Small Number Of Epidemiological Studies Research Articles

Frequency, Etiology, Mortality, Cost, and Prevention of Respiratory Tract Infections-Prospective, One Center Study.

Background: Ventilator-associated pneumonia (VAP) is the most monitored form of respiratory tract infections (RTIs). A small number of epidemiological studies have monitored community-acquired pneumonia (CAP), non-ventilator hospital-acquired pneumonia (NV-HAP) and ventilator-associated tracheobronchitis (VAT) in intensive care units (ICUs). The objective of this study was to assess the frequency, etiology, mortality, and additional costs of RTIs. Methods: One-year prospective RTI surveillance at a 30-bed ICU. The study assessed the rates and microbiological profiles of CAP, VAP, NV-HAP, VAT, and VAP prevention factors, the impact of VAP and NV-HAP on the length of ICU stays, and the additional costs of RTI treatment and mortality. Results: Among 578 patients, RTIs were found in 30%. The CAP, NV-HAP, VAP, and VAT rates/100 admissions were 5.9, 9.0, 8.65, and 6.05, respectively. The VAP incidence density/1000 MV-days was 10.8. The most common pathogen of RTI was Acinetobacter baumannii MDR. ICU stays were extended by VAP and NV-HAP for 17.8 and 3.7 days, respectively, and these RTIs increased the cost of therapy by 13,029 and 2708 EUR per patient, respectively. The mortality rate was higher by 11.55% in patients with VAP than those without device-associated and healthcare-associated infections (p = 0.0861). Conclusions: RTIs are a serious epidemiological problem in patients who are admitted and treated in ICU, as they may affect one-third of patients. Hospital-acquired RTIs extend hospitalization time, increase the cost of treatment, and worsen outcomes.

Association of Vitamin K Insufficiency With Cognitive Dysfunction in Community-Dwelling Older Adults.

Vitamin K is a fat-soluble vitamin shown to be associated with several age-related diseases. Although a small number of epidemiological studies described the relationship between vitamin K status and cognitive impairment, vitamin K status was estimated by relatively special methods in previous reports. Here, we demonstrated the association of the concentration of undercarboxylated osteocalcin (ucOC) in serum, which is a biomarker for vitamin K insufficiency, with cognitive function in a cross-sectional study. A total of 800 community-dwelling older adults (mean age = 75.9) were invited to geriatric health examination, including a Mini-Mental State Examination (MMSE) and a blood test. By using binary logistic regression analysis, the risk of cognitive impairment equivalent or below the mild cognitive impairment level for each tertile of ucOC was examined, with the lowest tertile as the reference. We found a significant association of impaired cognitive function and concentration of ucOC in the highest tertile of ucOC, with the odds ratio of 1.65 (95% CI, 1.06 to 2.59, P = 0.028). When the analysis was repeated with each domain of MMSE, the highest tertile of ucOC was associated with impaired orientation, calculation, and language. As far as we know, this is the first report on the significant association of single ucOC measurement and cognitive impairment. Our analysis also suggests that vitamin K insufficiency could be associated with selected categories of cognitive function. Since the single measurement of ucOC in serum is a simple and widely available method for vitamin K evaluation, it could be useful as a biomarker of neurodegenerative diseases affecting the cognitive functions.

A systematic review and meta-analysis of the aetiological agents of non-malarial febrile illnesses in Africa.

BackgroundThe awareness of non-malarial febrile illnesses (NMFIs) has been on the rise over the last decades. Therefore, we undertook a systematic literature review and meta-analysis of causative agents of non-malarial fevers on the African continent.MethodologyWe searched for literature in African Journals Online, EMBASE, PubMed, Scopus, and Web of Science databases to identify aetiologic agents that had been reported and to determine summary estimates of the proportional morbidity rates (PMr) associated with these pathogens among fever patients.FindingsA total of 133 studies comprising 391,835 patients from 25 of the 54 African countries were eligible. A wide array of aetiologic agents were described with considerable regional differences among the leading agents. Overall, bacterial pathogens tested from blood samples accounted for the largest proportion. The summary estimates from the meta-analysis were low for most of the agents. This may have resulted from a true low prevalence of the agents, the failure to test for many agents or the low sensitivity of the diagnostic methods applied. Our meta-regression analysis of study and population variables showed that diagnostic methods determined the PMr estimates of typhoidal Salmonella and Dengue virus. An increase in the PMr of Klebsiella spp. infections was observed over time. Furthermore, the status of patients as either inpatient or outpatient predicted the PMr of Haemophilus spp. infections.ConclusionThe small number of epidemiological studies and the variety of NMFI agents on the African continent emphasizes the need for harmonized studies with larger sample sizes. In particular, diagnostic procedures for NMFIs should be standardized to facilitate comparability of study results and to improve future meta-analyses. Reliable NMFI burden estimates will inform regional public health strategies.

Prolonged grief disorder prevalence in adults 65 years and over: a systematic review

BackgroundProlonged grief disorder (PGD) is a recently recognised mental health disorder with an estimated prevalence of 10% in the bereaved adult population. This review aims to appraise and summarise evidence...

Gender-age peculiarities of smoking and diabetes mellitus role in the development of myocardial infarction in patients with arterial hypertension

Arterial hypertension (AH), smoking and type 2 diabetes mellitus (T2DM) are the risk factors for the development of myocardial infarction (MI). Their age and gender peculiarities of AH have been studied only in a small number of epidemiological studies.
 Aim. To study the effect of smoking status and type 2 diabetes on the incidence of MI in men and women with hypertension.
 Materials and methods. The frequency of MI in men and women with hypertension confirmed by ECG criteria was analyzed depending on age, smoking status and type 2 diabetes. 28 899 hypertensive patients of primary health care in 20102016 were included in the registry of hypertension.
 Results. In the age of 2544 the number of visits of men and women with hypertension in primary health care was the same, thereafter the ratio of men progressively had been decreasing with the age. The incidence of MI in men with hypertension is significantly higher at all ages than in women (it is 18.3 times higher at the age of 2544). 37.4% of men and 94.8% of women with hypertension have never smoked. The maximum incidence of MI is in middle-aged men (33.0%) and in old-aged women (14.1%) groups, who stopped smoking. MI developed in 3.7 times more often in hypertensive young-age men group who are smoking than in nonsmokers, in those who stopped smoking 13 times more often. The maxima of the curves of the incidence of MI in women with hypertension, based on the smoking status, shifted towards an older age in comparison with men. Percutaneous coronary intervention / Coronary artery bypass graft surgery was performed 2 times more often in hypertensive patients with MI who stopped smoking, compared to nonsmokers. The incidence of MI in hypertensive patients with diabetes in middle-aged men increased by 1.6 times, in women 2.5 times. The higher influence of diabetes mellitus on escalation of MI incidence in women with hypertension than in men persisted until old age. The incidence of MI was 9.8% in never-smoked, 17.7% for smokers and 28.3% for stopped smoking hypertensive patients with diabetes. In the group of patients who never smoked, the risk of MI increased by 1.8 times in the men group and 2.8 in women with AH and DM. However, the odds of MI development in nonsmoking men and women groups with hypertension and diabetes did not significant.
 Conclusion. Gender-age characteristics of the influence of smoking and type 2 diabetes on the risk of MI in patients with hypertension in primary health care were disclosed. Such risk factors for MI as male gender and smoking are most significant at a young age. In old age, smoking status no longer affects the risk of MI, while the male gender remains important at all ages. The higher incidence of MI in men with hypertension (18.3 times at a young age) compared to women is explained by both the influence of gender and the higher frequency of smoking (12 times). T2DM increases the risk of developing MI in middle age and older. In hypertensive patients with type 2 diabetes, the incidence of MI is maximally increased in middle age in women by 2.5 times; in men 1.6 times. Smoking in patients with AH and type 2 diabetes leads to an additional increase of MI risk (up to 2.8 times).

Dietary Acrylamide Intake and the Risk of Liver Cancer: The Japan Public Health Center-Based Prospective Study.

Acrylamide has been studied for its carcinogenicity in experimental animals, causing tumors at several organ sites, and has been considered probably carcinogenic to humans as well. Given the small number of epidemiological studies that have been conducted, it is still uncertain whether the consumption of acrylamide is associated with liver cancer. Therefore, we investigated a study to determine the possible relationship between acrylamide intake and the risk of developing liver cancer in the Japanese population. A total of 85,305 participants, from the Japan Public Health Center-based Prospective Study, who provided a validated food-frequency questionnaire were enrolled between 1995 and 1998. During a median of 16.0 years follow-up, 744 new liver cancer cases were identified. Compared to the lowest tertile of acrylamide consumption (<4.8 µg/day), the multivariate hazard ratio (HR) for the highest tertile (≥7.6 µg/day) was 0.79 (95% confidence interval [CI] = 0.65–0.95) for liver cancer using multivariable model 1, adjusted for smoking status, body mass index (BMI), physical activity, medical history, and alcohol consumption; whereas the inverse relationship disappeared after additionally adjusting for coffee consumption in multivariable model 2 with HR of 1.08 (95% CI = 0.87–1.34) for the highest tertile. The effect of dietary acrylamide intake on the risk of liver cancer was not observed in the Japanese population.

Association between maternal antimony exposure and risk of gestational diabetes mellitus: A birth cohort study.

A small number of epidemiological studies have suggested the association of antimony (Sb) exposure with type 2 diabetes risk. However, little is known about the relationship between Sb exposure during pregnancy and risk of gestational diabetes mellitus (GDM). To investigate the associations of urinary Sb concentrations with GDM risk and blood glucose levels in pregnant women. We analyzed the baseline data of 1789 pregnant women enrolled in the Birth Cohort Study on Prenatal Environments and Offspring Health (PEOH) in Guangzhou, China. Sb concentrations in urine were measured by inductively coupled plasma mass spectrometry (ICP-MS). Logistic regression and analysis of covariance were used to evaluate associations of Sb exposure with GDM risk and blood glucose levels. A total of 437 (24.4%) women were diagnosed with GDM. The relative risk of GDM for women in the highest quartile of creatinine-corrected Sb (CC-Sb) concentrations was 1.55 [RR (95% CI) = 1.55 (1.12, 2.15), p-trend = 0.005], compared with women in the lowest quartile. Moreover, the women in the top quartile of CC-Sb levels had a 5.2% higher 1 h blood glucose and a 4.2% higher 2 h blood glucose than those in the bottom quartile. We also found an interactive effect between maternal age and CC-Sb on the risk of GDM (p-interaction < 0.001). This study suggested significant positive associations of Sb exposure with increased GDM risk and impaired blood glucose homeostasis in pregnant women, and the Sb-GDM association might be modified by maternal age.

Neighborhood Deprivation and Risk of Congenital Heart Defects, Neural Tube Defects and Orofacial Clefts: A Systematic Review and Meta-Analysis.

BackgroundWe conducted this systematic review and meta-analysis to address the open question of a possible association between the socioeconomic level of the neighborhoods in which pregnant women live and the risk of Congenital Heart Defects (CHDs), Neural Tube Defects (NTDs) and OroFacial Clefts (OFCs).MethodsWe searched MEDLINE from its inception to December 20th, 2015 for case-control, cohort and ecological studies assessing the association between neighborhood socioeconomic level and the risk of CHDs, NTDs and the specific phenotypes Cleft Lip with or without Cleft Palate (CLP) and Cleft Palate (CP). Study-specific risk estimates were pooled according to random-effect and fixed-effect models.ResultsOut of 245 references, a total of seven case-control studies, two cohort studies and two ecological studies were assessed in the systematic review; all studies were enrolled in the meta-analysis with the exception of the two cohort studies. No significant association has been revealed between CHDs or NTDs and neighborhood deprivation index. For CLP phenotype subgroups, we found a significantly higher rate in deprived neighborhoods (Odds Ratios (OR) = 1.22, 95% CI: 1.10, 1.36) whereas this was not significant for CP phenotype subgroups (OR = 1.20, 95%CI: 0.89, 1.61).ConclusionIn spite of the small number of epidemiological studies included in the present literature review, our findings suggest that neighborhood socioeconomic level where mothers live is associated only with an increased risk of CLP phenotype subgroups. This finding has methodological limitations that impede the formulation of firm conclusions, and further investigations should confirm this association.

Commentary on Imtiaz et al. (2016): The burden of disease attributable to cannabis-implications for policy.

The contribution that current patterns of cannabis use make to the burden of disease is very useful information, but it cannot decide policy. Sameer Imtiaz and colleagues have used the methods developed as part of the 2010 Global Burden of Disease Comparative Risk Assessment to estimate the contribution that cannabis use made to the burden of disease (BoD) in 2012 in Canada, a developed country where the prevalence of cannabis use is among the highest in the world 1. They included among the cannabis-related causes of disease burden: cannabis use disorders (CUD), road traffic injuries and deaths, schizophrenia and lung cancer. CUD are a consequence of cannabis use by definition; recent meta-analyses suggest that cannabis use modestly increases the risk of road traffic injuries and deaths, and there is reasonable evidence that regular cannabis is a contributory cause of the onset of psychoses 2, although some argue that we cannot exclude the possibility of residual confounding 3. The inclusion of lung cancer is more contentious, given that a recent meta-analysis concluded that there was not sufficient evidence to assess whether cannabis smoking increased the risk of lung cancer 4. The authors included uncertainty bounds around their estimates to reflect the fact that many of these estimated risks are based on a small number of epidemiological studies which have weakly quantified cannabis use. Their comparison of the BoD attributable to alcohol, tobacco and cannabis shows that cannabis contributes a very small fraction of the contribution of alcohol and tobacco. This reflects the combined effects of the very large difference in the prevalence of the regular use of these three drugs and the fact that there is a much larger research literature linking alcohol and tobacco to many more causes of death and disability than cannabis. A comparison of BoD attributed to cannabis and opioids shows that cannabis use is much more prevalent than opioid use, but the opioid drugs make a much larger contribution to BoD because they cause many more deaths in young adults by overdose, suicide, accidents and blood-borne virus (BBV) infections. Only 20 years ago, statements about the comparative harms of cannabis, alcohol, tobacco and opioids were highly controversial. Some authors (e.g. 5) insisted that such comparisons could not and should not be made. A paper that Robin Room, Susan Bondy and I prepared for a 1997 World Health Organization (WHO) report on the health effects of cannabis 6 caused enormous public controversy and was disowned by WHO (see 7). The successful development of the comparative risk assessment approach used in the GBD estimates has thankfully put paid to these objections to comparative assessments of contributions that different types of drugs make to BoD. Imtiaz et al. acknowledge an important qualification that applies to all such comparisons; namely, that they reflect the BoD attributable to current patterns of cannabis use. Those who defend current cannabis policies can argue reasonably that these policies can claim some credit for this fact. Many adults in developed countries have used cannabis at some time in their lives, but only a very small proportion of these (approximately 10%) have used regularly, and a still smaller proportion have used daily over decades. The latter is a miniscule proportion by comparison with the proportions of tobacco smokers who smoke daily and alcohol consumers who drink in a risky manner. It is clear that CUD can affect a substantial number of young people in developed societies. This fact demands the policy response suggested by the authors; namely, screening and early intervention in medical settings where problem cannabis users are likely to be seen. Is the contribution that cannabis use makes to BoD enough to justify a change from current prohibitionist policies to more liberal policies that may include legalization for recreational use, as has occurred in four US states? This is properly a matter for democratic deliberation that considers the social and economic costs and benefits of adopting different policies towards cannabis. Data on the effects of cannabis on BoD, as used currently, will play a useful role in such deliberations, but it cannot be decisive 8. None. I thank Sarah Yeates for her assistance in preparing this commentary.

Respiratory hospitalizations in association with fine PM and its components in New York State

Despite observed geographic and temporal variation in particulate matter (PM)-related health morbidities, only a small number of epidemiologic studies have evaluated the relation between PM2.5 chemical constituents and respiratory disease. Most assessments are limited by inadequate spatial and temporal resolution of ambient PM measurements and/or by their approaches to examine the role of specific PM components on health outcomes. In a case-crossover analysis using daily average ambient PM2.5 total mass and species estimates derived from the Community Multiscale Air Quality (CMAQ) model and available observations, we examined the association between the chemical components of PM (including elemental and organic carbon, sulfate, nitrate, ammonium, and other remaining) and respiratory hospitalizations in New York State. We evaluated relationships between levels (low, medium, high) of PM constituent mass fractions, and assessed modification of the PM2.5–hospitalization association via models stratified by mass fractions of both primary and secondary PM components. In our results, average daily PM2.5 concentrations in New York State were generally lower than the 24-hr average National Ambient Air Quality Standard (NAAQS). Year-round analyses showed statistically significant positive associations between respiratory hospitalizations and PM2.5 total mass, sulfate, nitrate, and ammonium concentrations at multiple exposure lags (0.5–2.0% per interquartile range [IQR] increase). Primarily in the summer months, the greatest associations with respiratory hospitalizations were observed per IQR increase in the secondary species sulfate and ammonium concentrations at lags of 1–4 days (1.0–2.0%). Although there were subtle differences in associations observed between mass fraction tertiles, there was no strong evidence to support modification of the PM2.5-respiratory disease association by a particular constituent. We conclude that ambient concentrations of PM2.5 and secondary aerosols including sulfate, ammonium, and nitrate were positively associated with respiratory hospitalizations, although patterns varied by season. Exposure to specific fine PM constituents is a plausible risk factor for respiratory hospitalization in New York State.Implications: The association between ambient concentrations of PM2.5 components has been evaluated in only a small number of epidemiologic studies with refined spatial and temporal scale data. In New York State, fine PM and several of its constituents, including sulfate, ammonium, and nitrate, were positively associated with respiratory hospitalizations. Results suggest that PM species relationships and their influence on respiratory endpoints are complex and season dependent. Additional work is needed to better understand the relative toxicity of PM species, and to further explore the role of co-pollutant relationships and exposure prediction error on observed PM–respiratory disease associations.

Myelofibrosis patients in Belgium: disease characteristics

Objective:To date, only a small number of epidemiological studies on myelofibrosis have been performed. The current study aimed to characterize the myelofibrosis patient population in Belgium according to pre-defined disease parameters (diagnosis, risk categories, hemoglobin <10 g/dl, spleen size, constitutional symptoms, platelet count, myeloblast count), with a view to obtaining a deeper understanding of the proportion of patients that may benefit from the novel myelofibrosis therapeutic strategies.Methods:A survey was used to collect data on prevalence and disease parameters on all myelofibrosis patients seen at each of 18 participating hematologic centers in 2011. Aggregated data from all centers were used for analysis. Analyses were descriptive and quantitative.Results:A total of 250 patients with myelofibrosis were captured; of these, 136 (54%) were male and 153 (61%) were over 65 years old. One hundred sixty-five (66%) of myelofibrosis patients had primary myelofibrosis and 85 (34%) had secondary myelofibrosis. One hundred ninety-three myelofibrosis patients (77%) had a palpable spleen. About a third of patients (34%) suffered from constitutional symptoms. Two hundred twenty-two (89%) myelofibrosis patients had platelet count ≧50 000/μl and 201 (80%) had platelet count ≧100 000/μl. Of 250 patients, 85 (34%) had a myeloblast count ≧1%. Six (2%) patients had undergone a splenectomy. Thirteen (5·2%) patients had undergone radiotherapy for splenomegaly.Conclusions:The results of this survey provide insight into the characteristics of the Belgian myelofibrosis population. They also suggest that a large proportion of these patients could stand to benefit from the therapies currently under development.

EFFECTS OF BERRY POLYPHENOLS ON COGNITIVE FUNCTION IN HUMANS

A small number of epidemiological studies have suggested that increased polyphenol intake over the lifespan is beneficial for cognition. The mechanisms by which polyphenols could improve cognitive function include increased cerebrovascular blood flow, increased synaptic plasticity and modulation of neuronal signalling pathways. This systematic review examines the effect of consumption of berry polyphenols on cognitive function in humans. Method: inclusion criteria were berry polyphenol vs. control interventions which employed an objective measure of cognitive function. Participants were healthy or mildly cognitively impaired adults. Studies were excluded if clinical assessment or diagnosis of Alzheimer’s disease, dementia, or cognitive impairment was the sole measure of cognitive function. Results: five berry juice studies, one resveratrol study, and five epidemiological studies were identified. Three studies of regular berry fruit juice consumption over 12-16 weeks showed benefits for verbal memory whereas three acute studies failed to show cognitive effects. Four epidemiological studies demonstrated cognitive benefits associated with increased polyphenol intake over the lifespan. Conclusions: evidence from long term intervention studies in combination with epidemiological trials suggests that consuming additional polyphenols by including berries in the diet can lead to cognitive benefits, especially improvements in memory.

Did the elimination of lead from petrol reduce crime in the USA in the 1990s?

This article assesses the evidence for the hypothesis that a decline in all types of crime since the early 1990s in the USA was a consequence of removing lead from petrol between 1975 and 1985. It describes ecological and econometric studies that have generally but not always found correlations between lead exposures in childhood and some types of crime 20 years later; a small number of epidemiological studies that have found a dose-response relationship between lead exposure in childhood and self-reported and officially recorded criminal offences in young adulthood; and evidence for the biological plausibility of a causal relationship. Lead exposure in childhood may have played a small role in rising and falling crime rates in the USA but it is unlikely to account for the very high percentage of the decline suggested by the ecological studies. The major anomaly in the evidence is that the associations reported in ecological studies are much stronger (explaining 56-90% of the variation in crime rates) than the weaker relationships found in the cohort studies (that typically explain less than 1% of the variance in offending). Suggestions are made for research that will better assess the contribution that reduced lead exposure has made to declining crime rates in the USA.

Parental programming: How can we improve study design to discern the molecular mechanisms?

The contribution of inherited non-genetic factors to complex diseases is of great current interest. The ways in which mothers and fathers can affect their offspring's health clearly differ as a result of the intimate interactions between mother and offspring during pre- and postnatal life. There is, however, potential for some overlap in mechanisms, particularly epigenetic mechanisms. A small number of epidemiological studies and animal models have investigated the non-genetic contribution of the parents to offspring health. Discovering new mechanisms of disease inheritance is technically difficult, especially in genetically, socially and environmentally heterogeneous human populations. Therefore, rigorous experimental design, appropriate sample numbers and the use of high-throughput technologies are necessary to provide convincing evidence. Based on recent examples from the literature, here we propose several ways to improve human studies that aim to identify the underlying mechanisms of transgenerational inheritance of metabolic disease.

Did the elimination of lead from petrol reduce crime in the USA in the 1990s?

This article assesses the evidence for the hypothesis that a decline in all types of crime since the early 1990s in the USA was an unintended consequence of removing lead from petrol between 1975 and 1985. It describes ecological and econometric studies that have generally but not always found correlations between lead exposures in childhood and some types of crime 20 years later; a small number of epidemiological studies that have found a dose-response relationship between lead exposure in childhood and self-reported and officially recorded criminal offences in young adulthood; and evidence for the biological plausibility of a causal relationship. The major anomaly in the evidence is that the associations reported in ecological studies are much stronger (explaining 56-90% of the variation in crime rates) than the weaker relationships found in the cohort studies (that typically explain less than 1% of the variance in offending). Suggestions are made for research that will better assess the contribution that reduced lead exposure has made to declining crime rates in the USA.

Association Between Diet During Preadolescence and Adolescence and Risk for Breast Cancer During Adulthood

It is increasingly evident that diet during preadolescence and adolescence has important consequences for breast cancer during adulthood. However, only a few epidemiologic studies have been conducted on the relationship between diet during preadolescence and adolescence, and cancer during adulthood. This situation is partly because of methodological challenges such as the long latency period, the complexity of breast cancer, the lack of validated diet assessment tools, and the large number of subjects that must be followed, all of which increase costs. In addition, funding opportunities are few for such studies. Results from the small number of epidemiologic studies are inconsistent, but evidence is emerging that specific aspects of the diet during preadolescence and adolescence are important. For example, during preadolescence and adolescence, severe calorie restriction with poor food quality, high total fat intake, and alcohol intake tend to increase risk, whereas high soy intake decreases risk. Research on preadolescent and adolescent diet is a paradigm shift in breast cancer investigations. This research paradigm has the potential to produce transformative knowledge to inform breast cancer prevention strategies through dietary intervention during preadolescence and adolescence, rather than later in life, as is current practice, when it is perhaps less effective. Methodological challenges that have plagued the field might now be overcome by leveraging several existing large-scale cohort studies in the U.S. and around the world to investigate the role of diet during preadolescence and adolescence in risk for adult breast cancer.

Are Low- and Middle-Income Countries Repeating Mistakes Made by High-Income Countries in the Control of HIV for Men who have Sex with Men?

Men who have sex with men (MSM) have been represented disproportionately in the HIV epidemic in high income countries since the first HIV/AIDS cases were reported in MSM in 1981. Among all vulnerable HIV populations, MSM account for the preponderance of prevalent AIDS cases in Western Europe [1,2]. Similarly, the largest numbers of persons with newly diagnosed HIV infections (range 45%–65%) are MSM in the United States, Canada, Australia, and New Zealand [3–7]. In contrast, in many low- and middle-income country (LMICs) HIV epidemics were driven by injection drug use (IDU), heterosexual sex, and/or contaminated blood collection and transfusion [8,9]. In recent years, rapid increases in the HIV epidemic among MSM have been observed LMICs in Asia [10], Africa [11], South America [12] and Eastern Europe and Central Asia [13]. For example, MSM account for nearly one third of prevalent AIDS cases in Thailand [14] and Brazil [15], and 30% –75% of estimated new HIV infections in various parts of Laos and China [16,17]. A small number of epidemiologic studies have also shown high incidence (6.8/100 person-years) among MSM in Kenya and South Africa [18] and high HIV prevalence (4–23%) in Ukraine [19], though MSM comprise a small proportion of the total HIV cases in Africa, Eastern Europe and Central Asia, perhaps due, in part, to stigmatization and underreporting. As the HIV/AIDS epidemic enters its 4th decade post-recognition, many LMICs are repeating the mistakes made by high income countries in HIV control targeting MSM. A series of questions arise continually: Are MSM epidemics in LMICs driven by imported cases from high income countries? Have LMICs missed the window of opportunity to control the HIV epidemic among MSM? What experiences from the prevention and care for HIV among MSM populations have been learned from high income countries that could be applicable to the burgeoning MSM epidemic in LMICs?

TRAFFIC POLLUTION AND COGNITIVE FUNCTION IN COMMUNITY-DWELLING SENIORS: THE MOBILIZE BOSTON STUDY

Background and Aims: A small number of epidemiologic studies report an association between long-term exposure to traffic pollution and decreased cognitive function, but additional studies are needed. Accordingly, we evaluated the association between long-term exposure to black carbon (a marker of traffic pollution) and cognitive function in a population-based cohort of community-dwelling seniors. Methods: Between 2005 and 2008, we evaluated cognitive function among 765 elderly participants from the MOBILIZE Boston Study (64% female, aged 64-97 years). Neurocognative assessments included the Mini Mental State Exam (MMSE) and a battery of five tests designed to evaluate verbal memory and executive function. Subjects with moderate or severe cognitive impairment, as determined by an MMSE&lt; 18 were excluded. We geocoded participants’ residential addresses and assessed average long-term exposure to traffic pollution in the 12 months prior to neurocognitive assessment using a validated spatiotemporal land-use regression model for black carbon. We used generalized linear models to evaluate the association with an interquartile range increase (IQR: 0.1 µg/m3) in predicted black carbon levels. Results: Adjusting for age, sex, race, history of stroke, and education, an interquartile range increase in predicted residential exposure to black carbon was associated with a 19% (95% Confidence Interval [CI]: 1%, 39%; p=0.032) increase in risk of having an MMSE score in the lowest quartile (MMSE≤25). Further adjustment for household income, smoking history, body mass index, season, and census level covariates attenuated the results slightly (excess relative risk: 17%; 95% CI: -1%, 40%; p=0.060). Among the other tests, only verbal memory functioning was associated with black carbon (p= 0.056). Conclusions: In this population-based cohort of elderly subjects, long-term residential exposure to traffic pollution was associated with decreased cognitive function. The increasing prevalence of cognitive impairment expected with the aging population underscores the need for additional studies in this area.

Green tea and breast cancer

The identification of modifiable lifestyle factors that could reduce the risk of breast cancer is a research priority. Despite the enormous chemopreventive potential of green tea and compelling evidence from animal studies, its role in breast cancer development in humans is still unclear. Part of the uncertainty is related to the relatively small number of epidemiological studies on green tea and breast cancer and that the overall results from case-control studies and prospective cohort studies are discordant. In addition, the mechanisms by which green tea intake may influence risk of breast cancer in humans remain not well studied. We review the human studies that have evaluated the relationship between green tea intake and four biomarkers (sex steroid hormones, mammographic density, insulin-like growth factor, adiponectin) that are believed to be important in breast cancer development. Results from these biomarker studies are also inconclusive. Limitations of observational studies and areas of further investigations are discussed.

Of Lives and Livers: Emerging Responses to the Hepatitis C Virus

Hepatitis C is an infectious disease affecting the liver, caused by the hepatitis C virus (HCV). HCV is an etiological agent of acute and chronic liver disease that exists throughout the world. The high genetic variability of the HCV genome is reflected by six genotypes (1 to 6). Each genotype has a characteristic geographical distribution, which is important epidemiologically. HCV is a blood-borne virus that generally circulates in low titers in the serum of infected individuals. Epidemiologic studies show that the most efficient transmission of HCV is through the transfusion of blood or blood products, the transplantation of organs from infected donors, and the sharing of contaminated needles among injection-drug users. However, fewer than half of patients with acute hepatitis C report a history of such exposure. A small number of epidemiologic studies demonstrate that perinatal, sexual, household, and occupational transmission occurs, but our understanding of the risks of transmission in these settings has been limited. The therapy for chronic hepatitis C has evolved steadily since alpha interferon was first approved for use. At present, the optimal regimen appears to be a 24- or 48-week course of a combined pegylated alpha interferon and ribavirin regimen. Currently, the combination of RNAi (LV-shIRES) with IFN-α has been proposed to prevent therapeutic resistance, and to promote enhanced antiviral activity against HCV. However, any RNAi based therapy may be years away due to off-target effects.