Daniel E. Noyola

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 childrens 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.

Candidal Meningitis in Neonates: A 10-Year Review

Candidal meningitis may complicate systemic candidiasis in the premature neonate. We conducted a 10-year retrospective review of 106 cases of systemic candidiasis in neonates to define the incidence, clinical features, laboratory findings, treatment, and outcome of candidal meningitis. Twenty-three of the 106 neonates had candidal meningitis (0.4% of admissions to the neonatal intensive care unit). The median gestational age was 26.2 weeks, the median birth weight was 820 g, and the median age at the onset of illness was 8 days. Clinical disease was severe and commonly was manifested by respiratory decompensation. Findings of cerebrospinal fluid (CSF) analyses varied: pleocytosis was inconsistent, hypoglycorrhachia was common, gram staining was uniformly negative, and Candida was isolated from 17 neonates (74%). Each infant was treated with amphotericin B (median cumulative dose, 30 mg/kg); 5 also received flucytosine therapy. In conclusion, initial clinical features of candidal meningitis are indistinguishable from those of other causes of systemic infection in premature neonates, and normal CSF parameters do not exclude meningitis. Timely initiation of amphotericin B monotherapy was associated with an excellent outcome.

Ophthalmologic, Visceral, and Cardiac Involvement in Neonates with Candidemia

A retrospective review of 86 neonates with candidemia hospitalized from January 1989 through June 1999 was conducted to determine the frequency of ophthalmologic, visceral, or cardiac involvement. Retinal abnormalities were observed in 4 (6%) of the 67 infants in whom indirect ophthalmoscopy examination was performed. Abdominal ultrasound abnormalities were detected in 5 (7.7%) of 65 infants. Echocardiogram revealed thrombi or vegetations in 11 (15.2%) of 72 infants. Age at onset, presence of central venous catheters, and species of Candida were not predictors for involvement at these sites. Infants with candidemia that lasted > or =5 days were more likely to demonstrate ophthalmologic, renal, or cardiac abnormalities than those with a shorter duration. Infants with involvement of these organs received larger cumulative doses of amphotericin B than those without detectable abnormalities. Because complication of disseminated candidiasis by eye, renal, or cardiac involvement has therapeutic implications, and because risk factors for candidemia inadequately predict these complications, evaluations are indicated for all neonates with candidemia.

Cytomegalovirus urinary excretion and long term outcome in children with congenital cytomegalovirus infection.

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.

Viral etiology of lower respiratory tract infections in hospitalized children in Mexico

Background. Respiratory viruses are the main cause of lower respiratory tract infections (LRTI) reported worldwide. The contribution of viral infections to respiratory infections in Mexico has not been fully determined. Objective. To determine the contribution of viral infections in hospitalized children with LRTI. Methods. Children younger than 15 years of age with the admission diagnosis of LRTI were eligible for this study. A nasal wash specimen for virus identification by direct immunofluorescent assay (DFA) was obtained as soon as possible after admission. Clinical and radiographic findings of children with positive and negative detection of viruses were compared. Results. Of 285 subjects admitted to the hospital with LRTI, 265 (93%) had an appropriate specimen for DFA. A viral agent was detected in 125 (47.2%) specimens. Viruses that were identified included respiratory syncytial virus (107), influenza (9) and parainfluenza type 3 (9). Clinical and radiologic diagnoses included bronchiolitis (127), interstitial pneumonia (47) and pneumonia (91). Of the subjects included in the study, 71.3% were younger than 1 year of age. Children with a confirmed viral etiology for their LRTI were younger, had higher respiratory rates on admission and were more likely to present with bronchiolitis than subjects with a negative DFA result. Conclusions. Respiratory viruses are responsible for at least 47.2% of LRTI requiring hospitalization at our hospital. Respiratory syncytial virus was the most important respiratory agent identified.

Association of candidemia and retinopathy of prematurity in very low birthweight infants

OBJECTIVE To determine if the presence of candidemia in infants is associated with an increased incidence of threshold retinopathy of prematurity (ROP). DESIGN Retrospective, case-controlled study. PARTICIPANTS AND CONTROLS Forty-six infants admitted to the Texas Childrens Hospital Neonatal Intensive Care Unit between 1989 and 1999 with a birth weight 1500 g or less, estimated gestational age (EGA) 28 weeks or less, and in whom candidemia developed were matched to a control group of 46 infants based on corresponding birth weight, EGA, and year of birth. METHODS Records of each infant were reviewed to determine the presence and severity of ROP. MAIN OUTCOME MEASURES Development of threshold ROP, including retinal detachment. RESULTS Forty-three infants (93.5%) with candidemia and 39 (84.8%) without candidemia had ROP. Twenty-four infants (52.2%) with candidemia reached threshold and required surgical intervention, compared with 11 infants (23.9%) without candidemia (adjusted odds ratio [OR], 7.4; 95% confidence interval [CI], 1.7-32.1; P = 0.008). Retinal detachment developed in 10 of 24 candidemic infants (41.7%) who reached threshold ROP, compared with 2 of 11 infants (18.2%) without candidemia (OR, 4.4; 95% CI, 0.73-26.9; P = 0.1). CONCLUSIONS Candidemia is associated with increased risk of threshold ROP. Infants with Candida sepsis should be monitored closely for the development of ROP and progression after treatment.

Evaluation of a Neuraminidase Detection Assay for the Rapid Detection of Influenza A and B Virus in Children

ABSTRACT A prototype version of a new diagnostic assay for influenza A and B (Zstat Flu™) 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 pediatricians office and at a large childrens 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 physicians 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.

Congenital cytomegalovirus infection in San Luis Potosi, Mexico.

The incidence of congenital cytomegalovirus infection in Mexico is unknown. We evaluated the presence of cytomegalovirus infection in 560 newborn infants at a public general hospital. There were five (0.89%) infected newborns. Infants with congenital infection were more likely to be born to primigravid mothers (P = 0.01) and were more often from rural areas (P = 0.058) than were noninfected newborns.

Contribution of respiratory syncytial virus, influenza and parainfluenza viruses to acute respiratory infections in San Luis Potosí, Mexico.

Background: Respiratory viruses are the main pathogens associated with acute respiratory illness (ARI) in children. Objective: To establish the relationship between the presence of respiratory syncytial virus (RSV), influenza and parainfluenza viruses in the community and the number of ARI and pneumonia cases reported to the State Health Services Epidemiology Department (SHSED) in San Luis Potosí, México. Methods: We compared the weekly number of ARI and pneumonia episodes in children younger than 5 years of age reported to the SHSED for weeks in which the different respiratory viruses were detected in the community. Excess respiratory infection episodes compared with nonepidemic periods were calculated for each of the viruses. Results: From July 2003 through June 2004, there were 236,597 ARI episodes and 2350 pneumonia cases reported to the SHSED. Distinct epidemic periods for parainfluenza type 1 and influenza were observed, whereas RSV and parainfluenza type 3 epidemic periods showed some overlap. The weekly number of excess ARI was greatest when influenza circulated in the community, whereas excess pneumonia cases were greatest when RSV was prevalent. Overall RSV was associated to the largest number of excess ARI and pneumonia cases reported to the SHSED. Conclusions: RSV detection is associated to the greatest number of ARI and pneumonia episodes in the state of San Luis Potosí. Influenza epidemics are associated to a significant number of ARI visits. Appropriate surveillance systems will be required to assess the impact of influenza immunization and other preventive measures on the number of ARI and pneumonia cases in our community.

Bacteremia with CDC Group IV c-2 in an Immunocompetent Infant

CDC group IV c-2 is a gram-negative bacillus that causes septicemia primarily in severely immunocompromised patients [1]. We recently treated an apparently healthy child with bacteremia caused by this organism. Such an occurrence has not, to our knowledge, been reported previously. A 6-month-old infant was well until 7 days prior to admission to Texas Children’s Hospital (Houston), when she developed fever (38.97C), vomiting, and diarrhea. She was evaluated at a local emergency department, where a presumptive diagnosis of pneumonia was made. She received parenteral cefotaxime and was discharged to her home to receive cefprozil. A blood culture subsequently yielded gram-negative rods, identified as CDC group IV c-2, and the patient was referred to Texas Children’s Hospital. The patient had been born at 30 weeks’ gestation and was hospitalized for 1 month after birth. She had no documented infections during her nursery stay and no subsequent hospital admissions or intercurrent illnesses. On physical examination she appeared well. Her temperature was 387C; pulse, 130/min; respiratory rate, 28/min; and weight, 6.6 kgs (10th–25th percentile). The complete blood cell count and CSF examination findings were normal. Blood cultures performed in duplicate on admission were sterile. No other source of infection was evident. The child received treatment for 10 days with cefotaxime (50 mg/kg every 8 h) and was discharged in good condition. An ELISA for HIV was negative, a blood smear for Howell-Jolly bodies was negative, and the total hemolytic complement value was 49 U/mL (normal range, 23–46 U/mL). The IgG level was 269 mg/dL, the IgA level was 12.3 mg/dL, and the IgM level was 39.9 mg/dL, all within the normal range for age 6 months. The blood isolate identified as CDC group IV c-2 by the referring institution was a nonfermenting, oxidase-positive, gram-negative bacillus. On referral to the Houston City Health Laboratory, the identity of the bacillus was confirmed to be CDC group IV c-2. The organism was urea-positive, demonstrated motility with peritrichous flagella, failed to reduce nitrate or nitrite, and did not produce gas from nitrate, characteristics that differentiate it from related organisms [2, 3]. Antibiotic susceptibility testing was performed by a microdilution MIC automated panel (Microscan, Negative Combo Panel No. 20; Dade Behring, West Sacramento, CA). The organism was susceptible to cefotetan (!16 mg/mL), ceftriaxone