Seroprevalence of hepatitis B in a cohort of HIV-infected children and adults in Swaziland.

Hepatitis B virus (HBV) is an important co-morbidity in the HIV epidemic. A retrospective chart review was performed of HIV-infected patients with no previous antiretroviral history enrolled in a Swaziland clinic from January 2009 to May 2011. The seroprevalence of HBV surface antigen (HBsAg) was calculated and the data were analyzed using Mann-Whitney U and Fisher's exact tests. A total of 1282 patients were included in analysis. Five hundred were children aged <15 years. Overall HBsAg seroprevalence was 3.7% (1.4% of children and 5.1% of adults). Prevalence in under-5s was low (0.4%). Among adult women and men, prevalence was 4.2% and 9.8%, respectively (P = 0.022). Median alanine aminotransferase level was 19 U/L in the HBsAg-negative adults and 25 U/L in the HBsAg-positive adults (P = 0.005). Given the number of patients found to be HBsAg-positive, especially among adults, it is important for antiretroviral programmes to consider universal screening and strategically utilize medications that have been found effective in treating both HBV and HIV.

Variable-number tandem repeats that are useful in genotyping isolates of Salmonella enterica subsp. enterica serovars Typhimurium and Newport.

The genome of Salmonella enterica subsp. enterica serovar Typhimurium strain LT2 was analyzed for direct repeats, and 54 sequences containing variable-number tandem repeat loci were identified. Ten primer pairs that anneal upstream and downstream of each selected locus were designed and used to amplify PCR targets in isolates of S. enterica serovars Typhimurium and Newport. Four of the 10 loci did not show polymorphism in the length of products. Six loci were selected for analysis. Isolates of S. enterica serovars Typhimurium and Newport that were related to specific outbreaks and showed identical pulsed-field gel electrophoresis patterns were indistinguishable by the length of the six variable-number tandem repeats. Isolates that differed in their pulsed-field gel electrophoresis patterns showed polymorphism in variable-number tandem repeat profiles. Length of the products was confirmed by DNA sequence analysis. Only 2 of the 10 loci contained exact integers of the direct repeat. Eight loci contained partial copies. The partial copies were maintained at the ends of the variable-number tandem repeat loci in all isolates. In spite of having partial copies that were maintained in all isolates, the number of direct repeats at a locus was polymorphic. Six variable-number tandem repeat loci were useful in distinguishing isolates of S. enterica serovars Typhimurium and Newport that had different pulsed-field gel electrophoresis patterns and in identifying outbreak-associated cases that shared a common pulsed-field gel pattern.

Genetic homogeneity among Listeria monocytogenes strains from infected patients and meat products from two geographic locations determined by phenotyping, ribotyping and PCR analysis of virulence genes.

Thirty Listeria monocytogenes isolates from human patients and foods originated from two different geographic locations without any epidemiological relations were analyzed for their genotypic and phenotypic virulence gene expressions and genetic relatedness. All strains contained virulence genes, inlA, inlB, actA, hlyA, plcA and plcB, with expected product size in PCR assay except for the actA gene. Some strains produced actA gene product of 268 and others 385 bp. Phenotypically, all were hemolytic but showed variable expressions of phospholipase activity. Ribotyping classified isolates into 12 different groups based on the similarity to DuPont Identification numbers (DID), which consisted primarily of clinical or food isolates or both. Cluster analysis also indicated possible existence of clones of L. monocytogenes that are found in food or human hosts or are evenly distributed between these two. Two isolates (F1 from food and CHL1250 from patient) had unique ribotype patterns that were not previously reported in the RiboPrinter database. This study indicates distribution of diverse L. monocytogenes strains in clinical and food environments. The isolates showed 92-99% genetic homogeneity, in spite of their origins from two different geographic locations and environments.

Failure of the conjugate pneumococcal vaccine to prevent recurrent bacteremia in a child with human immunodeficiency virus disease.

Patients with advanced HIV disease have a poor response to some immunizations. A case is presented of a Class C1 HIV-infected child who suffered three episodes of Streptococcus pneumoniae serotype 6B bacteremia despite having received the heptavalent conjugate and 23-valent polysaccharide pneumococcal vaccines. Clinicians should expect some vaccine failures with the heptavalent conjugate vaccine in children with advanced HIV disease.

Invasive pneumococcal infections in pediatric cardiac transplant patients.

BACKGROUND: Bacterial infections cause significant morbidity and mortality in cardiac transplant patients. Because Streptococcus pneumoniae is the most prominent bacterial pathogen of childhood, the objective of this study was to define the role of S. pneumoniae as a pathogen in the cardiac transplant population. METHODS: Medical records of cardiac transplant patients from March, 1990, through November, 2000, were reviewed to identify invasive pneumococcal infections after transplantation. Demographic, clinical and microbiologic data were reviewed. RESULTS: Nine (11%) of 80 patients had 12 episodes of pneumococcal bacteremia for an incidence rate of 39 cases/1,000 patient years. Patients who were African-American, transplanted before 2 years of age and transplanted because of idiopathic dilated cardiomyopathy were at increased risk of invasive pneumococcal disease (P < 0.05). Six patients were eligible for the 23-valent pneumococcal polysaccharide vaccine before their first invasive infection, but only 1 had received it at the recommended age. Most isolates (82%) were penicillin-susceptible, and no single serotype predominated. There were 2 deaths in the study group, but each was unrelated to infection. Three patients (33%) had recurrent invasive disease with a second serotype an average of 12 months after the first infection. CONCLUSIONS: The incidence of pneumococcal bacteremia in cardiac transplant patients is higher than in the general pediatric population. Risks for infection were being African-American, being younger than 2 years at the time of transplant and being transplanted because of idiopathic cardiomyopathy. It is plausible that pneumococcal vaccine would decrease this risk.

Nosocomial infections during extracorporeal membrane oxygenation.

OBJECTIVE: To examine trends in nosocomial infection associated with Extracorporeal Membrane Oxygenation (ECMO). DESIGN: Retrospective review of all patients who underwent ECMO over a 4-year period at our institution; specifically, examining reasons for placement and duration of time on ECMO, as well as nosocomial infections incurred while on or shortly after discontinuation of support. Infections were considered ECMO-related if the organism was recovered on support or within 7 days from decannulation. Analyses were performed utilizing Pearson's chi-square for dichotomous factors and t-tests for continuous factors. RESULTS: Of 141 patients requiring ECMO support, 90 (64%) survived to hospital discharge. Indication for support included circulatory failure (53%) and non-cardiac (47%). Twenty-six percent of patients developed infections on ECMO. Organisms isolated included: bacterial 20 (54%), fungal 10 (27%), mixed five (14%) and viral two (5%). Infection sites included: blood 13 (35%), urine nine (24%), mixed eight (22%), wound five (14%) and lung two (5%). Seventy-eight percent of infections noted occurred in cardiac patients. Patients with nosocomial infections were supported for a median of 169 h (range, 84-936 h), versus those without nosocomial infection [146 h (range, 50-886 h); P<0.001]. Procedures on ECMO were associated with an increased risk of infection (P<0.001) as was the presence of an open chest (P<0.025). CONCLUSIONS: The incidence of infection in ECMO patients at our institution has not increased significantly since our previous study. Cardiac patients have increased risk for nosocomial infection while on ECMO, which may be in part due to longer cannulation times, as well as increased likelihood of undergoing major procedures or having an open chest.

Pneumococcal infections in children after transplantation.

Bacterial infections in recipients of bone marrow and solid-organ transplants remain a major cause of morbidity and death. The cases of 42 children who had undergone transplantation and developed an infection with Streptococcus pneumoniae were retrospectively reviewed. Thirty-four patients had 1 episode of infection, whereas 7 had 2 episodes and 1 had 3 episodes of infection. Solid-organ recipients were more likely to have recurrent invasive disease (P<.02). A total of 31 (74%) of 42 patients were on immunosuppressive therapy, and 74% had been on antimicrobial therapy within 30 days before diagnosis of S. pneumoniae infection. Only 33% of eligible patients had received a pneumococcal vaccine. Twenty-six percent of isolates recovered were not susceptible to penicillin, and 18% were not susceptible to ceftriaxone. Two patients experienced infection-related deaths; one of these had a penicillin-nonsusceptible isolate. The antimicrobial susceptibilities and outcome of infections with S. pneumoniae in patients who have undergone transplantation are similar to those in the general pediatric population.

Outcome of invasive infections outside the central nervous system caused by Streptococcus pneumoniae isolates nonsusceptible to ceftriazone in children treated with beta-lactam antibiotics.

OBJECTIVE: To determine the outcome of children treated primarily with beta-lactam antibiotics for a systemic infection outside the central nervous system (CNS) caused by isolates of Streptococcus pneumoniae nonsusceptible to ceftriaxone (MIC > or = 1.0 microg/ml). DESIGN: Retrospective review of the medical records of children identified prospectively with invasive infections outside of the CNS caused by isolates of S. pneumoniae that were not susceptible to ceftriaxone between September, 1993, and August, 1999. A subset of this group treated primarily with beta-lactam antibiotics was analyzed for outcome. PATIENTS: Infants and children with pneumococcal infections cared for at eight children's hospitals. RESULTS: Among 2,100 patients with invasive infections outside the CNS caused by S. pneumoniae, 166 had isolates not susceptible to ceftriaxone. One hundred patients treated primarily with beta-lactam antibiotics were identified. From this group 71 and 14 children had bacteremia alone or with pneumonia, respectively, caused by strains with an MIC of 1.0 microg/ml. Bacteremia or pneumonia caused by isolates with a ceftriaxone MIC > or = 2.0 microg/ml occurred in 6 and 5 children, respectively. Three children with septic arthritis and 1 with cellulitis had infections caused by strains with an MIC to ceftriaxone of 1.0 microg/ml. Most were treated with parenteral ceftriaxone, cefotaxime or cefuroxime for one or more doses followed by an oral antibiotic. All but one child were successfully treated. The failure occurred in a child with severe combined immune deficiency and bacteremia (MIC = 1.0 microg/ml) who remained febrile after a single dose of ceftriaxone followed by 12 days of cefprozil. CONCLUSION: Ceftriaxone, cefotaxime or cefuroxime are adequate to treat invasive infections outside the CNS caused by pneumococcal isolates with MICs up to 2.0 microg/ml, a concentration currently considered resistant for these antibiotics by National Committee for Clinical Laboratory Standards breakpoints.

Pneumococcal facial cellulitis in children.

OBJECTIVE: To review the epidemiology and clinical course of facial cellulitis attributable to Streptococcus pneumoniae in children. DESIGN: Cases were reviewed retrospectively at 8 children's hospitals in the United States for the period of September 1993 through December 1998. RESULTS: We identified 52 cases of pneumococcal facial cellulitis (45 periorbital and 7 buccal). Ninety-two percent of patients were <36 months old. Most were previously healthy; among the 6 with underlying disease were the only 2 patients with bilateral facial cellulitis. Fever (temperature: >/=100.5 degrees F) and leukocytosis (white blood cell count: >15 000/mm(3)) were noted at presentation in 78% and 82%, respectively. Two of 15 patients who underwent lumbar puncture had cerebrospinal fluid with mild pleocytosis, which was culture-negative. All patients had blood cultures positive for S pneumoniae. Serotypes 14 and 6B accounted for 53% and 27% of isolates, respectively. Overall, 16% and 4% were nonsusceptible to penicillin and ceftriaxone, respectively. Such isolates did not seem to cause disease that was either more severe or more refractory to therapy than that attributable to penicillin-susceptible isolates. Overall, the patients did well; one third were treated as outpatients. CONCLUSIONS: Pneumococcal facial cellulitis occurs primarily in young children (<36 months of age) who are at risk for pneumococcal bacteremia. They present with fever and leukocytosis. Response to therapy is generally good in those with disease attributable to penicillin-susceptible or -nonsusceptible S pneumoniae. Ninety-six percent of the serotypes causing facial cellulitis in this series are included in the heptavalent-conjugated pneumococcal vaccine recently licensed in the United States.

Pneumococcal mastoiditis in children.

OBJECTIVE: To determine the impact of antibiotic resistance on the frequency, clinical features, and management/outcome of mastoiditis attributable to Streptococcus pneumoniae. DESIGN: Retrospective review of the medical records of children with mastoiditis caused by S pneumoniae from September 1993 through December 1998. PATIENTS: Infants and children with pneumococcal mastoiditis cared for at 8 children's hospitals in the United States. RESULTS: Thirty-four children with pneumococcal mastoiditis were identified. The median age of the children was 12 months (range: 2 months-12.5 years); 28 (82%) were

A call for the judicious use of antibiotics.

In the United States alone, more than one-fifth of antibiotic prescriptions written are for viral illnesses. Due to the increasing resistance rates among commonly encountered bacteria, it is imperative that physicians re-examine their prescription writing habits. Physician and patient re-education, better use of diagnostic testing, the use of narrow spectrum antibiotic agents and shorter course therapy are essential for this to occur. The future health of Arkansas residents is dependent upon changes being implemented before it is too late.

Citrobacter urinary tract infections in children.

BACKGROUND: Citrobacter species have been described as the etiologic agents in cases of bacteremia, meningitis, diarrhea and brain abscess, but little is known of their role as a cause of urinary tract infections in children. The purpose of this study was to define the role of Citrobacter species in pediatric urinary tract infections. METHODS: The project consisted of a retrospective chart review of microbiologic and medical records of patients younger than 18 years of age with urine cultures positive for Citrobacter species during a 3-year period. RESULTS: Thirty-four patients with 37 infections were included in the review. The average patient age was 6.9 years (range, 1 month to 18 years) and 71% were female. Fifty-six percent of the patients had urinary tract/renal anomalies or neurologic impairment and 26% represented nosocomial infections. Thirty-seven percent of patients were asymptomatic at the time of diagnosis, whereas 63% complained of at least one of the following findings: gastrointestinal symptoms; dysuria; fever; incontinence; penile/vaginal discharge; frequency; flank pain; and hematuria. Twenty-six of the isolates were Citrobacter freundii and 11 were Citrobacter koseri. Blood cultures were obtained in 9 patients and all were negative for Citrobacter isolates. CONCLUSIONS: Although it is uncommon Citrobacter can cause urinary tract infections in the pediatric population, which occur more frequently in children with underlying medical conditions. It appears that treatment similar to that of other gram-negative enteric organisms is the most prudent approach to these children until more information can be gathered.

The home environment and salmonellosis in children.

OBJECTIVE: To explore the role of foods and the home environment in the development of Salmonella infections in infants and children. METHODS: Home investigations were conducted of patients younger than 4 years of age infected with Salmonella. Cultures were obtained from foods, persons residing in the home, animals/pets/insects, and environmental sources. Like serotypes encountered in the index patients and isolates from the home underwent typing with pulsed-field gel electrophoresis. RESULTS: Home inspections were conducted in approximately 66% of eligible homes on the average of 3.4 days after the confirmation of the Salmonella isolate. A total of 526 cultures from 50 homes were obtained from foods (120), household members (73), refrigerators (52), water (47), countertops (46), soil (42), can-openers (36), vacuum cleaners (34), animals/pets/insects (26), and others (50). Isolates with a serotype identical to those in the index patient were found in 16 homes, 3 of which included an isolate of a second serotype, and an isolate of a different serotype was recovered in 3 homes. The pulsed-field gel electrophoresis patterns of the isolates of identical serotypes from the subjects and from their environment were indistinguishable in all but 2 patients. Among isolates of the same serotype encountered in different homes, all patterns were different. The identical serotype was found in multiple locations (4), dirt surrounding front doors (4), household members (3), vacuum cleaner (1), animals/pets/insects (1), and a refrigerator shelf (1). CONCLUSIONS: These data illustrate the importance of the child's environment in the development of salmonellosis. Clinicians should concentrate on educating the parents about the environmental spread of Salmonella. Contaminated foods in the home play a less significant role in the infection of infants and children.

Clinical characteristics and outcome of children with pneumonia attributable to penicillin-susceptible and penicillin-nonsusceptible Streptococcus pneumoniae.

OBJECTIVE: To compare the clinical characteristics, treatment, and outcome of pediatric patients with pneumonia attributable to isolates of Streptococcus pneumoniae that were either susceptible or nonsusceptible to penicillin. DESIGN: Multicenter, retrospective study. SETTING: Eight children's hospitals in the United States. PARTICIPANTS: Two hundred fifty-four children with pneumococcal pneumonia identified from patients enrolled in the United States Pediatric Multicenter Pneumococcal Surveillance Study during the 3-year period from September 1, 1993 to August 31, 1996. OUTCOME MEASURES: Demographic and clinical variables including necessity for and duration of hospitalization, frequency of chest tube placement, antimicrobial therapy, susceptibility of isolates, and clinical outcome. RESULTS: There were 257 episodes of pneumococcal pneumonia that occurred in 254 patients. Of the 257 isolates, 22 (9%) were intermediate and 14 (6%) were resistant to penicillin; 7 (3%) were intermediate to ceftriaxone and 5 (2%) were resistant to ceftriaxone. There were no differences noted in the clinical presentation of the patients with susceptible versus nonsusceptible isolates. Twenty-nine percent of the patients had a pleural effusion. The 189 (74%) hospitalized patients were more likely to have an underlying illness, multiple lung lobe involvement, and the presence of a pleural effusion than nonhospitalized patients. Fifty-two of 72 hospitalized patients with pleural effusions had a chest tube placed, and 27 subsequently underwent a decortication drainage procedure. Eighty percent of the patients treated as outpatients and 48% of the inpatients received a parenteral second or third generation cephalosporin followed by a course of an oral antimicrobial agent. Two hundred forty-eight of the patients (97.6%) had a good response to therapy. Six patients died; however, only 1 of the deaths was related to the pneumococcal infection. CONCLUSION: The clinical presentation and outcome of therapy did not differ significantly between patients with penicillin-susceptible versus those with nonsusceptible isolates of S pneumoniae. Hospitalized patients were more likely to have underlying illnesses, multiple lobe involvement, and the presence of pleural effusions than patients who did not require hospitalization. In otherwise normal patients with pneumonia attributable to penicillin-resistant pneumococcal isolates, therapy with standard beta-lactam agents is effective.

Pediatric pneumococcal bone and joint infections. The Pediatric Multicenter Pneumococcal Surveillance Study Group (PMPSSG).

OBJECTIVE: To describe the clinical and microbiological characteristics of infants and children with bone and joint infections caused by penicillin-susceptible and penicillin-nonsusceptible strains of Streptococcus pneumoniae. DESIGN: Multicenter, prospective patient accrual; retrospective chart review of identified patients. SETTING: Eight children's hospitals in the United States. PARTICIPANTS: Forty-two children with bone and/or joint infections prospectively enrolled in the United States Pediatric Multicenter Pneumococcal Surveillance Study from September 1, 1993 to August 31, 1996. OUTCOME MEASURES: Data were collected on multiple variables, including age, gender, race, days of symptoms before and during hospitalization, antibiotic and surgical therapy, laboratory and imaging studies. RESULTS: Of the 42 children enrolled (21 bone, 21 joint infections), 14 had isolates that were not susceptible to penicillin. Eight of 16 (50%) strains isolated from children who received antibiotics within 4 weeks before hospitalization were not susceptible to penicillin, compared with 4 of 15 (27%) strains isolated from children without previous antibiotic exposure. Clinical response to therapy was similar between children infected by penicillin-susceptible strains compared with those infected by penicillin-nonsusceptible strains, including duration of hospitalization (9.1 days vs 11.2 days), days of intravenous antibiotic therapy (25.3 days vs 24.6 days), days of fever (3.6 days vs 3.1 days), and sequelae (14% vs 7%). The most commonly prescribed single agents for parenteral therapy in definitive treatment were ceftriaxone (36%), penicillin (15%), and clindamycin (15%). Oral therapy followed parenteral therapy in 56% of children. The mean (+/- standard deviation) duration of total antibiotic therapy in children with osteomyelitis was 57.5 +/- 48.6 days (range, 23-196 days) and 29.2 +/- 11.8 days (range, 12-67 days) for arthritis. Late sequelae (long-term destructive changes of the bone or joint) were documented in 5 (12%) children, 4 with osteomyelitis, and 1 with arthritis. Sequelae occurred in 30% of children with long bone osteomyelitis associated with infection in the adjacent joint. The age of children with sequelae was younger than those without sequelae (6.4 months vs 18.6 months). CONCLUSIONS: The demographic characteristics and anatomic sites of infection in our patients were similar to previously published series collected from single institutions before the emergence of significant antibiotic resistance in S pneumoniae. Our analysis suggests that children infected by penicillin-nonsusceptible strains have a similar clinical response to therapy when compared with children infected by penicillin-susceptible strains.

Enzyme-linked immunoassay for respiratory syncytial virus is not predictive of bronchiolitis in sudden infant death syndrome.

Although respiratory syncytial virus (RSV)-infected infants may present with apnea, the role that RSV plays in sudden infant death syndrome (SIDS) is speculative. To determine whether RSV is associated with bronchiolitis in these patients, we examined histologic sections of lungs from 41 apparent SIDS cases and compared the results with those of enzyme-linked immunofluorescent assay (EIA) from nasal washings. Bronchiolitis was defined by a bronchiolar inflammatory cell infiltrate plus epithelial necrosis. A positive EIA was associated with bronchiolitis in 8 instances, compared with 6 having a positive EIA and negative histology, 14 having a negative EIA and positive histology, and 13 having EIA and histology both negative. These results yield a predictive value of a positive test of 57% and a predictive value of a negative test of 48% (P > .9 by chi square analysis). Although RSV of the upper respiratory tract may be related to SIDS, our results indicate that EIA of nasal washings is not predictive of bronchiolitis, and we recommend other means of verification of histologic results.

Three-year multicenter surveillance of pneumococcal meningitis in children: clinical characteristics, and outcome related to penicillin susceptibility and dexamethasone use.

OBJECTIVES: To evaluate the antibiotic susceptibility of Streptococcus pneumoniae isolates obtained from the blood and cerebrospinal fluid of children with meningitis. To describe and compare the clinical and microbiological characteristics, treatment, and outcome of children with meningitis caused by S pneumoniae based on antimicrobial susceptibility of isolates and the administration of dexamethasone. DESIGN AND PATIENTS: Children with pneumococcal meningitis were identified from among a group of patients with systemic infections caused by S pneumoniae who were enrolled prospectively in the United States Pediatric Multicenter Pneumococcal Surveillance Study at eight children's hospitals in the United States. From September 1, 1993 to August 31, 1996, 180 children with 181 episodes of pneumococcal meningitis were identified and data were collected by retrospective chart review. OUTCOME: Clinical and laboratory characteristics were assessed. All pneumococcal isolates were serotyped and antibiotic susceptibilities for penicillin and ceftriaxone were determined. Clinical presentation, hospital course, and outcome parameters at discharge were compared between children infected with penicillin-susceptible isolates and those with nonsusceptible isolates and for children who did and did not receive dexamethasone. RESULTS: Fourteen (7.7%) of 180 children died; none of the fatalities were because of a documented failure of treatment caused by a resistant strain. Only 1 child, who had mastoiditis and a lymphangioma, experienced a bacteriologic failure with a penicillin-resistant (minimum inhibitory concentration = 2 microgram/mL) organism. Of the 166 surviving children, 41 (25%) developed neurologic sequelae (motor deficits) and 48 (32%) of 151 children had unilateral (n = 26) or bilateral (n = 22) moderate to severe hearing loss at discharge. Overall, 12.7% and 6.6% of the pneumococcal isolates were intermediate and resistant to penicillin and 4.4% and 2.8% were intermediate and resistant to ceftriaxone, respectively. Clinical presentation, cerebrospinal fluid indices on admission, and hospital course, morbidity, and mortality rates were similar for patients infected with penicillin- or ceftriaxone-susceptible versus nonsusceptible organisms. However, the relatively small numbers of nonsusceptible isolates and the inclusion of vancomycin in the treatment regimen for the majority of the patients limit the power of this study to detect significant differences in outcome between patients infected with susceptible and nonsusceptible isolates. Nonetheless, our results show that the nonsusceptible organisms do not seem to be intrinsically more virulent. Forty children (22%) received dexamethasone (>/=8 doses) initiated before or within 1 hour after the first dose of antibiotics. The incidence of any moderate or severe hearing loss was significantly higher in the dexamethasone group (46%) compared with children not receiving any dexamethasone (23%). The incidence of any neurologic deficits, including hearing loss, also was significantly higher in the dexamethasone group (55% vs 33%). However, children in the dexamethasone group more frequently required intubation and mechanical ventilation and had lower initial concentration of glucose in the cerebrospinal fluid than children who did not receive any dexamethasone. When we controlled for the confounding factor, severity of illness (intubation), the incidence of any deafness and of any neurologic sequelae, including deafness, were no longer significantly different between children who did or did not receive dexamethasone. CONCLUSIONS: Children with pneumococcal meningitis caused by penicillin- or ceftriaxone-nonsusceptible organisms and those infected by susceptible strains had similar clinical presentation and outcome. The use of dexamethasone was not associated with a beneficial effect in this retrospective and nonrandomized study. (ABSTRACT TRUNCATED)