R. Yogev

Hepatitis C virus infection

Hepatitis C virus (HCV) has become the most significant cause of chronic liver disease of infectious etiology in the United States. The recognition that HCV can be transmitted perinatally or through blood transfusions warrants particular attention by the pediatrician. The American Academy of Pediatrics recommends screening infants born to HCV-infected mothers and persons with risk factors for HCV infection such as injection drug use, transfusion of ≥1 U of blood or blood products before 1992, or hemodialysis should be screened for anti-HCV. Also, persons who received clotting factor concentrates before 1987, when effective inactivation procedures were introduced, also should be screened. Guidelines for counseling families of HCV-infected children are provided.

Severe invasive group a streptococcal infections: A subject review

The course of severe invasive group A β-hemolytic streptococcal (GABHS) infections is often precipitous, requiring prompt diagnosis and rapid initiation of appropriate therapy. Therefore, physicians must have a high index of suspicion of this disease, particularly in patients at increased risk (eg, those with varicella or diabetes mellitus). Although a relationship between the use of nonsteroidal antiinflammatory drugs and severe invasive GABHS infections has been suggested, at present data on which to base a clinical decision about the use or restriction of nonsteroidal antiinflammatory drugs in children with varicella are insufficient. When necrotizing fasciitis is suspected, prompt surgical drainage, debridement, fasciotomy, or amputation often is necessary. Many experts recommend intravenously administered penicillin G and clindamycin for the treatment of invasive GABHS infections on the basis of animal studies. Some evidence exists that intravenous immunoglobulin given in addition to appropriate antimicrobial and surgical therapy may be beneficial. Although chemoprophylaxis for household contacts of persons with invasive GABHS infections has been considered by some experts, the limited available data indicate that the risk of secondary cases is low (2.9 per 1000) and data about the effectiveness of any drug are insufficient to make recommendations. Because of the low risk of secondary cases of invasive GABHS infections in schools or child care facilities, chemoprophylaxis is not indicated in these settings. Routine immunization of all healthy children against varicella is recommended and is an effective means to decrease the risk of invasive GABHS infections.

Serologic response to standard inactivated influenza vaccine in human immunodeficiency virus-infected children

We compared the serologic response of 46 human immunodeficiency virus (HIV)-infected children and adolescents and 61 age-matched controls to standard trivalent inactivated influenza vaccine (A/Taiwan (H1N1), A/Shanghai (H3N2), B/Yamagata). Children were immunized according to the package insert recommendations before the 1990 to 1991 influenza season. Serum antibody titers to influenza A were determined before and 1 month after each vaccination and compared for study and control subjects. Serologic responses of HIV-infected participants were correlated with absolute CD4 counts and stage of HIV disease. Regardless of age or HIV status, all groups responded with significant increases in antibody to the influenza A strains (range, 2.1-fold to 11.8-fold), with the exception that antibody to H3N2 rose only 1.5-fold (P = 0.058) among HIV-positive subjects > or = 9 years old. Pre- and postimmunization antibody titers were significantly higher for controls than for HIV-positive subjects. There was no correlation between serologic responses and CD4 counts among HIV-infected subjects, but those with Centers for Disease Control and Prevention-defined acquired immunodeficiency syndrome responded significantly less well to vaccine. We conclude that HIV-infected children and adolescents produce significant antibody rises after inactivated influenza A vaccination but that their absolute antibody concentrations are lower than those seen in age-matched controls.

Sequential, single-dose pharmacokinetic evaluation of meropenem in hospitalized infants and children.

Meropenem is a new carbapenem antibiotic which possesses a broad spectrum of antibacterial activity against many of the pathogens responsible for pediatric bacterial infections. In order to define meropenem dosing guidelines for children, an escalating, single-dose, pharmacokinetic study at 10, 20, and 40 mg/kg of body weight was performed. A total of 73 infants and children in four age groups were enrolled in the study: 2 to 5 months, 6 to 23 months, 2 to 5 years, and 6 to 12 years. The first patients enrolled were those in the oldest age group, who received the lowest dose. Subsequent enrollment was determined by decreasing age and increasing dose. Complete studies were performed on 63 patients. No age- or dose-dependent effects on pharmacokinetic parameter estimates were noted. Mean pharmacokinetic parameter estimates were as follows: half-life, 1.13 +/- 0.15 h; volume of distribution at steady state, 0.43 +/- 0.06 liters/kg; mean residence time, 1.57 +/- 0.11 h; clearance, 5.63 +/- 0.75 ml/min/kg; and renal clearance, 2.53 +/- 0.50 ml/min/liters kg. Approximately 55% of the administered dose was recovered as unchanged drug in the urine during the 12 h after dosing. No significant side effects were reported in any patients. By using the derived pharmacokinetic parameter estimates, a dose of 20 mg/kg given every 8 h will maintain plasma meropenem concentrations above the MIC that inhibits 90% of strains tested for virtually all potentially susceptible bacterial pathogens.

Fever of unknown origin

The causes of fever in a child can vary from minor brief illnesses to life-threatening infectious, malignant, or autoimmune diseases. The physician often has to evaluate children with fevers of as yet undiagnosed cause lasting fewer than 2 weeks, in whom it is important to determine whether localizing findings are present. Fever without localizing signs and fevers complicating chronic disease and resulting from specific localized infection are considered in the sections concerning infectious causes, immunodeficiency diseases, and rheumatic diseases. The diagnostic and therapeutic approaches to the child with both prolonged fever and fever of unknown origin are then discussed, with emphasis on rheumatic diseases.

Tuberculosis in Infancy in the 1990s

In 1990, 25,701 cases of tuberculosis (TB) were reported in the United States, the largest annual increase since 1953. Children younger than 15 years of age accounted for 1596 new cases. The resurgence of TB can largely be contributed to the HIV epidemic. The clinical course, diagnosis, therapy, and prevention of TB in the perinatal period and in infancy are discussed in view of the epidemics of HIV and TB in the adult population.