Antimicrobial prophylaxis

Antibiotics for preventing lower respiratory tract infections in high-risk children aged 12 years and under

BACKGROUND

Lower respiratory tract infections (LRTIs) in young children account for 1.4 million deaths annually worldwide. Antibiotics could be beneficial in preventing LRTIs in high-risk children, and may also help prevent school absenteeism and work days missed by children and/or carers. While it is well documented that the efficacy of antibiotic prophylaxis for RTIs decreases over time, there are no reviews that describe the use of antibiotic prophylaxis to prevent LRTIs in high-risk children aged 12 years and under.

OBJECTIVES

To assess the effectiveness and safety of antibiotic prophylaxis in the prevention of bacterial LRTIs in high-risk children aged 12 years and under.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 1) and the Database of Abstracts of Reviews of Effects (DARE), MEDLINE and MEDLINE In-Process (OvidSP) (1946 to 13 February 2015), EMBASE (OvidSP) (1974 to 12 February 2015), Science Citation Index Expanded (1945 to 13 February 2015) and Conference Proceedings Citation Index-Science (Web of Science Core Collection) (1990 to 13 February 2015). We searched for ongoing studies on ClinicalTrials.gov and the World Health Organization ICTRP. We handsearched the bibliographies of retrieved full texts of relevant studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing oral or intravenous antibiotics versus placebo or no treatment to prevent infections in high-risk children aged 12 years and under. We used a combination of the Centers for Disease Control and Prevention (CDC), National Health Service (NHS), American Academy of Paediatrics (AAP) and National Institute for Health and Care Excellence (NICE) guidelines to define conditions at higher risk of complications. Our primary outcome was the incidence of bacterial lower respiratory infections. Secondary outcomes included clinical function, hospital admission, mortality, growth, use of secondary antibiotics, time off school or parental work, quality of life and adverse events.

DATA COLLECTION AND ANALYSIS

We extracted data using a customised data extraction sheet, assessed the risk of bias of included studies using the Cochrane 'Risk of bias' criteria, and used the GRADE criteria to rate the quality of the evidence. We used a random-effects model for meta-analysis. We presented the results narratively where we could not statistically combine data.

MAIN RESULTS

We included 10 RCTs of high-risk children using antibiotics (azithromycin, ciprofloxacin, co-trimoxazole, isoniazid, oral penicillin V or vancomycin) to prevent LRTIs. Three studies included HIV-infected children (n = 1345), four cystic fibrosis (n = 429) and one each sickle cell disease (n = 219), cancer (n = 160) and low birth weight neonates with underlying respiratory disorders (n = 40). The study duration ranged from seven days to three years. The quality of the evidence from studies including children with HIV infection, cystic fibrosis or cancer was moderate. Due to inadequate data, we were unable to rate the quality of the evidence for two studies: one in children with sickle cell disease (low risk of bias), and another in low birth weight neonates with underlying respiratory disorders (high risk of bias).In HIV-infected children receiving continuous isoniazid prophylaxis, there was no significant difference in the incidence of pulmonary tuberculosis (risk ratio (RR) 0.64, 95% confidence interval (CI) 0.32 to 1.29, I(2) statistic = 47%, P value = 0.21). There was no significant effect on mortality with co-trimoxazole or isoniazid prophylaxis (RR 0.82, 0.46 to 1.46, I(2) statistic = 76%, P value = 0.58); however, analysis of one study that used co-trimoxazole showed a significant reduction in mortality (RR 0.67, 95% CI 0.53 to 0.85, P value = 0.001). There was a significant decrease in the rates of hospital admission per child-year of follow-up with co-trimoxazole prophylaxis in one study (P value = 0.01). There was no evidence of increased adverse events due to antibiotic prophylaxis (RR 1.10, 95% CI 0.75 to 1.64, I(2) statistic = 22%, P value = 0.28); however, there was scant reporting of antibiotic resistance - the one study that did assess this found no increase.In two studies of children with cystic fibrosis receiving ciprofloxacin prophylaxis, there was no significant difference in Pseudomonas infections (RR 0.76, 0.44 to 1.31, I(2) statistic = 0%, P value = 0.33). In two studies assessing the benefit of azithromycin prophylaxis, there was a significant reduction in the frequency of pulmonary exacerbations (RR 0.60, 95% CI 0.48 to 0.76, I(2) statistic = 0%, P value < 0.0001). The effect of antibiotic prophylaxis on growth in children with cystic fibrosis was inconsistent across the studies. There was an increased risk of emergence of pathogenic strains with either azithromycin or ciprofloxacin prophylaxis in two studies reporting this outcome. There was no significant difference in the quality of life (one study). In three studies, there was no significant increase in the frequency of adverse events with prophylaxis with azithromycin (two studies) or ciprofloxacin (one study). There was no evidence of increased antibiotic resistance in two studies.In the one study of children with sickle cell disease, a significantly lesser proportion of children with pneumococcal septicaemia was reported with penicillin V prophylaxis (P value = 0.0025).In the one study of children with cancer there was a significant decrease in Pneumocystis carinii pneumonia with trimethoprim-sulfamethoxazole prophylaxis (RR 0.03, 95% CI 0.00 to 0.47, P value < 0.01). There was no significant increase in the frequency of adverse events with antibiotic prophylaxis.In low birth weight children with underlying respiratory disorders, there was no significant difference in the proportion of children with pulmonary infection with vancomycin prophylaxis (P value = 0.18).No included studies reported time off school or carer time off work.

AUTHORS' CONCLUSIONS

There is inconclusive evidence that antibiotic prophylaxis in certain groups of high-risk children can reduce pneumonia, exacerbations, hospital admission and mortality in certain conditions. However, limitations in the evidence base mean more clinical trials assessing the effectiveness of antibiotics for preventing LRTIs in children at high risk should be conducted. Specifically, clinical trials assessing the effectiveness of antibiotics for preventing LRTIs in congenital heart disease, metabolic disease, endocrine and renal disorders, neurological disease or prematurity should be a priority.

Prophylaxis after first febrile urinary tract infection in children? A multicenter, randomized, controlled, noninferiority trial

OBJECTIVES

Febrile urinary tract infections are common in children and associated with the risk for renal scarring and long-term complications. Antimicrobial prophylaxis has been used to reduce the risk for recurrence. We performed a study to determine whether no prophylaxis is similar to antimicrobial prophylaxis for 12 months in reducing the recurrence of febrile urinary tract infections in children after a first febrile urinary tract infection.

METHODS

The study was a controlled, randomized, open-label, 2-armed, noninferiority trial comparing no prophylaxis with prophylaxis (co-trimoxazole 15 mg/kg per day or co-amoxiclav 15 mg/kg per day) for 12 months. A total of 338 children who were aged 2 months to <7 years and had a first episode of febrile urinary tract infection were enrolled: 309 with a confirmed pyelonephritis on a technetium 99m dimercaptosuccinic acid scan with or without reflux and 27 with a clinical pyelonephritis and reflux. The primary end point was recurrence rate of febrile urinary tract infections during 12 months. Secondary end point was the rate of renal scarring produced by recurrent urinary tract infections on technetium 99m dimercaptosuccinic acid scan after 12 months.

RESULTS

Intention-to-treat analysis showed no significant differences in the primary outcome between no prophylaxis and prophylaxis: 12 (9.45%) of 127 vs 15 (7.11%) of 211. In the subgroup of children with reflux, the recurrence of febrile urinary tract infections was 9 (19.6%) of 46 on no prophylaxis and 10 (12.1%) of 82 on prophylaxis. No significant difference was found in the secondary outcome: 2 (1.9%) of 108 on no prophylaxis versus 2 (1.1%) of 187 on prophylaxis. Bivariate analysis and Cox proportional hazard model showed that grade III reflux was a risk factor for recurrent febrile urinary tract infections. Whereas increasing age was protective, use of no prophylaxis was not a risk factor.

CONCLUSIONS

For children with or without primary nonsevere reflux, prophylaxis does not reduce the rate of recurrent febrile urinary tract infections after the first episode.

Is antibiotic prophylaxis necessary in infants with obstructive hydronephrosis?

PURPOSE

We investigated the relationship between the level of obstruction of the upper urinary tract and the risk and onset of urinary tract infection in infants with severe obstructive hydronephrosis to determine the need for antibiotic prophylaxis.

MATERIALS AND METHODS

A total of 105 patients were prenatally diagnosed with severe hydronephrosis (Society for Fetal Urology grade III or IV) due to upper urinary tract obstruction between 1994 and 2004. Of these patients 75 had ureteropelvic junction obstruction and 30 had lower ureteral obstruction. We retrospectively evaluated the clinical course and incidence of urinary tract infection during the first 12 months postnatally without antibiotic prophylaxis.

RESULTS

The incidence of overall urinary tract infection during followup was 36.2% (38 of 105 patients), and it demonstrated a higher trend with lower ureteral obstruction than with ureteropelvic junction obstruction (50% vs 30.7%, p=0.063). Most cases of urinary tract infection (92.8%) occurred before age 6 months, with a mean age at onset of 2.6 months. Of 105 patients 77 (73.3%) underwent corrective surgery at a mean age of 3.8 months. The incidence of urinary tract infection before surgical correction was 33.8% at a mean age of 2.1 months. The incidence of urinary tract infection in surgical cases was significantly higher with lower ureteral obstruction than with ureteropelvic junction obstruction (54.2% vs 24.5%, p=0.011).

CONCLUSIONS

Urinary tract infection in infants with severe obstructive hydronephrosis has a high incidence, occurs before age 6 months and is more common with lower ureteral obstruction than with ureteropelvic junction obstruction. These findings indicate that infants with severe hydronephrosis due to obstruction of the upper urinary tract should receive antibiotic prophylaxis.

Paediatric bronchiectasis in Europe: what now and where next?

Bronchiectasis has been defined as the abnormal and permanent dilation of bronchi. It has a variety of causes and has traditionally been viewed as a condition that is irreversible, often progressive and associated with significant morbidity and mortality. In the past, patients had relatively advanced disease by the time the diagnosis was established. By using high-resolution computed tomography (HRCT) scanning of the chest, the potential now exists for the much earlier detection and treatment of children with lesser degrees of bronchial dilation and bronchial wall thickening than was previously possible. In some, the HRCT changes have been seen to improve or completely resolve. This calls into question exactly what now should be termed bronchiectasis and how the parents of children with such HRCT findings should be counselled about the likely prognosis and the necessary or desirable treatment options.

May we go on with antibacterial prophylaxis for urinary tract infections?

Recurrent urinary tract infections (UTIs), with or without vesicoureteric reflux (VUR), are by far the most frequent reason for long-term antibacterial prophylaxis in infants and children today. However, the strategies of antibacterial prophylaxis for the prevention of recurrent urinary tract infection are no longer universally accepted. In infants and children at risk, the benefits of antibacterial prophylaxis definitively are not yet proven by evident data. To put antibacterial prophylaxis in its place, risk groups for recurrent symptomatic infections, ascending UTI and permanent renal damage have to be defined and the efficacy of prophylaxis in these groups has to be proved by prospective randomised studies. Nevertheless, until the results of these studies are available, antibacterial prophylaxis will remain one of the most frequently practised methods to protect risk patients from pyelonephritic damage and UTI recurrences.

In Vitro Efficacy of a Polyhexamethylene Biguanide-Impregnated Gauze Dressing Against Bacteria Found in Veterinary Patients

OBJECTIVE

To evaluate the in vitro efficacy of polyhexamethylene biguanide (PHMB)-impregnated gauze dressing in limiting the growth of bacteria both within and underneath the dressing.

STUDY DESIGN

In vitro study.

METHODS

Squares of PHMB-impregnated and control gauze were placed on agar plates inoculated with 1 of 11 bacterial species, including 8 multi-resistant organisms. Growth under the gauze was assessed qualitatively after 24-hour incubation. Repeated use of sponges was used to evaluate residual inhibitory activity against Micrococcus lutea and Staphylococcus schleiferi ss. schleiferi. In a second procedure, PHMB-impregnated and control gauze squares were placed in sterile plastic wells and inoculated with 1 of 5 bacterial species, including Pseudomonas spp. and Klebsiella spp. Inhibition of bacterial growth within and underneath the dressing after 24-hour incubation was evaluated by quantifying the numbers of bacteria on the well floor and within each square.

RESULTS

PHMB-impregnated gauze provided greater inhibition of growth of 4/4 Gram-positive species and 2/6 Gram-negative species on inoculated plates compared with control gauze. Residual inhibitory activity of PHMB-impregnated gauze was significantly greater against M. lutea on all days and against S. schleiferi ss. schleiferi on days 1 and 4 compared with control. No bacteria were recovered from inoculated PHMB-impregnated gauze squares placed in sterile wells or from the well floor underneath. More than 9 x 10(5) colony-forming units (CFU) were recovered from inoculated control samples placed in sterile wells and more than 8.4 x 10(4) CFU were recovered from control well floors.

CONCLUSION

PHMB-impregnated gauze dressing, when placed on inoculated agar plates, reduces growth of underlying bacteria, particularly Gram-positive species. Wet-inoculated PHMB-impregnated dressing prevents growth of Gram-positive and Gram-negative bacteria both within and underneath the dressing.

CLINICAL RELEVANCE

PHMB-impregnated dressings may be useful for reducing contamination of underlying wounds by bacterial pathogens.

The ethics of prophylactic antibiotics for neurosurgical procedures

The prophylactic use of antibiotics has become a routine procedure in many areas of medicine. In neurosurgery, however, there is considerable debate over their use in the prevention of postoperative infection. We pose several ethical questions about antibiotic prophylaxis in a neurosurgical setting. These questions are discussed under the following categories: responsible usage of antibiotics; the ethical dilemmas of controlled, antibiotic clinical trials, and some problems inherent in not using prophylactic antibiotics.

Neutrophil disorders and their management

Neutrophil disorders are an uncommon yet important cause of morbidity and mortality in infants and children. This article is an overview of these conditions, with emphasis on clinical recognition, rational investigation, and treatment. A comprehensive list of references is provided for further reading.