Monthly mean simulation experiments with a course-mesh global atmospheric model

Substitution of observed monthly mean sea-surface temperatures (SSTs) as lower boundary conditions, in place of climatological SSTs, failed to improve the model simulations. While the impact of SST anomalies on the model output is greater at sea level than at upper levels the impact on the monthly mean simulations is not beneficial at any level. Shifts of one and two days in initialization time produced small, but non-trivial, changes in the model-generated monthly mean synoptic fields. No improvements in the mean simulations resulted from the use of either time-averaged initial data or re-initialization with time-averaged early model output. The noise level of the model, as determined from a multiple initial state perturbation experiment, was found to be generally low, but with a noisier response to initial state errors in high latitudes than the tropics

'Atypical' bacteria are a common cause of community-acquired pneumonia in hospitalised adults

Objectives. To assess the proportion of cases of community· acquired pneumonia caused by 'atypical' bacteria, inclUding the recently discovered Chlamydia pneumoniae, and to compare the clinical, radiographic and laboratory features of patients with and without 'atypical' bacteria.Methods. A prospective serological study was carried out on consecutive adult pneumonia patients from July 1987 to July 1988. Acute and convalescent sera were tested in batches for antibodies against Legionella pneumophila serogroup 1, C. pneumoniae, Chlamydia psittaci, Coxiella burnetii (phase-2 antigen) and Mycoplasma pneumoniae (lgG and IgM). Records and chest radiographs were examined retrospectively.Results. Acute and convalescent sera were available from 113 patients. The records of 4 patients could not be traced and 17 patients did not fulfil the inclusion criteria. Thirty-two of these 92 patients (35,9%) were found to be infected with 'atypical' bacteria. The two most common organisms were C. pneumoniae (20,7%) and L. pneumophila (8,7%). There. were no differences in the clinical and radiographic features of patients with and without 'atypical' bacteria. Clinicians prescribed erythromycin or tetracyclines with equal frequency in the two groups.Conclusions. 'Atypical' bacteria, especially C. pneumoniae, are a common cause of community-acquired pneumonia in adults in South Africa. This is the first demonstration of an aetiological role of C. pneumoniae in this country. We confirmed the finding of other studies that there are no clinical, radiographic or laboratory features characteristic of 'atypical' bacterial infection in hospitalised patients. This has major implications for therapy, as these organisms respond to erythromycin and tetracyclines, but· not to β-lactam antibiotics

Impact of 13-valent pneumococcal conjugate vaccine (PCV13) in a pandemic similar to the 2009 H1N1 in the United States

Background: High rates of bacterial coinfection in autopsy data from the 2009 H1N1 influenza (“flu”) pandemic suggest synergies between flu and pneumococcal disease (PD) during pandemic conditions, and highlight the importance of interventions like the 13-valent pneumococcal conjugate vaccine (PCV13) that may mitigate the impact of a pandemic. Methods: We used a decision-analytic model, estimated from published sources, to assess the impact of pediatric vaccination with PCV13 versus the 7-valent vaccine (PCV7) on PD incidence and mortality in a normal flu season (10% flu incidence) and in a pandemic similar to 2009-2010 H1N1 (20% flu incidence, mild virulence, high impact in children). Both direct and indirect (herd) effects against PD were considered. Effectiveness of PCV13 was extrapolated from observed PCV7 data, using assumptions of serotype prevalence and PCV13 protection against the 6 serotypes not in PCV7. To simulate 2009–2010 H1N1, autopsy data were used to estimate the overall proportion of flu deaths with bacterial coinfections. By assuming that increased risk of death during the pandemic occurred among those with comorbidity (using obesity as proxy) and bacterial coinfections primarily due to S. pneumoniae or S. aureus, we estimated the proportion co-infected among all (fatal and non-fatal) flu cases (7.6% co-infected with any organism; 2.2% with S. pneumoniae). PD incidence, mortality, and total healthcare costs were evaluated over a 1-year horizon. Results: In a normal flu season, compared to PCV7, PCV13 is expected to prevent an additional 13,400 invasive PD (IPD) cases, 399,000 pneumonia cases, and 2,900 deaths, leading to cost savings of $472 M. In a pandemic similar to 2009–2010 H1N1, PCV13 would prevent 22,800 IPD cases, 872,000 pneumonia cases, and 3,700 deaths, resulting in cost savings of$1.0 B compared to PCV7. Conclusions: In a flu pandemic similar to the 2009–2010 H1N1, protection against the 6 additional serotypes in PCV13 would likely be effective in preventing pandemic-related PD cases, mortality, and associated costs

Maternal Influenza Immunization and Reduced Likelihood of Prematurity and Small for Gestational Age Births: A Retrospective Cohort Study

In an analysis of surveillance data from the state of Georgia (US), Saad Omer and colleagues show an association between receipt of influenza vaccination among pregnant women and reduced risk of premature births

Pulmonary alveolar proteinosis in a child from an informal settlement : 12 litres of fluid drained from the lungs and successful use of ECMO

Pulmonary alveolar proteinosis (PAP) is a rare cause of chronic interstitial lung disease, characterised by accumulation of pulmonary surfactant, respiratory insufficiency and an increased incidence of infections. The current standard therapy is whole-lung lavage to remove the accumulated surfactant. We report on a cachexic 12-year-old boy from an informal settlement in South Africa, presenting for the first time with PAP. Twelve litres of broncho-alveolar lavage fluid were drained under extracorporeal membrane oxygenation, and the patient gained 10 kg during his 2-month admission.http://www.sajch.org.za/index.php/SAJCHam2014ay201

Impact of Experimental Human Pneumococcal Carriage on Nasopharyngeal Bacterial Densities in Healthy Adults

Colonization of the nasopharynx by Streptococcus pneumoniae is a necessary precursor to pneumococcal diseases that result in morbidity and mortality worldwide. The nasopharynx is also host to other bacterial species, including the common pathogens Staphylococcus aureus, Haemophilus influenzae, and Moraxella catarrhalis. To better understand how these bacteria change in relation to pneumococcal colonization, we used species-specific quantitative PCR to examine bacterial densities in 52 subjects 7 days before, and 2, 7, and 14 days after controlled inoculation of healthy human adults with S. pneumoniae serotype 6B. Overall, 33 (63%) of subjects carried S. pneumoniae post-inoculation. The baseline presence and density of S. aureus, H. influenzae, and M. catarrhalis were not statistically associated with likelihood of successful pneumococcal colonization at this study’s sample size, although a lower rate of pneumococcal colonization in the presence of S. aureus (7/14) was seen compared to that in the presence of H. influenzae (12/16). Among subjects colonized with pneumococci, the number also carrying either H. influenzae or S. aureus fell during the study and at 14 days post-inoculation, the proportion carrying S. aureus was significantly lower among those who were colonized with S. pneumoniae (p = 0.008) compared to non-colonized subjects. These data on bacterial associations are the first to be reported surrounding experimental human pneumococcal colonization and show that co-colonizing effects are likely subtle rather than absolute

Effects of ecstasy/polydrug use on memory for associative information

Rationale Associative learning underpins behaviours that are fundamental to the everyday functioning of the individual. Evidence pointing to learning deficits in recreational drug users merits further examination. Objectives A word pair learning task was administered to examine associative learning processes in ecstasy/polydrug users. Methods After assignment to either single or divided attention conditions, 44 ecstasy/polydrug users and 48 non-users were presented with 80 word pairs at encoding. Following this, four types of stimuli were presented at the recognition phase: the words as originally paired (old pairs), previously presented words in different pairings (conjunction pairs), old words paired with new words, and pairs of new words (not presented previously). The task was to identify which of the stimuli were intact old pairs. Results Ecstasy/ploydrug users produced significantly more false-positive responses overall compared to non-users. Increased long-term frequency of ecstasy use was positively associated with the propensity to produce false-positive responses. It was also associated with a more liberal signal detection theory decision criterion value. Measures of long term and recent cannabis use were also associated with these same word pair learning outcome measures. Conjunction word pairs, irrespective of drug use, generated the highest level of false-positive responses and significantly more false-positive responses were made in the divided attention condition compared to the single attention condition. Conclusions Overall, the results suggest that long-term ecstasy exposure may induce a deficit in associative learning and this may be in part a consequence of users adopting a more liberal decision criterion value

Modeling the impact of the 13-valent pneumococcal conjugate vaccine serotype catch-up program using United States claims data

Background: Analysis of US claims data from April 2010 to June 2011 estimated that 39% of the 13-valent pneumococcal conjugate vaccine (PCV13) catch-up eligible cohort would ever receive the catch-up vaccination; a previous analysis assumed 87%. Methods: This updated figure was applied to a previously published 10-year Markov model while holding all other inputs constant. Results: Our model estimated that the catch-up program as currently implemented is estimated to prevent an additional 1.7 million cases of disease in children aged ≤59 months over a 10-year period, compared with routine PCV13 vaccination with no catch-up program. Conclusions: Because 39% catch-up uptake is less than the level of completion of the 4-dose primary PCV13 series, vaccine-preventable cases of pneumococcal disease and related deaths could be decreased further with additional uptake of catch-up vaccination in the catch-up eligible cohort

Increase in Pneumococcus Macrolide Resistance, United States

During year 6 of the study, the incidence rate rose from ≈30% to 35.3%