Invasive Pneumococcal Disease in UK Children <1 Year of Age in the Post–13-Valent Pneumococcal Conjugate Vaccine Era: What Are the Risks Now?

Background Invasive pneumococcal disease (IPD) has declined significantly since the introduction of pneumococcal conjugate vaccines (PCVs). It is not known whether certain infant populations remain at higher risk of IPD in countries with established 13-valent PCV (PCV13) programs. We aimed to describe the epidemiology, clinical characteristics, serotype distribution, and outcomes of IPD in infants, and to estimate the relative risk of PCV13-type, non-PCV13-type, and overall IPD in premature infants compared to term infants during a 4-year period after the PCV13 program was established. Methods This was a prospective, enhanced national surveillance of laboratory-confirmed IPD in England in infants aged <1 year diagnosed during 2013–2016. Results There were 517 cases of IPD (incidence: 19/100000 infants). Incidence was significantly higher in premature infants compared with those born at term (49/100000 vs 17/100000; incidence rate ratio [IRR], 2.87; P < .001), with infants born before 28 weeks’ gestation having the highest incidence (150/100000; IRR, 8.8; P < .001). Of the 454 IPD cases with serotyped isolates, most were caused by non-PCV13 serotypes (369 cases, 71.4%), with 85 cases (16.4%) due to PCV13 serotypes. There were 31 deaths (case fatality rate [CFR], 6.2% [95% confidence interval, 4.3%–8.6%]). Premature infants did not have a higher CFR than term infants (P = .62). Conclusions IPD incidence in infants remains lower than rates reported prior to PCV7 introduction in England. The risk of IPD remains significantly higher in premature infants compared to infants born at term, for both PCV13 and non-PCV13 serotypes. Any changes to the infant PCV13 immunization schedule may disproportionally affect premature infants

Safety of meningococcal group B vaccination in hospitalised premature infants.

OBJECTIVES: To assess the risk of significant adverse events in premature infants receiving the novel 4-component group B meningococcal vaccine (4CMenB) with their routine immunisations at 2 months of age. PARTICIPANTS, DESIGN AND SETTING: In December 2015, Public Health England requested neonatal units across England to voluntarily participate in a national audit; 19 units agreed to participate. Anonymised questionnaires were completed for infants receiving 4CMenB alongside their routine immunisations. For comparison, a historical cohort of premature infants receiving their primary immunisations without 4CMenB or paracetamol prophylaxis was used. MAIN OUTCOME MEASURES: Paracetamol use; temperature, cardiovascular, respiratory and neurological status before and after vaccination; and management and investigations postvaccination, including serum C reactive protein levels, infection screens and antibiotic use. RESULTS: Complete questionnaires were returned for 133 premature infants (38°C) after vaccination compared with 20% (5/25) of those receiving 4CMenB without paracetamol (P=0.06) and none of those in the historical cohort. There were no significant differences between cohorts in the proportion of infants with apnoea, bradycardia, desaturation and receiving respiratory support after vaccination. CONCLUSIONS: 4CMenB does not increase the risk of serious adverse events in hospitalised premature infants. This audit supports the current national recommendations to offer 4CMenB with other routine vaccinations and prophylactic paracetamol to premature infants at their chronological age

Lymphocyte subpopulations in premature infants: An observational study

Background and objectives The infant's immune system evolves over the first months and years of life. Strong correlation exists between lymphocyte count, lymphocyte subpopulations and gestational age at birth. Associations with antenatal and postnatal steroid treatment, infection and chronic lung disease have also been described. Few published studies report the effect of increasing postnatal age (PNA) and comorbidities on lymphocyte subpopulations in premature infants beyond the first 4 months of life. This study aimed to describe changes in lymphocyte subpopulations in preterm infants up to 13 months PNA. Methods Premature infants (23–34 weeks completed gestation) from five centres had lymphocyte subpopulations measured at 2, 5 or 7, 12 and 13 months PNA alongside their vaccine responses in a vaccination trial. Results 393 blood samples from 151 babies were analysed. There was an increase in absolute numbers of total lymphocytes (median cell count 6.21×109/L at 13 months compared with 4.9×109/L at 2 months PNA) and CD3+, CD4+, CD8+, natural killer and B cells with increasing age. At 2 months PNA, there was a positive correlation between gestation and CD3+ and CD4+ counts (r=0.32 and 0.46, respectively) and proportions (r=0.22 and 0.41, respectively), and CD4+:CD8+ ratios (r=0.57), but a negative correlation with CD8+ proportions (r=−0.32). Conclusions This longitudinal study describes the distribution of lymphocyte subpopulations in premature infants and provides reference ranges for the major lymphocyte subsets to help guide clinicians when assessing premature infants for immunodeficiency in the first year of life. Trial registration number EudraCT 2007-007535-23

Development and evaluation of a gentamicin pharmacokinetic model that facilitates opportunistic gentamicin therapeutic drug monitoring in neonates and infants.

Trough gentamicin therapeutic drug monitoring (TDM) is time-consuming, disruptive to neonatal clinical care and a patient safety issue. Bayesian models could allow TDM to be performed opportunistically at the time of routine blood tests. This study aimed to develop and prospectively evaluate a new gentamicin model and a novel Bayesian computer tool (neoGent) for TDM use in neonatal intensive care. We also evaluated model performance for predicting peak concentrations and AUC(0-t). A pharmacokinetic meta-analysis was performed on pooled data from three studies (1325 concentrations from 205 patients). A 3-compartment model was used with covariates being: allometric weight scaling, postmenstrual and postnatal age, and serum creatinine. Final parameter estimates (standard error) were: clearance: 6.2 (0.3) L/h/70kg; central volume (V) 26.5 (0.6) L/70kg; inter-compartmental disposition: Q=2.2 (0.3) L/h/70kg, V2=21.2 (1.5) L/70kg, Q2=0.3 (0.05) L/h/70kg, V3=148 (52.0) L/70kg. The model's ability to predict trough concentrations from an opportunistic sample was evaluated in a prospective observational cohort study that included data from 163 patients with 483 concentrations collected in five hospitals. Unbiased trough predictions were obtained: median (95% confidence interval (CI)) prediction error was 0.0004 (-1.07, 0.84) mg/L. Results also showed peaks and AUC(0-t) could be predicted (from one randomly selected sample) with little bias but relative imprecision with median (95% CI) prediction error being 0.16 (-4.76, 5.01) mg/L and 10.8 (-24.9, 62.2) mg h/L, respectively. NeoGent was implemented in R/NONMEM, and in the freely available TDMx software

Rationing tests for drug-resistant tuberculosis - who are we prepared to miss?

BACKGROUND: Early identification of patients with drug-resistant tuberculosis (DR-TB) increases the likelihood of treatment success and interrupts transmission. Resource-constrained settings use risk profiling to ration the use of drug susceptibility testing (DST). Nevertheless, no studies have yet quantified how many patients with DR-TB this strategy will miss. METHODS: A total of 1,545 subjects, who presented to Lima health centres with possible TB symptoms, completed a clinic-epidemiological questionnaire and provided sputum samples for TB culture and DST. The proportion of drug resistance in this population was calculated and the data was analysed to demonstrate the effect of rationing tests to patients with multidrug-resistant TB (MDR-TB) risk factors on the number of tests needed and corresponding proportion of missed patients with DR-TB. RESULTS: Overall, 147/1,545 (9.5%) subjects had culture-positive TB, of which 32 (21.8%) had DR-TB (MDR, 13.6%; isoniazid mono-resistant, 7.5%; rifampicin mono-resistant, 0.7%). A total of 553 subjects (35.8%) reported one or more MDR-TB risk factors; of these, 506 (91.5%; 95% CI, 88.9-93.7%) did not have TB, 32/553 (5.8%; 95% CI, 3.4-8.1%) had drug-susceptible TB, and only 15/553 (2.7%; 95% CI, 1.5-4.4%) had DR-TB. Rationing DST to those with an MDR-TB risk factor would have missed more than half of the DR-TB population (17/32, 53.2%; 95% CI, 34.7-70.9). CONCLUSIONS: Rationing DST based on known MDR-TB risk factors misses an unacceptable proportion of patients with drug-resistance in settings with ongoing DR-TB transmission. Investment in diagnostic services to allow universal DST for people with presumptive TB should be a high priority

Direct Determination of Pyrazinamide (PZA) Susceptibility by Sputum Microscopic Observation Drug Susceptibility (MODS) Culture at Neutral pH: the MODS-PZA Assay.

Pyrazinamide (PZA) is considered the pivot drug in all tuberculosis treatment regimens due to its particular action on the persistent forms of Mycobacterium tuberculosis However, no drug susceptibility test (DST) is considered sufficiently reliable for routine application. Although molecular tests are endorsed, their application is limited to known PZA resistance associated mutations. Microbiological DSTs for PZA have been restricted by technical limitations, especially the necessity for an acidic pH. Here, for the first time, MODS culture at neutral pH was evaluated using high PZA concentrations (400 and 800 μg/ml) to determine PZA susceptibility directly from sputum samples. Sputum samples were cultured with PZA for up to 21 days at 37°C. Plate reading was performed at two time points: R1 (mean, 10 days) and R2 (mean, 13 days) for each PZA concentration. A consensus reference test, composed of MGIT-PZA, pncA sequencing, and the classic Wayne test, was used. A total of 182 samples were evaluated. The sensitivity and specificity for 400 μg/ml ranged from 76.9 to 89.7 and from 93.0 to 97.9%, respectively, and for 800 μg/ml ranged from 71.8 to 82.1 and from 95.8 to 98.6%, respectively. Compared to MGIT-PZA, our test showed a similar turnaround time (medians of 10 and 12 days for PZA-sensitive and -resistant isolates, respectively). In conclusion, MODS-PZA is presented as a fast, simple, and low-cost DST that could complement the MODS assay to evaluate resistance to the principal first-line antituberculosis drugs. Further optimization of test conditions would be useful in order to increase its performance

Feasibility of magnetic bead technology for concentration of mycobacteria in sputum prior to fluorescence microscopy

<p>Abstract</p> <p>Background</p> <p>Direct sputum smear microscopy is the mainstay of TB diagnosis in most low and middle income countries, and is highly specific for <it>Mycobacterium tuberculosis </it>in such settings. However it is limited by low sensitivity, particularly in HIV co-infected patients. Concentration by centrifugation has been reported to be more sensitive than direct smear preparation, but is only suitable for referral laboratories. Simpler concentration methods that could be applied in peripheral laboratories are urgently needed.</p> <p>Methods</p> <p>We evaluated the feasibility of an early prototype ligand-coated magnetic bead technology to concentrate <it>M. tuberculosis </it>prior to detection by LED-based fluorescence microscopy compared with direct Ziehl-Neelsen microscopy and direct and concentrated fluorescence microscopy in a reference laboratory in Kampala, Uganda. Results were compared with MGIT 960 liquid culture and Lowenstein-Jensen culture.</p> <p>Results</p> <p>Compared to culture, concentrated FM had significantly higher sensitivity than direct ZN (74.8% and 51.4%), magnetic bead-FM (65.4%) and direct FM (58.9%). The sensitivity of magnetic bead FM was significantly higher than direct ZN (p < 0.001) but not significantly higher than direct FM (p = 0.210). The specificity of magnetic bead FM and concentrated FM was significantly lower than direct ZN (88.6%, 94.3% and 98.9% respectively) and direct FM (99.4%). There was no significant difference in specificity between magnetic bead FM and concentrated FM. Allowing for blinded resolution of discrepant results, the specificity of magnetic bead FM increased to 93.1%. Direct microscopy was simpler than concentrated FM and Magnetic bead FM which both had a similar number of steps.</p> <p>Conclusion</p> <p>The sensitivity of the early prototype magnetic bead FM was lower than concentrated FM, similar to direct FM, and significantly higher than direct ZN. Both magnetic bead and concentration by centrifugation led to reduced specificity compared with the direct smear methods. Some magnetic bead FM false positive results were not easily explained and should be further investigated. The prototype version of the magnetic bead procedure tested here was of similar complexity to concentration by centrifugation. As such, if the sensitivity of the magnetic bead FM could be improved in future versions of the technology, this may offer a viable alternative to centrifugation.</p

Integrative analyses identify modulators of response to neoadjuvant aromatase inhibitors in patients with early breast cancer

Introduction Aromatase inhibitors (AIs) are a vital component of estrogen receptor positive (ER+) breast cancer treatment. De novo and acquired resistance, however, is common. The aims of this study were to relate patterns of copy number aberrations to molecular and proliferative response to AIs, to study differences in the patterns of copy number aberrations between breast cancer samples pre- and post-AI neoadjuvant therapy, and to identify putative biomarkers for resistance to neoadjuvant AI therapy using an integrative analysis approach. Methods Samples from 84 patients derived from two neoadjuvant AI therapy trials were subjected to copy number profiling by microarray-based comparative genomic hybridisation (aCGH, n = 84), gene expression profiling (n = 47), matched pre- and post-AI aCGH (n = 19 pairs) and Ki67-based AI-response analysis (n = 39). Results Integrative analysis of these datasets identified a set of nine genes that, when amplified, were associated with a poor response to AIs, and were significantly overexpressed when amplified, including CHKA, LRP5 and SAPS3. Functional validation in vitro, using cell lines with and without amplification of these genes (SUM44, MDA-MB134-VI, T47D and MCF7) and a model of acquired AI-resistance (MCF7-LTED) identified CHKA as a gene that when amplified modulates estrogen receptor (ER)-driven proliferation, ER/estrogen response element (ERE) transactivation, expression of ER-regulated genes and phosphorylation of V-AKT murine thymoma viral oncogene homolog 1 (AKT1). Conclusions These data provide a rationale for investigation of the role of CHKA in further models of de novo and acquired resistance to AIs, and provide proof of concept that integrative genomic analyses can identify biologically relevant modulators of AI response