Case and partnership reproduction numbers for a curable sexually transmitted infection

Sexually transmitted infections (STIs) are, by definition, transmitted between sexual partners. For curable STIs an infected index case can potentially re-infect the same partner multiple times. Thus, R0, the average number of secondary infections one typical infected individual will produce during his or her infectious period is not necessarily the same as the average number of secondary cases (infected persons). Here we introduce the new concept of the case reproduction number (Rc). In addition, we define the partnership reproduction number (Rp) as the average number of secondary partnerships consisting of two infected individuals one typical infected individual will produce over his or her infectious lifetime. Rp takes into account clearance and re-infection within partnerships, which results in a prolongation of the duration of the infectious period. The two new reproduction numbers were derived for a deterministic pair model with serial monogamous partnerships using infection parameters for Chlamydia trachomatis, an example of a curable STI. We showed that re-infection within partnerships means that curable STIs can be sustained endemically even when the average number of secondary cases a person produces during his or her infectious period is below one.

Spatial and temporal patterns of greenness on the Yamal Peninsula, Russia: interactions of ecological and social factors affecting the Arctic normalized difference vegetation index

The causes of a greening trend detected in the Arctic using the normalized difference vegetation index (NDVI) are still poorly understood. Changes in NDVI are a result of multiple ecological and social factors that affect tundra net primary productivity. Here we use a 25 year time series of AVHRR-derived NDVI data (AVHRR: advanced very high resolution radiometer), climate analysis, a global geographic information database and ground-based studies to examine the spatial and temporal patterns of vegetation greenness on the Yamal Peninsula, Russia. We assess the effects of climate change, gas-field development, reindeer grazing and permafrost degradation. In contrast to the case for Arctic North America, there has not been a significant trend in summer temperature or NDVI, and much of the pattern of NDVI in this region is due to disturbances. There has been a 37% change in early-summer coastal sea-ice concentration, a 4% increase in summer land temperatures and a 7% change in the average time-integrated NDVI over the length of the satellite observations. Gas-field infrastructure is not currently extensive enough to affect regional NDVI patterns. The effect of reindeer is difficult to quantitatively assess because of the lack of control areas where reindeer are excluded. Many of the greenest landscapes on the Yamal are associated with landslides and drainage networks that have resulted from ongoing rapid permafrost degradation. A warming climate and enhanced winter snow are likely to exacerbate positive feedbacks between climate and permafrost thawing. We present a diagram that summarizes the social and ecological factors that influence Arctic NDVI. The NDVI should be viewed as a powerful monitoring tool that integrates the cumulative effect of a multitude of factors affecting Arctic land-cover change.

Incident cancer burden attributable to excess body mass index in 30 European countries

Excess adiposity is associated with increased risks of developing adult malignancies. To inform public health policy and guide further research, the incident cancer burden attributable to excess body mass index (BMI >or= 25 kg/m(2)) across 30 European countries were estimated. Population attributable risks (PARs) were calculated using European- and gender-specific risk estimates from a published meta-analysis and gender-specific mean BMI estimates from a World Health Organization Global Infobase. Country-specific numbers of new cancers were derived from Globocan2002. A ten-year lag-period between risk exposure and cancer incidence was assumed and 95% confidence intervals (CI) were estimated in Monte Carlo simulations. In 2002, there were 2,171,351 new all cancer diagnoses in the 30 countries of Europe. Estimated PARs were 2.5% (95% CI 1.5-3.6%) in men and 4.1% (2.3-5.9%) in women. These collectively corresponded to 70,288 (95% CI 40,069-100,668) new cases. Sensitivity analyses revealed estimates were most influenced by the assumed shape of the BMI distribution in the population and cancer-specific risk estimates. In a scenario analysis of a plausible contemporary (2008) population, the estimated PARs increased to 3.2% (2.1-4.3%) and 8.6% (5.6-11.5%), respectively, in men and women. Endometrial, post-menopausal breast and colorectal cancers accounted for 65% of these cancers. This analysis quantifies the burden of incident cancers attributable to excess BMI in Europe. The estimates reported here provide a baseline for future modelling, and underline the need for research into interventions to control weight in the context of endometrial, breast and colorectal cancer.

Methods to convert continuous outcomes into odds ratios of treatment response and numbers needed to treat: meta-epidemiological study

Clinicians find standardized mean differences (SMDs) calculated from continuous outcomes difficult to interpret. Our objective was to determine the performance of methods in converting SMDs or means to odds ratios of treatment response and numbers needed to treat (NNTs) as more intuitive measures of treatment effect.

Relationship of horse owner assessed respiratory signs index to characteristics of recurrent airway obstruction in two Warmblood families

REASONS FOR PERFORMING STUDY: The horse owner assessed respiratory signs index (HOARSI-1-4, healthy, mildly, moderately and severely affected, respectively) is based on owner-reported clinical history and has been used for the investigation of recurrent airway obstruction (RAO) genetics utilising large sample sizes. Reliable phenotype identification is of paramount importance in genetic studies. Owner reports of respiratory signs have shown good repeatability, but the agreement of HOARSI with an in-depth examination of the lower respiratory tract has not been investigated. OBJECTIVES: To determine the correlation of HOARSI grades 3/4 with the characteristics of RAO and of HOARSI-2 with the characteristics of inflammatory airway disease. Further, to test whether there are phenotypic differences in the manifestation of lung disease between families. METHODS: Seventy-one direct offspring of 2 RAO-affected Warmblood stallions (33 from the first family, 38 from the second) were graded as HOARSI-1-4 and underwent a clinical examination of the respiratory system, arterial blood gas analysis, endoscopic mucus scoring, cytology of tracheobronchial secretion (TBS) and bronchoalveolar lavage fluid (BALF), and clinical assessment of airway reactivity to methacholine chloride. RESULTS: HOARSI-3/4 animals in clinical exacerbation showed signs consistent with RAO: coughing, nasal discharge, abnormal lung sounds and breathing pattern as well as increased numbers of neutrophils in TBS and BALF, excessive mucus accumulation and airway hyper-responsiveness to methacholine. HOARSI-3/4 horses in remission only had increased amounts of tracheal mucus and TBS neutrophil percentages. Clinical phenotypes were not significantly different between the 2 families. CONCLUSIONS AND CLINICAL RELEVANCE: HOARSI reliably identifies RAO-affected horses in our population.

Health risk appraisal in older people 2: the implications for clinicians and commissioners of social isolation risk in older people

BACKGROUND: Social isolation is associated with poorer health, and is seen by the World Health Organisation (WHO) as one of the major issues facing the industrialised world. AIM: To explore the significance of social isolation in the older population for GPs and for service commissioners. DESIGN OF STUDY: Secondary analysis of baseline data from a randomised controlled trial of health risk appraisal. SETTING: A total of 2641 community-dwelling, non-disabled people aged 65 years and over in suburban London. METHOD: Demographic details, social network and risk for social isolation based on the 6-item Lubben Social Network Scale, measures of depressed mood, memory problems, numbers of chronic conditions, medication use, functional ability, self-reported use of medical services. RESULTS: More than 15% of the older age group were at risk of social isolation, and this risk increased with advancing age. In bivariate analyses risk of social isolation was associated with older age, education up to 16 years only, depressed mood and impaired memory, perceived fair or poor health, perceived difficulty with both basic and instrumental activities of daily living, diminishing functional ability, and fear of falling. Despite poorer health status, those at risk of social isolation did not appear to make greater use of medical services, nor were they at greater risk of hospital admission. Half of those who scored as at risk of social isolation lived with others. Multivariate analysis showed significant independent associations between risk of social isolation and depressed mood and living alone, and weak associations with male sex, impaired memory and perceived poor health. CONCLUSION: The risk of social isolation is elevated in older men, older persons who live alone, persons with mood or cognitive problems, but is not associated with greater use of services. These findings would not support population screening for individuals at risk of social isolation with a view to averting service use by timely intervention. Awareness of social isolation should trigger further assessment, and consideration of interventions to alleviate social isolation, treat depression or ameliorate cognitive impairment.

Re-evaluation of pulmonary titanium dioxide nanoparticle distribution using the "relative deposition index": Evidence for clearance through microvasculature

ABSTRACT: BACKGROUND: Translocation of nanoparticles (NP) from the pulmonary airways into other pulmonary compartments or the systemic circulation is controversially discussed in the literature. In a previous study it was shown that titanium dioxide (TiO2) NP were "distributed in four lung compartments (air-filled spaces, epithelium/endothelium, connective tissue, capillary lumen) in correlation with compartment size". It was concluded that particles can move freely between these tissue compartments. To analyze whether the distribution of TiO2 NP in the lungs is really random or shows a preferential targeting we applied a newly developed method for comparing NP distributions. METHODS: Rat lungs exposed to an aerosol containing TiO2 NP were prepared for light and electron microscopy at 1 h and at 24 h after exposure. Numbers of TiO2 NP associated with each compartment were counted using energy filtering transmission electron microscopy. Compartment size was estimated by unbiased stereology from systematically sampled light micrographs. Numbers of particles were related to compartment size using a relative deposition index and chi-squared analysis. RESULTS: Nanoparticle distribution within the four compartments was not random at 1 h or at 24 h after exposure. At 1 h the connective tissue was the preferential target of the particles. At 24 h the NP were preferentially located in the capillary lumen. CONCLUSION: We conclude that TiO2 NP do not move freely between pulmonary tissue compartments, although they can pass from one compartment to another with relative ease. The residence time of NP in each tissue compartment of the respiratory system depends on the compartment and the time after exposure. It is suggested that a small fraction of TiO2 NP are rapidly transported from the airway lumen to the connective tissue and subsequently released into the systemic circulation.

Mortality of patients lost to follow-up in antiretroviral treatment programmes in resource-limited settings: systematic review and meta-analysis

BACKGROUND: The retention of patients in antiretroviral therapy (ART) programmes is an important issue in resource-limited settings. Loss to follow up can be substantial, but it is unclear what the outcomes are in patients who are lost to programmes. METHODS AND FINDINGS: We searched the PubMed, EMBASE, Latin American and Caribbean Health Sciences Literature (LILACS), Indian Medlars Centre (IndMed) and African Index Medicus (AIM) databases and the abstracts of three conferences for studies that traced patients lost to follow up to ascertain their vital status. Main outcomes were the proportion of patients traced, the proportion found to be alive and the proportion that had died. Where available, we also examined the reasons why some patients could not be traced, why patients found to be alive did not return to the clinic, and the causes of death. We combined mortality data from several studies using random-effects meta-analysis. Seventeen studies were eligible. All were from sub-Saharan Africa, except one study from India, and none were conducted in children. A total of 6420 patients (range 44 to 1343 patients) were included. Patients were traced using telephone calls, home visits and through social networks. Overall the vital status of 4021 patients could be ascertained (63%, range across studies: 45% to 86%); 1602 patients had died. The combined mortality was 40% (95% confidence interval 33%-48%), with substantial heterogeneity between studies (P<0.0001). Mortality in African programmes ranged from 12% to 87% of patients lost to follow-up. Mortality was inversely associated with the rate of loss to follow up in the programme: it declined from around 60% to 20% as the percentage of patients lost to the programme increased from 5% to 50%. Among patients not found, telephone numbers and addresses were frequently incorrect or missing. Common reasons for not returning to the clinic were transfer to another programme, financial problems and improving or deteriorating health. Causes of death were available for 47 deaths: 29 (62%) died of an AIDS defining illness. CONCLUSIONS: In ART programmes in resource-limited settings a substantial minority of adults lost to follow up cannot be traced, and among those traced 20% to 60% had died. Our findings have implications both for patient care and the monitoring and evaluation of programmes.

Independent association between lower level of social support and higher coagulation activity before and after acute psychosocial stress

OBJECTIVE: To investigate the relationship between social support and coagulation parameter reactivity to mental stress in men and to determine if norepinephrine is involved. Lower social support is associated with higher basal coagulation activity and greater norepinephrine stress reactivity, which in turn, is linked with hypercoagulability. However, it is not known if low social support interacts with stress to further increase coagulation reactivity or if norepinephrine affects this association. These findings may be important for determining if low social support influences thrombosis and possible acute coronary events in response to acute stress. We investigated the relationship between social support and coagulation parameter reactivity to mental stress in men and determined if norepinephrine is involved. METHODS: We measured perceived social support in 63 medication-free nonsmoking men (age (mean +/- standard error of the mean) = 36.7 +/- 1.7 years) who underwent an acute standardized psychosocial stress task combining public speaking and mental arithmetic in front of an audience. We measured plasma D-dimer, fibrinogen, clotting Factor VII activity (FVII:C), and plasma norepinephrine at rest as well as immediately after stress and 20 minutes after stress. RESULTS: Independent of body mass index, mean arterial pressure, and age, lower social support was associated with higher D-dimer and fibrinogen levels at baseline (p < .012) and with greater increases in fibrinogen (beta = -0.36, p = .001; DeltaR(2) = .12), and D-dimer (beta = -0.21, p = .017; DeltaR(2) = .04), but not in FVII:C (p = .83) from baseline to 20 minutes after stress. General linear models revealed significant main effects of social support and stress on fibrinogen, D-dimer, and norepinephrine (p < .035). Controlling for norepinephrine did not change the significance of the reported associations between social support and the coagulation measures D-dimer and fibrinogen. CONCLUSIONS: Our results suggest that lower social support is associated with greater coagulation activity before and after acute stress, which was unrelated to norepinephrine reactivity.

Fecal calprotectin more accurately reflects endoscopic activity of ulcerative colitis than the Lichtiger Index, C-reactive protein, platelets, hemoglobin, and blood leukocytes

BACKGROUND The correlation between noninvasive markers with endoscopic activity according to the modified Baron Index in patients with ulcerative colitis (UC) is unknown. We aimed to evaluate the correlation between endoscopic activity and fecal calprotectin (FC), C-reactive protein (CRP), hemoglobin, platelets, blood leukocytes, and the Lichtiger Index (clinical score). METHODS UC patients undergoing complete colonoscopy were prospectively enrolled and scored clinically and endoscopically. Samples from feces and blood were analyzed in UC patients and controls. RESULTS We enrolled 228 UC patients and 52 healthy controls. Endoscopic disease activity correlated best with FC (Spearman's rank correlation coefficient r = 0.821), followed by the Lichtiger Index (r = 0.682), CRP (r = 0.556), platelets (r = 0.488), blood leukocytes (r = 0.401), and hemoglobin (r = -0.388). FC was the only marker that could discriminate between different grades of endoscopic activity (grade 0, 16 [10-30] μg/g; grade 1, 35 [25-48] μg/g; grade 2, 102 [44-159] μg/g; grade 3, 235 [176-319] μg/g; grade 4, 611 [406-868] μg/g; P < 0.001 for discriminating the different grades). FC with a cutoff of 57 μg/g had a sensitivity of 91% and a specificity of 90% to detect endoscopically active disease (modified Baron Index ≥ 2). CONCLUSIONS FC correlated better with endoscopic disease activity than clinical activity, CRP, platelets, hemoglobin, and blood leukocytes. The strong correlation with endoscopic disease activity suggests that FC represents a useful biomarker for noninvasive monitoring of disease activity in UC patients.

Strategies for partner notification for sexually transmitted infections, including HIV

BACKGROUND Partner notification (PN) is the process whereby sexual partners of an index patient are informed of their exposure to a sexually transmitted infection (STI) and the need to obtain treatment. For the person (index patient) with a curable STI, PN aims to eradicate infection and prevent re-infection. For sexual partners, PN aims to identify and treat undiagnosed STIs. At the level of sexual networks and populations, the aim of PN is to interrupt chains of STI transmission. For people with viral STI, PN aims to identify undiagnosed infections, which can facilitate access for their sexual partners to treatment and help prevent transmission. OBJECTIVES To assess the effects of different PN strategies in people with STI, including human immunodeficiency virus (HIV) infection. SEARCH METHODS We searched electronic databases (the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE) without language restrictions. We scanned reference lists of potential studies and previous reviews and contacted experts in the field. We searched three trial registries. We conducted the most recent search on 31 August 2012. SELECTION CRITERIA Published or unpublished randomised controlled trials (RCTs) or quasi-RCTs comparing two or more PN strategies. Four main PN strategies were included: patient referral, expedited partner therapy, provider referral and contract referral. Patient referral means that the patient notifies their sexual partners, either with (enhanced patient referral) or without (simple patient referral) additional verbal or written support. In expedited partner therapy, the patient delivers medication or a prescription for medication to their partner(s) without the need for a medical examination of the partner. In provider referral, health service personnel notify the partners. In contract referral, the index patient is encouraged to notify partner, with the understanding that the partners will be contacted if they do not visit the health service by a certain date. DATA COLLECTION AND ANALYSIS We analysed data according to paired partner referral strategies. We organised the comparisons first according to four main PN strategies (1. enhanced patient referral, 2. expedited partner therapy, 3. contract referral, 4. provider referral). We compared each main strategy with simple patient referral and then with each other, if trials were available. For continuous outcome measures, we calculated the mean difference (MD) with 95% confidence intervals (CI). For dichotomous variables, we calculated the risk ratio (RR) with 95% CI. We performed meta-analyses where appropriate. We performed a sensitivity analysis for the primary outcome re-infection rate of the index patient by excluding studies with attrition of greater than 20%. Two review authors independently assessed the risk of bias and extracted data. We contacted study authors for additional information. MAIN RESULTS We included 26 trials (17,578 participants, 9015 women and 8563 men). Five trials were conducted in developing countries. Only two trials were conducted among HIV-positive patients. There was potential for selection bias, owing to the methods of allocation used and of performance bias, owing to the lack of blinding in most included studies. Seven trials had attrition of greater than 20%, increasing the risk of bias.The review found moderate-quality evidence that expedited partner therapy is better than simple patient referral for preventing re-infection of index patients when combining trials of STIs that caused urethritis or cervicitis (6 trials; RR 0.71, 95% CI 0.56 to 0.89, I(2) = 39%). When studies with attrition greater than 20% were excluded, the effect of expedited partner therapy was attenuated (2 trials; RR 0.8, 95% CI 0.62 to 1.04, I(2) = 0%). In trials restricted to index patients with chlamydia, the effect was attenuated (2 trials; RR 0.90, 95% CI 0.60 to 1.35, I(2) = 22%). Expedited partner therapy also increased the number of partners treated per index patient (three trials) when compared with simple patient referral in people with chlamydia or gonorrhoea (MD 0.43, 95% CI 0.28 to 0.58) or trichomonas (MD 0.51, 95% CI 0.35 to 0.67), and people with any STI syndrome (MD 0.5, 95% CI 0.34 to 0.67). Expedited partner therapy was not superior to enhanced patient referral in preventing re-infection (3 trials; RR 0.96, 95% CI 0.60 to 1.53, I(2) = 33%, low-quality evidence). Home sampling kits for partners (four trials) did not result in lower rates of re-infection in the index case (measured in one trial), or higher numbers of partners elicited (three trials), notified (two trials) or treated (one trial) when compared with simple patient referral. There was no consistent evidence for the relative effects of provider, contract or other patient referral methods. In one trial among men with non-gonococcal urethritis, more partners were treated with provider referral than with simple patient referral (MD 0.5, 95% CI 0.37 to 0.63). In one study among people with syphilis, contract referral elicited treatment of more partners than provider referral (MD 2.2, 95% CI 1.95 to 2.45), but the number of partners receiving treatment was the same in both groups. Where measured, there was no statistical evidence of differences in the incidence of adverse effects between PN strategies. AUTHORS' CONCLUSIONS The evidence assessed in this review does not identify a single optimal strategy for PN for any particular STI. When combining trials of STI causing urethritis or cervicitis, expedited partner therapy was more successful than simple patient referral for preventing re-infection of the index patient but was not superior to enhanced patient referral. Expedited partner therapy interventions should include all components that were part of the trial intervention package. There was insufficient evidence to determine the most effective components of an enhanced patient referral strategy. There are too few trials to allow consistent conclusions about the relative effects of provider, contract or other patient referral methods for different STIs. More high-quality RCTs of PN strategies for HIV and syphilis, using biological outcomes, are needed.

Social control and smoking: Examining the moderating effects of different dimensions of relationship quality

A common form of social regulation of an individual’s health behavior is social control. The contextual model of social control assumes that higher relationship quality goes along with more beneficial effects of social control on health behavior. This study examined potential differential moderating effects of different dimensions of relationship quality on the associations between positive and negative social control and smoking behavior and hiding smoking. The sample consisted of 144 smokers (n = 72 women; mean age = 31.78, SD = 10.04) with a nonsmoking partner. Positive and negative social control, dimensions of relationship quality consensus, cohesion and satisfaction, numbers of cigarettes smoked (NCS), hiding smoking (HS), and control variables were assessed at baseline. Four weeks later NCS and HS were assessed again. Only for smokers with high consensus, but not cohesion and satisfaction, a negative association between positive control and NCS emerged. Moreover, smokers with high consensus tended to report more HS when being positively and negatively socially controlled. This also emerged for cohesion and positive control. Satisfaction with the relationship did not display any interaction effects. This study’s results emphasize the importance of differentiating not only between positive and negative social control but also between different dimensions of relationship quality in order to gain a comprehensive understanding of the dynamics in romantic dyads with regard to social regulation of behavioral change.