A new respiratory fluoroquinolone, oral gemifloxacin: a safety profile in context.

Gemifloxacin is a broad-spectrum quinolone antibacterial with enhanced potency against Gram-positive bacteria, including multi-drug resistant Streptococcus pneumoniae, and retained potency against Gram-negative bacilli and bacterial strains resistant to other antibiotics. It has proven particularly effective in respiratory and urinary tract infection. This review presents safety data from 6775 patients included in clinical trials, receiving either the recommended 320 mg once daily oral dose of gemifloxacin, or standard dose of other quinolones, macrolides or beta-lactams (n = 5248). Studies in healthy volunteer and special populations are also reported. Adverse experiences (AEs) were observed in 44.7% of gemifloxacin-treated patients and 47.5% of those who received comparator drugs. Mild gastro-intestinal adverse drug reactions (ADRs) (diarrhoea 5.1%, nausea 3.9%) predominated. Rash, usually maculo-papular and in no case proceeding to more severe eruptions, was observed in 3.6% of those receiving gemifloxacin. A higher incidence of rash (>20%) was observed in young women and was the subject of further study. Adverse drug reactions suspected or probably related to treatment occurred in 17.4% of patients receiving gemifloxacin and in 20% of those receiving comparator antibiotics. Diarrhoea and nausea were experienced by 3.6 and 2.7%, respectively, of gemifloxacin-treated patients (4.6 and 3.2% of comparators), rash by 2.8% (0.6% of comparators) and headache by 1.2% (1.5% of comparators). Gemifloxacin-related vomiting (0.9%), dizziness (0.8%) and taste perversion (0.3%) were uncommon. Treatment discontinuation followed one or more adverse drug reactions in 2.2% of gemifloxacin-treated patients (0.9% due to rash) and 2.1% of comparator-treated patients. A total of 63 deaths (33 receiving gemifloxacin) occurred in the trial population: none were considered related to treatment. A slight prolongation in QT interval (2.56 ms (S.D. +/-24.5)) was observed in gemifloxacin-treated patients: no cardiac arrhythmias were reported. There was a low incidence of liver function tests (LFTs) classified as of potential clinical concern: gemifloxacin (0.4-1.2%), comparators (0.2-1.3%). Serious adverse events (SAEs), occurring during but not necessarily related to therapy, occurred in 3.6% of gemifloxacin-treated patients (4.3% of comparators). SAEs related to treatment agents were rare (0.4% in each group) and included rash (0.1%) and elevated liver enzymes (<0.1%). Gemifloxacin was well tolerated by the elderly, those with renal or hepatic impairment and when co-administered with omeprazole, digoxin, theophylline, warfarin (with which there were no significant interactions) and Maalox. In conclusion, gemifloxacin 320 mg once daily demonstrated a favourable safety and tolerability profile similar to that of comparator antibiotics, including other quinolones.

Impact of protease inhibitor-containing combination antiretroviral therapies on height and weight growth in HIV-infected children.

OBJECTIVE: To examine beneficial or detrimental effects of protease inhibitor (PI)-containing antiretroviral regimens on height and weight growth in children with human immunodeficiency virus (HIV) infection. METHODS: A prospective cohort study was conducted of 906 HIV-infected children, from pediatric research clinics in the United States, who were between 3 months and 18 years of age and who had height and weight assessed in 1995 (before introduction of PIs in this population) and at least once more through 1999. Changes in age- and gender-adjusted height and weight growth associated with PI use were assessed. RESULTS: Compared with a healthy reference population, children were more affected in height (mean z score: -0.90 [18th percentile]) than in weight (mean z score: -0.42 [34th percentile]) at baseline (1995). Two thirds of children received at least 1 PI during 1996 to 1999. In the multivariate mixed effects regression models adjusted for baseline log(10) CD4 cell count, baseline age, gender, and race/ethnicity, the use of PIs was associated with per-year gains of 0.13 z scores in height and 0.05 z scores in weight relative to the expected growth with non-PI-containing regimens (eg, after 1 year of PI use, a representative 6-year-old boy in our study would be approximately 0.7 cm taller and 0.1 kg heavier than if he had not received PIs). No significant differential effects of PIs on height or weight growth according to specific agents or children's sociodemographic or clinical characteristics were found. CONCLUSIONS: Although the use of PI-containing regimens was not associated with growth retardation, it was associated with only small annual increments in height and weight growth in HIV-infected children.

Correlates of opportunistic infections in children infected with the human immunodeficiency virus managed before highly active antiretroviral therapy.

BACKGROUND: Opportunistic infections (OIs) are an important cause of morbidity and mortality in children infected with HIV. However, few data are available regarding the overall prevalence, incidence and immunologic correlates associated with these diseases in the pediatric HIV population. The Pediatric AIDS Clinical Trials Group (PACTG) has conducted multicenter studies in HIV-infected children since 1988 and through these studies has collected prospective data on the immunologic and virologic status of study participants and recorded complications, including infectious diseases, related to HIV infection and its treatments. Therefore data were analyzed from across 13 PACTG studies, performed before treatment with highly active antiretroviral therapy was given, to determine the rates of various infectious complications and the immunologic correlates, specifically CD4 cell counts, associated with these diseases. RESULTS: OIs were tabulated from 3331 HIV-infected children who participated in 13 clinic trials undertaken before highly effective antiretroviral therapy was available. Five OIs occurred at event rates of >1.0 per 100 patient years (person years): serious bacterial infections, 15.1; herpes zoster, 2.9; disseminated Mycobacterium avium complex (DMAC), 1.8; Pneumocystis carinii pneumonia, 1.3; and tracheobronchial and esophageal candidiasis, 1.2. Six other OIs evaluated, cytomegalovirus (CMV) disease, cryptosporidiosis, tuberculosis, systemic fungal infections, toxoplasmosis and progressive multifocal leukoencephalopathy, occurred at event rates of <1.0 per 100 person years. Pneumonia (11.1 per 100 person years) and bacteremia (3.3 per 100 person years) were the most common bacterial infections. An AIDS-defining OI before entry was a risk factor for the development of a new OI during a trial. Bacterial infections, herpes zoster and tuberculosis occurred frequently at all stages of HIV infection; whereas DMAC, P. carinii pneumonia, CMV and other OIs occurred primarily in children with severe immunosuppression. CONCLUSIONS: The frequency of OIs in HIV-infected children in the pre-highly active antiretroviral therapy era varies with age, pathogen, prior OI and immunologic status. Analysis of CD4 counts at the time of DMAC, CMV and PCP provide validation for current prophylaxis guidelines in children > or =2 years old. This information on infectious complications of pediatric HIV will be especially valuable for contemporary management of HIV infection that is poorly responsive to highly active antiretroviral therapy.

Effect of combination therapy including protease inhibitors on mortality among children and adolescents infected with HIV-1.

BACKGROUND: Combination therapy including protease inhibitors has been shown to be effective in treating adults infected with human immunodeficiency virus type 1 (HIV-1), but there are only limited data regarding the treatment of children and adolescents. METHODS: A cohort of 1028 HIV-1-infected children and adolescents, from birth through 20 years of age, who were enrolled in research clinics in the United States before 1996 was followed prospectively through 1999. We used proportional-hazards regression models to estimate the effect on mortality of combination therapy including protease inhibitors. RESULTS: Seven percent of the subjects were receiving combination therapy including protease inhibitors in 1996; by 1999, 73 percent were receiving such therapy. In univariate analyses, a higher base-line percentage of lymphocytes that were CD4-positive, a higher weight for age, a higher height for age, black race, Hispanic ethnic background, younger age, and perinatally acquired infection were associated with a longer median time to the initiation of this type of therapy (P<0.001). After adjustment for covariates, the differences among racial and ethnic groups in the time to initiation were not statistically significant. Mortality declined from 5.3 percent in 1996 to 2.1 percent in 1997, 0.9 percent in 1998, and 0.7 percent in 1999 (P for trend <0.001). There were reductions in mortality in all subgroups defined according to age, sex, percentage of CD4+ lymphocytes, educational level of the parent or guardian, and race or ethnic background. In adjusted analyses, the initiation of combination therapy including protease inhibitors was independently associated with reduced mortality (hazard ratio for death, 0.33; 95 percent confidence interval, 0.19 to 0.58; P<0.001). CONCLUSIONS: The use of combination therapy including protease inhibitors has markedly reduced mortality among children and adolescents infected with HIV-1.

Oral ganciclovir in children: pharmacokinetics, safety, tolerance, and antiviral effects. The Pediatric AIDS Clinical Trials Group.

The pharmacokinetics, safety, tolerance, and antiviral effects of ganciclovir (Gcv) administered orally were evaluated in 36 children infected with cytomegalovirus (CMV) who were severely immunocompromised by infection with human immunodeficiency virus type 1. In this dose-escalation study, 30 mg/kg of Gcv administered every 8 h produced serum levels similar to the dose (1 g/8 h) effective for maintenance treatment of CMV retinitis in adults. In older children, serum Gcv concentrations were similar after the administration of capsules and suspension. All doses (10-50 mg/kg/8 h) studied were safe and, except for the volume of suspension or number of pills, were well tolerated. Oral Gcv was associated with a decrease in the detection of CMV by culture or polymerase chain reaction. CMV disease occurred in 3 children during the study: one developed Gcv resistance, another had harbored resistant virus at study entry, and a third had wild-type CMV

Mycobacterium bovis as a significant cause of tuberculosis in children residing along the United States-Mexico border in the Baja California region.

OBJECTIVE: To determine the role of Mycobacterium bovis in active pediatric tuberculosis (TB) in a United States-Mexico border region. METHOD: We reviewed all new cases of pediatric (<15 years old) TB presenting to San Diego hospitals and clinics from 1980 to 1997. Patients were categorized by age, ethnicity, country of origin, culture results, and disease manifestations. Case definitions were similar to those used by the Centers for Disease Control and Prevention. M bovis was distinguished from Mycobacterium tuberculosis by standard biochemical tests. RESULTS: The median age of the 563 identified patients was 4.1 years old. The yearly incidence began rising in 1989 and peaked in the mid-1990s. Hispanics constituted 78.9% of the patients, but they were less likely to be foreign-born (21.6%) than were black children and Asian/Pacific Islanders. Overall, M bovis caused 10.8% of all TB during this period. Of the 180 patients with positive culture results, however, M bovis accounted for 33.9% and M tuberculosis 66. 1%. This high percentage of M bovis infections was largely attributable to its contribution to extrapulmonary TB (55.2% of all culture-positive specimens). M bovis patients were also even more likely to be Hispanic (90.2%), to present with extrapulmonary disease (95.1%), and to be older than 12 months (96.8%). CONCLUSION: These data demonstrate the dramatic impact of this underappreciated cause of zoonotic TB on US children at the Mexican border and underscore the need for cross-collaboration to enforce existing Mexican pasteurization laws.

Gastrostomy tube insertion for improvement of adherence to highly active antiretroviral therapy in pediatric patients with human immunodeficiency virus.

OBJECTIVES: Newer combination antiretroviral therapies used to treat human immunodeficiency virus (HIV)-infected individuals have resulted in dramatic delays in HIV progression, with reduction in mortality and morbidity. However, adherence to highly active antiretroviral therapy (HAART) may be problematic, particularly in HIV-infected children. Reasons for nonadherence include refusal, drug tolerability, and adverse reactions. We assess: 1) the potential benefits of gastrostomy tube (GT) for the improvement of adherence to HAART in HIV-infected children, and 2) the factors that may result in improved viral suppression after GT placement. METHODS: The medical records of 17 pediatric HIV-infected patients, in whom GT was used to improve HAART adherence, were retrospectively reviewed for clinical and laboratory parameters. Each record was reviewed for the period of 1 year before and after GT insertion. The main outcome parameters were virologic (plasma HIV RNA polymerase chain reaction quantification) and immunologic (CD4 cell counts). Documentation of adherence to medications in medical records was also assessed during the study. Parental questionnaires were used to determine GT satisfaction and medication administration times. The Wilcoxon rank sum test was used to assess change in viral load (VL) and CD4 cell percentages. RESULTS: GT was well-tolerated with minor complications, such as local site tenderness, reported by 4 patients (23%). Before GT insertion, only 6 patients (35%) were documented as being adherent, compared with all patients after GT insertion. Ten patients (58%) had >/=2 log(10) VL decline after GT insertion (median: 3.2 log(10)), compared with 7 patients (42%) who had /=2 log(10) VL decline, therapy was changed at the time of or soon after GT insertion (median:.8 months; range: 0-6 months), compared with 7 patients with <2 log(10) VL decline who had therapy changed before GT insertion (median: 3.2 months; range: 1-8 months). Parental questionnaires reported significantly shorter medication administration times after GT insertion, with 70% of patients taking >5 minutes before GT, compared with 0% after GT. Questionnaires indicated satisfaction with GT, with perceived benefits being reduced medication administration time and improved behavior surrounding taking medications. CONCLUSIONS: GT is well-tolerated in pediatric HIV-infected patients and should be considered for selected patients to overcome difficulties with medication administration and to improve adherence. For maximal virologic response, combination therapy should be changed at the time of GT insertion.

Group-specific antibody levels surrounding invasive pneumococcal illness in children infected with human immunodeficiency virus.

Pneumococcal antibody levels surrounding systemic pneumococcal illness (SPI) were measured in children infected with human immunodeficiency virus (HIV). Archived serum samples were collected from 28 HIV-infected children who had 34 cases of SPI, caused by pneumococcal groups 4, 6, 9, 14, 19, and 23. Serum samples collected within 23 weeks before and 13 weeks after the SPI were assayed by ELISA for antipneumococcal polysaccharide (PnPs) IgG antibody to 6 representative pneumococcal serotypes. There was a wide range (0. 16-30.80 microg/mL) of pre-SPI anti-PnPs antibody levels to the presumed infecting serotypes, with a geometric mean level of 0.83 microg/mL (n=34). Seventy-six percent of the antibody values were <2.0 microg/mL, and 95% were <5.0 microg/mL. Homologous seroresponses (>/=4-fold rise in anti-PnPs antibody) were detected in only 4 (27%) of 15 paired serum samples. Heterologous, noninfecting group seroresponses were detected frequently (72%) in the paired serum samples from these 4 homologous group seroresponders.

Nosocomial transmission of Mycobacterium bovis bacille Calmette-Guerin to children receiving cancer therapy and to their health care providers.

A previous report of nosocomial infection due to Mycobacterium bovis bacille Calmette-Guerin (BCG) implicated contamination of chemotherapy solutions reconstituted under the same biosafety hood as BCG vaccine used for bladder cancer therapy. We report 3 similar BCG infections in children and describe evidence of respiratory transmission to health care workers (HCWs) from 1 patient. These children were receiving chemotherapy for leukemia when they presented with active tuberculosis. Each isolate was identified biochemically and by both gas-liquid chromatography and major polymorphic tandem repeat-polymerase chain reaction. Pulsed-field gel electrophoresis showed that 2 isolates were identical strains and identical to the Tice and Connaught strains licensed in the United States for bladder chemotherapy. The third isolate differed by a single fragment after DraI restriction. One patient with heavily positive sputum exposed numerous HCWs. Of 41 HCWs, 2 (5%) converted their purified protein derivatives (PPD) skin test. These data underscore the risk of nosocomial BCG transmission by contamination of chemotherapy solutions and demonstrate the potential for transmission to HCWs from patients with active pulmonary disease.

Resolution of HIV-associated nephrotic syndrome with highly active antiretroviral therapy delivered by gastrostomy tube.

There is no consensus regarding the specific management of HIV-associated nephrotic syndrome. We report a child whose first manifestation of human immunodeficiency virus type 1 (HIV-1) infection was nephropathy and wasting syndrome associated with profound immunodeficiency. The patient had a dramatic clinical and immunologic response to triple antiretroviral therapy delivered through a gastrostomy tube, with complete resolution of nephrotic syndrome. A 51/2-year-old African-American girl presented with a 2-week history of cough, chest pain, vomiting, loose stools, abdominal distention, anorexia, and fever. In addition, she had recurrent oral thrush. Her weight and height were below the 5th percentile. She was chronically ill, appearing with oropharyngeal thrush and pitting edema in lower extremities. She had scattered rhonchi and decreased breath sounds on both lung bases. Her abdomen was distended and diffusely tender. A chest radiograph showed consolidation of the right upper and left lower lobes with bilateral pleural effusion. Admission laboratories were consistent with nephrotic syndrome. Streptococcus pneumoniae grew from the blood culture and the child responded well to treatment with intravenous ceftriaxone. She was found to be HIV-infected, her CD4(+) cell count was 3 cells/mcL and her plasma HIV-1 RNA was >750 000 copies/mL. A percutaneous gastrostomy tube was placed for supplemental nutrition. She was treated with stavudine, lamivudine, and nelfinavir via gastrostomy tube with good clinical response. Twenty-one months after instituting antiretroviral therapy, her weight and height had increased to the 50th and 10th percentile respectively, and she had complete resolution of her nephrotic syndrome. Her CD4(+) cell count increased to 1116 cells/mcL and her viral load has remained undetectable. HIV-1 associated nephrotic syndrome has been described in children with profound immunodeficiency. The course of untreated HIV-associated nephrotic syndrome is rapid progression to renal failure in up to 40% of the children. Regardless of the presence of renal insufficiency, if untreated, it is uniformly fatal. A modest improvement of HIV-1 associated nephrotic syndrome has been observed in patients treated with zidovudine. Steroid and cyclosporine treatment have resulted in improved renal function but long-term use of immunosuppressive therapy has raised concerns about safety. We have described, to our knowledge, the first child with HIV-associated nephrotic syndrome who had a remarkable clinical, immunologic, and virologic response to triple-drug combination therapy given by gastrostomy tube, with complete resolution of proteinuria and normalization of the serum albumin. She also had a striking improvement in weight, height, and quality-of-life. Whether the presence of a gastrostomy tube contributed to the excellent response because of improved compliance is unknown, but warrants systematic evaluation.

Combination therapy with efavirenz, nelfinavir, and nucleoside reverse-transcriptase inhibitors in children infected with human immunodeficiency virus type 1. Pediatric AIDS Clinical Trials Group 382 Team.

BACKGROUND: Consistent long-term viral suppression has been difficult to achieve in children with human immunodeficiency virus type 1 (HIV-1) infection. We tested the safety and antiviral efficacy of a novel combination consisting of efavirenz, nelfinavir, and one or more nucleoside reverse-transcriptase inhibitors in 57 children previously treated with only nucleoside reverse-transcriptase inhibitors. METHODS: The children were monitored for 48 weeks after the initiation of therapy. We assessed plasma concentrations of efavirenz and nelfinavir, plasma HIV-1 RNA levels, and lymphocyte subpopulations. RESULTS: At base line, the 57 HIV-1-infected children (age range, 3.8 to 16.8 years) had a median of 699 CD4 cells per cubic millimeter and 10,000 copies of HIV-1 RNA per milliliter of plasma. The most common treatment-related effects of at least moderate severity were rash (in 30 percent of children), diarrhea (in 18 percent), neutropenia (in 12 percent), and biochemical abnormalities (in 12 percent). Serious side effects were uncommon. The mean values for the area under the curve for efavirenz and nelfinavir corresponded to expected values. In an intention-to-treat analysis, 76 percent of children had plasma HIV-1 RNA levels of less than 400 copies per milliliter after 48 weeks of therapy and 63 percent had levels of less than 50 copies per milliliter. A high plasma HIV-1 RNA level at base line significantly decreased the likelihood that plasma levels of HIV-1 RNA would become undetectable during treatment. CONCLUSIONS: In HIV-1-infected children who were previously treated with nucleoside reverse-transcriptase inhibitors, the combination of efavirenz, nelfinavir, and nucleoside reverse-transcriptase inhibitors was generally well tolerated and had a potent and sustained antiviral effect.

Pharmacokinetics of dapsone administered daily and weekly in human immunodeficiency virus-infected children.

Although dapsone is a commonly used alternative agent for prophylaxis against Pneumocystis carinii pneumonia in children intolerant to trimethoprim-sulfamethoxazole, there are few data that describe dapsone pharmacokinetics in children. We studied dapsone pharmacokinetics in 30 children (median age, 2.8 years; age range, 0. 3 to 12 years) receiving a new proprietary liquid preparation by three dosing regimens (1 mg/kg of body weight daily, 2 mg/kg daily, or 4 mg/kg weekly). Dosing of children with 2 mg/kg daily or 4 mg/kg weekly resulted in peak concentrations equivalent to those reached in adults receiving 100-mg tablets daily. For the entire population, the median half-life was 22.2 h (range, 7.1 to 40.3 h), the median oral clearance was 0.0365 liter/kg/h (range, 0.0104 to 0.1021 liter/kg/h), and the median oral apparent volume of distribution was 1.13 liters/kg (range, 0.50 to 2.32 liters/kg). The median dapsone oral clearance was significantly increased in those infants less than 2 years of age compared to the oral clearance in those over 2 years of age (0.0484 versus 0.0278 liter/kg/h; P = 0.011). These data suggest that absorption of this liquid preparation is adequate and that the concentrations in the sera of children receiving 2 mg/kg daily or 4 mg/kg weekly are equivalent to those seen in adults receiving standard dapsone dosing. Dapsone oral clearance appears to be increased in children under 2 years of age.

Treatment of human immunodeficiency virus 1-infected infants and children with the protease inhibitor nelfinavir mesylate.

An open-label study was conducted of nelfinavir mesylate, given with reverse transcriptase inhibitors to human immunodeficiency virus 1 (HIV-1)-infected infants and children 3 months to 13 years of age. Doses of nelfinavir mesylate of 20-30 mg/kg yielded drug exposures comparable to those seen in adults. The drug was well tolerated; mild diarrhea was the primary toxic effect observed. Seventy-one percent (39) of the 55 evaluable subjects had an initial decrease in plasma HIV-1 RNA, of at least 0.7 log10 copies/mL; suppression of plasma HIV-1 RNA levels to < 400 copies/mL was observed in 15. Children who began taking at least one new reverse transcriptase inhibitor near the time when nelfinavir mesylate was started, and those with a > or = 24% proportion of CD4 lymphocytes, had a greater chance of achieving and maintaining a decline in plasma HIV-1 RNA to < 400 copies/mL. Suppression of viremia was achieved in children as young as 3 months of age.

Pharmacokinetics of azithromycin administered alone and with atovaquone in human immunodeficiency virus-infected children. The ACTG 254 Team.

To evaluate if atovaquone (ATQ) interacts pharmacokinetically with azithromycin (AZ) in human immunodeficiency virus-infected children, 10 subjects (ages, 4 to 13 years) were randomized in a crossover study to receive AZ (5 mg/kg/day) alone (ALONE) or AZ (5 mg/kg/day) and ATQ (30 mg/kg/day) simultaneously (SIM) prior to receiving AZ and ATQ staggered by 12 h. Despite a lack of significant difference in the mean AZ pharmacokinetic parameters, the steady-state values of AZ's area under the concentration-time curve from 0 to 24 h and maximum concentration in serum were consistently lower (n = 7 of 7) for the SIM regimen than they were for the ALONE regimen. A larger study will be required to determine if ATQ affects AZ pharmacokinetics and efficacy in a clinically significant manner.

A phase I study of abacavir (1592U89) alone and in combination with other antiretroviral agents in infants and children with human immunodeficiency virus infection. AIDS Clinical Trials Group 330 Team.

OBJECTIVES: To evaluate the pharmacokinetic features, safety, and tolerance of abacavir, given alone and in combination with other nucleoside antiretroviral agents, in symptomatic human immunodeficiency virus (HIV)-infected children. METHODS: HIV-infected children discontinued prior antiretroviral therapy and were given abacavir orally, 4 mg/kg every 12 hours for 6 weeks, followed by 8 mg/kg every 12 hours for 6 weeks (n = 39); or 8 mg/kg every 12 hours for 12 weeks (n = 8). Children then were randomized to receive a second nucleoside antiretroviral agent (zidovudine, stavudine, didanosine, or lamivudine), plus abacavir. Pharmacokinetics, safety, tolerance, CD4(+) lymphocyte counts, and plasma HIV RNA concentrations were evaluated. RESULTS: At a dose of 8 mg/kg every 12 hours, area under the plasma concentration-versus-time curves and plasma half-life values were comparable with those reported for adults receiving abacavir at a dose of 300 mg twice daily. One case each of hypersensitivity reaction and peripheral neuropathy occurred during abacavir monotherapy. Three children experienced neutropenia while receiving abacavir in combination with another antiretroviral agent. Mean CD4(+) lymphocyte count and plasma HIV RNA concentration did not change when prior antiretroviral therapy was changed to abacavir monotherapy. CONCLUSIONS: Abacavir therapy is associated with good short-term tolerance and safety in HIV-infected children. Phase III studies are in progress to assess the antiviral activity of abacavir in children and adults.

Genetic diversity among Mycobacterium avium complex strains recovered from children with and without human immunodeficiency virus infection.

The genetic diversity and molecular epidemiology of Mycobacterium avium complex (MAC) infections in children with and without human immunodeficiency virus (HIV) infection were evaluated. Isolates recovered from 136 children were subtyped by sequence analysis of a 360-bp region of the gene (hsp65) encoding a 65-kDa heat-shock protein. Twenty-one distinct hsp65 alleles were identified. On the basis of hsp65 genotype, 6 isolates were not MAC organisms. Of the remaining 130 samples, 61% were M. avium, 37% were Mycobacterium intracellulare, and 2% were species nonspecific MAC. Eighty-eight percent of the isolates obtained from HIV-infected children were M. avium. In contrast, only 38% of the isolates obtained from children without HIV infection were M. avium (chi2 test, P < .001). M. avium isolates were further subtyped by Southern blot analysis with insertion element IS1245. Taken together, no evidence for a single clonal M. avium strain causing infection was detected.

Zidovudine pharmacokinetics in premature infants exposed to human immunodeficiency virus.

We used population analysis techniques to determine zidovudine (ZDV) pharmacokinetic parameters in 15 preterm neonates (mean gestational age, 29.4 weeks; mean birth weight, 1,230 g) at a mean age of 5.5 days. The values of the pharmacokinetic parameters were as follows: clearance, 2.53 +/- 0.44 ml/min/kg; volume of distribution, 1.59 +/- 0.51 liters/kg; and half-life, 7.2 +/- 1.5 h. For seven infants studied a second time, at a mean age of 17.7 days, an increase in the mean clearance (2.33 versus 4.35 ml/min/kg; P = 0.024) and a decrease in the half-life (7.3 versus 4.4 h; P = 0.003) were found. The ZDV clearance is low and the half-life is prolonged in premature neonates, but the clearance increases and the half-life decreases with postnatal age. Potentially toxic concentrations may accumulate in serum if the standard dosage for full-term infants is used. We suggest that initial ZDV dosing should be reduced to 1.5 mg every 12 h for preterm neonates.

Ganciclovir treatment of symptomatic congenital cytomegalovirus infection: results of a phase II study. National Institute of Allergy and Infectious Diseases Collaborative Antiviral Study Group.

Congenital cytomegalovirus (CMV) infection occurs in approximately 1% of newborns in the United States. A phase II evaluation was done of ganciclovir for the treatment of symptomatic congenital CMV infection. Daily doses of 8 or 12 mg/kg were administered in divided doses at 12-h intervals for 6 weeks. Clinical and laboratory evaluations sought evidence of toxicity, quantitative virologic responses in urine, plasma drug concentrations, and clinical outcome. A total of 14 and 28 babies received 8 and 12 mg/kg/day, respectively. Five additional babies received ganciclovir on a compassionate plea basis. Significant laboratory abnormalities included thrombocytopenia (< or = 50,000/mm3) in 37 babies and absolute neutropenia (< or = 500 mm3) in 29 babies. Quantitative excretion of CMV in the urine decreased; however, after cessation of therapy, viruria returned to near pretreatment levels. Hearing improvement or stabilization occurred in 5 (16%) of 30 babies at 6 months or later, indicating efficacy.

Cost effectiveness of magnetic resonance imaging in diagnosing Pseudomonas aeruginosa infection after puncture wound.

This study was performed to determine the cost effectiveness of radiologic imaging studies in diagnosing Pseudomonas aeruginosa infections after puncture wounds and the respective comparison of imaging and scintigraphy. Using retrospective medical record review, we studied 12 patients with culture-proven Pseudomonas infections of bone, cartilage or joint, or soft tissues. Attention was paid to radiographic presentation, scintigraphic studies, and magnetic resonance imaging results. All available imaging studies were reviewed. A survey of the costs of each imaging study was conducted. All patients underwent surgery. Three patients had magnetic resonance imaging studies that provided definitive diagnosis of osteomyelitis and precise localization of involved bones, soft tissue edema, and periosteal abscess. Eight patients had bone scans, one of which was consistent with cellulitis; seven, with osteomyelitis; and two with no abnormalities. All patients had radiographs of the involved foot. Case 4 had three series of radiographs. Nine of the twelve patients (75%) had normal findings on radiographs, with only soft tissue swelling or osteoporosis. Five patients had evidence of osteomyelitis. Magnetic resonance imaging is a cost-effective method in diagnosing Pseudomonas osteomyelitis. Early use of magnetic resonance imaging can provide definitive diagnosis and more precise anatomic localization necessary for surgical intervention.