitudinal cohort study of children (n = 41) with symptomatic congenital CMV infection evaluated at birth and followed up with serial age-appropriate neurodevelopmental testing. The performance of birth characteristics as predictors of long-term outcome were determined, and clinical and CT scoring systems were developed and correlated with intellectual outcome. RESULTS: Microcephaly was the most specific predictor of mental retardation (100%; 95% CI 84.5-100) and major motor disability (92.3%; 95% CI 74.8-99). An abnormality detected by CT was the most sensitive predictor for mental retardation (100%; 95% CI 82.3-100) and motor disability (100%; 95% CI 78.2-100). A highly significant (P <.001) positive correlation was found between head size at birth and the intelligence/developmental quotient (IQ/DQ). Approximately 29% of children had an IQ/DQ >90. There was no association between sensorineural hearing loss at birth and cognitive outcome. However, children with sensorineural hearing loss on follow-up (congenital and late-onset) had a lower IQ/DQ (P =.006) than those with normal hearing. CONCLUSIONS: The presence of microcephaly at birth was the most specific predictor of poor cognitive outcome in children with symptomatic congenital CMV infection, whereas children with normal findings on head CT and head circumference proportional to weight exhibited a good cognitive outcome.

Results of a quality assurance program for detection of cytomegalovirus infection in the pediatric pulmonary and cardiovascular complications of vertically transmitted human immunodeficiency virus infection study.

A quality assurance program was established by the Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted Human Immunodeficiency Virus Type 1 Infection Study Group for monitoring cytomegalovirus (CMV) antibody and culture results obtained from nine different participating laboratories. Over a 3-year period, every 6 months, each laboratory was sent by the designated reference laboratory six coded samples: three urine samples for CMV detection and three serum samples for CMV immunoglobulin G (IgG) and IgM antibody determination. Overall, the participating laboratories exhibited the following composite performance statistics, relative to the reference laboratory (sensitivity and specificity, respectively): 100 and 97.4% for CMV cultures, 95.5 and 94.4% for CMV IgG antibody assays, and 92.6 and 90.2% for CMV IgM assays. The practice of having individual laboratories use different commercial methods and reagents for CMV detection and antibody determination was successfully monitored and provided useful information on the comparable performance of different assays.

Dental caries in HIV-infected children: a longitudinal study.

PURPOSE: The purpose of this descriptive longitudinal clinical study was to determine primary and permanent dentition caries status in HIV-infected children, and to compare caries status with the CD4 percentage (CD4%) and immune suppression category. MATERIALS AND METHODS: 73 children up to 9 years of age with vertical HIV transmission were evaluated for caries in the primary dentition at baseline and at 6 month intervals over a 30 month period; while 19 HIV-infected children between 5 and 11 years of age had their permanent dentition evaluated for caries at baseline and at 6 month intervals over a 24 month period. Caries status was also compared with CDC CD4 percentage (> 25%, 15-24%, < 15%), and CDC immune suppression categories (immune suppression: none, moderate, severe). With primary dentition caries, comparisons were made among all children (2-9 yr-olds, N = 73), < 2 yr-olds (N = 28), 2 to 4 yr-olds (N = 20), and 5 to 9 yr-olds (N = 25), and compared with NHANES III data. Caries-free status was also determined. RESULTS: During the 30-month period, there was an almost two-fold increase in primary tooth surface caries for the 2 to 9 year-olds. Caries-free status in the primary dentition declined from 60% at baseline to 37% at the 30-month period. With 5 to 11 years-olds, DMFS and DMFT remained relatively stable, while the proportion of caries-free individuals declined from 72% at baseline to 50% at 18 months. Caries in the primary dentition was increased substantially for those in the low CDC CD4 percentage categories and CDC moderate to severe immune suppression categories. CONCLUSION: Primary dentition caries status in HIV-infected children is considerably greater than that for the US pediatric population, and increases with decreasing CD4 percentage and moderate to severe immune suppression. HIV-infected children with caries-free primary dentitions are less frequent than in the US pediatric population, and caries-free status decreases with age, lower CD4 percentage and moderate to severe immune suppression.

Respiratory syncytial virus in patients with congenital heart disease: a contemporary look at epidemiology and success of preoperative screening.

Awareness of respiratory syncytial virus (RSV) as a serious pathogen in the child with congenital heart disease is increasing. We studied the impact of RSV lower respiratory tract disease on patients in a large academic pediatric cardiology practice. We found that RSV disease necessitating hospitalization occurs in congenital heart disease patients well into the second year of life. Although pulmonary hypertension remains a significant risk factor for morbidity in these patients, it does not appear to be as much of a factor as in the past. By implementing a nasopharyngeal RSV enzyme-linked immunoassay screening of young patients prior to cardiac surgery we found a reduction in community-acquired postoperative RSV disease. We postulate this will lead to a reduction in nosocomial disease in the postoperative care unit.

Intrauterine cytomegalovirus infection and glycoprotein B genotypes.

Cytomegalovirus (CMV) strains display polymorphisms for the gene encoding glycoprotein B (gB; gpUL55). Recent data suggest that the gB genotype may influence the outcome of acquired CMV infections. To determine whether the gB genotype also contributes to the outcome of intrauterine infection, CMV strains were studied from 56 infants with culture-confirmed intrauterine CMV infections who were born in Iowa or Texas. CMV gB genotypes were compared with the neonatal clinical features and neurodevelopmental outcomes. Fifty-three strains (95%) could be assigned a gB genotype. The overall distribution of genotypes was as follows: type 1, 50%; type 2, 18%; type 3, 23%; and type 4, 4%. Strains with the gB 3 genotype were more common among the Iowa infants (P=.082). The gB 3 genotype was more common among infants with asymptomatic infections (P=.004), but geographic location and ascertainment biases may have accounted for these differences. The gB genotypes did not correlate with the neurodevelopmental outcome of intrauterine infection.

Cytomegalovirus urinary excretion and long term outcome in children with congenital cytomegalovirus infection. Congenital CMV Longitudinal Study Group.

BACKGROUND: Cytomegalovirus (CMV) is the most frequent cause of congenital infection, and both symptomatic and asymptomatic infants may have long term sequelae. Children with congenital CMV infection are chronically infected and excrete CMV in the urine for prolonged periods. However, the effect of prolonged viral replication on the long term outcome of these children is unknown. OBJECTIVE: To determine whether duration of CMV excretion is associated with outcome at 6 years of life in symptomatic and asymptomatic congenitally infected children. METHODS: Longitudinal cohort study. Children congenitally infected with CMV were identified at birth and followed prospectively in a study of long term effects of congenital CMV infection. The relationship between duration of CMV urinary excretion and growth, neurodevelopment and presence and progression of sensorineural hearing loss (SNHL) at 6 years of age was determined. RESULTS: There was no significant difference in the duration of viral urinary excretion between children born with asymptomatic (median, 4.55 years) and symptomatic (median, 2.97 years) congenital CMV infection (P = 0.11). Furthermore there was no association between long term growth or cognitive outcome and duration of viral excretion. However, a significantly greater proportion of children who excreted CMV for <4 years had SNHL and progressive SNHL compared with children with CMV excretion >4 years (P = 0.019, P = 0.009, respectively). CONCLUSIONS: Children congenitally infected with CMV are chronically infected for years, but the duration of CMV urinary excretion is not associated with abnormalities of growth, or neurodevelopmental deficits. However, SNHL and progressive SNHL were associated with a shorter duration of CMV excretion.

Disinfection of eyelid specula with chlorhexidine gluconate (Hibiclens) after examinations for retinopathy of prematurity.

BACKGROUND: The preferred method of cleaning eyelid specula between examinations for retinopathy of prematurity is unknown. A previous study showed that disinfection with 70% isopropyl alcohol swabs fails to eliminate viruses and bacteria from the specula. OBJECTIVE: To determine if alternative sterilization procedures would allow multiple use of a single speculum without risking nosocomial infection. METHODS: In phase 1, 40 autoclave-sterilized eyelid specula were randomized into either "cleaned" or "patient control" groups after being used for routine retinopathy of prematurity examinations performed in the outpatient setting. Specula in the cleaned group were cleaned with chlorhexidine gluconate (Hibiclens). Specula in the patient control group were not cleaned after use. All study specula were placed into enriched culture media from which bacterial and fungal cultures were obtained. In phase 2, 20 autoclave-sterilized eyelid specula were inoculated with a clinically relevant dilution of adenovirus serovar 5 or herpes simplex type 2. Specula were randomized into either a cleaned or a control group, and cell cultures and immunofluorescence assays were used to document and confirm, respectively, viral growth. RESULTS: In phase 1, all 20 cultures from the patient control group grew bacteria compared with 0 (0%) of 20 cultures from the cleaned group and 0 (0%) of 5 from the cleaned control group. No fungi were isolated from any group. In phase 2, all 10 cultures from specula inoculated with adenovirus serovar 5 grew virus. None of the cultures from the 5 cleaned specula inoculated with herpes simplex type 2 grew virus. In contrast, all 5 cultures in the control group were positive for growth of herpes simplex type 2. CONCLUSIONS: Autoclave sterilization is the ideal method of sterilization of eyelid specula between neonate examinations. When an alternative disinfection technique is required, washing the speculum with chlorhexidine gluconate and tap water is preferred over wiping with a 70% isopropyl alcohol swab. Arch Ophthalmol. 2000;118:786-789

Ophthalmologic findings in children with congenital cytomegalovirus infection.

BACKGROUND: Cytomegalovirus (CMV) infection is the most common congenital viral infection in the United States, affecting 0.5% to 2% of live births. Approximately 90% of infected infants are asymptomatic at birth. We undertook this study to determine the incidence and etiology of visual impairment and other ophthalmologic abnormalities in children with congenital CMV infection. METHODS: We prospectively evaluated 42 symptomatic and 83 asymptomatic children with congenital CMV infection, along with 21 control patients. One or more comprehensive ophthalmologic examinations were performed on each patient. The frequency and etiology of visual impairment and other ophthalmologic problems were tabulated for each patient. RESULTS: Nine of 42 (22%) patients in the symptomatic group had moderate to severe visual impairment in 16 eyes. Visual impairment was primarily due to optic atrophy in 6 of 16 (37%) eyes, macular scars in 2 of 16 (13%) eyes, and cortical visual impairment in 8 of 16 (50%) eyes. In comparison, none of 83 asymptomatic patients had severe visual impairment (P <.001). One asymptomatic patient had mild unilateral visual impairment caused by a macular scar. Strabismus developed in 12 of 42 (29%) symptomatic patients compared with 1 of 83 (1.2%) asymptomatic patients (P <.001). CONCLUSIONS: Visual impairment and strabismus are common in patients with symptomatic congenital CMV infection and rare in patients with asymptomatic congenital CMV infection. Visual impairment may be caused by cortical, optic nerve, and/or retinal abnormalities. Infants with symptomatic congenital CMV infection should undergo careful ophthalmologic screening and follow-up examinations.

Effect of rapid diagnosis on management of influenza A infections.

BACKGROUND: Few studies have examined the impact of rapid viral diagnostic tests on patient management. OBJECTIVE: To assess the effect of rapid diagnosis of influenza A infections on patient management. METHODS: The medical records of children with respiratory infections who were evaluated at a children's hospital between July 1, 1995, and June 30, 1997, were reviewed. Children (n = 56) evaluated in the Emergency Department (ED) who had a positive influenza A enzyme immunoassay (EIA) were compared with two control groups for the likelihood of admission, antibiotic use and duration of hospitalization and antibiotic administration. RESULTS: Patients discharged from the ED with a positive EIA test were less likely to receive antibiotics than those with a negative EIA test (20% vs. 53%; P = 0.04). Patients admitted to the hospital with a positive EIA test were as likely to receive antibiotics as those without a rapid diagnosis, but the duration of antibiotic administration was significantly shorter in the group with a positive EIA test (3.5 vs. 5.4 days; P = 0.03). Patients with a positive EIA test also were more likely to receive antiviral therapy than either control group (25% vs. 0 and 1.8%; P < 0.001). CONCLUSIONS: The detection of influenza A by EIA has a positive impact on medical management by decreasing antibiotic use in pediatric patients evaluated in an ED, by decreasing the duration of antibiotic use in hospitalized patients and by encouraging antiviral therapy.

Evaluation of a neuraminidase detection assay for the rapid detection of influenza A and B virus in children.

A prototype version of a new diagnostic assay for influenza A and B (Zstat Flutrade mark) based on detection of viral neuraminidase was evaluated and compared to culture in 196 clinical samples. Children with respiratory illnesses were prospectively evaluated at a pediatrician's office and at a large children's hospital using the neuraminidase assay and viral culture performed on respiratory secretions. Influenza virus was isolated from 51 samples and 83 were positive by the neuraminidase assay. When compared to culture the sensitivity of the assay was 96%, specificity was 77%, positive predictive value was 59%, and negative predictive value was 98%. Testing in the laboratory of pure cultures of bacteria and non-influenza viruses frequently found in the respiratory tract showed 0% cross-reactivity with the neuraminidase assay and 100% specificity for influenza virus in vitro. This new assay provided useful information for the preliminary diagnosis of influenza A and B infections and appears to be suitable for both point-of-care use in the physician's office and rapid diagnosis in a virology laboratory. The high sensitivity makes it particularly useful as a screening test for exclusion of influenza A and B infections. To confirm the diagnosis and exclude a false-positive result, as well as to determine the influenza virus type, a viral culture may be considered.

Comparison of a new neuraminidase detection assay with an enzyme immunoassay, immunofluorescence, and culture for rapid detection of influenza A and B viruses in nasal wash specimens.

The performance of a new, rapid, easy-to-perform assay based on neuraminidase enzyme activity for detection of influenza virus types A and B was compared to detection by culture, indirect immunofluorescence, and enzyme immunoassay in 479 nasal wash specimens from children with respiratory infections. Compared to isolation of influenza virus by culture, the neuraminidase assay had a sensitivity of 70.1%, specificity of 92.4%, positive predictive value of 76.3%, and negative predictive value of 89.9%. There was a higher sensitivity for the detection of influenza A virus (76.4%) than for influenza B virus (40.9%). Indirect immunofluorescence showed a sensitivity of 59.8% and specificity of 97% compared to culture isolation for detection of influenza A and B viruses. Enzyme immunoassay showed a sensitivity of 89.7% and specificity of 98.1% for the detection of influenza A alone. The quality of the nasal wash specimen had a significant effect on the detection of influenza virus by all of the assays. A strong response of the neuraminidase assay was more likely to represent a culture-confirmed influenza infection. This new rapid neuraminidase assay was useful for the detection of influenza A and B viruses in nasal wash specimens.

Cytomegalovirus infection and HIV-1 disease progression in infants born to HIV-1-infected women. Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV Infection Study Group.

BACKGROUND AND METHODS: Cytomegalovirus (CMV) has been implicated as a cofactor in the progression of human immunodeficiency virus type 1 (HIV-1) disease. We assessed 440 infants (75 of whom were HIV-1-infected and 365 of whom were not) who had known CMV status and were born to HIV-1-infected women and who were followed prospectively. HIV-1 disease progression was defined as the presence of class C symptoms (according to the criteria of the Centers for Disease Control and Prevention [CDC]) or CD4 counts of less than 750 cells per cubic millimeter by 1 year of age and less than 500 cells per cubic millimeter by 18 months of age. RESULTS: At birth the frequency of CMV infection was similar in the HIV-1-infected and HIV-1-uninfected infants (4.3 percent and 4.5 percent, respectively), but the HIV-1-infected infants had a higher rate of CMV infection at six months of age (39.9 percent vs. 15.3 percent, P=0.001) and continued to have a higher rate of CMV infection through four years of age (P=0.04). By 18 months of age, the infants with both infections had higher rates of HIV-1 disease progression (70.0 percent vs. 30.4 percent, P=0.001), CDC class C symptoms or death (52.5 percent vs. 21.7 percent, P=0.008), and impaired brain growth or progressive motor deficits (35.6 percent vs. 8.7 percent, P=0.005) than infants infected only with HIV-1. In a Cox regression analysis, CMV infection was associated with an increased risk of HIV-1 disease progression (relative risk, 2.59; 95 percent confidence interval, 1.13 to 5.95). Among children infected with HIV-1 alone, but not among those infected with both viruses, children with rapid progression of HIV-1 disease had higher mean levels of HIV-1 RNA than those with slower or no progression of disease. CONCLUSIONS: HIV-1-infected infants who acquire CMV infection in the first 18 months of life have a significantly higher rate of disease progression and central nervous system disease than those infected with HIV-1 alone.