Frequent human-poultry interactions and low prevalence of Salmonella in backyard chicken flocks in Massachusetts.

The backyard chicken (BYC) movement in the USA has increased human contact with poultry and subsequently, human contact with the pathogen Salmonella. However, to date, there have been few studies assessing prevalence of Salmonella in backyard flocks, despite the known public health risk this zoonotic bacterium poses. The objective of this study was to characterize human-BYC interactions and assess the prevalence of Salmonella among BYC flocks. We interviewed 50 BYC owners using a structured questionnaire to determine flock and household characteristics that facilitate contact with BYC and that may be associated with Salmonella in the BYC environment. Composite faecal material, cloacal swabs and dust samples from 53 flocks housed on 50 residential properties in the Greater Boston, Massachusetts area were tested for Salmonella using standard culture techniques and confirmed using Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometer. Microbroth dilution and whole genome sequencing were used to determine phenotypic and genotypic resistance profiles, respectively, and sequence results were used to determine multilocus sequencing type. No owners self-reported a diagnosis of salmonellosis in the household. Over 75% of a subset of owners reported that they and their children consider BYC pets. This perception is evident in how owners reported interacting with their birds. Salmonella enterica subspecies enterica serotype Kentucky ST152 (serogroup C)-a strain not commonly associated with human infection-was confirmed in one flock, or 2% of tested flocks, and demonstrated resistance to tetracycline and streptomycin. We detected Salmonella at low prevalence in BYC. Further study of the health effects of exposure to zoonotic gastrointestinal pathogens such as Salmonella among families with BYC is warranted.

Nonnative Cattle Ownership, Diet, and Child Height-for-Age: Evidence from the 2011 Uganda Demographic and Health Survey.

In underresourced settings where domestic animals and children often cohabitate, there is limited evidence about the net impact of domestic animal ownership on child health. We analyzed the 2011 Uganda Demographic and Health Survey to determine whether household ownership of native cattle, goats, sheep, chickens, pigs, and nonnative cattle was associated with child height-for-age z-scores (HAZ), and to assess the influence of diet on this association in rural and urban environments. Using weighted multivariable linear regression, we found that nonnative cattle ownership was positively associated with HAZ in rural children 0 to < 2 years of age (+1.32 standard deviations [SD], 95% confidence interval [CI] = 0.2-2.5) and 2 to < 5 years of age (+0.58 SD, 95% CI = 0.003-1.2), and urban children 2 to < 5 years of age (+1.08 SD, 95% CI = 0.38-1.8). Sheep ownership was positively associated with HAZ in rural children 2 to < 5 years of age (+0.29 SD, 95% CI = 0.002-0.58) and goat ownership was positively associated with HAZ in rural children 0 to < 2 years of age (+0.27 SD, 95% CI = 0.003-0.55). We observed no other significant associations. Children who lived in households that owned nonnative cattle consumed dairy more frequently; however, the relationship between child HAZ and nonnative cattle ownership was not mediated by child dairy consumption. These findings suggest that domestic animal ownership may not be detrimental to child HAZ, and that nonnative cattle ownership is beneficial for child HAZ through pathways other than dairy consumption.

Putting Meaning Back Into the Mean: A Comment on the Misuse of Elementary Statistics in a Sample of Manuscripts Submitted to Clinical Therapeutics.

PURPOSE: Errors in the statistical presentation and analyses of data in the medical literature remain common despite efforts to improve the review process, including the creation of guidelines for authors and the use of statistical reviewers. This article discusses common elementary statistical errors seen in manuscripts recently submitted to Clinical Therapeutics and describes some ways in which authors and reviewers can identify errors and thus correct them before publication. METHODS: A nonsystematic sample of manuscripts submitted to Clinical Therapeutics over the past year was examined for elementary statistical errors. FINDINGS: Clinical Therapeutics has many of the same errors that reportedly exist in other journals. IMPLICATIONS: Authors require additional guidance to avoid elementary statistical errors and incentives to use the guidance. Implementation of reporting guidelines for authors and reviewers by journals such as Clinical Therapeutics may be a good approach to reduce the rate of statistical errors.

Food insecurity, depression, and social support in HIV-infected Hispanic individuals.

Previous research has identified an association between food insecurity and depression in a variety of world regions in both healthy and HIV-infected individuals. We examined this association in 183 HIV-infected Hispanic adults from the greater Boston area. We measured depression with the Burnam depression screen and food insecurity with the Radimer/Cornell Questionnaire. Dietary intake was assessed with an adapted version of the Block Food Frequency Questionnaire. Logistic regression models were created with depression as the outcome variable and food insecurity as the main predictor. In bivariate analyses, food insecurity was significantly associated with depression [odds ratio (OR) 2.5; 95% confidence interval (CI) 1.1, 5.5; p = 0.03]. When we accounted for social support, food insecurity was no longer significant. We found no differences in the quality or quantity of dietary intake between the food insecure and food secure groups. Our findings highlight the importance of social support in the association between food insecurity and depression. Food insecurity may reflect social support more than actual dietary intake in this population.

Hypertension prevalence and knowledge assessment in rural Haiti.

OBJECTIVE: Hypertension is an important risk factor for cardiovascular disease throughout the world. Little is known about the prevalence of hypertension in rural Haiti. Our study aims to estimate prevalence and knowledge of hypertension in Northern Haiti. DESIGN: Cross-sectional. SETTING: Four rural communities surrounding Milot, Haiti. PARTICIPANTS: Participants (69 males, 106 females, 175 total) were eligible to take part if they were aged > 18 years and not pregnant. Enrollment was voluntary. METHODS: Two initial blood pressure measurements were taken for each participant. Participants who had an average systolic blood pressure > or = 140 mm Hg or diastolic blood pressure > or = 90 mm Hg were instructed to return in 1 week for two additional confirmatory measurements. Based on these measures, participants were classified as either hypertensive or not. All participants were surveyed to assess their knowledge of hypertension. RESULTS: The prevalence of hypertension among the study sample was 36.6%. Overall, 47% of women and 21% of men were hypertensive. Approximately 30% of women of reproductive age (18-39 years) were hypertensive. Participants showed little knowledge of the asymptomatic nature of hypertension and the need for lifelong treatment. CONCLUSIONS: Hypertension is prevalent in Haiti. The high prevalence of hypertension among women of reproductive age is a concern since it is a risk factor for cardiovascular disease. Lack of knowledge surrounding hypertension indicates low awareness of the condition and is a possible target for future educational interventions.

Limited infection with occult hepatitis B virus in drug users in the USA.

AIM: Occult HBV infection (O-HBV) is defined as low level HBV replication in the absence of detectable circulating HBV surface antigen. O-HBV has been implicated in HBV reactivation, advanced liver fibrosis and cirrhosis, reduced interferon response rates, elevated liver enzyme levels, and the development of hepatocellular carcinoma. However, the prevalence of O-HBV has not been clearly established in certain at-risk populations, such as injection drug users. METHODS: Therefore, the current pilot study examined the prevalence of O-HBV in a prospective cohort designed to assess the role of injection and non-injection drug use (IDU) on HIV-associated comorbidities. RESULTS: Utilizing two distinct real-time polymerase chain reaction assays, HBV DNA was not detected in 99 participants examined. CONCLUSION: This finding is in contrast to other data from US IDU cohorts and suggests that the prevalence of O-HBV infection is very specific to the cohort studied, is sensitive to other confounding variables such as hepatitis C virus and/or HIV serostatus, and should not be generalized across risk groups or distinct cohorts.

Micronutrients in HIV/AIDS: is there evidence to change the WHO 2003 recommendations?

To establish whether there is new evidence to inform changes to WHO 2003 recommendations for micronutrient intake in persons with HIV/AIDS, we conducted a narrative review of the literature published from 2003 to 2010. Although the review focused on new randomized controlled trials of multiple micronutrients in HIV-infected adults, including pregnant and lactating women, we also considered randomized trials of single micronutrients. The review found that there are few published randomized controlled trials of micronutrients in HIV-infected persons and that most trials used high-dose multiple micronutrient supplementation. The trials were heterogeneous with respect to the composition and dose of micronutrients used and the target population studied. Despite this heterogeneity, 5 of 6 trials that used high-dose multiple micronutrients showed benefits in terms of either improved CD4 cell counts or survival. However, many of these trials were small and of short duration, and therefore the long-term risks and benefits of high-dose multiple micronutrients are not established. The current WHO recommendation for an intake of micronutrients at Recommended Dietary Allowance amounts continues to be a reasonable target for persons with clinically stable HIV infection. In light of new data that show adverse effects of high-dose vitamin A, the current recommendation for a single high dose of vitamin A in HIV-infected women within 6 wk of delivery should be reviewed.

Heavy injection drug use is associated with lower percent body fat in a multi-ethnic cohort of HIV-positive and HIV-negative drug users from three U.S. cities.

BACKGROUND: The clinical implications of lower body weight in drug using populations are uncertain given that lower mean weights may still fall within the healthy range. OBJECTIVES: To determine the effect of type, mode and frequency of drug use on underlying body composition after accounting for differences in body shape and size. METHODS: We conducted a cross-sectional analysis of 511 participants from the Tufts Nutrition Collaborative (TNC) Study. Data included measures of body composition, a 24-hour dietary recall, and a detailed health history and lifestyle questionnaire. Multivariate regression analysis was used to determine the independent effect of drug use on percent body fat (BF) after adjusting for BMI and waist circumference. RESULTS: Heavy injection drug users (IDUs) had a 2.6% lower percent BF than non-users after adjusting for BMI, waist circumference, and other confounders. (p = 0.0006). Differences in percent BF were predominantly due to higher lean mass, rather than lower fat mass. Cocaine and heroin had similar effects on body composition. CONCLUSIONS: In the U.S., where the general population is prone to over-nutrition, the average percent BF for heavy injectors does not fall into a range low enough to suggest harmful effects. However, in populations with substantial levels of under-nutrition, small differences in percent BF among drug users will have a greater impact on health status. SCIENTIFIC SIGNIFICANCE: Differences in BMI, weight and body composition are not always straightforward. Accounting for underlying nutritional status and relative differences in fat and FFM is critical when interpreting results. diagnosed patients and prevent them from returning to prison.

Factors associated with serum retinol, alpha-tocopherol, carotenoids, and selenium in Hispanics with problems of HIV, chronic hepatitis C, and drug use.

The effects of hepatitis and drug use on nutritional problems in HIV infection have rarely been examined despite the importance of drug use in the global HIV pandemic. We examined the effects of HIV, hepatitis C, and drug use on serum micronutrients in 300 US Hispanic adults. Chronic hepatitis C infection was associated with lower serum retinol (-8.2 microg/dl, P < 0.0001), alpha-tocopherol (-0.10 ln microg/dl, P = 0.024), and carotenoids (-19.8 microg/dl, P < 0.0001). HIV infection was associated with lower selenium (-6.1 microg/l, P = 0.028). Elevated triglycerides in HIV infection were associated with higher serum retinol and alpha-tocopherol. Drug use was not independently associated with micronutrient alterations. We conclude that hepatitis C is an important determinant of low serum micronutrients, and should be considered in any nutritional assessment of HIV infected populations. As the safety of micronutrient supplementation is not established, policy for appropriate HIV clinical care should distinguish between populations with and without hepatitis coinfection.

Multivariate Limited Translation Hierarchical Bayes Estimators.

Based on the notion of predictive influence functions, the paper develops multivariate limited translation hierarchical Bayes estimators of the normal mean vector which serve as a compromise between the hierarchical Bayes and maximum likelihood estimators. The paper demonstrates the superiority of the limited translation estimators over the usual hierarchical Bayes estimators in terms of the frequentist risks when the true parameter to be estimated departs widely from the grand average of all the parameters.

Risk factors for proteinuria in HIV-infected and -uninfected Hispanic drug users.

BACKGROUND: Proteinuria may be an early marker of chronic kidney disease in human immunodeficiency virus (HIV)-infected patients with coexisting chronic hepatitis and/or drug use. Minorities are at greater risk of chronic kidney disease. Data are limited about risk factors for proteinuria in Hispanic drug users with and without HIV infection. STUDY DESIGN: A cross-sectional study. SETTING & PARTICIPANTS: A community-recruited Hispanic cohort to study the role of drug use in HIV-associated malnutrition composed of 4 groups (106 HIV-infected drug users, 96 HIV-uninfected drug users, 38 HIV-infected non-drug users, and 47 healthy controls). Patients on renal replacement therapy were excluded. PREDICTORS: HIV infection, chronic hepatitis, history of hypertension or diabetes, and intravenous drug use (never, prior, or current). OUTCOMES & MEASUREMENTS: The presence of proteinuria was defined as urine dipstick result of 1+ or greater. Multivariable logistic regression was used to identify independent risk factors for proteinuria. RESULTS: Of 287 patients with available data, 24 (8.4%) had proteinuria. In univariate analyses, those with HIV infection; prior, but not current, intravenous drug use; and a history of hypertension or diabetes were more likely to have proteinuria. In multivariate analyses, significant risk factors for proteinuria were HIV infection (odds ratio, 9.2; 95% confidence interval, 1.9 to 45.8; P = 0.007); prior, but not current, intravenous drug use (odds ratio, 4.7; 95% confidence interval, 1.4 to 15.3; P = 0.01); and history of hypertension or diabetes (odds ratio, 8.2; 95% confidence interval, 3.1 to 21.7; P < 0.001). LIMITATIONS: The cross-sectional study design makes it difficult to establish the temporal relationship. The number of outcomes in relation to the number of predictors is small. CONCLUSIONS: HIV and prior intravenous drug use, but not chronic hepatitis or current intravenous drug use, were independently associated with proteinuria in this Hispanic population. Longitudinal studies to assess the development of proteinuria and chronic kidney disease in this high-risk population are warranted.

A validation study of body composition by bioelectrical impedance analysis in human immunodeficiency virus (HIV)-positive and HIV-negative Hispanic men and women.

Bioelectrical impedance analysis (BIA) is a potentially useful tool for measuring body composition in people with human immunodeficiency virus (HIV). However, it is not clear that equations derived in healthy non-Hispanic whites can be applied to people who are of other races or ethnicities and who are infected with HIV. Body composition measures done by BIA, using the equations of Lukaski, were compared to measures of body composition derived from dual-energy x-ray absorptiometry (DXA) in Hispanic men and women of Caribbean origin (predominantly Puerto Rican) with and without HIV infection. In cross-sectional analyses, body composition was measured by BIA and DXA in four groups of Hispanics: 97 HIV-positive men, 70 HIV-negative men, 38 HIV-positive women, and 14 HIV-negative women. The method of Bland and Altman was used to evaluate the validity of BIA compared to DXA. Compared to DXA, BIA provided accurate measures of fat-free mass in HIV-positive and HIV-negative Hispanic men. Fat-free mass by BIA compared to DXA was overestimated by 2.7 kg (standard deviation=2.5; P<0.0001) in the HIV-positive Hispanic women and by 3.4 kg (standard deviation=2.6; P<0.01) in the HIV-negative women. The magnitude of the bias in fat-free mass was dependent on fat mass in both the men and the women. BIA, using the equations of Lukaski, appears to be useful in this Hispanic population of Caribbean origin with and without HIV, for whom it provided reasonable estimates of body composition. Fat mass affects the accuracy of estimates.

Assessing dietary intake of drug-abusing Hispanic adults with and without human immunodeficiency virus infection.

OBJECTIVE: Drug abuse is an important risk factor for the human immunodeficiency virus (HIV) among Hispanics living in the northeastern United States, and both drug abuse and HIV are associated with nutritional deficiencies. The selection of a dietary assessment method most appropriate for Hispanic adults with/without HIV infection who may be drug abusers remains unclear. DESIGN: Participants were recruited into one of the three groups: HIV-infected drug abusers, HIV-noninfected drug abusers, and HIV-infected non-drug abusers. Subjects who completed two of the three dietary methods were included in cross-sectional pairwise comparisons. SETTING: The baseline data from a prospective cohort study of the role of drug abuse in HIV/acquired immunodeficiency syndrome-related weight loss. RESULTS: The 286 enrolled participants completed 282 food frequency questionnaires (FFQs), 142 3-day diet records, and 270 24-hour recalls. Energy-adjusted and deattenuated correlations between the FFQ and 3-day diet records ranged from 0.11 (carbohydrate) to 0.75 (caffeine). Twenty-seven of 33 nutrient intakes estimated by 3-day diet record were significantly lower than by FFQ (P<0.05). Three-day diet records underestimated dietary intake relative to the FFQ and 24-hour recall methods. Fifty percent of records were not completed. Energy estimates from the FFQ and 24-hour recall were similar to each other. CONCLUSIONS: The 24-hour recall gave higher mean dietary intake estimates, but would require multiple contacts with this difficult-to-reach population. The FFQ that was specifically designed for this Hispanic population performed well relative to the other methods.

Micronutrient levels and HIV disease status in HIV-infected patients on highly active antiretroviral therapy in the Nutrition for Healthy Living cohort.

BACKGROUND: Low serum micronutrient levels were common before widespread use of highly active antiretroviral therapy (HAART) and were associated with adverse outcomes. Few data are available on micronutrient levels in subjects taking HAART. OBJECTIVE: To determine the prevalence of low serum retinol, alpha-tocopherol, zinc, and selenium in HIV-infected subjects taking HAART and to assess the association of micronutrient levels with HIV disease status. DESIGN: Cross-sectional. SETTING: Nutrition for Healthy Living (NFHL) study. PARTICIPANTS: HIV-infected subjects on HAART. METHODS: Retinol, alpha-tocopherol, zinc, and selenium were determined in frozen serum samples from 171 men and 117 women. Low serum levels were defined as retinol <30 microg/dL, selenium <85 microg/L, alpha-tocopherol <500 microg/dL, and zinc <670 microg/L. Association of micronutrient quartiles with CD4 cell count, CD4 count <200 cells/mm, HIV viral load (VL), and undetectable VL was assessed using adjusted multivariate regression. RESULTS: Five percent of men and 14% of women had low retinol, 8% of men and 3% of women had low selenium, and 7% of men and no women had low alpha-tocopherol. Forty percent of men and 36% of women had low zinc, however. Subjects in the upper quartiles of zinc had lower log VL levels than those in the lowest quartile (significant for women). Subjects in the upper quartiles of selenium also tended to have lower VL levels compared with those in the lowest quartile. Surprisingly, women in the upper quartiles of retinol had higher log VLs than those in the lowest quartile. There was no significant association of any micronutrient with CD4 cell count or likelihood of CD4 count <200 cells/mm. The level of CD4 cell count influenced the association of retinol with log VL in men, however. In men with CD4 counts >350 cells/mm, those with higher retinol had higher log VLs compared with the lowest quartile, whereas in men with CD4 counts <350, those with higher retinol levels had lower log VLs compared with the lowest quartile. CONCLUSIONS: Low retinol, alpha-tocopherol, and selenium are uncommon in HIV-infected subjects on HAART. Zinc deficiency remains common, however. Decreased retinol levels in women and in men with CD4 counts >350 cells/mm and increased zinc and selenium levels in both genders may be associated with improved virologic control.

Nutritional Alterations in Drug Abusers With and Without HIV.

Many studies have found that drug abusers have nutritional deficits, including weight deficits. The most plausible explanation for these deficits is dietary insufficiency. However, studies using objective measures of the dietary intake of drug abusers have failed to provide evidence of dietary insufficiency. Other mechanisms have rarely been examined. This article reviews the published literature on the nutritional status of drug abusers with and without HIV, with emphasis on dietary energy and macronutrient intake.

The effect of drug abuse on body mass index in Hispanics with and without HIV infection.

OBJECTIVE: There is a widely held view that the lower weight of drug abusers is attributable to diet. However, many studies on the dietary intake of drug abusers have failed to find energy insufficiency, while non-dietary factors have rarely been examined. The purpose of this study was to examine non-dietary factors that could affect the weight of drug abusers with and without HIV infection. DESIGN: Participants were recruited into one of three groups: HIV-positive drug abusers (n=85), HIV-negative drug abusers (n=102) and HIV-positive persons who do not use drugs ('non-drug abusers', n=98). Non-dietary factors influencing weight included infection with HIV and/or hepatitis, malabsorption, resting energy expenditure and physical activity. SETTING: The baseline data from a prospective cohort study of the role of drug abuse in HIV/AIDS weight loss conducted in Boston, USA. SUBJECTS: The first 286 participants to enroll in the study. RESULTS: HIV-positive drug abusers had a body mass index (BMI) that was significantly lower than that of HIV-positive non-drug abusers. The differences in weight were principally differences in fat. In the men, cocaine abuse, either alone or mixed with opiates, was associated with lower BMI, while strict opiate abuse was not. Infection with HIV or hepatitis, intestinal malabsorption, resting energy expenditure and physical activity, as measured in this study, did not explain the observed differences in weight and BMI. CONCLUSIONS: Drug abuse, and especially cocaine abuse, was associated with lower weight in men. However, infection with HIV and/or hepatitis, malabsorption and resting energy expenditure do not explain these findings.

Dietary intake and body mass index in HIV-positive and HIV-negative drug abusers of Hispanic ethnicity.

OBJECTIVE: Malnutrition in drug abusers has been attributed to poor diet. However, previous studies are conflicting. Many studies have not considered possible concurrent HIV disease. The purpose of this study was to determine the relationship between drug abuse and dietary intake in Hispanic Americans with and without HIV infection. DESIGN: Dietary intake was measured using 3-day food records and 24-hour dietary recalls in three groups: HIV-positive drug abusers, HIV-negative drug abusers and HIV-positive persons who do not use drugs ('non-drug abusers'). SETTING: The baseline data from a prospective cohort study of the role of drug abuse in HIV/AIDS weight loss and malnutrition conducted in Boston, Massachusetts, USA. SUBJECTS: The first 284 participants to enroll in the study. RESULTS: HIV-positive drug abusers had a body mass index (BMI) that was significantly lower than that of HIV-positive non-drug abusers. Reported energy, fat and fibre intakes did not differ between groups. All groups had median reported intakes of vitamin A, vitamin B6, vitamin B12, selenium and zinc that were in excess of the dietary reference values (DRI). Intakes of alpha-tocopherol were below the DRI, but did not differ from intakes of the general US population. However, increasing levels of drug abuse were associated with lower reported intakes of vitamin B6, vitamin B12, selenium and zinc. CONCLUSIONS: Overall, this study does not support the notion that dietary intake can explain the lower BMI of HIV-positive drug abusers. Further studies examining non-dietary determinants of nutritional status in drug abusers are warranted.

Effect of dietary intake and protease inhibitors on serum vitamin B12 levels in a cohort of human immunodeficiency virus-positive patients.

The dietary intake of micronutrients and serum micronutrient status have been topics of concern in relation to human immunodeficiency virus (HIV) progression. Most data, however, were collected prior to the introduction of protease inhibitors (PIs). We analyzed dietary intake and serum values of vitamin B(12), including the effect of PIs, in a cohort of persons with HIV infection. During intervals with no PI use, each 1 microg/day increase in B(12) intake was associated with a 1.06 pg/mL increase in serum B(12) levels. However, during intervals with PI use, each 1 microg/day increase in intake was associated with only a 0.12 increase in serum B(12) levels. Adequate serum B(12) levels (>350 pg/mL) cannot be assumed even in the presence of PIs, and dietary supplementation may not be adequate to significantly increase serum B(12) levels. Serum B(12) levels should be determined yearly in persons with HIV infection, regardless of whether they are receiving PI treatment.

Statistical analysis of correlated data using generalized estimating equations: an orientation.

The method of generalized estimating equations (GEE) is often used to analyze longitudinal and other correlated response data, particularly if responses are binary. However, few descriptions of the method are accessible to epidemiologists. In this paper, the authors use small worked examples and one real data set, involving both binary and quantitative response data, to help end-users appreciate the essence of the method. The examples are simple enough to see the behind-the-scenes calculations and the essential role of weighted observations, and they allow nonstatisticians to imagine the calculations involved when the GEE method is applied to more complex multivariate data.