Randomised comparison of ciprofloxacin suspension and pivmecillinam for childhood shigellosis

Azithromycin for Bacterial Watery Diarrhea: A Reanalysis of the AntiBiotics for Children With Severe Diarrhea (ABCD) Trial Incorporating Molecular Diagnostics

BACKGROUND

Bacterial pathogens cause substantial diarrhea morbidity and mortality among children living in endemic settings, yet antimicrobial treatment is only recommended for dysentery or suspected cholera.

METHODS

AntiBiotics for Children with severe Diarrhea was a 7-country, placebo-controlled, double-blind efficacy trial of azithromycin in children 2-23 months of age with watery diarrhea accompanied by dehydration or malnutrition. We tested fecal samples for enteric pathogens utilizing quantitative polymerase chain reaction to identify likely and possible bacterial etiologies and employed pathogen-specific cutoffs based on genomic target quantity in previous case-control diarrhea etiology studies to identify likely and possible bacterial etiologies.

RESULTS

Among 6692 children, the leading likely etiologies were rotavirus (21.1%), enterotoxigenic Escherichia coli encoding heat-stable toxin (13.3%), Shigella (12.6%), and Cryptosporidium (9.6%). More than one-quarter (1894 [28.3%]) had a likely and 1153 (17.3%) a possible bacterial etiology. Day 3 diarrhea was less common in those randomized to azithromycin versus placebo among children with a likely bacterial etiology (risk difference [RD]likely, -11.6 [95% confidence interval {CI}, -15.6 to -7.6]) and possible bacterial etiology (RDpossible, -8.7 [95% CI, -13.0 to -4.4]) but not in other children (RDunlikely, -0.3% [95% CI, -2.9% to 2.3%]). A similar association was observed for 90-day hospitalization or death (RDlikely, -3.1 [95% CI, -5.3 to -1.0]; RDpossible, -2.3 [95% CI, -4.5 to -.01]; RDunlikely, -0.6 [95% CI, -1.9 to .6]). The magnitude of risk differences was similar among specific likely bacterial etiologies, including Shigella.

CONCLUSIONS

Acute watery diarrhea confirmed or presumed to be of bacterial etiology may benefit from azithromycin treatment.

CLINICAL TRIALS REGISTRATION

NCT03130114.

Safety of Quinolones in Children: A Systematic Review and Meta-Analysis

BACKGROUND

The results of animal experiments show that quinolone antibacterial drugs may permanently damage the soft tissues of the weight-bearing joints of young animals. Out of safety concerns, using quinolones in children has always been controversial.

OBJECTIVE

The aim of this study was to assess the risk of using quinolones in children and provide evidence for clinicians to support decision making.

DATA SOURCES

The MEDLINE (Ovid), EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), International Pharmaceutical Abstracts (Ovid), CINAHL, CNKI, VIP, and WanFang Data databases were searched from inception to 8 September 2021.

STUDY SELECTION

All types of studies that reported the safety data of quinolones in children, including clinical trials and observational studies.

DATA EXTRACTION

Data extraction and cross-checking were completed by two independent reviewers using a pilot-tested standardized data extraction form.

RESULTS

The overall incidence rate of adverse drug events (ADEs) in children using systemic quinolones was 5.39% and the most common ADEs were gastrointestinal reactions (incidence rate, 2.02%). Quinolone-induced musculoskeletal ADEs in children were uncommon (0.76%). Meta-analysis results showed that the risk of musculoskeletal ADEs in children using quinolones was higher than children in the control group (51 studies; rate ratio [RR] 2.03, 95% confidence interval [CI] 1.82-2.26; p < 0.001; I² = 18.6%; moderate-quality evidence). However, the subgroup analysis results showed that differences might only be observed in children who were followed up for 2 months to 1 year (2-6 months: RR 2.56, 95% CI 2.26-2.89; 7 months to 1 year: RR 1.35, 95% CI 0.98-1.86). Moreover, children (adolescents) aged between 13 and 18 years might be sensitive to the musculoskeletal toxicity of quinolones (RR 2.69, 95% CI 2.37-3.05; moderate-quality evidence) and the risk of levofloxacin-induced musculoskeletal ADEs might be higher (RR 1.33, 95% CI 1.00-1.77; low-quality evidence).

CONCLUSIONS

Although the existing evidence shows that quinolone-induced musculoskeletal ADEs seem to be only short-term and reversible, and no serious skeletal and muscular system damage cases have been reported in children, quinolones should be avoided unless necessary in children because the incidence rate of quinolone-related ADEs is not low and they are broad-spectrum antibiotics that will induce the emergence of resistant strains if used frequently.

Vaginal bleeding in prepubertal females: a case of Shigella vaginitis and review of literature

Shigella vulvovaginitis is an uncommon aetiology of prepubertal vaginal bleeding that should be considered in the differential diagnosis, especially in patients who have travelled to developing countries. A young girl presented with prepubertal vaginal bleeding, pelvic pain, occasional dysuria and no gastrointestinal symptoms. After a year-long extensive workup, including vaginoscopy and biopsy, genital culture and Gram stain revealed vulvovaginitis due to Shigella flexneri After review of bacterial sensitivity, the patient was given a 30-day course of sulfamethoxazole-trimethoprim. The patient returned to the clinic 1 month later with no signs of vaginal bleeding, discharge or pelvic pain. This case prompted review of the indicated evaluation and differential diagnosis of prepubertal vaginal bleeding, including infectious aetiologies such as Shigella vulvovaginitis with the authors' goal to expedite diagnosis and treatment in paediatric patients.

Clinical Outcomes of Drug-resistant Shigellosis Treated With Azithromycin in Bangladesh

BACKGROUND

Azithromycin is frequently used to treat shigellosis; however, clinical outcomes are uncertain.

METHODS

We performed an observational cohort study in Bangladesh of patients with invasive diarrhea treated empirically with azithromycin. Susceptibility testing was performed by broth microdilution and disk diffusion post hoc on all Shigella isolates and clinical response was correlated with in vitro susceptibility.

RESULTS

There were 149 Shigella culture-positive patients in the primary analysis. Infection with Shigella with decreased susceptibility to azithromycin was significantly associated with persistence of diarrhea at day 5 (31% vs 12%; relative risk [RR], 2.66; 95% confidence interval [CI], 1.34-5.28), culture positivity at day 5 or 6 (35% vs 5%; RR, 5.26; 95% CI, 1.84-14.85), and a higher rate of overnight hospitalization (58% vs 39%; RR, 1.49; 95% CI, 1.06-2.09). Shigella flexneri was more common than Shigella sonnei (58% vs 36%); however, S. sonnei constituted most of the isolates with decreased susceptibility to azithromycin (67%) and most of the multidrug-resistant strains (54%); thus, poor clinical outcomes were associated with S. sonnei. The current epidemiological cutoff for S. flexneri of ≥16 µg/mL to define decreased susceptibility to azithromycin was clinically predictive of poor outcome. Patients with S. sonnei and a low MIC (4 µg/mL) still had elevated rates of persistent diarrhea and culture positivity.

CONCLUSIONS

This study documents worse clinical outcomes for S. flexneri with decreased susceptibility to azithromycin, as well as S. sonnei, and supports the utility of susceptibility testing and clinical breakpoints for azithromycin. S. sonnei is an emerging drug-resistant threat.

CLINICAL TRIALS REGISTRATION

NCT03778125.

Population pharmacokinetics of intravenous and oral ciprofloxacin in children to optimize dosing regimens

PURPOSE

This study aimed to characterize pharmacokinetics of intravenous and oral ciprofloxacin in children to optimize dosing scheme.

METHODS

Children treated with ciprofloxacin were included. Pharmacokinetics were described using non-linear mixed-effect modelling and validated with an external dataset. Monte Carlo simulations investigated dosing regimens to achieve a target AUC_0-24 h/MIC ratio ≥ 125.

RESULTS

A total of 189 children (492 concentrations) were included. A two-compartment model with first-order absorption and elimination best described the data. An allometric model was used to describe bodyweight (BW) influence, and effects of estimated glomerular filtration rate (eGFR) and age were significant on ciprofloxacin clearance.

CONCLUSION

The recommended IV dose of 10 mg/kg q8h, not exceeding 400 mg q8h, would achieve AUC_0-24 h to successfully treat bacteria with MICs ≤ 0.25 (e.g. Salmonella, Escherichia coli, Proteus, Haemophilus, Enterobacter, and Klebsiella). A dose increase to 600 mg q8h in children > 40 kg and to 15 mg/kg q8h (max 400 mg q8h, max 600 mg q8h if augmented renal clearance, i.e., eGFR > 200 mL/min/1.73 m²) in children < 40 kg would be needed for the strains with highest MIC (16% of Pseudomonas aeruginosa and 47% of Staphylococcus aureus). The oral recommended dose of 20 mg/kg q12h (not exceeding 750 mg) would cover bacteria with MICs ≤ 0.125 but may be insufficient for bacteria with higher MIC and a dose increase according bodyweight and eGFR would be needed. These doses should be prospectively confirmed, and a therapeutic drug monitoring could be used to refine them individually.

Multidrug-resistant organisms in urinary tract infections in children

The global spread of multidrug-resistant organisms has led to an increase in urinary tract infections (UTIs) in children that are difficult to treat. This review explores the current literature regarding multidrug-resistant UTIs in childhood and proposes an approach to management. Multidrug-resistant organisms include a wide range of potential urinary tract pathogens and, while most literature on drug resistance in UTIs during childhood has focused on extended-spectrum beta-lactamase producing organisms, in this review, we have included a discussion of multidrug resistance including and beyond beta-lactamase production. We provide definitions for multidrug-resistant organisms in line with current consensus guidelines and summarise clinically relevant mechanisms of resistance. Additionally, in this review, we outline the global epidemiology of multidrug-resistant UTIs in children, summarising published prevalence rates, which range from 5 to 90% in different settings. Finally, we also critically review the evidence on risk factors for colonisation and infection of the urinary tract with multidrug-resistant organisms, including prior antibiotic use, hospitalisation and underlying urological malformations. We also highlight multidrug-resistant UTI occurring in children without any identifiable risk factors, reflecting an increasing prevalence of colonisation with these organisms in the general community. Taken as a whole, this emphasises a need for careful and evidence-based use of antibiotics when treating UTIs in children and, to aide clinicians, we have outlined here potential management strategies for when infection with a multidrug-resistant organism is suspected or confirmed.

Assessment of the risk of musculoskeletal adverse events associated with fluoroquinolone use in children: A meta-analysis

BACKGROUND

The use of fluoroquinolone antibiotics has been restricted in children because of their potential to cause adverse musculoskeletal events. This study was performed to systematically evaluate whether there is a difference between fluoroquinolone and non-fluoroquinolone antibiotics in terms of their associated risk of adverse musculoskeletal events in children.

METHODS

Cochrane Library, Embase, and PubMed databases were used to retrieve studies related to fluoroquinolone and non-fluoroquinolone-induced musculoskeletal adverse events in children. A meta-analysis was performed using Stata 11.

RESULTS

A total of 10 studies were included in the analysis. The combined results showed that there was no statistical difference between fluoroquinolone and non-fluoroquinolone groups in terms of musculoskeletal adverse events in children (risk ratio = 1.145, 95% confidence interval = 0.974 - 1.345, P = .101). Subgroup analysis was performed using a random-effects model. Here, the effects on the trovafloxacin and levofloxacin groups were significantly different from that of the control group. However, musculoskeletal adverse events due to either drug was not reported after long-term follow-up.

CONCLUSIONS

The results showed that fluoroquinolone and non-fluoroquinolone antibiotics were not different in terms of their ability to cause musculoskeletal adverse events in children. For this reason, fluoroquinolone antibiotics can be used in children as appropriate.

PROSPERO REGISTRATION NUMBER

CRD42019133900.

A Physiologically-Based Pharmacokinetic Model to Describe Ciprofloxacin Pharmacokinetics Over the Entire Span of Life

Background

Physiologically-based pharmacokinetic (PBPK) modeling has received growing interest as a useful tool for the assessment of drug pharmacokinetics by continuous knowledge integration.

Objective

The objective of this study was to build a ciprofloxacin PBPK model for intravenous and oral dosing based on a comprehensive literature review, and evaluate the predictive performance towards pediatric and geriatric patients.

Methods

The aim of this report was to establish confidence in simulations of the ciprofloxacin PBPK model along the development process to facilitate reliable predictions outside of the tested adult age range towards the extremes of ages. Therefore, mean data of 69 published clinical trials were identified and integrated into the model building, simulation and verification process. The predictive performance on both ends of the age scale was assessed using individual data of 258 subjects observed in own clinical trials.

Results

Ciprofloxacin model verification demonstrated no concentration-related bias and accurate simulations for the adult age range, with only 4.8% of the mean observed data points for intravenous administration and 12.1% for oral administration being outside the simulated twofold range. Predictions towards the extremes of ages for the area under the plasma concentration–time curve (AUC) and the maximum plasma concentration (C_max) over the entire span of life revealed a reliable estimation, with only two pediatric AUC observations outside the 90% prediction interval.

Conclusion

Overall, this ciprofloxacin PBPK modeling approach demonstrated the predictive power of a thoroughly informed middle-out approach towards age groups of interest to potentially support the decision-making process.

Electronic supplementary material

The online version of this article (10.1007/s40262-018-0661-6) contains supplementary material, which is available to authorized users.

Identification and management of Shigella infection in children with diarrhoea: a systematic review and meta-analysis

BACKGROUND

Shigella infections are a leading cause of diarrhoeal death among children in low-income and middle-income countries. WHO guidelines reserve antibiotics for treating children with dysentery. Reliance on dysentery for identification and management of Shigella infection might miss an opportunity to reduce Shigella-associated morbidity and mortality. We aimed to systematically review and evaluate Shigella-associated and dysentery-associated mortality, the diagnostic value of dysentery for the identification of Shigella infection, and the efficacy of antibiotics for children with Shigella or dysentery, or both.

METHODS

We did three systematic reviews (for mortality, diagnostic value, and antibiotic treatment of Shigella and dysentery), and meta-analyses where appropriate, of studies in resource-limited settings. We searched MEDLINE, Embase, and LILACS database for studies published before Jan 1, 2017, in English, French, and Spanish. We included studies of human beings with diarrhoea and accepted all study-specific definitions of dysentery. For the mortality and diagnostic value searches, we excluded studies that did not include an effect estimate or data necessary to calculate this estimate. The search for treatment included only randomised controlled trials that were done after Jan 1, 1980, and assessed antibiotics in children (aged <18 years) with dysentery or laboratory-confirmed Shigella. We extracted or calculated odds ratios (ORs) and 95% CIs for relative mortality and did random-effects meta-analysis to arrive at pooled ORs. We calculated 95% CIs assuming a binomial distribution and did random-effects meta-regression of log-transformed sensitivity and specificity estimates for diagnostic value. We assessed the heterogeneity of papers included in these meta-analyses using the I2 statistic and evaluated publication bias using funnel plots. This review is registered with PROSPERO (CRD42017063896).

FINDINGS

3649 papers were identified and 60 studies were included for analyses: 13 for mortality, 27 for diagnostic value, and 20 for treatment. Shigella infection was associated with mortality (pooled OR 2·8, 95% CI 1·6-4·8; p=0·000) whereas dysentery was not associated with mortality (1·3, 0·7-2·3; p=0·37). Between 1977 and 2016, dysentery identified 1·9-85·9% of confirmed Shigella infections, with sensitivity decreasing over time (p=0·04). Ten (50%) of 20 included antibiotic trials were among children with dysentery, none were placebo-controlled, and two (10%) evaluated antibiotics no longer recommended for acute infectious diarrhoea. Ciprofloxacin showed superior microbiological, but not clinical, effectiveness compared with pivmecillinam, and no superior microbiological and clinical effectiveness compared with gatifloxacin. Substantial heterogeneity was reported for meta-analyses of the Shigella-associated mortality studies (I2=78·3%) and dysentery-associated mortality studies (I2=73·2%). Too few mortality studies were identified to meaningfully test for publication bias. No evidence of publication bias was found in this analysis of studies of diagnostic value.

INTERPRETATION

Current WHO guidelines appear to manage dysentery effectively, but might miss opportunities to reduce mortality among children infected with Shigella who present without bloody stool. Further studies should quantify potential decreases in mortality and morbidity associated with antibiotic therapy for children with non-dysenteric Shigella infection.

FUNDING

Bill & Melinda Gates Foundation and the Center for AIDS Research International Core.

Vaccinomics Approach for Designing Potential Peptide Vaccine by Targeting Shigella spp. Serine Protease Autotransporter Subfamily Protein SigA

Shigellosis, a bacillary dysentery, is closely associated with diarrhoea in human and causes infection of 165 million people worldwide per year. Casein-degrading serine protease autotransporter of enterobacteriaceae (SPATE) subfamily protein SigA, an outer membrane protein, exerts both cytopathic and enterotoxic effects especially cytopathic to human epithelial cell type-2 (HEp-2) and is shown to be highly immunogenic. In the present study, we have tried to impose the vaccinomics approach for designing a common peptide vaccine candidate against the immunogenic SigA of Shigella spp. At first, 44 SigA proteins from different variants of S. flexneri, S. dysenteriae, S. boydii, and S. sonnei were assessed to find the most antigenic protein. We retrieved 12 peptides based on the highest score for human leukocyte antigen (HLA) supertypes analysed by NetCTL. Initially, these peptides were assessed for the affinity with MHC class I and class II alleles, and four potential core epitopes VTARAGLGY, FHTVTVNTL, HTTWTLTGY, and IELAGTLTL were selected. From these, FHTVTVNTL and IELAGTLTL peptides were shown to have 100% conservancy. Finally, IELAGTLTL was shown to have the highest population coverage (83.86%) among the whole world population. In vivo study of the proposed epitope might contribute to the development of functional and unique widespread vaccine, which might be an operative alleyway to thwart dysentery from the world.

Safety Concerns Surrounding Quinolone Use in Children

Fluoroquinolones are highly effective antibiotics with many desirable pharmacokinetic and pharmacodynamic properties including high bioavailability, large volume of distribution, and a broad spectrum of antimicrobial activity. Despite their attractive profile as anti-infective agents, their use in children is limited, primarily due to safety concerns. In this review we highlight the pharmacological properties of fluoroquinolones and describe their current use in pediatrics. In addition, we provide a comprehensive assessment of the safety data associated with fluoroquinolone use in children. Although permanent or destructive arthropathy remains a significant concern, currently available data demonstrate that arthralgia and arthropathy are relatively uncommon in children and resolve following cessation of fluoroquinolone exposure without resulting in long-term sequelae. The concern for safety and risk of adverse events associated with pediatric fluoroquinolone use is likely driving the limited prescribing of this drug class in pediatrics. However, in adults, fluoroquinolones are the most commonly prescribed broad-spectrum antibiotics, resulting in the development of drug-resistant bacteria that can be challenging to treat effectively. The consequence of misuse and overuse of fluoroquinolones leading to drug resistance is a greater, but frequently overlooked, safety concern that applies to both children and adults and one that should be considered at the point of prescribing.

Fluoroquinolone resistance mechanisms of Shigella flexneri isolated in Bangladesh

OBJECTIVE

To investigate the prevalence and mechanisms of fluoroquinolone resistance in Shigella species isolated in Bangladesh and to compare with similar strains isolated in China.

METHODS

A total of 3789 Shigella isolates collected from Clinical Microbiology Laboratory of icddr,b, during 2004-2010 were analyzed for antibiotic susceptibility. Analysis of plasmids, plasmid-mediated quinolone-resistance genes, PFGE, and sequencing of genes of the quinolone-resistance-determining regions (QRDR) were conducted in representative strains isolated in Bangladesh and compared with strains isolated in Zhengding, China. In addition, the role of efflux-pump was studied by using the efflux-pump inhibitor carbonyl cyanide-m-chlorophenylhydrazone (CCCP).

RESULTS

Resistance to ciprofloxacin in Shigella species increased from 0% in 2004 to 44% in 2010 and S. flexneri was the predominant species. Of Shigella spp, ciprofloxacin resistant (CipR) strains were mostly found among S. flexneri (8.3%), followed by S. sonnei (1.5%). Within S. flexneri (n = 2181), 14.5% were resistance to ciprofloxacin of which serotype 2a was predominant (96%). MIC of ciprofloxacin, norfloxacin, and ofloxacin were 6-32 mg/L, 8-32 mg/L, and 8-24 mg/L, respectively in S. flexneri 2a isolates. Sequencing of QRDR genes of resistant isolates showed double mutations in gyrA gene (Ser83Leu, Asp87Asn/Gly) and single mutation in parC gene (Ser80Ile). A difference in amino acid substitution at position 87 was found between strains isolated in Bangladesh (Asp87Asn) and China (Asp87Gly) except for one. A novel mutation at position 211 (His→Tyr) in gyrA gene was detected only in the Bangladeshi strains. Susceptibility to ciprofloxacin was increased by the presence of CCCP indicating the involvement of energy dependent active efflux pumps. A single PFGE type was found in isolates from Bangladesh and China suggesting their genetic relatedness.

CONCLUSIONS

Emergence of fluoroquinolone resistance in Shigella undermines a major challenge in current treatment strategies which needs to be followed up by using empirical therapeutic strategies.

Antibiotics for the treatment of Cholera, Shigella and Cryptosporidium in children

Background

Diarrhea is a major contributor to the burden of morbidity and mortality in children; it accounts for a median of 11% of all deaths among children aged less than 5 years, amounting to approximately 0.8 million deaths per year. Currently there is a dearth of literature exploring the effectiveness of antibiotics for diarrhea due to Cholera, Shigella and cryptosporidiosis in children.

Methods

We reviewed the literature reporting the effect of antibiotics for the treatment of diarrhea due to Cholera, Shigella and Cryptosporidium in children under five years. We used a standardized abstraction and grading format and performed meta-analyses to determine the effect of the treatment with various antibiotics on mortality and rates of clinical and bacteriological/parasitological failure. The CHERG Standard Rules were applied to determine the final effect of treatment with antibiotics on diarrhea morbidity and mortality.

Results

For Cholera; the evidence was weak to recommend any effect on mortality. For Shigella; there was no data on mortality; either all-cause or cause specific, hence we used clinical failure rates as a proxy for Shigella deaths and propose that treatment of Shigella dysentery with antibiotics can result in a 82% reduction in diarrhea mortality due to Shigella. For cryptosporidiosis; there was data on all-cause mortality but the evidence was weak hence we used clinical failure rates as a proxy for mortality to estimate that antimicrobial treatment of diarrhea due to cryptosporidiosis can result in a 54% reduction in mortality.

Conclusions

There is evidence to recommend antibiotic use for reduction of morbidity and mortality due to Cholera, Shigella and Cryptosporidium. We recommend that more clinical trials should be conducted to evaluate the efficacy and safety of first- and second- line drugs currently in use for treatment for diarrhea and dysentery in both developing and developed countries.

Genetic characterization of antimicrobial resistance of Shigella flexneri 1c isolates from patients in Egypt and Pakistan

Background

Shigella flexneri serotype 1c emerged as a critical isolate from children in Egypt and Pakistan. The pattern of antimicrobial susceptibility (AMS) and resistance genes of this serotype have yet to be characterized.

Findings

Sixty nine S. flexneri 1c isolates isolates were identified from both Egypt (n-46) and Pakistan (n = 23) and tested for AMS by disk diffusion method and minimal inhibitory concentrations were also determined. Isolates were genotyped by pulsed field gel electrophoresis (PFGE) and five relevant resistance genes (bla_TEM, bla_SHV, bla_OXA, sulI and sulII) were detected by polymerase chain reaction (PCR) and confirmed by DNA sequencing. High resistance was observed in all isolates for ampicillin (AM >96%); trimethoprim-sulphamethoxazole and tetracycline (>88%). Most AM-resistant isolates from Egypt (70%) harbored bla_TEM resistance, while 52% of isolates from Pakistan expressed bla_OXA. All isolates were closely related by PFGE, irrespective of source or time of collection. The sulII gene was present in 100% of isolates from pediatric cases in Egypt, 65% of Pakistan isolates, and 53% of isolates from older Egyptian patients.

Conclusions

While different Shigella serotypes gathered in specific genotypic groups, 1c serotype isolates formed multiple clusters. Although AMS was considerably high to most commonly used drugs, genetic determinants were variable between countries over time. The data stress the need for a more careful selection of antibiotics in the treatment of shigellosis.

Interventions to address deaths from childhood pneumonia and diarrhoea equitably: what works and at what cost?

Global mortality in children younger than 5 years has fallen substantially in the past two decades from more than 12 million in 1990, to 6·9 million in 2011, but progress is inconsistent between countries. Pneumonia and diarrhoea are the two leading causes of death in this age group and have overlapping risk factors. Several interventions can effectively address these problems, but are not available to those in need. We systematically reviewed evidence showing the effectiveness of various potential preventive and therapeutic interventions against childhood diarrhoea and pneumonia, and relevant delivery strategies. We used the Lives Saved Tool model to assess the effect on mortality when these interventions are applied. We estimate that if implemented at present annual rates of increase in each of the 75 Countdown countries, these interventions and packages of care could save 54% of diarrhoea and 51% of pneumonia deaths by 2025 at a cost of US$3·8 billion. However, if coverage of these key evidence-based interventions were scaled up to at least 80%, and that for immunisations to at least 90%, 95% of diarrhoea and 67% of pneumonia deaths in children younger than 5 years could be eliminated by 2025 at a cost of $6·715 billion. New delivery platforms could promote equitable access and community platforms are important catalysts in this respect. Furthermore, several of these interventions could reduce morbidity and overall burden of disease, with possible benefits for developmental outcomes.

Options for treating resistant Shigella species infections in children

Infection due to Shigella species remains an important public health problem, especially in developing countries where it remains the most common cause of bloody diarrhea. In the United States (US), 10,000 to 15,000 cases of shigellosis are reported each year in both children and adults. US surveillance data from 2004 has demonstrated increased resistance in Shigella species to first-line antibiotics such as ampicillin and trimethoprim-sulfamethoxazole, with approximately 37% of isolates demonstrating resistance to both ampicillin and trimethoprim-sulfamethoxazole. Since approximately 69% of Shigella infections occur in children younger than 5 years of age, it is important that alternative antibiotics other than typical first-line agents such as ampicillin and trimethoprim-sulfamethoxazole be available to treat Shigella infections in this population. The American Academy of Pediatrics (AAP) recommends cefixime, ceftriaxone, azithromycin, and fluoroquinolones as alternative antibiotics for the treatment of Shigella species infections in children. This paper will review the microbiology, susceptibility, efficacy and safety data of these alternative antibiotics with regard to the treatment of Shigella species infections in children, and will attempt to define the role of each of these agents in the pediatric population.

A multi-center randomized trial to assess the efficacy of gatifloxacin versus ciprofloxacin for the treatment of shigellosis in Vietnamese children

BACKGROUND

The bacterial genus Shigella is the leading cause of dysentery. There have been significant increases in the proportion of Shigella isolated that demonstrate resistance to nalidixic acid. While nalidixic acid is no longer considered as a therapeutic agent for shigellosis, the fluoroquinolone ciprofloxacin is the current recommendation of the World Health Organization. Resistance to nalidixic acid is a marker of reduced susceptibility to older generation fluoroquinolones, such as ciprofloxacin. We aimed to assess the efficacy of gatifloxacin versus ciprofloxacin in the treatment of uncomplicated shigellosis in children.

METHODOLOGY/PRINCIPAL FINDINGS

We conducted a randomized, open-label, controlled trial with two parallel arms at two hospitals in southern Vietnam. The study was designed as a superiority trial and children with dysentery meeting the inclusion criteria were invited to participate. Participants received either gatifloxacin (10 mg/kg/day) in a single daily dose for 3 days or ciprofloxacin (30 mg/kg/day) in two divided doses for 3 days. The primary outcome measure was treatment failure; secondary outcome measures were time to the cessation of individual symptoms. Four hundred and ninety four patients were randomized to receive either gatifloxacin (n=249) or ciprofloxacin (n=245), of which 107 had a positive Shigella stool culture. We could not demonstrate superiority of gatifloxacin and observed similar clinical failure rate in both groups (gatifloxacin; 12.0% and ciprofloxacin; 11.0%, p=0.72). The median (inter-quartile range) time from illness onset to cessation of all symptoms was 95 (66-126) hours for gatifloxacin recipients and 93 (68-120) hours for the ciprofloxacin recipients (Hazard Ratio [95%CI]=0.98 [0.82-1.17], p=0.83).

CONCLUSIONS

We conclude that in Vietnam, where nalidixic acid resistant Shigellae are highly prevalent, ciprofloxacin and gatifloxacin are similarly effective for the treatment of acute shigellosis.

Ciprofloxacin safety in paediatrics: a systematic review

OBJECTIVE

To determine the safety of ciprofloxacin in paediatric patients in relation to arthropathy, any other adverse events (AEs) and drug interactions.

METHODS

A systematic search of MEDLINE, EMBASE, CINAHL, CENTRAL and bibliographies of relevant articles was carried out for all published articles, regardless of design, that involved the use of ciprofloxacin in any paediatric age group ≤ 17 years. Only articles that reported on safety were included.

RESULTS

105 articles met the inclusion criteria and involved 16 184 paediatric patients. There were 1065 reported AEs (risk 7%, 95% CI 3.2% to 14.0%). The most frequent AEs were musculoskeletal AEs, abnormal liver function tests, nausea, changes in white blood cell counts and vomiting. There were six drug interactions (with aminophylline (4) and methotrexate (2)). The only drug related death occurred in a neonate who had an anaphylactic reaction. 258 musculoskeletal events occurred in 232 paediatric patients (risk 1.6%, 95% CI 0.9% to 2.6%). Arthralgia accounted for 50% of these. The age of occurrence of arthropathy ranged from 7 months to 17 years (median 10 years). All cases of arthropathy resolved or improved with management. One prospective controlled study estimated the risk of arthropathy as 9.3 (OR 95% CI 1.2 to 195). Pooled safety data of controlled trials in this review estimated the risk of arthropathy as 1.57 (OR 95% CI 1.26 to 1.97).

CONCLUSION

Musculoskeletal AEs occur due to ciprofloxacin use. However, these musculoskeletal events are reversible with management. It is recommended that further prospective controlled studies should be carried out to evaluate the safety of ciprofloxacin, with particular focus on the risk of arthropathy.

Antibiotic therapy for Shigella dysentery

BACKGROUND

Shigella dysentery is a relatively common illness and occasionally causes death, worldwide. Mild symptoms are self-limiting but in more severe cases, antibiotics are recommended for cure and preventing relapse. The antibiotics recommended are diverse, have regional differences in sensitivity, and have side effects.

OBJECTIVES

To evaluate the efficacy and safety of antibiotics for treating Shigella dysentery.

SEARCH STRATEGY

In June 2009 we identified all relevant trials from the following databases: Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 4), MEDLINE, EMBASE, LILACS and the metaRegister of Controlled Trials (mRCT). We also checked conference proceedings for relevant abstracts, and contacted researchers, organizations, and pharmaceutical companies.

SELECTION CRITERIA

Randomized controlled trials of antibiotics for Shigella dysentery.

DATA COLLECTION AND ANALYSIS

Four authors, working in pairs, independently assessed trial eligibility, methodological quality, and extracted data. We calculated risk ratios (RR) with 95% confidence intervals (CI) for dichotomous data, and used the random-effects model for significant heterogeneity. We explored possible sources of heterogeneity, when present, in subgroup analyses of participant age and percentage of participants with confirmed Shigella infection.

MAIN RESULTS

Sixteen trials (1748 participants), spanning four decades and with differing sensitivity to Shigella isolates, met the inclusion criteria. Seven were judged to be at risk of bias due to inadequate allocation concealment or blinding, and 12 due to incomplete reporting of outcome data. Limited data from one three-armed trial of people with moderately severe illness suggest that antibiotics reduce the episodes of diarrhoea at follow-up (furazolidone versus no drug RR 0.21, 95% CI 0.09 to 0.48, 73 participants; cotrimoxazole versus no drug RR 0.30, 95% CI 0.15 to 0.59, 76 participants).There was insufficient evidence to consider any class of antibiotic superior in efficacy in treating Shigella dysentery, but heterogeneity for some comparisons limits confidence in the results. All the antibiotics studied were safe. There was inadequate evidence regarding the role of antibiotics in preventing relapses.

AUTHORS' CONCLUSIONS

Antibiotics reduce the duration of Shigella dysentery.Regularly updated local or regional antibiotic sensitivity patterns to different species and strains of Shigella are required to guide empiric therapy. More trials adhering to standard guidelines are required to evaluate the role of antibiotics in the treatment of severe forms of Shigella dysentery and in groups who are at high risk of complications.

Antibiotics for the treatment of dysentery in children

BACKGROUND

Ciprofloxacin, ceftriaxone and pivmecillinam are the antibiotics currently recommended by the World Health Organization (WHO) for the treatment of dysentery in children; yet there have been no reviews of the clinical effectiveness of these antibiotics in recent years.

METHODS

We reviewed all literature reporting the effect of ciprofloxacin, ceftriaxone and pivmecillinam for the treatment of dysentery in children in the developing countries. We used a standardized abstraction and grading format and performed meta-analyses to determine the effect of treatment with these antibiotics on rates of treatment failure, bacteriological failure and bacteriological relapse. The CHERG Standard Rules were applied to determine the final effect of treatment with these antibiotics on diarrhoea mortality.

RESULTS

Eight papers were selected for abstraction. Treatment with ciprofloxacin, ceftriaxone or pivmecillinam resulted in a cure rate of >99% while assessing clinical failure, bacteriological failure and bacteriological relapse.

CONCLUSIONS

The antibiotics recommended by the WHO--ciprofloxacin, ceftriaxone and pivmecillinam--are effective in reducing the clinical and bacteriological signs and symptoms of dysentery and thus can be expected to decrease diarrhoea mortality attributable to dysentery.

Antibiotic therapy for Shigella dysentery

BACKGROUND

Shigella dysentery is a relatively common illness and occasionally causes death, worldwide. Mild symptoms are self-limiting but in more severe cases, antibiotics are recommended for cure and preventing relapse. The antibiotics recommended are diverse, have regional differences in sensitivity, and have side effects.

OBJECTIVES

To evaluate the efficacy and safety of antibiotics for treating Shigella dysentery.

SEARCH STRATEGY

In June 2009 we identified all relevant trials from the following databases: Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 4), MEDLINE, EMBASE, LILACS and the metaRegister of Controlled Trials (mRCT). We also checked conference proceedings for relevant abstracts, and contacted researchers, organizations, and pharmaceutical companies.

SELECTION CRITERIA

Randomized controlled trials of antibiotics for Shigella dysentery.

DATA COLLECTION AND ANALYSIS

Four authors, working in pairs, independently assessed trial eligibility, methodological quality, and extracted data. We calculated risk ratios (RR) with 95% confidence intervals (CI) for dichotomous data, and used the random-effects model for significant heterogeneity. We explored possible sources of heterogeneity, when present, in subgroup analyses of participant age and percentage of participants with confirmed Shigella infection.

MAIN RESULTS

Sixteen trials (1748 participants), spanning four decades and with differing sensitivity to Shigella isolates, met the inclusion criteria. Seven were judged to be at risk of bias due to inadequate allocation concealment or blinding, and 12 due to incomplete reporting of outcome data. Limited data from one three-armed trial of people with moderately severe illness suggest that antibiotics reduce the episodes of diarrhoea at follow-up (furazolidone versus no drug RR 0.21, 95% CI 0.09 to 0.48, 73 participants; cotrimoxazole versus no drug RR 0.30, 95% CI 0.15 to 0.59, 76 participants).There was insufficient evidence to consider any class of antibiotic superior in efficacy in treating Shigella dysentery, but heterogeneity for some comparisons limits confidence in the results. All the antibiotics studied were safe. There was inadequate evidence regarding the role of antibiotics in preventing relapses.

AUTHORS' CONCLUSIONS

Antibiotics reduce the duration of Shigella dysentery.Regularly updated local or regional antibiotic sensitivity patterns to different species and strains of Shigella are required to guide empiric therapy. More trials adhering to standard guidelines are required to evaluate the role of antibiotics in the treatment of severe forms of Shigella dysentery and in groups who are at high risk of complications.

Antibiotic therapy for Shigella dysentery

BACKGROUND

Shigella dysentery is a relatively common illness and occasionally causes death, worldwide. Mild symptoms are self-limiting but in more severe cases, antibiotics are recommended for cure and preventing relapse. The antibiotics recommended are diverse, have regional differences in sensitivity, and have side effects.

OBJECTIVES

To evaluate the efficacy and safety of antibiotics for treating Shigella dysentery.

SEARCH STRATEGY

In June 2009 we identified all relevant trials from the following databases: Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 4), MEDLINE, EMBASE, LILACS and the metaRegister of Controlled Trials (mRCT). We also checked conference proceedings for relevant abstracts, and contacted researchers, organizations, and pharmaceutical companies.

SELECTION CRITERIA

Randomized controlled trials of antibiotics for Shigella dysentery.

DATA COLLECTION AND ANALYSIS

Four authors, working in pairs, independently assessed trial eligibility, methodological quality, and extracted data. We calculated risk ratios (RR) with 95% confidence intervals (CI) for dichotomous data, and used the random-effects model for significant heterogeneity. We explored possible sources of heterogeneity, when present, in subgroup analyses of participant age and percentage of participants with confirmed Shigella infection.

MAIN RESULTS

Sixteen trials (1748 participants), spanning four decades and with differing sensitivity to Shigella isolates, met the inclusion criteria. Seven were judged to be at risk of bias due to inadequate allocation concealment or blinding, and 12 due to incomplete reporting of outcome data. Limited data from one three-armed trial of people with moderately severe illness suggest that antibiotics reduce the episodes of diarrhoea at follow-up (furazolidone versus no drug RR 0.21, 95% CI 0.09 to 0.48, 73 participants; cotrimoxazole versus no drug RR 0.30, 95% CI 0.15 to 0.59, 76 participants).There was insufficient evidence to consider any class of antibiotic superior in efficacy in treating Shigella dysentery, but heterogeneity for some comparisons limits confidence in the results. All the antibiotics studied were safe. There was inadequate evidence regarding the role of antibiotics in preventing relapses.

AUTHORS' CONCLUSIONS

Antibiotics reduce the duration of Shigella dysentery.Regularly updated local or regional antibiotic sensitivity patterns to different species and strains of Shigella are required to guide empiric therapy. More trials adhering to standard guidelines are required to evaluate the role of antibiotics in the treatment of severe forms of Shigella dysentery and in groups who are at high risk of complications.

The effect of fluoroquinolone antibiotics on growing cartilage in the lamb model

BACKGROUND

The fluoroquinolones are a relatively new class of antimicrobials with an appealing spectrum of activity. Their use in pediatric medicine is limited because of the concern over possible growth inhibition, as published reports have documented articular cartilage damage in animal models after their administration. These data, extrapolated to include the epiphyseal cartilage, suggest that these agents may reduce growth rates, but limited human data are at the least equivocal, if not strictly contradictory to such claims. Specific investigations into the effects of fluoroquinolones on epiphyseal plate cartilage and growth velocity have not been performed.

METHODS

Gatifloxacin and ciprofloxacin were used as representative agents of the fluoroquinolone class. Each drug was administered to experimental lambs over a 14-day interval at a dose designed to reflect those used in pediatric medicine. Recumbent versus standing intervals were used to monitor for arthropathy. Upon completion of fluoroquinolone administration, lambs underwent double fluorochrome labeling for determination of growth velocity. Gross and microscopic analysis of articular cartilage was performed to assess for pathologic changes. Age- and sex-matched lambs served as controls.

RESULTS

Neither gatifloxacin nor ciprofloxacin negatively affected growth velocity of the proximal tibial growth plate as measured by double fluorochrome labeling. In addition, no difference between experimental and control lambs in regard to recumbent versus standing intervals was noted. Examination of the articular cartilage failed to suggest chondrotoxicity.

CONCLUSION

Fluoroquinolone antimicrobials do not affect growth velocity in the ovine model when administered along a dosing regimen that closely models that seen in pediatric medicine.

CLINICAL RELEVANCE

Fluoroquinolones may be acceptable for use in the pediatric population, as concerns over chondrotoxicity and growth inhibition may not be valid. These data suggest that expanded studies in lambs and other species, including humans, with differences in dosing and duration are justified to ultimately demonstrate clinical safety.

Molecular characterization of multidrug-resistant Shigella species isolated from epidemic and endemic cases of shigellosis in India

Shigella species represent one of the growing numbers of antimicrobial-resistant bacteria in developing countries. Fluoroquinolone-resistant strains of Shigella dysenteriae type 1 and Shigella flexneri type 2a emerged in India during 2002 and 2003, respectively. Sixty strains of Shigella from different parts of India were analysed for antimicrobial susceptibility, the presence of the qnr plasmid, mutations in the quinolone resistance determining regions (QRDRs), fluoroquinolone accumulation, and the presence of other genes encoding resistance to various antimicrobials. Fluoroquinolone-resistant strains had mutations in gyrA and parC genes and had an active efflux system. They were also resistant to several other antimicrobials but were susceptible to azithromycin and ceftriaxone. The majority of the strains harboured genes encoding resistance to ampicillin (97 %), tetracycline (95 %), streptomycin (95 %) and chloramphenicol (94 %). PFGE analysis revealed clonality among strains of S. dysenteriae types 1 and 5, S. flexneri type 2a and Shigella boydii type 12.

[Shigellosis or bacillary dysentery]

Shigellosis, commonly known as bacillary dysentery, is an enterobacterial disease caused by the Shigella genus, which now belongs to the Escherichia tribe, because of their genetic and phenotypic similarities. S. sonnei, flexneri, boydii and dysenteriae differ in their epidemiologic and pathogenic characteristics. S. sonnei is predominant in industrialized countries and causes the mildest disease. S. dysentery is especially dangerous because it occurs in outbreaks, sometimes in catastrophic situations, and has a high mortality rate. Shigellosis typically causes watery diarrhea followed by dysentery. It may be associated with a variety of mild to severe or even life-threatening complications. Shigellosis is a significant public health problem in developing countries where it remains a major cause of diarrhea-related morbidity and mortality, especially among children. Annual cases worldwide are estimated at 160 million. Shigellosis is a highly contagious disease of poor and crowded communities, with fecal-oral (hand-to-mouth) transmission, and an extremely low minimum infectious dose. Multidrug resistance is a serious problem. Ciprofloxacin is the first-line antibiotic, recommended for 3 days. Prevention and control should include personal hygiene, hand washing, sanitation, and water supply. No vaccine is available, but several candidates are currently being evaluated.

Bacterial gut infections

Infections of the bowel as a result of bacterial enteropathogens are one of the most common medical problems. The use of novel molecular biology techniques and the recent development of new antimicrobial drugs and vaccines are helping us to identify, understand, treat and prevent these infections.

High prevalence of antimicrobial resistance among Shigella isolates in the United States tested by the National Antimicrobial Resistance Monitoring System from 1999 to 2002

Shigella spp. infect approximately 450,000 persons annually in the United States, resulting in over 6,000 hospitalizations. Since 1999, the National Antimicrobial Resistance Monitoring System (NARMS) for Enteric Bacteria has tested every 10th Shigella isolate from 16 state or local public health laboratories for susceptibility to 15 antimicrobial agents. From 1999 to 2002, NARMS tested 1,604 isolates. Among 1,598 isolates identified to species level, 1,278 (80%) were Shigella sonnei, 295 (18%) were Shigella flexneri, 18 (1%) were Shigella boydii, and 7 (0.4%) were Shigella dysenteriae. Overall, 1,251 (78%) were resistant to ampicillin and 744 (46%) were resistant to trimethoprim-sulfamethoxazole (TMP-SMX). Prevalence of TMP-SMX- or ampicillin- and TMP-SMX-resistant Shigella sonnei isolates varied by geographic region, with lower rates in the South and Midwest regions (TMP-SMX resistance, 27% and 30%, respectively; ampicillin and TMP-SMX resistance, 25% and 22%, respectively) and higher rates in the East and West regions (TMP-SMX resistance, 66% and 80%, respectively; ampicillin and TMP-SMX resistance, 54% and 65%, respectively). Nineteen isolates (1%) were resistant to nalidixic acid (1% of S. sonnei and 2% of S. flexneri isolates); 12 (63%) of these isolates had decreased susceptibility to ciprofloxacin. One S. flexneri isolate was resistant to ciprofloxacin. All isolates were susceptible to ceftriaxone. Since 1986, resistance to ampicillin and TMP-SMX has dramatically increased. Shigella isolates in the United States remain susceptible to ciprofloxacin and ceftriaxone.

Low Risk of Hemolytic Uremic Syndrome after Early Effective Antimicrobial Therapy for Shigella dysenteriae Type 1 Infection in Bangladesh

BACKGROUND

Hemolytic uremic syndrome (HUS) may complicate up to 15% of cases of Shiga toxin (Stx)-expressing enterohemorrhagic Escherichia coli (STEC) O157:H7 infections in children. Administration of antimicrobials has been reported to increase the risk of STEC-associated HUS by >10-fold, presumably by increasing the expression and release of Stx by dying STEC bacteria. Shigella dysenteriae type 1 also expresses Stx. However, the effect of antimicrobial therapy on Stx release and the risk of HUS in humans is unknown.

METHODS

We measured serial stool Stx concentrations before and after administration of antimicrobials in 20 children infected with S. dysenteriae type 1 who had frank dysentery of <72 h duration. We also reviewed the results of 7 shigellosis drug trials performed in Bangladesh during 1988-2000 to estimate the risk of HUS. In these studies, antimicrobials were administered within 96 h after the onset of dysentery.

RESULTS

Stx levels decreased in stool samples obtained from 17 of 20 children after administration of antimicrobial agents; none of the 20 children developed HUS. Of 378 individuals infected with S. dysenteriae type 1 who were enrolled in drug trials (128 adult men [age, 18-60 years] and 250 children [age, 6 months to 15 years]), 351 (93%) received an antimicrobial agent to which the S. dysenteriae organism was susceptible <or=96 h after the onset of symptoms; HUS developed in 1 child. The risk of developing HUS was 0.0026 for all participants (95% confidence interval, <0.001 to 0.015) and was 0.004 for children (95% confidence interval, 0.001-0.022).

CONCLUSION

In persons infected with S. dysenteriae type 1, early administration of effective antibiotics is associated with decreased Stx concentrations in stool and a low risk of developing HUS.

Fluoroquinolone Antibiotics in Infants and Children

The use of fluoroquinolones in children is limited because of the potential of these agents to induce arthropathy in juvenile animals and to potentiate development of bacterial resistance. No quinolone-induced cartilage toxicity as described in animal experiments has been documented unequivocally in patients, but the risk fro rapid emergence of bacterial resistance associated with widespread, uncontrolled fluoroquinolones use in children is a realistic threat. Overall, the fluoroquinolones have been safe and effective in the treatment of selected bacterial infections in pediatric patients. There are clearly defined indications for these compounds in children who are ill.

Systemic quinolone antibiotics in children: a review of the use and safety

Historically, healthcare providers have reluctantly used systemic quinolone antibiotics to treat infections in children when they have been used at all. Concerns regarding the oral or parenteral use of quinolones in children rose from research observations demonstrating cartilage and joint toxicity in juvenile animal models following the administration of this class of antibiotics to immature animals. A voluntary moratorium on the use of quinolone and fluoroquinolone antibiotics in children resulted in restricting their use to treat in infections in specific settings such as immunocompromised states due to chemotherapy, pseudomonas infections in cystic fibrosis patients, complicated urinary tract infections, and quinolone sensitive infectious disease where parenteral antibiotic administration is not available and quinolones were the only effective therapy. This article aims to review retrospective and prospective safety and efficacy data to provide a comprehensive summary of the systemic use of this class of antibiotics in children.

Mixed diarrhoeal infection caused by Vibrio cholerae and several other enteric pathogens in a 4-year-old child returning to Germany from Pakistan

We report a mixed enteric infection in a 4-y-old child who returned from Pakistan with fever, vomiting and profuse diarrhoea leading to severe dehydration. Vibrio cholerae O1, Salmonella paratyphi A and Campylobacter coli were cultured from stool. Furthermore, Giardia lamblia antigen and hepatitis A RNA were detected. This is the first paediatric cholera case seen in Frankfurt/Main.

Shigella infections in children: new insights

Shigellosis , the acute enteric infection caused by bacteria of the genus Shigella , has a worldwide distribution with an estimated annual incidence of 164.7 million cases, of which 163.2 million occur in developing countries, and 1.1 million deaths. Sixty-nine percent of all episodes and 61 percent of all Shigella -related deaths involve children younger than 5 years old. In the United States, 10,000 to 15,000 cases of shigellosis are reported each year. Although usually confined to the colonic mucosa, shigellosis sometimes can cause extraintestinal complications. Recent publications have shed light on the clinical characteristics of Shigella -induced bacteremia, surgical complications, urogenital symptoms, and neurologic manifestations, and on the unique manifestations in the neonatal period. The mainstay of treatment of shigellosis in children is correction of the fluid and electrolyte loss, which often is achieved by the administration of oral rehydration solutions. Appropriate antibiotic therapy shortens the duration of both clinical symptoms and fecal excretion of the pathogen. However, the increasing antimicrobial resistance of shigellae worldwide constitutes a major problem. Regarding the pathophysiology of shigellosis and its complications, recent data not only elucidated the molecular mechanisms involved but also linked manifestations of disease to the interplay of bacterial virulence factors and host responses. The improved understanding of the pathophysiology is hoped to lead to innovative therapeutic approaches against shigellosis and new generations of vaccine candidates.

Case management of a multidrug-resistant Shigella dysenteriae serotype 1 outbreak in a crisis context in Sierra Leone, 1999-2000

From December 1999 to the end of February 2000, 4218 cases of dysentery were reported in Kenema district, southeastern Sierra Leone, by a Médecins Sans Frontières team operating in this region. Shigella dysenteriae serotype 1 was isolated from the early cases. The overall attack rate was 7.5% but higher among children under 5 years (11.2%) compared to the rest of the population (6.8%) (RR = 1.6; 95% CI 1.5-1.8). The case fatality ratio was 3.1%, and higher for children under 5 years (6.1% vs. 2.1%) (RR = 2.9; 95% CI 2.1-4.1). A case management strategy based on stratification of affected cases was chosen in this resource-poor setting. Patients considered at higher risk of death were treated with a 5 day ciprofloxacin regimen in isolation centres. Five hundred and eighty-three cases were treated with a case fatality ratio of 0.9%. Patients who did not have signs of severity when seen by health workers were given hygiene advice and oral rehydration salts. This strategy was effective in this complex emergency.

Antimicrobial susceptibility trends among Escherichia coli and Shigella spp. isolated from rural Egyptian paediatric populations with diarrhoea between 1995 and 2000

Antimicrobial susceptibility testing was performed on 3,627 isolates of Escherichia coli and 180 isolates of Shigella spp. collected in rural locations from 875 Egyptian children with diarrhoea between 1995 and 2000. The cumulative rates of resistance for E. coli and Shigella spp. were high (respectively, 68.2% and 54.8% for ampicillin, 24.2% and 23.5% for ampicillin-sulbactam, 57.2% and 42.5% for trimethoprim-sulphamethoxazole, and 50.9% and 75.4% for tetracycline). Non-enterotoxigenic E. coli (NETEC) isolates had a consistently higher level of antimicrobial resistance than did enterotoxigenic E. coli (ETEC) isolates. Trend testing showed significant decreases in resistance to ampicillin, ampicillin-sulbactam and tetracycline among all E. coli isolates. Increasing rates of resistance were observed for trimethoprim-sulphamethoxazole in ETEC isolates and Shigella spp., but not in NETEC isolates. Low levels of resistance were observed for all other antimicrobial agents tested. Overall, high levels, but decreasing trends, of resistance to commonly used antimicrobial agents were detected among isolates of E. coli and Shigella spp. from children in rural Egypt.

Traitement antibiotique des gastro-entérites à Shigella sonnei

THE INTEREST OF ANTIBIOTIC TREATMENT OF SHIGELLA INFECTIONS: to reduce the carriage and contamination, duration of the symptoms and the risk of complications.

THE EVOLUTION OF THE TREATMENT

Over the past years, strains of Shigella sonnei have become resistant to aminopenicillin and cotrimoxazole (treatment recommended till now) and now predominate. INTER-HUMAN TRANSMISSION: The Shigella reservoir is human. The bacteria are easily transmitted in fecal-oral mode. The populations most at risk are those in situations of great promiscuity.

REGARDING DIAGNOSIS

Shigella sonnei infections are commonly characterised by intermediate diarrhoea and fever, following a short period of incubation. Only culture of the faeces permits the diagnosis.

THE DECISION TO TREAT

Confronted with an isolated case, treatment can only be initiated after bacteriological diagnosis. Confronted with symptomatic cases with at least one confirmed bacteriologically, treatment can be initiated without waiting for the results of the faecal culture.

IN CHILDREN

Azithromycine has become the treatment of choice. Ceftriaxone, administered via the parenteral route, can hardly be considered as the first-line treatment. Quinolones can only be considered in last intention; only ciprofloxacine can be recommended.

IN ADULTS

Ciprofloxacine and ofloxacine can be recommended first-line over a period of 3 days.

GUIDELINES

A summary, including good faecal culture practices, can be found on the Website of the French Agency for the saitary of health products (Afssaps) (www.afssaps.sante.fr).

Safety profile of quinolone antibiotics in the pediatric population

Fluoroquinolone-induced joint/cartilage toxicity has been observed in juvenile animal studies and is species- and dose-specific with canines exhibiting the highest rate of arthralgias. These early observations led to the contraindication of fluoroquinolones in the pediatric population. Despite these recommendations fluoroquinolones continue to be prescribed for select children with difficult-to-treat infections for whom the benefit of quinolone therapy may outweigh the risk of cartilage toxicity. A review of retrospective and prospective safety data of ciprofloxacin-treated children showed that the rates of arthralgia and quinolone-induced cartilage toxicity were low. Episodes of arthralgia were mostly reversible based on published surveillance data in children. Recent data from Bayer's ciprofloxacin clinical trials database found that the incidence of arthralgia in children did not differ between the ciprofloxacin and nonquinolone antimicrobial control groups. The role of fluoroquinolones in the treatment of certain serious infections in children does not appear to be compromised by safety concerns when used appropriately.

Acute gastroenteritis in children : what role for antibacterials?

The aim of this article is to define the currently accepted role of antibacterials in the treatment of acute gastroenteritis in children. Most cases of acute gastroenteritis in children are viral, self-limited, and need only supportive treatment. Appropriate fluid and electrolyte therapy, with close attention to nutrition, remain central to therapy.Antibacterial therapy serves as an adjunct, to shorten the clinical course, eradicate causative organisms, reduce transmission, and prevent invasive complications. Selection of antibacterials to use in acute bacterial gastroenteritis is based on clinical diagnosis of the likely pathogen prior to definitive laboratory results. Antibacterial therapy should be restricted to specific bacterial pathogens and disease presentations. In general, infections with Shigella spp. and Vibrio cholera should usually be treated with antibacterials, while antibacterials are only used in severe unresponsive infections with Salmonella, Yersinia, Aeromonas, Campylobacter, Plesiomonas spp., and Clostridium difficile. Antibacterials should be avoided in enterohemorrhagic Escherichia coli infection. However, empiric therapy may be appropriate in the presence of a severe illness with bloody diarrhea and stool leucocytes, particularly in infancy and the immunocompromised. The benefits and risks of adverse drug reactions should be weighed before prescribing antibacterials. Moreover, a major concern is the emergence of antibacterial-resistant strains due to the widespread use of antibacterial agents.

Multicenter, randomized, double blind clinical trial of short course versus standard course oral ciprofloxacin for Shigella dysenteriae type 1 dysentery in children

BACKGROUND

Shigella dysenteriae type 1 (Sd1) dysentery is associated with serious morbidity and mortality. Treatment is either costly or complicated by the emergence of bacterial resistance. This study compared the efficacy and safety of short course (3 days) and standard course (5 days) oral ciprofloxacin in children with Sd1 dysentery.

METHODS

A multicenter, randomized, double blind, controlled clinical trial. Children between 1 and 12 years of age with Sd1 dysentery were randomized to receive oral ciprofloxacin suspension 15 mg/kg every 12 h for 3 days followed by placebo for 2 days or ciprofloxacin suspension for 5 days. Treatment success was defined as either resolution of illness or marked improvement on Day 6 of study. Bacteriologic cure was defined as failure to grow Sd1 on a stool sample collected on Day 6. Clinical assessments and joint examinations were performed at baseline, at discharge and 2 weeks later.

RESULTS

Of 253 patients enrolled 128 were assigned to short course ciprofloxacin and 125 to standard course ciprofloxacin. The success rates were 65 and 69% for short and standard course ciprofloxacin, respectively. All patients had bacteriologic cure, and all Sd1 isolates were susceptible to ciprofloxacin. No bacteriologic relapses occurred during the study period. Eight patients reported arthralgia. All patients had normal joint function including at follow-up.

CONCLUSION

In this study twice daily ciprofloxacin for 3 days achieved clinical cure rates similar to those for the same dosage given for 5 days in children with Sd1 dysentery.

Comparison of single-dose azithromycin and 12-dose, 3-day erythromycin for childhood cholera: a randomised, double-blind trial

BACKGROUND

Cholera is a major public-health problem, with children most affected. However, effective single-dose antimicrobial regimens have been identified only for adults. Our aim was to compare the efficacy of azithromycin and erythromycin regimens in the treatment of children.

METHODS

We did a double-blind, randomised study of 128 severely dehydrated children (age 1-15 years) with cholera, treated at one of two treatment centres in Bangladesh in 1999. Children were assigned single-dose azithromycin (20 mg/kg bodyweight, maximum individual dose 1 g; n=65) or 12.5 mg/kg erythromycin (maximum dose 500 mg; n=63) every 6 h for 3 days. Patients stayed in hospital for 5 days. We measured fluid balance every 6 h, and obtained a rectal swab or stool sample for culture daily. Our primary outcome measures were clinical success of treatment-ie, cessation of watery diarrhoea within 48 h-and bacteriological success-ie, absence of Vibrio cholerae O1 or O139 from cultures of stool or rectal swab samples after study day 2. Analysis was per protocol.

FINDINGS

Two children in both groups withdrew from the study, and we excluded one child in the erythromycin group. Treatment was clinically successful in 48 (76%) patients who received azithromycin and 39 (65%) who received erythromycin (difference 11%, 95% CI -5 to 27, p=0.244); and bacteriologically successful in 45 (71%) and 49 (82%) patients, respectively (10%, -5 to 25, p=0.261). Patients treated with azithromycin had a shorter duration of diarrhoea (median 24 h vs 42 h; difference 12 h, 0-18 h, p=0.019) and fewer episodes of vomiting (1 vs 4; difference 1 episode, 0-3 episodes, p=0.023).

INTERPRETATION

Single-dose azithromycin is as effective for treatment of cholera in children as standard erythromycin therapy, but is associated with less vomiting.

Ciprofloxacin for the treatment of uncomplicated gonorrhea infection in adolescents: does the benefit outweigh the risk?

The highest rates of reported gonorrhea infections occur among adolescent females aged 15-19 years. Among the Centers for Disease Control and Prevention (CDC)-recommended single-dose gonorrhea treatment regimens, ciprofloxacin, a fluoroquinolone antibiotic, is approximately half the cost of other CDC-recommended oral treatment regimens. Fluoroquinolone use in patients aged <18 years has been limited because of irreversible articular cartilage damage demonstrated in large, weight-bearing joints of young animals. We reviewed the medical literature to assess whether the risks of a single 500-mg dose of ciprofloxacin to treat uncomplicated gonorrhea infection in adolescents appears to outweigh the benefits. We found no reports of irreversible cartilage toxicity or age-associated adverse events in 5236 human children and adolescents (aged 5 days-24 years) treated with a total of 5486 courses of fluoroquinolones.

The battle against emerging antibiotic resistance: should fluoroquinolones be used to treat children?

Inappropriate use of antibiotic drugs in humans and animals has led to widespread resistance among microbial pathogens. Resistance is the phenotypic expression corresponding to genetic changes caused by either mutation or acquisition of new genetic information. In some cases, multidrug resistance occurs. Streptococcus pneumoniae is one of the most important respiratory pathogens, playing a major role in both upper and lower respiratory tract infections. Pneumococcal resistance to antimicrobials may be acquired by means of horizontal transfer followed by homologous recombination of genetic material from the normal flora of the human oral cavity or by means of mutation. Resistance to penicillins and macrolides has been increasing for some time, but, recently, fluoroquinolone resistance has become an issue as well. We are concerned that, if fluoroquinolones are approved for use in children, their widespread use will result in rapid emergence of pneumococcal resistance, because children are more often colonized in the nasopharynx with high-density populations of pneumococci than are adults.

Medical management of vulnerable populations and co-morbid conditions of victims of bioterrorism

Planning for the medical response to bioterrorism has primarily focused around the needs of the population as a whole. There has been little discussion pertaining to certain vulnerable groups such as children, pregnant women, or immunocompromised patients, yet they will likely comprise a significant subset of the exposed population. In addition, they will be at increased risk for morbidity and mortality following an attack. The emergency response to bioterrorism will be more complex as it relates to these vulnerable populations. Careful consideration of their special needs, some of which are presented in this article, may refine our efforts.

Chronic vulvovaginitis caused by antibiotic-resistant Shigella flexneri in a prepubertal child

A 7-year 8-month-old girl was diagnosed with a prolonged course of vulvovaginitis caused by Shigella flexneri. The child was symptomatic with intermittent vaginal bleeding, dysuria and foul smelling vaginal discharge for a 3-year period. Initial attempts to resolve the infection with successive courses of antibiotic therapy using ampicillin, trimethoprim-sulfamethoxazole, cefixime and amoxicillin/clavulanic acid failed. The child's infection was finally resolved by a 14-day course of ciprofloxacin.

Global aspects of antimicrobial-resistant enteric bacteria

Antibiotics have been considered to be safe and effective 'magic bullets', with no disadvantages to their widespread use. This has been proven to be a complacent attitude, with ever-increasing prevalences of resistance now evident. The present review covers aspects of the development, mechanisms and genetics of antimicrobial resistance in enteric commensals and pathogens.