Factors associated with health-seeking behavior among migrant workers in Beijing, China

<p>Abstract</p> <p>Background</p> <p>Migrant workers are a unique phenomenon in the process of China's economic transformation. The household registration system classifies them as temporary residents in cities, putting them in a vulnerable state with an unfair share of urban infrastructure and social public welfare. The amount of pressure inflicted by migrant workers in Beijing, as one of the major migration destinations, is currently at a threshold. This study was designed to assess the factors associated with health-seeking behavior and to explore feasible solutions to the obstacles migrant workers in China faced with when accessing health-care.</p> <p>Methods</p> <p>A sample of 2,478 migrant workers in Beijing was chosen by the multi-stage stratified cluster sampling method. A structured questionnaire survey was conducted via face-to-face interviews between investigators and subjects. The multilevel methodology (MLM) was used to demonstrate the independent effects of the explanatory variables on health seeking behavior in migrant workers.</p> <p>Results</p> <p>The medical visitation rate of migrant workers within the past two weeks was 4.8%, which only accounted for 36.4% of those who were ill. Nearly one-third of the migrant workers chose self-medication (33.3%) or no measures (30.3%) while ill within the past two weeks. 19.7% of the sick migrants who should have been hospitalized failed to receive medical treatment within the past year. According to self-reported reasons, the high cost of health service was a significant obstacle to health-care access for 40.5% of the migrant workers who became sick. However, 94.0% of the migrant workers didn't have any insurance coverage in Beijing. The multilevel model analysis indicates that health-seeking behavior among migrants is significantly associated with their insurance coverage. Meanwhile, such factors as household monthly income per capita and working hours per day also affect the medical visitation rate of the migrant workers in Beijing.</p> <p>Conclusion</p> <p>This study assesses the influence of socio-demographic characteristics on the migrant workers' decision to seek health care services when they fall ill, and it also indicates that the current health service system discourages migrant workers from seeking appropriate care of good quality. Relevant policies of public medical insurance and assistance program should be vigorously implemented for providing affordable health care services to the migrants. Feasible measures need to be taken to reduce the health risks associated with current hygiene practices and equity should be assured in access to health care services among migrant workers.</p

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Elevated exopolysaccharide levels in Pseudomonas aeruginosa flagellar mutants have implications for biofilm growth and chronic infections.

Pseudomonas aeruginosa colonizes the airways of cystic fibrosis (CF) patients, causing infections that can last for decades. During the course of these infections, P. aeruginosa undergoes a number of genetic adaptations. One such adaptation is the loss of swimming motility functions. Another involves the formation of the rugose small colony variant (RSCV) phenotype, which is characterized by overproduction of the exopolysaccharides Pel and Psl. Here, we provide evidence that the two adaptations are linked. Using random transposon mutagenesis, we discovered that flagellar mutations are linked to the RSCV phenotype. We found that flagellar mutants overexpressed Pel and Psl in a surface-contact dependent manner. Genetic analyses revealed that flagellar mutants were selected for at high frequencies in biofilms, and that Pel and Psl expression provided the primary fitness benefit in this environment. Suppressor mutagenesis of flagellar RSCVs indicated that Psl overexpression required the mot genes, suggesting that the flagellum stator proteins function in a surface-dependent regulatory pathway for exopolysaccharide biosynthesis. Finally, we identified flagellar mutant RSCVs among CF isolates. The CF environment has long been known to select for flagellar mutants, with the classic interpretation being that the fitness benefit gained relates to an impairment of the host immune system to target a bacterium lacking a flagellum. Our new findings lead us to propose that exopolysaccharide production is a key gain-of-function phenotype that offers a new way to interpret the fitness benefits of these mutations

<i>Pseudomonas aeruginosa</i> rugose small-colony variants evade host clearance, are hyper-inflammatory, and persist in multiple host environments

<div><p><i>Pseudomonas aeruginosa</i> causes devastating infections in immunocompromised individuals. Once established, <i>P</i>. <i>aeruginosa</i> infections become incredibly difficult to treat due to the development of antibiotic tolerant, aggregated communities known as biofilms. A hyper-biofilm forming clinical variant of <i>P</i>. <i>aeruginosa</i>, known as a rugose small-colony variant (RSCV), is frequently isolated from chronic infections and is correlated with poor clinical outcome. The development of these mutants during infection suggests a selective advantage for this phenotype, but it remains unclear how this phenotype promotes persistence. While prior studies suggest RSCVs could survive by evading the host immune response, our study reveals infection with the RSCV, PAO1Δ<i>wspF</i>, stimulated an extensive inflammatory response that caused significant damage to the surrounding host tissue. In both a chronic wound model and acute pulmonary model of infection, we observed increased bacterial burden, host tissue damage, and a robust neutrophil response during RSCV infection. Given the essential role of neutrophils in <i>P</i>. <i>aeruginosa</i>-mediated disease, we investigated the impact of the RSCV phenotype on neutrophil function. The RSCV phenotype promoted phagocytic evasion and stimulated neutrophil reactive oxygen species (ROS) production. We also demonstrate that bacterial aggregation and TLR-mediated pro-inflammatory cytokine production contribute to the immune response to RSCVs. Additionally, RSCVs exhibited enhanced tolerance to neutrophil-produced antimicrobials including H₂O₂ and the antimicrobial peptide LL-37. Collectively, these data indicate RSCVs elicit a robust but ineffective neutrophil response that causes significant host tissue damage. This study provides new insight on RSCV persistence, and indicates this variant may have a critical role in the recurring tissue damage often associated with chronic infections.</p></div

PAO1Δ<i>wspF</i> exhibits tolerance to neutrophil antimicrobial products.

<p>Log phase cultures of PAO1 or PAO1Δ<i>wspF</i> were treated with A) LL-37, B) H₂O₂ and C) HOCl at the labeled concentrations for 15min. CFUs were quantified before and after treatment and log fold killing determined. Data presented as mean ± SEM. ***p<0.001.</p

Bacterial aggregation promotes neutrophil ROS production, but exopolysaccharides alone are not sufficient.

<p>A) ePS was purified from PAO1Δ<i>pel</i>P_BAD-psl, PAO1Δ<i>psl</i>P_BAD-pel, or PAO1Δ<i>pel</i>Δ<i>psl</i> and total carbohydrate was quantified by phenol sulfuric acid assay. PAO1 levels or 10-times PAO1 levels of ePS was added to human neutrophils and the ROS response was measured with a luminol reporter. B) PAO1Δ<i>psl</i>Δ<i>pel</i>/pHERD20T and PAO1Δ<i>psl</i>Δ<i>pel</i>/pCdrAB were grown to log phase in the presence of 1% arabinose leading to the formation of CdrA-mediated aggregates in the strain containing pCdrAB. Primary human neutrophils were infected with bacteria at an MOI (1:50). C) Neutrophils were treated with supernatant collected from cultures of PAO1/pCdrAB or PAO1Δ<i>cdrA</i>/pHERD20T, and ROS was quantified. The AUC of the ROS response over 1h was calculated and normalized by CFUs of the inoculation culture to ensure identical cell numbers regardless of aggregation.</p

D-PAO1Δ<i>wspF</i> pulmonary infection leads to severe tissue damage and neutrophil infiltration compared to PAO1 infection.

<p>Mouse lungs 24 h.p.i. were stained with H&E to assess neutrophil infiltration and lung damage based on pulmonary architecture, necrosis, and suppurative inflammation. Images are representative of lungs treated or infected with A) PBS, B) PAO1, C) PAO1Δ<i>wspF</i>, D) D-PAO1Δ<i>wspF</i>. Scale bars indicate 200μm.</p

PAO1Δ<i>wspF</i> induces pro-inflammatory cytokine production in a TLR-dependent manner.

<p>NR-9456 wild type and NR-15632 MyD88^-/-/TRIF^-/- mouse macrophages were infected with PAO1 or PAO1Δ<i>wspF</i> for 4h. A) IL-1β and B) IL-6 was measured in cell supernatants via ELISA. ** p< 0.01. Data presented as mean ± SEM.</p

RSCVs persist during a model for chronic burn wound infection and inhibit wound healing.

<p>Porcine burn injuries were infected after 3 days with PAO1 or PAO1Δ<i>wspF</i>. A) Wound biopsies were quantified for CFUs. B and C) CLSM was used to assess bacterial burden. <i>P</i>. <i>aeruginosa</i> was stained with Alexa Fluor 488 (green) and host tissue with DAPI (blue). Area of green fluorescence was quantified. Scale bars indicate 35μm. D and E) Wound strips were H&E stained to assess re-epithelization 35 d.p.i. The distance between epithelial tongues (ET) in H&E stained tissue sections was measured. Due to H&E size constraints, images in panel D were generated by merging scans from two different slides containing half of the biopsy. Data presented as mean ± SEM. *p<0.05, **p<0.01, ***p<0.001.</p