Serious Infection In Children Research Articles

Common genetic variants in the interleukin-6 and chitotriosidase genes are associated with the risk for serious infection in children undergoing therapy for acute myeloid leukemia

Infectious complications represent a substantial cause of morbidity and mortality in children undergoing therapy for acute myeloid leukemia (AML). Since it has been shown that alterations in innate immune pathways contribute to the risk for serious infections, we analyzed well-characterized variants in innate immune genes (TNF, IL6, IL8, MPO, CHIT, FCGR2A, TLR2, and TLR4) to determine their possible contribution to infectious complications during therapy for pediatric AML. The study population consisted of 168 North European Caucasian children enrolled on the clinical trial AML-BFM 93. We found an association between Gram-negative bacterial infection and common, functional variants in two genes, IL6 and CHIT. The risk for infection was significantly higher in children with the G allele in the IL6 promoter at -174 bp (P=0.026) and in patients with the H allele of CHIT (P=0.033). The promoter variant in IL6 has been shown to increase expression while the H allele disrupts both function and circulating levels. Our data suggest that variant alleles of both IL6 and CHIT could influence susceptibility to infection with Gram-negative bacteria in children undergoing therapy for AML. Follow-up studies, namely replication association studies and in vitro investigation of these common polymorphisms, are warranted to confirm these observations.

Atypical mycobacterial infections in children with cancer.

Atypical mycobacteria are seen more frequently as a cause of serious infection in children with cancer. Thirteen pediatric cancer patients with blood or tissue cultures positive for atypical mycobacteria were identified by review of records over a 5-year period at one center. All had central venous catheters and were lymphopenic at the time of infection. Eleven children had rapidly growing mycobacteria and two children had M. avium-intracellulare. Nine patients had positive blood cultures. Three were treated with catheter removal as sole therapy, five had catheter removal plus antibiotics, and one had antibiotics alone. Two patients with pulmonary M. avium-intracellulare infection received antibiotic therapy alone. It is concluded that infection with rapidly growing mycobacteria in children with cancer is associated with presence of a central venous catheter and lymphopenia. Some children with uncomplicated catheter-associated infection with rapidly growing mycobacteria may be sufficiently treated with removal of the catheter alone.

Innate and acquired resistance to amebiasis in bangladeshi children.

Entamoeba histolytica infection and colitis occurred in 55% and 4%, respectively, of a cohort of Bangladeshi preschool children observed for 2 years. DNA typing demonstrated that infecting E. histolytica isolates were genetically diverse. Innate resistance to infection in children was linked to the absence of serum anti-trophozoite IgG. Most children who lacked serum anti-trophozoite IgG failed to develop it in response to a new infection. The serum anti-trophozoite IgG response clustered in families, which is consistent with genetic inheritance. Acquired resistance to infection was linked to intestinal IgA against the carbohydrate-recognition domain of the E. histolytica galactose N-acetyl-d-galactosamine lectin. This was associated with an 86% reduction in new infection over 1 year. Amebiasis is a common and potentially serious infection in children from Dhaka, and both innate and acquired immune responses limit infection.

Community-acquired pneumonia in children.

Pneumonia remains a common and potentially serious infection in children. This review summarizes the problems involved in making the diagnosis and establishing a cause and offers a practical guide to treatment. Decisions should be based first on the age of the child, then on clinical and epidemiologic considerations, and finally, on the findings on chest radiography.

Infections with Rhodococcus equi in children

Three cases of serious infection in children, including the first two reports of bacteremia, due to Rhodococcus equi are described. Only seven pediatric cases have been reported to date. In the laboratory, R. equi can easily be misidentified as a nonpathogenic Corynebacterium spp. (diphtheroid) or a Mycobacterium spp. Despite an overall mortality rate of 25% in adults, no pediatric deaths have occurred due to R. equi. The organism is generally susceptible to vancomycin, aminoglycosides, chloramphenicol, and erythromycin, but, optimal duration of antibiotic therapy is unknown. Treatment with multiple antibiotics was successful in all three cases reported here. Although only a small number of cases have been reported in children, R. equi appears to be an important pediatric pathogen.

Group F Streptococcus

Bacterial arthritis is a serious infection in children occurring either as the result of direct inoculation of organisms into the joint space, of spreading from a contiguous focus of infection, or of hematogenous seeding of the synovium. Although the etiologic agent can be identified in 60% to 70% of cases, joint fluid cultures may remain negative in a substantial number of patients. The most likely etiologic agent depends both on the route of infection and the age of the child. Overall Staphylococcus aureus, Hemophilus influenzae type b and streptococci are the leading causes of bacterial arthritis. Lancefield groups A, B, C, D, and G have all been implicated. However, septic arthritis due to hematogenous seeding with Group F Streptococcus has not been previously reported. A normal 10-month-old boy presented with acute monoarticular arthritis of the knee and had Group F Streptococcus isolated from the blood. Antimicrobial therapy resulted in complete resolution of the arthritis.

Antibiotic Therapy for Severe Infections in Infants and Children

In infants and children, drug absorption, distribution, metabolism, and excretion may differ considerably from these factors in adults; thus, differences also exist in therapeutic efficacy and toxicity of various antibiotics. Because of known toxicity, certain drugs--such as chloramphenicol in high doses, the sulfonamides, and tetracycline--should not be used in neonates. Antibiotic therapy should be modified in neonates because of biologic immaturity of organs important for the termination of drug action. Because of poor conjugation, inactivation, or excretion, the serum concentrations of many antibiotics may be higher and more prolonged in neonates than in older infants. Thus, the dosages of many antibiotics must be lower and the intervals between administration must be longer. The appearance of strains of ampicillin-resistant Haemophilus influenzae, the slow development of resistance to chloramphenicol among gram-negative and gram-positive bacteria, and the development of improved analytic methods to measure chloramphenicol have all resulted in the use of this drug in select cases of serious infection in children beyond the neonatal age. Third-generation cephalosporins have an important role in empiric treatment of pediatric bacterial meningitis because of their ability to penetrate the central nervous system and their effectiveness against ampicillin- or chloramphenicol-resistant Haemophilus strains and against many gram-negative bacteria in the Enterobacteriaceae group.

Pneumococcal bacteraemia—a study of 75 black children

Seventy-five black children from 0 to ten years old with pneumococcal bacteraemia, who were hospitalized during a one-year period, were studied retrospectively from case records. Half the children were under one year and 68% under two years of age. Sixty-seven per cent were malnourished, 34% severely so. The overall case-fatality-rate was 26.7% being highest in children presenting in autumn (52.4%) and in those with meningitis (54.5%), severe protein-calorie malnutrition (42.8%) or associated infections (61.5%). Host defences against the pneumococcus are discussed, especially in relation to their deficiencies in malnourished and young children. Special mention is made of early-onset neonatal sepsis due to the pneumococcus and of the association between pneumococcal bacteraemia and acute post-streptococcal glomerulonephritis. This study indicates that pneumococcal bacteraemia is a serious infection in children, especially in those with malnutrition and other infections. In view of the emergence of penicillin-resistant strains, its treatment may become more difficult in the future.

INCIDENCE OF INFECTION IN CHILDREN AFTER SPLENECTOMY

Eighty-one cases of splenectomy and 94 cases of appendectomy that were carefully followed are reviewed in relation to subsequent infections. One child in each group developed purulent meningitis and four cases of aseptic meningitis were observed in the appendectomized group. It would appear from this series that the incidence of serious infection in children after splenectomy is no higher than in a somewhat similar group after appendectomy.