The impact of antenatal and postnatal indoor air pollution or tobacco smoke exposure on lung function at 3 years in an African birth cohort.

BACKGROUND AND OBJECTIVE: Indoor air pollution (IAP) and tobacco smoke exposure (ETS) are global health concerns contributing to the burden of childhood respiratory disease. Studies assessing the effects of IAP and ETS in preschool children are limited. We assessed the impact of antenatal and postnatal IAP and ETS exposure on lung function in a South African birth cohort, the Drakenstein Child Health Study. METHODS: Antenatally enrolled mother-child pairs were followed from birth. Lung function measurements (oscillometry, multiple breath washout and tidal breathing) were performed at 6 weeks and 3 years. Quantitative antenatal and postnatal IAP (particulate matter [PM10 ], volatile organic compounds [VOC]) and ETS exposures were measured. Linear regression models explored the effects of antenatal and postnatal exposures on lung function at 3 years. RESULTS: Five hundred eighty-four children had successful lung function testing, mean (SD) age of 37.3 (0.7) months. Exposure to antenatal PM10 was associated with a decreased lung clearance index (p < 0.01) and postnatally an increase in the difference between resistance at end expiration (ReE) and inspiration (p = 0.05) and decrease in tidal volume (p = 0.06). Exposure to antenatal VOC was associated with an increase in functional residual capacity (p = 0.04) and a decrease in time of expiration over total breath time (tE /tTOT ) (p = 0.03) and postnatally an increase in respiratory rate (p = 0.05). High ETS exposure postnatally was associated with an increase in ReE (p = 0.03). CONCLUSION: Antenatal and postnatal IAP and ETS exposures were associated with impairment in lung function at 3 years. Strengthened efforts to reduce IAP and ETS exposure are needed.

The Standardization of Outpatient Procedure (STOP) Narcotics after anorectal surgery: a prospective non-inferiority study to reduce opioid use.

BACKGROUND: Prescription of opioid medication after ambulatory anorectal surgery may be excessive and lead to opioid misuse. The purpose of this study was to evaluate the efficacy of a multi-modality opioid-sparing approach to control postoperative pain and reduce opioid prescriptions after outpatient anorectal surgery. METHODS: A prospective non-inferiority pre- and post-intervention study was completed at three academic hospitals. Patients included were 18-75 years of age who had outpatient anorectal surgeries. The Standardization of Outpatient Procedure (STOP) Narcotics intervention was implemented, which is a multi-pronged analgesia bundle integrating patient education, health care provider education, and intra-/postoperative analgesia focused on multi-modal pain control strategies and opioid-reduced prescriptions. The primary outcome was patient-reported average pain in the first 7 postoperative days. Secondary outcomes included patient-reported quality of pain management, medication utilization, prescription refills and medication disposal. RESULTS: Ninety-three patients had outpatient anorectal surgery (42 pre-intervention and 51 post-intervention). No difference was seen in average postoperative pain in the pre- vs. post-intervention groups (2.8 vs. 2.6 on an 11-point scale, p = 0.33) or patient-reported quality of pain control (good/very good in 57% vs. 63%, p = 0.58). The median oral morphine equivalents (OME) prescribed was significantly less [112.5 (IQR 50-150) pre-intervention vs. 50 (IQR 50-50) post-intervention, p < 0.001]. In the post-intervention group, only 45% of patients filled their opioid prescription and median opioid use was 12.5 OME (2.5 pills). CONCLUSIONS: While pain control after anorectal surgery must consider the individual patient's needs, a standardized pain care bundle significantly decreased opioid prescribing without an increase in patient-reported postoperative pain.

Systematic reanalysis of genomic data improves quality of variant interpretation.

As genomic sequencing expands, so does our knowledge of the link between genetic variation and disease. Deeper catalogs of variant frequencies improve identification of benign variants, while sequencing affected individuals reveals disease-associated variation. Accumulation of human genetic data thus makes reanalysis a means to maximize the benefits of clinical sequencing. We implemented pipelines to systematically reassess sequencing data from 494 individuals with developmental disability. Reanalysis yielded pathogenic or likely pathogenic (P/LP) variants that were not initially reported in 23 individuals, 6 described here, comprising a 16% increase in P/LP yield. We also downgraded 3 LP and 6 variants of uncertain significance (VUS) due to updated population frequency data. The likelihood of identifying a new P/LP variant increased over time, as ~22% of individuals who did not receive a P/LP variant at their original analysis subsequently did after 3 years. We show here that reanalysis and data sharing increase the diagnostic yield and accuracy of clinical sequencing.

Describing mate preference functions and other function-valued traits.

Mate preferences are important causes of sexual selection. They shape the evolution of sexual ornaments and displays, sometimes maintaining genetic diversity and sometimes promoting speciation. Mate preferences can be challenging to study because they are expressed in animal brains and because they are a function of the features of potential mates that are encountered. Describing them requires taking this into account. We present a method for describing and analysing mate preference functions, and introduce a freely available computer program that implements the method. We give an overview of how the program works, and we discuss how it can be used to visualize and quantitatively analyse preference functions. In addition, we provide an informal review of different methods of testing mate preferences, with recommendations for how best to set up experiments on mate preferences. Although the program was written with mate preferences in mind, it can be used to study any function-valued trait, and we hope researchers will take advantage of it across a broad range of traits.

Memory impairment in aged primates is associated with region-specific network dysfunction.

Age-related deficits in episodic memory result, in part, from declines in the integrity of medial temporal lobe structures, such as the hippocampus, but are not thought to be due to widespread loss of principal neurons. Studies in rodents suggest, however, that inhibitory interneurons may be particularly vulnerable in advanced age. Optimal encoding and retrieval of information depend on a balance of excitatory and inhibitory transmission. It is not known whether a disruption of this balance is observed in aging non-human primates, and whether such changes affect network function and behavior. To examine this question, we combine large-scale electrophysiological recordings with cell-type-specific imaging in the medial temporal lobe of cognitively assessed, aged rhesus macaques. We found that neuron excitability in the hippocampal region CA3 is negatively correlated with the density of somatostatin-expressing inhibitory interneurons in the vicinity of the recording electrodes in the stratum oriens. By contrast, no hyperexcitability or interneuron loss was observed in the perirhinal cortex of these aged, memory-impaired monkeys. These data provide a link, for the first time, between selective increases in principal cell excitability and declines in a molecularly defined population of interneurons that regulate network inhibition.

EVAR with Flared Iliac Limbs has a High Risk of Late Type 1b Endoleak.

INTRODUCTION: Re-interventions are still the Achilles' heel of endovascular aneurysm repair (EVAR). Ectatic common iliac arteries (CIA) can be treated with flared iliac limbs but a dilated artery used as sealing zone could increase the risk of a late type 1b endoleak. The aim of the present analysis was to evaluate the risk of late type 1b endoleak after EVAR in patients with CIA limbs ≥20 mm compared with those <20 mm. METHODS: A retrospective analysis was performed of patients treated by EVAR at the study institution between 2006 and 2012, including patients with available information about the type of iliac stent grafts and a minimum follow-up (FU) of 3 years with contrast enhanced CT, or those that had developed a type 1b endoleak earlier. The cohort was divided into two groups: Group I included iliac limbs with a distal diameter <20 mm, and Group II included all iliac limbs with a distal diameter ≥20 mm. RESULTS: Of 692 limbs (346 patients), 239 limbs (34.5%) from 129 patients were included in the analysis. Mean CT FU was 53 months, 178 had an iliac stent graft diameter <20 mm (Group I), and 61 a diameter of ≥20 mm (Group II). Mean oversizing for iliac limbs was 17.2% (IQR 14) and there was no case of immediate type 1b endoleak. For the whole group, 18 type 1b endoleaks occurred during FU (7.5%) after a mean of 37.7 months (range 4-96). Eleven of 61 (18%) iliac limbs in Group II developed a type 1b endoleak during FU in contrast to 7/178 (3.9%) in Group I (OR 5.3, 95% CI 1.98-14.59, p = 0,001). The ROC curve analysis indicated a limb diameter of 19 mm as a cutoff value for a higher probability of developing a type 1b endoleak. CONCLUSION: Patients treated with iliac limbs ≥20 mm had a fivefold higher risk of late (mean 37 months) type 1b endoleak compared with patients treated with a distal iliac limb diameter <20 mm.

Maternal HIV and Paediatric Lung Health.

With improved prevention of mother to child transmission of HIV, paediatric HIV disease is less common. However, the number of HIV exposed but uninfected infants is growing. Exposure to maternal HIV impacts infant respiratory health through an increase in known risk factors such as increased preterm birth and low birth weight, suboptimal breastfeeding, increased psychosocial stressors and increased exposure to infective pathogens. Exposure to the HIV virus and altered maternal immune environment result in immunologic changes in the infant that may contribute to respiratory disease risk. HIV exposed infants are at increased risk for severe pneumonia with poorer outcomes compared to unexposed infants. Maternal ART and optimal nutrition, including breastfeeding in high infective disease burden settings, reduce morbidity and mortality in HIV exposed infants and should be prioritized. The impact of exposure to maternal HIV on normal lung growth and risk for chronic respiratory disease is unknown and warrants further investigation.

Participation in activities and secondary health complications among persons aging with traumatic spinal cord injury.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To describe participation in activities and explore the relationship with secondary complications among persons aging with a traumatic spinal cord injury (SCI). SETTING: A regional SCI outpatient center in Sweden. METHODS: Data were collected through a phone survey, which included 10 activities from the instrument PARTS/M-v3 (PARTicipation Survey/Mobility version-3) together with data from the participants' medical records. Cross-tabulation and χ2 were used for data analysis. RESULTS: In this study, 121 persons matched the inclusion criteria and the final study sample comprised 73 participants (60% response rate): 55 men and 18 women. Mean age was 63.7±9.4 years, and mean time since injury was 36.3±9.2 years. Regardless of duration of SCI, all 73 participated in dressing, bathing and leisure activities. Women reported better health than men. Particularly for those who lived 36-55 years after injury; increasing pain, fatigue, spasticity and decreased muscle strength were negatively affecting participation in activities, especially exercise and active recreation. Additionally, a need to save strength/energy was also a reason for not participating in the activities. Perceived future support and concerns in relation to personal assistance, assistive devices and rehabilitation was also reported. CONCLUSION: Increasing secondary health complications and a need to save strength/energy influenced participation in activities. Laws and/or governmental policies regarding personal assistance and assistive devices did not always support participation in activities. Interventions should aim to create a balance among activities in everyday life.

Impact of loss of NF-κB1, NF-κB2 or c-REL on SLE-like autoimmune disease and lymphadenopathy in Fas(lpr/lpr) mutant mice.

Defects in apoptosis can cause autoimmune disease. Loss-of-function mutations in the 'death receptor' FAS impair the deletion of autoreactive lymphocytes in the periphery, leading to progressive lymphadenopathy and systemic lupus erythematosus-like autoimmune disease in mice (Fas(lpr/lpr) (mice homozygous for the lymphoproliferation inducing spontaneous mutation)) and humans. The REL/nuclear factor-κB (NF-κB) transcription factors regulate a broad range of immune effector functions and are also implicated in various autoimmune diseases. We generated compound mutant mice to investigate the individual functions of the NF-κB family members NF-κB1, NF-κB2 and c-REL in the various autoimmune pathologies of Fas(lpr/lpr) mutant mice. We show that loss of each of these transcription factors resulted in amelioration of many classical features of autoimmune disease, including hypergammaglobulinaemia, anti-nuclear autoantibodies and autoantibodies against tissue-specific antigens. Remarkably, only c-REL deficiency substantially reduced immune complex-mediated glomerulonephritis and extended the lifespan of Fas(lpr/lpr) mice. Interestingly, compared with the Fas(lpr/lpr) animals, Fas(lpr/lpr)nfkb2(-/-) mice presented with a dramatic acceleration and augmentation of lymphadenopathy that was accompanied by severe lung pathology due to extensive lymphocytic infiltration. The Fas(lpr/lpr)nfkb1(-/-) mice exhibited the combined pathologies caused by defects in FAS-mediated apoptosis and premature ageing due to loss of NF-κB1. These findings demonstrate that different NF-κB family members exert distinct roles in the development of the diverse autoimmune and lymphoproliferative pathologies that arise in Fas(lpr/lpr) mice, and suggest that pharmacological targeting of c-REL should be considered as a strategy for therapeutic intervention in autoimmune diseases.

Multivariate female preference tests reveal latent perceptual biases.

The question of why males of many species produce elaborate mating displays has now been largely resolved: females prefer to mate with males that produce such displays. However, the question of why females prefer such displays has been controversial, with an emerging consensus that such displays often provide information to females about the direct fitness benefits that males provide to females and/or the indirect fitness benefits provided to offspring. Alternative explanations, such as production of arbitrarily attractive sons or innate pre-existing female sensory or perceptual bias, have also received support in certain taxa. Here, we describe multivariate female preference functions for male acoustic traits in two chirping species of field crickets with slow pulse rates; our data reveal cryptic female preferences for long trills that have not previously been observed in other chirping species. The trill preferences are evolutionarily pre-existing in the sense that males have not (yet?) exploited them, and they coexist with chirp preferences as alternative stable states within female song preference space. We discuss escape from neuronal adaptation as a possible mechanism underlying such latent preferences.

Single Centre Results of Total Endovascular Repair of Complex Aortic Aneurysms with Custom Made Anaconda Fenestrated Stent Grafts.

OBJECTIVE: Fenestrated endovascular aneurysm repair (F-EVAR) has increased the number of patients with aneurysmal disease and a short or no existing neck being eligible for endovascular treatment. The aim of the study is to report experience using the Anaconda fenestrated device with special emphasis on target vessel patency and pitfalls with the device. METHODS: Between 2011 and 2016, 48 F-EVAR procedures were performed in 37 males and 11 females under general anaesthesia using the Anaconda custom made device (CMD). Cerebrospinal fluid drainage was performed in selected cases only. Primary endpoints were 30 day mortality and any stent graft related complications. RESULTS: The median aneurysm diameter was 56 mm. Most of the patients had a juxtarenal aneurysm and six had an aorto-iliac aneurysm. The primary technical success was 94% with three unsuccessful cannulations of reno-visceral arteries, two of which were successfully performed later. In the third patient an open repair was necessary because of occlusion of the main graft. The 30 day mortality was 4% because of colonic ischemia with two thrombotic occlusions of the superior mesenteric artery. Thirty day morbidity included four cases (8%) of acute limb ischemia: one with a complete limb occlusion caused by a torsion of the main body; two cases (4%) of assumed temporary spinal cord ischemia; six cases (12%) of acute renal failure; and 16 endoleaks (33%) (15 type II, 1 type III). During the median 24 months (range 0-53) follow up, three patients died (6%). One had migration of the stent graft, leading to open repair and post-operative multi-organ failure. The second had graft limb occlusion and died because of multi-organ failure caused by post-operative thrombosis of the reno-visceral stents. The third patient died of an unrelated cause. Two occlusions of the right renal stent/artery were detected. Moreover, there were three cases (6%) of late partial and seven cases (15%) of total graft limb thrombosis, with one being bilateral. CONCLUSIONS: "Real world" feasibility of the fenestrated Anaconda stent graft is demonstrated with 4% peri-operative mortality. Target vessel patency is in line with other series; however, limb thrombosis during follow up is of concern.

Intrarenal B Cell Cytokines Promote Transplant Fibrosis and Tubular Atrophy.

Renal transplantation is the optimum treatment for end-stage renal failure. B cells have been identified in chronic allograft damage (CAD) and associated with the development of tertiary lymphoid tissue within the human renal allograft. We performed renal transplantation in mice to model CAD and identified B cells forming tertiary lymphoid tissue with germinal centers. Intra-allograft B220(+) B cells comprised of IgM(high) CD23(-) B cells, IgM(lo) CD23(+) B cells, and IgM(lo) CD23(-) B cells with elevated expression of CD86. Depletion of B cells with anti-CD20 was associated with an improvement in CAD but only when administered after transplantation and not before. Isolated intra-allograft B cells were cultured and shown to synthesize multiple cytokines, the most abundant of these were GRO-α (CXCL1), RANTES (CCL5), IL-6 and MCP-1 (CCL2). Tubular loss was observed with T cell accumulation within the allograft and development of interstitial fibrosis, whilst type III collagen deposition was observed in areas of F4/80(+) macrophages and PDGFR-ß(+) and transgelin(+) fibroblasts, all of which were reduced by B cell depletion. We have shown that intra-allograft B cells are key mediators of CAD. B cells possibly contribute to CAD by intra-allograft secretion of cytokines and chemokines.

Accurate calibration of S(2) and interferometry based multimode fiber characterization techniques.

We present a novel method to validate the relative amount of power carried by high order modes in a multimode fiber using a Spatial and Spectral (S(2)) imaging technique. The method can be utilized to calibrate the S(2) set-up and uses Fresnel reflections from a thin glass plate to compare theoretical values with experimental results. We have found that, in the most general case, spectral leakage and sampling errors can lead S(2) to underestimate the multipath interference (MPI) of high order modes by several decibels, thus significantly impairing the result of the measurement. On the other hand, by applying suitable corrections as described in this work, we demonstrate that the S(2) produces MPI estimates that are accurate to within 1dB or better.

Optical side scattering radiometry for high resolution, wide dynamic range longitudinal assessment of optical fibers.

Current optical reflectometric techniques used to characterize optical fibers have to trade-off longitudinal range with spatial resolution and therefore struggle to provide simultaneously wide dynamic range (>20dB) and high resolution (<10cm). In this work, we develop and present a technique we refer to as Optical Side Scattering Radiometry (OSSR) capable of resolving discrete and distributed scattering properties of fibers along their length with up to 60dB dynamic range and 5cm spatial resolution. Our setup is first validated on a standard single mode telecoms fiber. Then we apply it to a record-length 11km hollow core photonic band-gap fiber (HC-PBGF) the characterization requirements of which lie far beyond the capability of standard optical reflectometric instruments. We next demonstrate use of the technique to investigate and explain the unusually high loss observed in another HC-PBGF and finally demonstrate its flexibility by measuring a HC-PBGF operating at a wavelength of 2µm. In all of these examples, good agreement between the OSSR measurements and other well-established (but more limited) characterization methods, i.e. cutback loss and OTDR, was obtained.

Conservation of multivariate female preference functions and preference mechanisms in three species of trilling field crickets.

Divergence in mate recognition systems among closely related species is an important contributor to assortative mating and reproductive isolation. Here, we examine divergence in male song traits and female preference functions in three cricket species with songs consisting of long trills. The shape of female preference functions appears to be mostly conserved across species and follows the predictions from a recent model for song recognition. Multivariate preference profiles, combining the pulse and trill parameters, demonstrate selectivity for conspecific pulse rates and high trill duty cycles. The rules for integration across pulse and trill timescales were identical for all three species. Generally, we find greater divergence in male song traits than in associated female preferences. For pulse rate, we find a strong match between divergent male traits and female peak preferences. Preference functions for trill parameters and carrier frequency are similar between species and show less congruence between signal and preference. Differences among traits in the degree of trait-preference (mis)match may reflect the strength of preferences and the potential for linkage disequilibrium, selective constraints and alternative selective pressures, but appear unrelated to selection for mate recognition per se.

Endovascular aneurysm repair of aortoiliac aneurysms with an iliac side-branched stent graft: studying the morphological applicability of the Cook device.

OBJECTIVE/BACKGROUND: Endovascular aneurysm (EVAR) repair of an aortic aneurysm extending to the iliac artery remains a challenge. Interventional occlusion of the internal iliac artery (IIA) intending to create a distal landing zone in the external iliac artery is a common approach with inherent morbidity (e.g., buttock claudication, impotence). Alternatively, iliac side-branched stent grafts can maintain pelvic blood supply, but the applicability is limited. The objective was to investigate the morphological applicability of the Cook Zenith branched graft (ZBIS) among patients with aorto-iliac or isolated iliac aneurysms. METHODS: This was a retrospective single centre analysis of 66 patients (60 men; median age 74 years, range 53-90 years) undergoing repair of aorto-iliac aneurysms (open repair, IIA occlusion prior to EVAR and ZBIS) between January 2008 and December 2012. All available computed tomography angiograms with post-processing imaging were compared with the criteria for morphological applicability to (i) the manufacturer's instruction for use (IFU), and (ii) to criteria published in the literature, as well as (iii) to the institutional protocol. RESULTS: In 66 patients, 88 targeted iliac aneurysms were studied. Of these, 36/88 (40.9%) were compliant with the manufacturer's IFU, 35/88 (39.8%) were compliant with the published criteria, and 51/88 (58.0%) were compliant with the in house protocol. The most common morphological exclusion criterion was an aneurysmal IIA. CONCLUSION: In the present cohort with aorto-iliac aneurysm, a maximum of 58% could have been treated with an iliac side branch based on the current experience. In particular, an aneurysmal IIA seems to be a limiting factor for the use of the iliac side-branched stent graft.

Cameron lesions in patients with hiatal hernias: prevalence, presentation, and treatment outcome.

Cameron lesions, as defined by erosions and ulcerations at the diaphragmatic hiatus, are found in the setting of gastrointestinal (GI) bleeding in patients with a hiatus hernia (HH). The study aim was to determine the epidemiology and clinical manifestations of Cameron lesions. We performed a retrospective cohort study evaluating consecutive patients undergoing upper endoscopy over a 2-year period. Endoscopy reports were systematically reviewed to determine the presence or absence of Cameron lesions and HH. Inpatient and outpatient records were reviewed to determine prevalence, risk factors, and outcome of medical treatment of Cameron lesions. Of 8260 upper endoscopic examinations, 1306 (20.2%) reported an HH. When categorized by size, 65.6% of HH were small (<3 cm), 23.0% moderate (3-4.9 cm), and 11.4% were large (≥5 cm). Of these, 43 patients (mean age 65.2 years, 49% female) had Cameron lesions, with a prevalence of 3.3% in the presence of HH. Prevalence was highest with large HH (12.8%). On univariate analysis, large HH, frequent non-steroidal anti-inflammatory drug (NSAID) use, GI bleeding (both occult and overt), and nadir hemoglobin level were significantly greater with Cameron lesions compared with HH without Cameron lesions (P ≤ 0.03). Large HH size and NSAID use were identified as independent risk factors for Cameron lesions on multivariate logistic regression analysis. Cameron lesions are more prevalent in the setting of large HH and NSAID use, can be associated with GI bleeding, and can respond to medical management.

X-ray tomography for structural analysis of microstructured and multimaterial optical fibers and preforms.

Specialty optical fibers, in particular microstructured and multi-material optical fibers, have complex geometry in terms of structure and/or material composition. Their fabrication, although rapidly developing, is still at a very early stage of development compared with conventional optical fibers. Structural characterization of these fibers during every step of their multi-stage fabrication process is paramount to optimize the fiber-drawing process. The complexity of these fibers restricts the use of conventional refractometry and microscopy techniques to determine their structural and material composition. Here we present, to the best of our knowledge, the first nondestructive structural and material investigation of specialty optical fibers using X-ray computed tomography (CT) methods, not achievable using other techniques. Recent advances in X-ray CT techniques allow the examination of optical fibers and their preforms with sub-micron resolution while preserving the specimen for onward processing and use. In this work, we study some of the most challenging specialty optical fibers and their preforms. We analyze a hollow core photonic band gap fiber and its preforms, and bond quality at the joint between two fusion-spliced hollow core fibers. Additionally, we studied a multi-element optical fiber and a metal incorporated dual suspended-core optical fiber. The application of X-ray CT can be extended to almost all optical fiber types, preforms and devices.

Effects of guided imagery on biobehavioral factors in women with fibromyalgia.

Women diagnosed with fibromyalgia (N = 72) participated in a 10-week randomized trial to examine the effectiveness of guided imagery on self-efficacy, perceived stress, and selected biobehavioral factors (FMS symptoms; immune biomarkers). Participants in both guided imagery and usual care control conditions completed measures and donated 3 cc of blood at baseline, 6- and 10-weeks. A mixed effects linear model to test for differences between groups for all behavioral and biologic variables demonstrated that after 10 weeks of daily intervention use, guided imagery participants reported statistically significant increases in self-efficacy and statistically significant decreases in stress, fatigue, pain, and depression. There were no statistically significant changes in biomarker levels, although total group C-reactive protein was elevated at baseline (4.7 mg/L), indicating an inflammatory process. Subsequent studies should be undertaken to more fully elucidate the biobehavioral aspects of nonpharmacological intervention effectiveness.

Aetiology of pleural effusions in children living in a high TB endemic setting.

Confirming the aetiology of pleural effusion in children may be difficult in TB-endemic settings. We investigated the role of polymerase chain reaction (PCR) and routine biochemical tests in discriminating pleural effusion caused by bacteria from other aetiologies.This is a cross-sectional post-hoc analysis among children with pleural effusion in a tertiary hospital in South Africa, incorporating new data from PCR testing of stored pleural fluid. Aetiological classification was defined by microbiological confirmation.Ninety-one children were enrolled; the median age 31 months (IQR 12-102). The aetiology of pleural effusion was 40% (36/91) bacteria, 11% (10/91) TB, 3% (3/91) viruses, 11% (10/91) polymicrobial and 35% (32/91) had no pathogen identified. The most common pathogen was Staphylococcus aureus (27/91, 30%) with similar yields on culture and PCR, followed by Streptococcus pneumoniae (12/91, 13%), detected more commonly by PCR. PCR reduced the number of children with unconfirmed aetiologies from 48 to 32. Characteristics of children with no pathogen most resembled those with TB. Pleural fluid lactate dehydrogenase ≥1,716 U/L best discriminated bacterial pleural effusion from other aetiologies (sensitivity of 86%; specificity 95%).PCR improved detection of pathogens and reduced number of children with unconfirmed aetiologies in presumed exudative pleural effusion..