A randomised controlled trial of long NY-ESO-1 peptide-pulsed autologous dendritic cells with or without alpha-galactosylceramide in high-risk melanoma.

AIM: We have previously reported that polyfunctional T cell responses can be induced to the cancer testis antigen NY-ESO-1 in melanoma patients injected with mature autologous monocyte-derived dendritic cells (DCs) loaded with long NY-ESO-1-derived peptides together with α-galactosylceramide (α-GalCer), an agonist for type 1 Natural Killer T (NKT) cells. OBJECTIVE: To assess whether inclusion of α-GalCer in autologous NY-ESO-1 long peptide-pulsed DC vaccines (DCV + α-GalCer) improves T cell responses when compared to peptide-pulsed DC vaccines without α-GalCer (DCV). DESIGN, SETTING AND PARTICIPANTS: Single-centre blinded randomised controlled trial in patients ≥ 18 years old with histologically confirmed, fully resected stage II-IV malignant cutaneous melanoma, conducted between July 2015 and June 2018 at the Wellington Blood and Cancer Centre of the Capital and Coast District Health Board. INTERVENTIONS: Stage I. Patients were randomised to two cycles of DCV or DCV + α-GalCer (intravenous dose of 10 × 106 cells, interval of 28 days). Stage II. Patients assigned to DCV + α-GalCer were randomised to two further cycles of DCV + α-GalCer or observation, while patients initially assigned to DCV crossed over to two cycles of DCV + α-GalCer. OUTCOME MEASURES: Primary: Area under the curve (AUC) of mean NY-ESO-1-specific T cell count detected by ex vivo IFN-γ ELISpot in pre- and post-treatment blood samples, compared between treatment arms at Stage I. Secondary: Proportion of responders in each arm at Stage I; NKT cell count in each arm at Stage I; serum cytokine levels at Stage I; adverse events Stage I; T cell count for DCV + α-GalCer versus observation at Stage II, T cell count before versus after cross-over. RESULTS: Thirty-eight patients gave written informed consent; 5 were excluded before randomisation due to progressive disease or incomplete leukapheresis, 17 were assigned to DCV, and 16 to DCV + α-GalCer. The vaccines were well tolerated and associated with increases in mean total T cell count, predominantly CD4+ T cells, but the difference between the treatment arms was not statistically significant (difference - 6.85, 95% confidence interval, - 21.65 to 7.92; P = 0.36). No significant improvements in T cell response were associated with DCV + α-GalCer with increased dosing, or in the cross-over. However, the NKT cell response to α-GalCer-loaded vaccines was limited compared to previous studies, with mean circulating NKT cell levels not significantly increased in the DCV + α-GalCer arm and no significant differences in cytokine response between the treatment arms. CONCLUSIONS: A high population coverage of NY-ESO-1-specific T cell responses was achieved with a good safety profile, but we failed to demonstrate that loading with α-GalCer provided an additional advantage to the T cell response with this cellular vaccine design. CLINICAL TRIAL REGISTRATION: ACTRN12612001101875. Funded by the Health Research Council of New Zealand.

On the robustness of latent class models for diagnostic testing with no gold standard.

It is difficult to estimate sensitivity and specificity of diagnostic tests when there is no gold standard. Latent class models have been proposed as a potential solution as they provide estimates without the need for a gold standard. Using a motivating example of the evaluation of point of care tests for leptospirosis in Tanzania, we show how a realistic violation of assumptions underpinning the latent class model can lead directly to substantial bias in the estimates of the parameters of interest. In particular, we consider the robustness of estimates of sensitivity, specificity, and prevalence, to the presence of additional latent states when fitting a two-state latent class model. The violation is minor in the sense that it cannot be routinely detected with goodness-of-fit procedures, but is major with regard to the resulting bias.

Child undernutrition in households with microbiologically safer drinking water and 'improved water' in Tanna, Vanuatu.

The Sustainable Development Goal drinking water indicators include microbiological safety measures, whereas the Millennium Development Goal indicator 'improved water' may be microbiologically unsafe. In rural Vanuatu, we undertook household surveys, child anthropometry, and tested stored drinking water, to investigate relationships between water and undernutrition. Using Escherichia coli most probable number, we categorized results according to Compartment Bag Test drinking water cutoffs: <1/100 mL (safe), 1-10/100 mL (intermediate risk), >10-100/100 mL (high risk), and >100/100 mL (very high risk). Of 201 households, 191 (95%) had microbiologically unsafe drinking water, regardless of 'improved' status. We investigated cross-sectional associations between households with microbiologically safer drinking water (≤10 E. coli/100 mL) versus 'improved water' and undernutrition among children. Of children under 5, 145 (48.8%, 95% CI: 42.8, 54.8) were stunted and 59 (19.1%, 95% CI: 14.4, 23.8) were underweight. Among households with 'improved water', the adjusted prevalence ratio (95% CI) of stunting was 0.61 (0.46, 0.80) and underweight was 0.46 (0.29, 0.73) compared with 'unimproved water'. However, we found no association between having drinking water with ≤10 E. coli/100 mL at one point in time and undernutrition. Longer-term variations in water quality and unmeasured conditions beyond water may have contributed to these associations.

Estimating acute human leptospirosis incidence in northern Tanzania using sentinel site and community behavioural surveillance.

Many infectious diseases lack robust estimates of incidence from endemic areas, and extrapolating incidence when there are few locations with data remains a major challenge in burden of disease estimation. We sought to combine sentinel surveillance with community behavioural surveillance to estimate leptospirosis incidence. We administered a questionnaire gathering responses on established locally relevant leptospirosis risk factors and recent fever to livestock-owning community members across six districts in northern Tanzania and applied a logistic regression model predicting leptospirosis risk on the basis of behavioural factors that had been previously developed among patients with fever in Moshi Municipal and Moshi Rural Districts. We aggregated probability of leptospirosis by district and estimated incidence in each district by standardizing probabilities to those previously estimated for Moshi Districts. We recruited 286 community participants: Hai District (n = 11), Longido District (59), Monduli District (56), Moshi Municipal District (103), Moshi Rural District (44) and Rombo District (13). The mean predicted probability of leptospirosis by district was Hai 0.029 (0.005, 0.095), Longido 0.071 (0.009, 0.235), Monduli 0.055 (0.009, 0.206), Moshi Rural 0.014 (0.002, 0.049), Moshi Municipal 0.015 (0.004, 0.048) and Rombo 0.031 (0.006, 0.121). We estimated the annual incidence (upper and lower bounds of estimate) per 100,000 people of human leptospirosis among livestock owners by district as Hai 35 (6, 114), Longido 85 (11, 282), Monduli 66 (11, 247), Moshi Rural 17 (2, 59), Moshi Municipal 18 (5, 58) and Rombo 47 (7, 145). Use of community behavioural surveillance may be a useful tool for extrapolating disease incidence beyond sentinel surveillance sites.

Risk factors for Staphylococcus capitis pulsotype NRCS-A colonisation among premature neonates in the neonatal intensive care unit of a tertiary-care hospital: a retrospective case-control study.

BACKGROUND: A S. capitis strain called NRCS-A (S. capitis NRCS-A) has emerged as a cause of bloodstream infections and sepsis in neonatal intensive care units (NICUs) worldwide. AIM: To identify risk factors for S. capitis NRCS-A colonisation among neonates, Dunedin Hospital NICU, Dunedin, New Zealand, from September 2013 through March 2015. METHODS: Weekly axillary swabs categorised eligible neonates as a case or a control. A case was defined as a week ending with a neonate's first positive swab for S. capitis NRCS-A and a control as a week in which a neonate remained negative. Weekly exposures were abstracted from hospital medical records. Analyses were performed using conditional logistic regression. FINDINGS: The median (range) gestational age at birth of participants was 32.7 (23.1-41.3) weeks. Participants contributed 26 weeks of case data and 177 weeks of control data. On adjusted analysis compared with matched controls, cases had higher odds of requiring invasive mechanical ventilation (OR 3.6, 95% CI: 1.1-11.6, p=0.035) and of a patent ductus arteriosus (PDA) (OR 3.0, 95% CI: 1.0-9.0, p=0.044). Cases had lower odds of being part of a multiple birth (OR 0.24, 95% CI 0.08-0.73, p=0.001), having an area of inflamed skin (OR 0.31, 95% CI: 0.13-0.75, p=0.009), and specifically an area of inflamed axillary skin (OR 0.08, 95% CI: 0.01-0.50, p=0.006). CONCLUSIONS: We found that premature neonates with invasive mechanical ventilation and PDA had greater odds for S. capitis NRCS-A colonisation. Transmission may be mediated by increased staff contact, but prospective research is needed to confirm this.

Risk factors for human acute leptospirosis in northern Tanzania.

INTRODUCTION: Leptospirosis is a major cause of febrile illness in Africa but little is known about risk factors for human infection. We conducted a cross-sectional study to investigate risk factors for acute leptospirosis and Leptospira seropositivity among patients with fever attending referral hospitals in northern Tanzania. METHODS: We enrolled patients with fever from two referral hospitals in Moshi, Tanzania, 2012-2014, and performed Leptospira microscopic agglutination testing on acute and convalescent serum. Cases of acute leptospirosis were participants with a four-fold rise in antibody titers, or a single reciprocal titer ≥800. Seropositive participants required a single titer ≥100, and controls had titers <100 in both acute and convalescent samples. We administered a questionnaire to assess risk behaviors over the preceding 30 days. We created cumulative scales of exposure to livestock urine, rodents, and surface water, and calculated odds ratios (OR) for individual behaviors and for cumulative exposure variables. RESULTS: We identified 24 acute cases, 252 seropositive participants, and 592 controls. Rice farming (OR 14.6), cleaning cattle waste (OR 4.3), feeding cattle (OR 3.9), farm work (OR 3.3), and an increasing cattle urine exposure score (OR 1.2 per point) were associated with acute leptospirosis. CONCLUSIONS: In our population, exposure to cattle and rice farming were risk factors for acute leptospirosis. Although further data is needed, these results suggest that cattle may be an important source of human leptospirosis. Further investigation is needed to explore the potential for control of livestock Leptospira infection to reduce human disease.

The New Zealand PIPER Project: colorectal cancer survival according to rurality, ethnicity and socioeconomic deprivation-results from a retrospective cohort study.

AIM: To investigate differences in survival after diagnosis with colorectal cancer (CRC) by rurality, ethnicity and deprivation. METHODS: In this retrospective cohort study, clinical records and National Collections data were merged for all patients diagnosed with CRC in New Zealand in 2007-2008. Prioritised ethnicity was classified using New Zealand Cancer Registry data; meshblock of residence at diagnosis was used to determine rurality and socioeconomic deprivation. RESULTS: Of the 4,950 patients included, 1,938 had died of CRC by May 2014. The five-year risks of death from CRC were: Maori 47%; Pacific 59%; non-Maori-non-Pacific (nMnP) 38%. After adjustment for demographic characteristics, comorbidity and disease stage at diagnosis, compared to nMnP the relative risk (RR) for Maori was 1.1 (95%CI: 0.8-1.3) and for Pacific 1.8 (95% CI: 1.4-2.5). We found no differences in risk of death from CRC by rurality, but some differences by deprivation. CONCLUSIONS: Disparity in outcome following diagnosis with CRC exists in New Zealand. Much of this disparity can be explained by stage of disease at diagnosis for Maori, but for Pacific peoples and those in deprived areas other factors may influence outcome. Further analyses of the PIPER data will explore the impact of any differences in management.

Outcomes for women without conventional treatment for stage 1A (microinvasive) carcinoma of the cervix.

BACKGROUND: An unethical clinical study that entailed withholding treatment from women diagnosed with cervical intraepithelial neoplasia 3 (CIN3) was conducted at National Women's Hospital, Auckland, New Zealand. Women with microinvasive carcinoma of the cervix also had treatment withheld. AIMS: To describe the management and outcomes for women with microinvasive carcinoma for many of whom conventional treatment was withheld. MATERIALS AND METHODS: Retrospective cohort study of women with a diagnosis of stage 1A cervical carcinoma at National Women's Hospital. Medical records, cytology and histopathology were reviewed and data linked with cancer and death registries up to December 2000. RESULTS: Between 1955 and 1976, 62 women were initially diagnosed with stage 1A cervical cancer and 20 were diagnosed during follow up (to 1995). Sixty of the 82 women had initial management characterised as 'probably non-curative'; 20 of these received only a small diagnostic excision. Women in the latter group were more likely to: (i) subsequently have positive cytology (P < 0.0005), (ii) have untreated positive cytology (P = 0.02), and (iii) undergo multiple biopsies after initial management (P = 0.001). Of the women who received only a small diagnostic excision, eight of 20 developed invasive carcinoma of the cervix (≥ stage 1B) or vaginal vault, compared to two of 22 women who received initial treatment characterised as 'probably curative'. CONCLUSIONS: Women with microinvasive carcinoma were included in a natural history study of CIN3; they underwent numerous procedures designed to observe rather than treat their condition, and had a substantial risk of invasive cancer.

Risk Factors for Human Brucellosis in Northern Tanzania.

Little is known about the epidemiology of human brucellosis in sub-Saharan Africa. This hampers prevention and control efforts at the individual and population levels. To evaluate risk factors for brucellosis in northern Tanzania, we conducted a study of patients presenting with fever to two hospitals in Moshi, Tanzania. Serum taken at enrollment and at 4-6 week follow-up was tested by Brucella microagglutination test. Among participants with a clinically compatible illness, confirmed brucellosis cases were defined as having a ≥ 4-fold rise in agglutination titer between paired sera or a blood culture positive for Brucella spp., and probable brucellosis cases were defined as having a single reciprocal titer ≥ 160. Controls had reciprocal titers < 20 in paired sera. We collected demographic and clinical information and administered a risk factor questionnaire. Of 562 participants in the analysis, 50 (8.9%) had confirmed or probable brucellosis. Multivariable analysis showed that risk factors for brucellosis included assisting goat or sheep births (Odds ratio [OR] 5.9, 95% confidence interval [CI] 1.4, 24.6) and having contact with cattle (OR 1.2, 95% CI 1.0, 1.4). Consuming boiled or pasteurized dairy products was protective against brucellosis (OR 0.12, 95% CI 0.02, 0.93). No participants received a clinical diagnosis of brucellosis from their healthcare providers. The under-recognition of brucellosis by healthcare workers could be addressed with clinician education and better access to brucellosis diagnostic tests. Interventions focused on protecting livestock keepers, especially those who assist goat or sheep births, are needed.

A phase I vaccination study with dendritic cells loaded with NY-ESO-1 and α-galactosylceramide: induction of polyfunctional T cells in high-risk melanoma patients.

Vaccines that elicit targeted tumor antigen-specific T-cell responses have the potential to be used as adjuvant therapy in patients with high risk of relapse. However, the responses induced by vaccines in cancer patients have generally been disappointing. To improve vaccine function, we investigated the possibility of exploiting the immunostimulatory capacity of type 1 Natural killer T (NKT) cells, a cell type enriched in lymphoid tissues that can trigger improved antigen-presenting function in dendritic cells (DCs). In this phase I dose escalation study, we treated eight patients with high-risk surgically resected stage II-IV melanoma with intravenous autologous monocyte-derived DCs loaded with the NKT cell agonist α-GalCer and peptides derived from the cancer testis antigen NY-ESO-1. Two synthetic long peptides spanning defined immunogenic regions of the NY-ESO-1 sequence were used. This therapy proved to be safe and immunologically effective, inducing increases in circulating NY-ESO-1-specific T cells that could be detected directly ex vivo in seven out of eight patients. These responses were achieved using as few as 5 × 105 peptide-loaded cells per dose. Analysis after in vitro restimulation showed increases in polyfunctional CD4+ and CD8+ T cells that were capable of manufacturing two or more cytokines simultaneously. Evidence of NKT cell proliferation and/or NKT cell-associated cytokine secretion was seen in most patients. In light of these strong responses, the concept of including NKT cell agonists in vaccine design requires further investigation.

Simvastatin dose and acute kidney injury without concurrent serious muscle injury: A nationwide nested case-control study.

BACKGROUND: Inconsistent findings from four observational studies suggest that the risk of acute kidney injury (AKI) may increase with increasing statin dose or potency, but none of the studies took statin-related severe muscle injury, including rhabdomyolysis, into account. We undertook a nationwide nested case-control study in New Zealand to examine the risk of AKI without concurrent serious muscle injury according to simvastatin dose in two cohorts: people without a history of renal disease and people with non-dialysis dependent chronic kidney disease. MATERIALS AND METHODS: A total of 334,710 people aged ≥ 18 years without a history of renal disease (cohort 1) and 5,437 with non-dialysis dependent chronic kidney disease (cohort 2) who initiated simvastatin therapy between 1 January 2006 and 31 December 2013 were identified using national pharmaceutical dispensing and hospital discharge data. Patients who developed AKI without concurrent serious muscle injury during follow-up (cases) were ascertained using hospital discharge and mortality data (n = 931 from cohort 1, n = 160 from cohort 2). Up to 10 controls per case, matched by date of birth, sex, and cohort entry date were randomly selected from the relevant cohort using risk set sampling. RESULTS: Relative to current use of 20mg simvastatin daily, the adjusted odds ratios and 95% confidence intervals (95% CI) in cohort 1 for current use of 40mg and 80mg were 0.9 (95% CI 0.7-1.2) and 1.3 (95% CI 0.7-2.3), respectively. The adjusted odds ratio for 40mg in cohort 2 was 1.1 (95% CI 0.7-1.9); the numbers taking 80mg were very small and the confidence interval was correspondingly wide. CONCLUSION: The findings of this study suggest that a relationship between statin dose and AKI may not exist independent of serious muscle injury.

Demographic and regional disparities in insulin pump utilization in a setting of universal funding: a New Zealand nationwide study.

AIMS: Insulin pumps have been publically funded in New Zealand since 2012 for patients who meet certain clinical criteria; however, the patterns of utilization have not been described. We undertook a nationwide study to estimate the annual proportions of patients with type 1 diabetes mellitus who used a pump between 2012 and 2014, overall, and according to sex, age, ethnicity, socioeconomic position, and region. METHODS: We used data from the New Zealand Virtual Diabetes Register and routinely collected national demographic, health, and pharmaceutical dispensing data from the Ministry of Health to identify patients with type 1 diabetes and to calculate the overall, and subgroup, proportions using pumps. RESULTS: Between 2012 and 2014, funded pump use among patients with type 1 diabetes (n = 13,727) increased from 1.8 to 9.3 % overall; however, there were differences in uptake according to demographic characteristics and region. In 2014, proportionate pump use was significantly higher in females versus males (adjusted odds ratio (OR) 2.0 [95 % confidence interval 1.8-2.3]), in those aged <20 years, and in some regions. Maori (indigenous people), Pacific, and Asian patients were significantly less likely to use pumps than New Zealand Europeans (ORs 0.30 [0.23-0.41], 0.26 [0.14-0.46], 0.22 [0.14-0.35], respectively), as were those in the most versus the least deprived socioeconomic decile (OR 0.36 [0.25-0.52]). CONCLUSIONS: It is essential to explore the factors driving differential insulin pump uptake, in both New Zealand and elsewhere, if all patients are to have equal opportunity to benefit from intensive diabetes management.

Methods of a national colorectal cancer cohort study: the PIPER Project.

AIM: Colorectal cancer is one of the most common cancers, and second-leading cause of cancer-related death, in New Zealand. The PIPER (Presentations, Investigations, Pathways, Evaluation, Rx [treatment]) project was undertaken to compare presentation, investigations, management and outcomes by rurality, ethnicity and deprivation. This paper reports the methods of the project, a comparison of PIPER patient diagnoses to the New Zealand Cancer Registry (NZCR) data, and the characteristics of the PIPER cohort. METHOD: National, retrospective cohort review of secondary care medical records (public and private) of all cases of ICD-10-AM C18-C20 on the NZCR in the calendar years 2007 and 2008 (main cohort) and an extended sample of Maori and Pacific cases, and non-Maori non-Pacific controls in 2006 and 2009 (extended cohort). RESULTS: Of the 6,387 patients identified from the NZCR 5,610 (88%) were eligible for PIPER. Reasons for exclusion were non-adenocarcinoma histology (3%) and non-colorectal primary (2%). Data were collected on 3,695 patients with colon cancer, 1,385 with rectal cancer and 466 with cancer of the recto sigmoid junction. CONCLUSIONS: The PIPER Project has generated comprehensive population level data detailing the diagnosis and management of colorectal adenocarcinoma in New Zealand. This will be used to assess the care provided to patients, and the impact of variations in care occurring between patient groups.

Community prevalence of fever and relationship with malaria among infants and children in low-resource areas.

We used Demographic and Health Survey data to describe the 2-week period prevalence of fever, cough, and diarrhea among children aged < 5 years in low-resources areas. We then explored the relationship between prevalence of isolated fever and national malaria risk. Fever and isolated fever occurred in 26.7% and 7.0% of children, respectively, and was not fully explained by malaria.

Dendritic cell vaccination combined with temozolomide retreatment: results of a phase I trial in patients with recurrent glioblastoma multiforme.

There is no standard treatment for recurrent glioblastoma multiforme (GBM). Retreatment with temozolomide (TMZ) is one treatment option. We reasoned this could be more effective if combined with a vaccine that preferentially targeted TMZ-resistant cells. To test the feasibility and safety of such an approach, a phase 1 trial was conducted in which patients with GBM tumors relapsing after standard chemoradiotherapy were retreated with TMZ in combination with a vaccine consisting of monocyte-derived dendritic cells (DC) pulsed with autologous tumor cells that had previously been exposed to TMZ in vivo in the course of primary treatment. Of 14 participants, nine patients completed the initial phase of priming vaccinations and two cycles of TMZ, one proved to have radionecrosis, one rapidly progressed, and in three the yield of DC vaccine was insufficient to proceed with treatment. Other than expected toxicities related to TMZ, there were no adverse events attributable to the combined treatment. Two patients had objective radiological responses. Six month progression-free survival was 22 %, similar to retreatment with TMZ alone. Anti-tumor immune responses were assessed in peripheral blood mononuclear cells using interferon-γ ELISpot, with two patients meeting criteria for a vaccine-induced immune response, one of whom remained disease-free for nearly three years. Another patient with an anti-tumor immune response at baseline that was sustained post-vaccination experienced a 12-month period of progression-free survival. In summary, the combined treatment was safe and well-tolerated but feasibility in the recurrent setting was marginal. Evidence of immune responses in a few patients broadly correlated with better clinical outcome.

Pseudomonas aeruginosa uses multiple pathways to acquire iron during chronic infection in cystic fibrosis lungs.

Pseudomonas aeruginosa chronically infects the lungs of more than 80% of adult patients with cystic fibrosis (CF) and is a major contributor to the progression of disease pathology. P. aeruginosa requires iron for growth and has multiple iron uptake systems that have been studied in bacteria grown in laboratory culture. The purpose of this research was to determine which of these are active during infection in CF. RNA was extracted from 149 sputum samples obtained from 23 CF patients. Reverse transcription-quantitative real-time PCR (RT-qPCR) was used to measure the expression of P. aeruginosa genes encoding transport systems for the siderophores pyoverdine and pyochelin, for heme, and for ferrous ions. Expression of P. aeruginosa genes could be quantified in 89% of the sputum samples. Expression of genes associated with siderophore-mediated iron uptake was detected in most samples but was at low levels in some samples, indicating that other iron uptake mechanisms are active. Expression of genes encoding heme transport systems was also detected in most samples, indicating that heme uptake occurs during infection in CF. feoB expression was detected in all sputum samples, implying an important role for ferrous ion uptake by P. aeruginosa in CF. Our data show that multiple P. aeruginosa iron uptake mechanisms are active in chronic CF infection and that RT-qPCR of RNA extracted from sputum provides a powerful tool for investigating bacterial physiology during infection in CF.

Capture-recapture using multiple data sources: estimating the prevalence of diabetes.

OBJECTIVE: To examine the potential for using multiple list sources and capture-recapture methods for estimating the prevalence of diagnosed diabetes. METHOD: A model-averaging procedure using an adjusted Akaike's Information Criterion (QAICc) was used to combine capture-recapture estimates from log-linear models obtained from simultaneously analysing four sources of data. The method was illustrated using four separate lists of patients with diabetes, resident in Otago, New Zealand. RESULTS: Eighteen candidate models with a QAICc weight of more than 0.01 were obtained. A total of 5,716 individuals were enrolled on one or more of the four lists, of whom 379 (6.6%) appeared on all four lists and 1,670 (29.2%) appeared on one list only. The model-averaged estimate of the total number of people with diagnosed diabetes was 6,721 (95% CI: 6,097, 7,346). The age-standardised prevalence was 3.70% (95% CI: 3.36-4.04%) for the total population and 4.45% (95% CI: 4.03-4.86) for adults aged 15+ years. CONCLUSIONS: Estimated diabetes prevalence was consistent with national survey results. Capture-recapture methods, combined with model averaging, are a cheap, efficient tool to estimate the prevalence of diagnosed diabetes. IMPLICATIONS: This method provides a relatively easy way to estimate the prevalence of diagnosed diabetes using routinely collected diabetes information, thus providing the opportunity to monitor the diabetes epidemic and inform planning decisions and resource allocation.

Pseudomonas siderophores in the sputum of patients with cystic fibrosis.

The lungs of patients with cystic fibrosis become chronically infected with the bacterium Pseudomonas aeruginosa, which heralds progressive lung damage and a decline in health. Iron is a crucial micronutrient for bacteria and its acquisition is a key factor in infection. P. aeruginosa can acquire this element by secreting pyoverdine and pyochelin, iron-chelating compounds (siderophores) that scavenge iron and deliver it to the bacteria. Siderophore-mediated iron uptake is generally considered a key factor in the ability of P. aeruginosa to cause infection. We have investigated the amounts of pyoverdine in 148 sputum samples from 36 cystic fibrosis patients (30 infected with P. aeruginosa and 6 as negative controls). Pyoverdine was present in 93 samples in concentrations between 0.30 and 51 µM (median 4.6 µM) and there was a strong association between the amount of pyoverdine and the number of P. aeruginosa present. However, pyoverdine was not present, or below the limits of detection (~0.3 µM), in 21 sputum samples that contained P. aeruginosa. Pyochelin was also absent, or below the limits of detection (~1 µM), in samples from P. aeruginosa-infected patients with little or no detectable pyoverdine. Our data show that pyoverdine is an important iron-scavenging molecule for P. aeruginosa in many cystic fibrosis patients, but other P. aeruginosa iron-uptake systems must be active in some patients to satisfy the bacterial need for iron.