Songbird preen oil odour reflects haemosporidian parasite load.

Investigating the impact of parasitism on host phenotype is key to understanding parasite transmission ecology, host behavioural ecology and host-parasite coevolution. Previous studies have provided evidence that avian odour is one such phenotypic trait, as mosquitoes that vector the haemosporidian blood parasite Plasmodium tend to prefer birds that are already infected. Preen oil is a major source of avian odour, yet studies to date have not identified differences in preen oil odour based on the presence or absence of haemosporidian infection. Because preen oil can vary with physiological dynamics, we predicted that the composition of preen oil odours might vary according to parasite load, rather than solely by the presence or absence of infection. We used gas chromatography-mass spectrometry to characterize the composition of volatile compounds in preen oil taken from female dark-eyed juncos, Junco hyemalis carolinensis, and asked whether their composition varied with relative haemosporidian parasite load, which we assessed using quantitative PCR. We identified a subset of volatile compounds (a 'blend') and two specific compounds that varied with increasing parasite load. Importantly, the quantity of these compounds did not vary based on parasite presence or absence, suggesting that birds with low parasite loads might be phenotypically indistinguishable from uninfected birds. The volatile blend associated with parasite load also varied with sampling date, suggesting a possible seasonal relapse of chronic infections triggered by shifts in junco host reproductive state. Furthermore, we found a positive relationship between parasite load and a volatile blend shown in a previous study to predict reproductive success in juncos. This is the first study to demonstrate quantitative differences in avian host odour based on haemosporidian parasite load. Our findings highlight the importance of focusing on parasite load, rather than solely presence or absence, in investigating host-parasite interactions.

Functional mutants of Azospirillum brasilense elicit beneficial physiological and metabolic responses in Zea mays contributing to increased host iron assimilation.

Iron (Fe), an essential element for plant growth, is abundant in soil but with low bioavailability. Thus, plants developed specialized mechanisms to sequester the element. Beneficial microbes have recently become a favored method to promote plant growth through increased uptake of essential micronutrients, like Fe, yet little is known of their mechanisms of action. Functional mutants of the epiphytic bacterium Azospirillum brasilense, a prolific grass-root colonizer, were used to examine mechanisms for promoting iron uptake in Zea mays. Mutants included HM053, FP10, and ipdC, which have varying capacities for biological nitrogen fixation and production of the plant hormone auxin. Using radioactive iron-59 tracing and inductively coupled plasma mass spectrometry, we documented significant differences in host uptake of Fe2+/3+ correlating with mutant biological function. Radioactive carbon-11, administered to plants as 11CO2, provided insights into shifts in host usage of 'new' carbon resources in the presence of these beneficial microbes. Of the mutants examined, HM053 exhibited the greatest influence on host Fe uptake with increased plant allocation of 11C-resources to roots where they were transformed and exuded as 11C-acidic substrates to aid in Fe-chelation, and increased C-11 partitioning into citric acid, nicotianamine and histidine to aid in the in situ translocation of Fe once assimilated.

Ketoprofen pharmacokinetics of R- and S-isomers in juvenile loggerhead sea turtles (Caretta caretta) after single intravenous and single- and multidose intramuscular administration.

Ketoprofen is a nonsteroidal anti-inflammatory and analgesic agent that nonselectively inhibits cyclooxygenase, with both COX-1 and COX-2 inhibition. Recent studies on COX receptor expression in reptiles suggest that nonselective COX inhibitors may be more appropriate than more selective inhibitors in some reptiles, but few pharmacokinetic studies are available. The goal of this study was to determine single- and multidose (three consecutive days) pharmacokinetics of racemic ketoprofen administered intravenously and intramuscularly at 2 mg/kg in healthy juvenile loggerhead turtles (Caretta caretta). The S-isomer is the predominant isomer in loggerhead sea turtles, similar to most mammals, despite administration of a 50:50 racemic mixture. Multidose ketoprofen administration demonstrated no bioaccumulation; therefore, once-daily dosing will not require dose adjustment over time. S-isomer pharmacokinetic parameters determined in this study were Cmax of 10.1 µg/ml by IM injection, C0 of 13.4 µg/ml by IV injection, AUC of 44.7 or 69.4 µg*hr/ml by IM or IV injection, respectively, and T½ of 2.8 or 3.6 hr by IM or IV injection, respectively. Total ketoprofen plasma concentrations were maintained for at least 12 hr above concentrations determined to be effective for rats and humans. A dose of 2 mg/kg either IM or IV every 24 hr is likely appropriate for loggerhead turtles.

El Niño episodes coincide with California moray Gymnothorax mordax settlement around Santa Catalina Island, California.

The hypothesis that El Niño events influence the settlement patterns of the California moray Gymnothorax mordax is tested. The pelagic larval duration (PLD) of larval G. mordax is unknown, but studies on leptocephalus of related species suggest that larvae are long-lived, up to 2 years. Gymnothorax mordax, an elusive predatory species and the only muraenid off the coast of California, is considered abundant in the waters around Catalina Island. Thirty-three individuals were collected from Two Harbors, Catalina Island, and otoliths were taken to provide estimates of their age. Settlement year for each individual was backcalculated using estimated age from otolith measurements. These ages were then cross referenced with the Oceanic Niño Index (ONI) developed by the National Oceanographic and Atmospheric Administration (NOAA) to correlate estimated age of settlement with known El Niño years. Of the 33 individuals collected, 30 settled at Catalina Island during El Niño years. The oldest individual in the data-set was 22 years old, placing G. mordax as one of the longer-lived predatory fishes in the system. The present study represents the first account of wild G. mordax ages and suggests that El Niño events have an important role in driving the settlement of recruits towards the northern edge of their range.

Food Allergy Emergencies in Children - To what extent are Early Years Services Prepared? A cross-sectional survey.

Food allergies are common in preschool children. This study's aims are to establish prevalence, to clarify management practices, levels of preparedness and the perceived role of General Practitioners amongst Early Years Services providers. This study is an anonymous, quantitative, cross sectional study. An online questionnaire was distributed to 282 Early Years Service providers. Data were analysed using SPSS. Response rate was 35% (n=98). Prevalence of food allergy was 3% (n=119). Allergic reactions to food had occurred on site in 16% (n=15). Written emergency action plans were available in 47% of facilities (n=46). Medications were not kept on site in 63% (n=62) of facilities. General practitioners were felt to have an important role in the management of food allergies by 76% of respondents (n=61). This study identifies significant areas for improvement in the management of food allergic child in Early Years Services.

Suction among pickers: jaw mechanics, dietary breadth and feeding behaviour in beach-spawning Leuresthes spp. compared with their relatives.

Jaw mechanics and dietary breadth in California grunion Leuresthes tenuis and Gulf grunion Leuresthes sardina were compared with three other members of the tribe Atherinopsini to test whether these two species have evolved a novel jaw protrusion that might be associated with feeding narrowly on abundant prey near spawning beaches. Quantitative comparison of cleared-and-stained specimens of five members of the atherinopsine clade showed that, compared with false grunion Colpichthys regis, topsmelt Atherinops affinis and jacksmelt Atherinopsis californiensis, L. tenuis and L. sardina have longer, more downwardly directed premaxillary protrusion, expanded dentary and premaxillary bones, greater lower jaw rotation and larger premaxilla-vomer separation. Leuresthes tenuis showed greater differences than L. sardina in these features. Comparison of the gut contents of L. tenuis and A. affinis with zooplankton samples collected simultaneously with these fishes in the water column within 1 km of shore showed that, as predicted, L. tenuis fed predominantly on mysid crustaceans and had a narrower diet than A. affinis. High-speed video analysis showed that L. tenuis exhibits a mean time to maximum jaw protrusion c. 2.5 times shorter than that of A. affinis. The grunion sister species, especially L. tenuis, have evolved suction feeding that may allow efficient feeding on common, evasive prey near spawning sites. The morphological traits seen in both species of Leuresthes signify a marked difference from their closest relatives in prey capture and suggest a type of jaw protrusion not yet seen in cyprinodontiforms or perciforms.

Duration of acetowhitening as a novel objective tool for diagnosing high risk neoplasia in Barrett's esophagus: a prospective cohort trial.

BACKGROUND AND STUDY AIMS: Acetic acid reacts with Barrett's mucosa to produce acetowhitening which disappears with time. The clinical significance of this is unknown. We aimed to quantify the acetowhitening time, developing an objective tool for diagnosis of neoplasia in Barrett's esophagus. PATIENTS AND METHODS: Prospective cohort study in a tertiary referral center, enrolling patients undergoing surveillance of Barrett's metaplasia or referred with suspected neoplasia. Acetic acid 2.5 % was applied to the mucosa via a spray catheter. Acetowhitening was observed and time to disappearance recorded. Targeted biopsies of any neoplasia and quadrantic 2-cm biopsies of residual Barrett's area were then taken. Histological findings were investigated in relation to duration of acetowhitening. RESULTS: 132 patients were examined. A receiver operating characteristic (ROC) curve was produced for identifying high risk neoplasia according to acetowhitening duration. The area under the curve (AUC) was 0.93 (0.89 - 0.97). Using a threshold of 142 seconds yielded a sensitivity for neoplasia of 98 % (95 % confidence interval [95 %CI] 89 % - 100 %) and specificity of 84 % (74 % - 91 %). The ROC curve for mucosal neoplasia (high grade dysplasia or intramucosal carcinoma) versus deep invasive cancer showed an AUC of 0.786 (0.61 - 0.96); a cutoff of 20 seconds yielded a sensitivity and specificity for invasive cancer of 67 % (35 % - 90 %) and 85 % (69 % - 95 %), respectively. CONCLUSION: The time to disappearance of acetowhitening can serve as a simple but very sensitive tool for the diagnosis of high risk neoplasia in Barrett's esophagus. It can be used to distinguish mucosal neoplasia from deep invasive cancer.

High-definition vs. standard-definition colonoscopy in the characterization of small colonic polyps: results from a randomized trial.

BACKGROUND AND STUDY AIMS: The resolution of endoscopes has increased in recent years. Modern Fujinon colonoscopes have a charge-coupled device (CCD) pixel density of 650,000 pixels compared with the 410,000 pixel CCD in standard-definition scopes. Acquiring high-definition scopes represents a significant capital investment and their clinical value remains uncertain. The aim of the current study was to investigate the impact of high-definition endoscopes on the in vivo histology prediction of colonic polyps. PATIENTS AND METHODS: Colonoscopy procedures were performed using Fujinon colonoscopes and EPX-4400 processor. Procedures were randomized to be performed using either a standard-definition EC-530 colonoscope or high-definition EC-530 and EC-590 colonoscopes. Polyps of <10 mm were assessed using both white light imaging (WLI) and flexible spectral imaging color enhancement (FICE), and the predicted diagnosis was recorded. Polyps were removed and sent for histological analysis by a pathologist who was blinded to the endoscopic diagnosis. The predicted diagnosis was compared with the histology to calculate the accuracy, sensitivity, and specificity of in vivo assessment using either standard or high-definition scopes. RESULTS: A total of 293 polyps of <10 mm were examined­150 polyps using the standard-definition colonoscope and 143 polyps using high-definition colonoscopes. There was no difference in sensitivity, specificity or accuracy between the two scopes when WLI was used (standard vs. high: accuracy 70% [95% CI 62­77] vs. 73% [95% CI 65­80]; P=0.61). When FICE was used, high-definition colonoscopes showed a sensitivity of 93% compared with 83% for standard-definition colonoscopes (P=0.048); specificity was 81% and 82%, respectively. CONCLUSIONS: There was no difference between high- and standard-definition colonoscopes when white light was used, but FICE significantly improved the in vivo diagnosis of small polyps when high-definition scopes were used compared with standard definition.

Weekend admission and mortality from acute exacerbations of chronic obstructive pulmonary disease in winter.

Historically, acute medical staffing numbers have been lower on weekends and in winter numbers of medical admissions rise. An analysis of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) admissions to Portsmouth Hospitals over a seven-year period was undertaken to examine the effects of admission on a weekend, of winter, and with the opening of a medical admissions unit (MAU). In total, 9,915 admissions with AECOPD were identified. Weekend admissions accounted for 2,071 (20.9%) of cases, winter accounted for 3,026 (30.5%) admissions, and 522 (34.4%) deaths. Adjusted odds ratio (OR) for death on day 1 after winter weekend admission was 2.89 (95% confidence interval (CI) 1.035 to 8.076). After opening the MAU, the OR for death day 1 after weekend winter admission fell from 3.63 (95% CI 1.15 to 11.5) to 1.65 (95% CI 0.14 to 19.01). AECOPD patients have an increased risk of death after admission over a weekend in winter and this effect was reduced by opening a MAU. These findings have implications for the planning of acute care provision in different seasons.

Operating room nurses' perceptions of the effects of physician-perpetrated abuse.

BACKGROUND: Operating room (OR) nurses experience abuse perpetrated by physicians; however, little research has been conducted to examine nurses' perceptions of the effects of such abuse. AIMS: The aim of this research was to understand participants' perceptions of physician-perpetrated abuse on their health and ability to provide patient care. MATERIALS/METHODS: In this qualitative descriptive study, ten operating room nurses working in Eastern Canada participated in open-ended, individual audiotaped interviews that were transcribed for analysis using Boyatzis' method for code development. RESULTS: Three categories of factors contributing to abuse were developed. The first, culture of the OR, included environment and hierarchy. The second, catalysts of abuse, included nurses' positions and experience as well as non-nurse factors such as resources and interpersonal relationships among physicians. The third category, perceived effects, included psychological, physical and social health consequences for nurses. Effects on patient care consisted of safety and potential challenges to access. DISCUSSION: Nursing practice implications included mentoring, support and accountability for action. Educational implications related to interdisciplinary education and increased education on communication, assertiveness, and awareness of abuse. Implications for research included studying perceptions of other health-care providers including physicians, studying recruitment and retention in relation to abuse, and studying other abuse in health care such as horizontal violence. CONCLUSION: We suggest a proactive approach for empowering OR nurses to address abuse and an increased focus on interdisciplinary roles.

The use of transarticular external skeletal fixation in the management of failed tibial tuberosity transposition in five dogs.

The management of tibial tuberosity fracture-avulsion after tibial tuberosity transposition can be challenging. Implants must be able to resist the strong distractive force of the quadriceps mechanism, yet implant size is limited by the amount of tuberosity bone stock available. Revision fixation is compromised further by fragmentation of the tubercle. Five stifle joints had temporary transarticular external skeletal fixators applied to manage complications of tibial tuberosity transposition. Fracture reduction was confirmed in four out of five tibial tuberosity fractures. Frames were in place for a mean of 44 days. Frame associated complications occurred in four out of five limbs, the most common being pin tract discharge and associated osteolucency. All frame-associated complications resolved. Long-term follow-up information was available for three of the five animals at 13 to 18 months after frame removal. All three owners reported occasional lameness, but this was attributed to concurrent orthopaedic disease. Transarticular external skeleton fixation protects internal fixation techniques, and good limb function was achieved in most cases. Transarticular external skeleton fixation can be successfully used to augment repair of tibial tuberosity fracture after tibial tuberosity transposition.

Time trends in the prevalence of peanut allergy: three cohorts of children from the same geographical location in the UK.

BACKGROUND: This article investigated the prevalence of peanut allergy in three cohorts of children born in the same geographical location, Isle of Wight, UK and seeks to determine whether the prevalence of peanut allergy has changed between 1994 and 2004. METHODS: Three cohorts of children (age 3-4 years) born on the Isle of Wight, were assessed for peanut allergy and the outcomes compared: Cohort A: Born in 1989; reviewed at 4 years of age (n = 2181). Cohort B: Born between 1994 and 1996; reviewed between 3 and 4 years of age (n = 1273). Cohort C: Born between 2001 and 2002; reviewed at 3 years of age (n = 891). RESULTS: Peanut sensitization increased significantly from 1.3% in Cohort A to 3.3% (P = 0.003) in Cohort B before falling back to 2.0% in Cohort C (P = 0.145). Similarly, clinical peanut allergy increased significantly from 0.5% in Cohort A to 1.4% (P = 0.023) in Cohort B, with a subsequent fall to 1.2% in Cohort C (P = 0.850). CONCLUSIONS: Our data from three cohorts of 3- to 4-year-old children born in the same geographical area shows that peanut allergy prevalence has changed over time. Peanut sensitization and reported allergy in children born in 1994-1996 increased from 1989 but seems to have stabilized or slightly decreased since the late 1990s, although not significant.

Coagulation factors in the airways in moderate and severe asthma and the effect of inhaled steroids.

BACKGROUND: There is evidence of activation of the extrinsic coagulation cascade in the asthmatic airway, and both plasma and locally derived factors may be involved. The hypothesis that the normal haemostatic balance of healthy airways sampled by sputum induction favours fibrin formation in asthmatic airways, and that inhaled corticosteroids (ICS) and plasma exudation influence this balance, was tested. METHODS: ELISA and activity assays were used to measure alpha(2)-macroglobulin (an index of plasma leakage) and coagulation factors in hypertonic saline-induced sputum of 30 stable subjects (10 controls, 10 with moderate asthma and 10 with severe asthma). Additionally, the moderate cohort were weaned off their ICS, followed by further sputum induction 5 days after cessation of steroids. RESULTS: ICS wean induced a significant rise in plasminogen (median (interquartile range (IQR)): 13.92 (6.12-16.17) vs 4.82 (2.14-13.32) ng/ml; 95% CI 0.003 to 8.596, p = 0.0499) and tissue plasminogen activator (tPA; 5.57 (3.57-14.35) vs 3.88 (1.74-4.05) ng/ml; 95% CI 0.828 to 9.972, p = 0.0261) levels in sputum, such that tPA in untreated moderate asthma was significantly (p = 0.0029) higher than normal (2.14 (0.0-2.53) ng/ml). Subjects with severe asthma had significantly more alpha(2)-macroglobulin (p = 0.0003), tissue factor (p = 0.023), plasminogen activator inhibitor (p = 0.0091), thrombin-activatable fibrinolysis inhibitor (p = 0.0031) and fibrin degradation products (p = 0.0293) in their sputum than control subjects. CONCLUSION: Untreated moderate asthma is associated with increased fibrinolysis that is corrected by ICS. Severe asthma and high dose corticosteroid therapy is associated with a profibrinogenic, antifibrinolytic environment in the airways. This study suggests that inhibition of fibrin deposition in severe asthma may be a therapeutic approach.

Hypercapnic acidosis attenuates pulmonary epithelial wound repair by an NF-kappaB dependent mechanism.

BACKGROUND: Hypercapnic acidosis exerts protective effects in acute lung injury but may also slow cellular repair. These effects may be mediated via inhibition of nuclear factor-kappaB (NF-kappaB), a pivotal transcriptional regulator in inflammation and repair. OBJECTIVES: To determine the effects of hypercapnic acidosis in pulmonary epithelial wound repair, to elucidate the role of NF-kappaB and to examine the mechanisms by which these effects are mediated. METHODS: Confluent small airway epithelial cell, human bronchial epithelial cell and type II alveolar A549 cell monolayers were subjected to wound injury under conditions of hypercapnic acidosis (pH 7.0, carbon dioxide tension (P(CO(2))) 11 kPa) or normocapnia (pH 7.37, P(CO(2)) 5.5 kPa) and the rate of healing determined. Subsequent experiments investigated the role of hypercapnia versus acidosis and elucidated the role of NF-kappaB and mitogen-activated protein kinases. The roles of cellular mitosis versus migration and of matrix metalloproteinases in mediating these effects were then determined. RESULTS: Hypercapnic acidosis reduced wound closure (mean (SD) 33 (6.3)% vs 64 (5.9)%, p<0.01) and reduced activation of NF-kappaB compared with normocapnia. Buffering of the acidosis did not alter this inhibitory effect. Prior inhibition of NF-kappaB activation occluded the effect of hypercapnic acidosis. Inhibition of ERK, JNK and P38 did not modulate wound healing. Hypercapnic acidosis reduced epithelial cell migration but did not alter mitosis, and reduced matrix metalloproteinase-1 while increasing concentrations of tissue inhibitor of metalloproteinase-2. CONCLUSIONS: Hypercapnic acidosis inhibits pulmonary epithelial wound healing by reducing cell migration via an NF-kappaB dependent mechanism that may involve alterations in matrix metalloproteinase activity.

Breast cancer follow up: a randomised controlled trial comparing point of need access versus routine 6-monthly clinical review.

AIM: To examine a model of care for breast cancer patients based on the concept of point of need access and investigate the effectiveness of this model compared to routine 6-monthly clinical reviews. DESIGN: A parallel randomised controlled trial was used to examine point of need access to specialist care via the nurse specialist, compared to routine hospital based 6-monthly clinical review at year two post breast cancer diagnosis. A total of 237 patients were recruited to the study. METHODS: Outcome measures at baseline, 9 and 18 months included psychological morbidity using the GHQ12 questionnaire, quality of life using the FACT-B plus endocrine subscale, fear and isolation. An analysis of covariance was used to detect changes over time. Recurrences and methods of detection were recorded as secondary outcome measures. RESULTS: Two hundred and fourteen patients completed the study. Overall patients were not exposed to risks of increased psychological morbidity (p=0.767) or decline of quality of life (p=0.282) when routine review was discontinued and no significant differences were detected during an 18-month period. Patients not receiving regular review did not feel isolated, and at the end of 18 months did not wish to return to 6-monthly clinical reviews. The presentation of recurrences and short symptom history demonstrate that the recurrences observed were unlikely to have been detected at a routine visit. CONCLUSIONS: Point of need access is acceptable to the majority of patients. Although a third of patients may wish to maintain a regular review, patient choice is important. Findings suggest that after 2 years following the diagnosis of breast cancer there is no evidence to support the view that regular clinical review improves psychological morbidity or quality of life. Patients do not appear to be compromised in terms of early detection of recurrence. Point of need access can be provided by suitably trained specialist nurses and provides a fast, responsive management system at a time when patients really need it.

Characterization of 155 EST-derived microsatellites from Atlantic cod (Gadus morhua) and validation for linkage mapping.

Microsatellite markers for Atlantic cod (Gadus morhua) were identified from a collection of 30 630 expressed sequence tags. Primers were designed for 395 microsatellites and 155 were successfully amplified. Allele number varied from 1 to 26 (average 6.34). Average observed and expected heterozygosities were 0.50 and 0.54, respectively. A subset of 105 microsatellites tested for Mendelian segregation showed no significant distortion of segregation when correcting for multiple tests. Null alleles were detected at four loci. Significant blastx matches were found for 23 loci. These microsatellites will be used to create a linkage map to enhance genetic selection in commercial cod breeding.

Mixed state discrimination using optimal control.

We present theory and experiment for the task of discriminating two nonorthogonal states, given multiple copies. We implement several local measurement schemes, on both pure states and states mixed by depolarizing noise. We find that schemes which are optimal (or have optimal scaling) without noise perform worse with noise than simply repeating the optimal single-copy measurement. Applying optimal control theory, we derive the globally optimal local measurement strategy, which outperforms all other local schemes, and experimentally implement it for various levels of noise.

Factors influencing the occurrence of multicentric and 'recurrent' Warthin's tumour: a cross sectional study.

The multicentric nature of Warthin's tumour has been well recognised, though the factors predicting its occurrence and its influence on management remain speculative. In this cross sectional study, the authors analysed the presentation, management and outcome of solitary and multicentric Warthin's tumour, treated in the maxillofacial unit and investigated factors that could influence the occurrence of multicentric and recurrent tumours. Warthin's tumour was found in 24% (150/628) of patients presenting with parotid neoplasms and multicentric tumours were found in 13% (21/ 161) of parotidectomy specimens. Age, sex, side, site and smoking history were not predictors of multicentricity (P>0.40). Clinical examination (19%), imaging investigations (28%) and intra-operative palpation (33%) were poor at detecting multicentric tumours. Superficial parotidectomy was the most commonly performed operation. The recurrence rate was 0% in the solitary and 10% in the multicentric tumour group. Intra-operative rupture was not uncommon (11%), but was not associated with tumour recurrence (P= or >0.999). Incomplete excision (P=0.007) and multicentricity (P=0.026) were predictors of recurrence.

Prevalence and cumulative incidence of food hypersensitivity in the first 3 years of life.

BACKGROUND: Prevalence and incidence of food hypersensitivity (FHS) and its trends in early childhood are unclear. METHODS: A birth cohort born on the Isle of Wight (UK) between 2001 and 2002 was followed-up prospectively. Children were clinically examined and skin prick tested at set times and invited for food challenges when indicated. RESULTS: Nine hundred and sixty-nine children were recruited and 92.9%, 88.5% and 91.9% of them respectively were assessed at 1, 2 and 3 years of age. Prevalence of sensitization to foods was 2.2%, 3.8% and 4.5% respectively at these ages. Cumulatively, 5.3% [95% confidence interval (CI): 3.9-7.1] children were sensitized to a food. Using open food challenge and a good clinical history, the cumulative incidence of FHS was 6.0% (58/969, 95% CI: 4.6-7.7). Based on double-blinded, placebo-controlled, food challenge (DBPCFC) and a good clinical history, the cumulative incidence was 5.0% (48/969, 95% CI: 3.7-6.5). There is no evidence to suggest that the incidence of FHS has increased, comparing these results with previous studies. Overall, 33.7% of parents reported a food-related problem and of these, 16.1% were diagnosed with FHS by open challenge and history and 12.9% by DBPCFC and history. Main foods implicated were milk, egg and peanut. CONCLUSIONS: By the age of 3 years, 5-6% of children suffer from FHS based on food challenges and a good clinical history. There were large discrepancies between reported and diagnosed FHS. Comparing our data with a study performed in the USA more than 20 years ago, there were no significant differences in the cumulative incidence of FHS.

Comparison of open and double-blind placebo-controlled food challenges in diagnosis of food hypersensitivity amongst children.

BACKGROUND: Correct diagnosis of food hypersensitivity (FHS) is important to ensure appropriate patient care and to accurately establish the population prevalence and incidence. Food challenges play a very important role in the diagnosis of FHS, but it is unclear when open food challenges (OFCs) opposed to double-blind placebo-controlled food challenges (DBPCFCs) should be used. This study investigated the use of OFCs and DBPCFCs when diagnosing FHS. METHODS: Children with a reported history of FHS or with sensitization to a food without known previous consumption were invited to undergo food challenges. Children of consenting parents underwent an OFC and those with a positive OFC were approached to undergo a DBPCFC. Food challenges were either performed as 1-day or 1-week challenges depending on sensitization status and clinical history. RESULTS: Forty-one children underwent both OFCs and DBPCFCs. The positive predictive values for 1-day and 1-week OFCs were 73% (8/11; 95% CI: 39-94%) and 57% (20/35; 95% CI: 39-74%) respectively. There was no evidence to indicate that the younger children were more likely to have a positive OFC confirmed by a DBPCFC compared to older children (Fisher's exact P = 0.53). In the 1-day challenges parents indicated a preference for OFC rather than DBPCFC. By contrast, in the 1-week challenge parents indicated a preference for DBPCFC (P = 0.0192). CONCLUSION: Open food challenge may be suitable for diagnosing immediate objective symptoms, whereas DBPCFC may be needed for the diagnosis of delayed and mainly subjective symptoms, irrespective of the child's age.