LaCrosse viral encephalitis mimics herpes simplex viral encephalitis.

Temporal lobe abnormalities, findings commonly associated with herpes simplex virus encephalitis, were observed in a male 10 years of age found to have LaCrosse virus encephalitis. Diagnostic features included magnetic resonance imaging revealing abnormal signal intensity in the bilateral frontotemporal regions, and left-sided periodic lateralizing epileptiform discharges. LaCrosse virus encephalitis should be included in the differential diagnosis of viral encephalitis associated with structural and electrographic temporal lobe lesions, represented by periodic lateralizing epileptiform discharges. The recently developed LaCrosse RNA polymerase chain reaction for cerebrospinal fluid may enable rapid diagnosis, prevent the need for treatment with acyclovir, and give parents an encouraging prognosis.

Maternal and infant use of erythromycin and other macrolide antibiotics as risk factors for infantile hypertrophic pyloric stenosis.

OBJECTIVES: To evaluate the risk for infantile hypertrophic pyloric stenosis (IHPS) among infants prescribed systemic erythromycin, infants prescribed a course of erythromycin ophthalmic ointment, and infants whose mothers were prescribed a macrolide antibiotic during pregnancy. STUDY DESIGN: Retrospective cohort study of infants born at an urban hospital from June 1993 through December 1999. RESULTS: Of 14,876 eligible infants, 43 (0.29%) developed IHPS. Infants prescribed systemic erythromycin had increased risk of IHPS, with the highest risk in the first 2 weeks of age (relative risk = 10.51 for erythromycin in first 2 weeks, 95% CI 4.48, 24.66). Erythromycin ophthalmic ointment for conjunctivitis was not associated with increased risk of IHPS. Maternal macrolide antibiotics within 10 weeks of delivery may have been associated with higher risk of IHPS but the data were not conclusive. CONCLUSIONS: This study confirms an association between systemic erythromycin in infants and subsequent IHPS, with the highest risk in the first 2 weeks of age. No association was found with erythromycin ophthalmic ointment. A possible association with maternal macrolide therapy in late pregnancy requires further study. Systemic erythromycin should be used with prudence in early infancy.

The Histoplasma capsulatum antigen assay in disseminated histoplasmosis in children.

Progressive disseminated histoplasmosis is often fatal without treatment and requires rapid and accurate laboratory diagnosis. Radioimmunoassay for Histoplasma capsulatum var. capsulatum antigen has been established as a sensitive and accurate diagnostic technique for disseminated histoplasmosis in adults; this study examines the radioimmunoassay in children. The clinical and laboratory records of 26 patients 18 years old or younger in whom H. capsulatum antigen was detected in urine by radioimmunoassay and at least one other positive corroborative standard test were evaluated. Twenty-two (85%) had disseminated disease, and 4 (15%) had self-limited pulmonary disease. Positive corroborative tests included serologic tests in 17 of 22 (77%) patients tested, tissue stains in 5 of 9 (56%) and fungal cultures in 16 of 24 (67%). Patients with disseminated histoplasmosis had a greater degree of antigenuria than those with self-limited infection. In 20 patients with progressive disease treated with amphotericin B, antigen levels declined, and the decrease in antigenuria correlated with clinical improvement. The radioimmunoassay for H. capsulatum antigen in urine is an important test in the diagnosis of disseminated histoplasmosis and is useful for assessing the efficacy of treatment. The presence of urinary antigen is strong evidence for progressive disease that requires treatment.

Acute disseminated encephalomyelitis presenting as a neurodegenerative disease in infancy.

An infant with acute demyelinating encephalomyelitis resulting from California virus infection presented with a neurodegenerative clinical picture. The clinical course was complicated by infantile spasms which responded to treatment with corticotropin. Acute demyelinating encephalomyelitis should be included in the diagnostic evaluation of patients who present with subacute regression of developmental milestones.

Osteomyelitis and pyogenic infection of the sacroiliac joint. MRI findings and review.

Acute pyogenic sacroiliac joint infection and osteomyelitis of adjacent bones often present with severe, poorly localized lower back, pelvic or hip pain. Five cases of sacroiliac joint infection or sacroiliac bone osteomyelitis were evaluated by MRI. MRI may be a helpful diagnostic tool to evaluate early changes of infection in the sacroiliac area. It is very sensitive for detecting bone marrow abnormalities; however, it is non-specific and can not accurately differentiate osteomyelitis from sacroiliitis.

Operative intervention in active endocarditis in children: report of a series of cases and review.

We describe in detail 14 children (age, less than or equal to 19 years) who underwent operative intervention during active infection of the heart and/or great vessels. The series included five children less than 6 years old, who constitute 10% of all such cases reported in this age group to date. We also review the 132 published reports in which children underwent operative intervention during active endocarditis. We found the following: (1) The survival rate for all cases was 77%. (2) Persistent infection, embolic phenomena, and increasing congestive heart failure were the most frequent indications for operative intervention. (3) Survival rates were independent of the duration of preoperative antibiotic treatment. (4) Survival rates were independent of positive results of cultures of blood or tissue obtained at operation. (5) The perioperative mortality in our series was 14%. (6) Only 67% of patients had conditions thought to predispose to endocarditis. (7) Except for removal of catheter-associated cardiac masses from neonates, operative intervention in active endocarditis was uncommon among children less than 4 years old. (8) Staphylococcus aureus and viridans streptococci were the etiologic agents in the majority of cases of endocarditis requiring operation during active infection in children.

Evaluation of an enzyme-linked immunosorbent assay that uses ferrous metal beads for determination of antihistoplasmal immunoglobulins G and M.

A rapid enzyme-linked immunosorbent assay (ELISA) for the detection of human class-specific antibodies to Histoplasma capsulatum (histoplasmal immunoglobulin M [HIgM] and histoplasmal IgG [HIgG]) was developed by using antigen adsorbed onto polycarbonate-coated ferrous beads. In the ELISA method all the reagents used were commercially available. In 135 specimens from patients with confirmed histoplasmosis, sensitivities were 76% for complement fixation (CF), 53% for immunodiffusion (ID), and 64% for the ELISA for HIgM and HIgG combined. The ELISA detected histoplasmal antibody in 36% of the specimens with negative antibody titers by CF and 46% of the specimens with negative antibody titers by ID. The ELISA detected histoplasmal antibody in 27% of specimens that were negative by both CF and ID. When limited to specimens collected within 4 months of the onset of histoplasmosis symptoms, sensitivities were 82% for CF, 63% for ID, and 86% for ELISA for HIgG and HIgM combined. Within this group, ELISA detected histoplasmal antibody in 90% of the specimens that were negative by CF, 76% that were negative by ID, and 100% that were negative by both CF and ID. The specificity of the ELISA could not be fully addressed since sera from patients with other fungal infections were not available.

Volume of blood submitted for culture from neonates.

We prospectively examined 298 sets (298 aerobic, 299 anaerobic, and 73 resin cultures) of blood cultures from 161 critically ill newborns. The attending physicians were unaware of the study. The mean blood volume per patient (aerobic and anaerobic) was 1.05 (range, 0.11 to 3.04) ml. The mean blood volume per aerobic bottle was 0.53 (range, 0.01 to 1.90) ml. Among aerobic samples 2.7% were less than or equal to 0.1 ml, 16% were less than or equal to 0.3 ml, 33% were less than or equal to 0.4 ml, and 55% were less than or equal to 0.5 ml. For anaerobic cultures the mean blood volume was 0.52 (range, 0.01 to 1.79) ml. Among anaerobic samples 2.7% were less than or equal to 0.1 ml, 15% were less than or equal to 0.3 ml, 35% were less than or equal to 0.4 ml, and 58% were less than or equal to 0.5 ml. Blood volume did not correlate with gestational age, chronologic age, or weight. The mean volume of blood submitted in positive cultures was not significantly greater than that in negative cultures. The blood volume used for culture from ill newborns may be inadequate for detecting sepsis, and the adequacy of currently available culture methods needs to be assessed for the small samples submitted from critically ill newborns.

Neurologic complications in oral polio vaccine recipients.

Between April 1982 and June 1983 four children 3 to 24 months of age were referred for evaluation of neurologic abnormalities found to be compatible with vaccine-related poliovirus infection, which had not been suspected by referring physicians. Patients were epidemiologically unrelated residents of Indiana, and none had prior symptoms suggestive of immunodeficiency. All had received poliovirus vaccine orally (first dose in three, fourth dose in one) and a diphtheria-tetanus-pertussis injection in the left anterior thigh within 30 days of symptoms. A vaccine-like strain of poliovirus was isolated from each patient, and each had symptoms (left leg paralysis in three; developmental regression, spasticity, and progressive fatal cerebral atrophy in one) persisting for at least 6 months. Immune function was normal in two with poliovirus type 3 infection, and abnormal (hypogammaglobulinemia, combined immunodeficiency) in two with type 1 and type 2 infection, respectively. The incidence of observed vaccine-related poliovirus infection in Indiana recipients of orally administered poliovirus vaccine was 0.058 per 100,000 per year, significantly greater (P less than 0.001) than predicted.