Influenza vaccine failure in the tropics: a retrospective cohort study of waning effectiveness.

Influenza vaccine effectiveness (VE) wanes over the course of a temperate climate winter season but little data are available from tropical countries with year-round influenza virus activity. In Singapore, a retrospective cohort study of adults vaccinated from 2013 to 2017 was conducted. Influenza vaccine failure was defined as hospital admission with polymerase chain reaction-confirmed influenza infection 2-49 weeks after vaccination. Relative VE was calculated by splitting the follow-up period into 8-week episodes (Lexis expansion) and the odds of influenza infection in the first 8-week period after vaccination (weeks 2-9) compared with subsequent 8-week periods using multivariable logistic regression adjusting for patient factors and influenza virus activity. Records of 19 298 influenza vaccinations were analysed with 617 (3.2%) influenza infections. Relative VE was stable for the first 26 weeks post-vaccination, but then declined for all three influenza types/subtypes to 69% at weeks 42-49 (95% confidence interval (CI) 52-92%, P = 0.011). VE declined fastest in older adults, in individuals with chronic pulmonary disease and in those who had been previously vaccinated within the last 2 years. Vaccine failure was significantly associated with a change in recommended vaccine strains between vaccination and observation period (adjusted odds ratio 1.26, 95% CI 1.06-1.50, P = 0.010).

Bioactive components in human milk are differentially associated with rates of lean and fat mass deposition in infants of mothers with normal vs. elevated BMI.

OBJECTIVE: To model breastfed infant growth and body composition patterns over the first 4 months with multiple bioactive components of human milk (HM) and clinical factors (including maternal BMI status), which are related to growth. METHODS: Longitudinal observation of infant growth and body composition from 0 to 4 months among 41 predominantly breastfed infants (25 mothers of Normal-weight and 16 mothers with overweight/obesity). Fasted morning HM samples were collected at 5 time-points. Macronutrients, leptin, adiponectin, ghrelin, insulin, cytokines and n-6:n-3 esterified fatty acid ratio were measured. Infant weight-for-length Z-score (WLZ) trajectory, fat-free mass (FFM) gain, fat mass gain and %fat gain were modelled controlling for clinical covariates. RESULTS: HM insulin negatively associated with WLZ trajectory among infants of NW mothers (P = 0.028), but not associated with WLZ trajectory among infants of OW/Ob mothers. HM glucose (P < 0.001) was associated with slower rates of infant FFM gain. Infants of mothers with OW/Ob exhibited slower rates of FFM gain. HM protein, adiponectin and insulin concentrations, and n-6:n-3 ratio were all significant predictors in the model of infant fat mass gain (P < 0.03). Any amount of formula supplementation was associated with faster fat gain (P = 0.002). The model of %fat gain was similar to that of fat mass gain, excepting HM adiponectin was not a significant covariate, and a trend for maternal OW/Ob to correlate with faster %fat gain (P = 0.056). CONCLUSIONS: Bioactive components in HM may contribute to regulation of partitioning of body composition, and these contributions may differ between mothers of normal-weight vs. with OW/Ob.

Human milk insulin is related to maternal plasma insulin and BMI: but other components of human milk do not differ by BMI.

BACKGROUND/OBJECTIVES: The impact of maternal BMI and insulin sensitivity on bioactive components of human milk (HM) is not well understood. As the prevalence of obesity and diabetes rises, it is increasingly critical that we understand how maternal BMI and hormones associated with metabolic disease relate to concentrations of bioactive components in HM. SUBJECTS/METHODS: This longitudinal cohort design followed 48 breastfeeding mothers through the first four months of lactation, collecting fasting morning HM samples at 2-weeks and 1, 2, 3 and 4-months, and fasting maternal blood at 2-weeks and 4-months. Insulin, glucose, adipokines leptin and adiponectin, appetite regulating hormone ghrelin, marker of oxidative stress 8OHdG and inflammatory cytokines (IL-6, IL-8, and TNF-a) were measured in HM and maternal plasma. RESULTS: A total of 26 normal weight (NW) (BMI=21.4±2.0 kg/m2) and 22 overweight/obese (OW/Ob) (BMI=30.4±4.2 kg/m2) were followed. Of all HM analytes measured, only insulin and leptin were different between groups - consistently higher in the OW/Ob group (leptin: P<0.001; insulin: P<0.03). HM insulin was 98% higher than maternal plasma insulin at 2-weeks and 32% higher at 4-months (P<0.001). Maternal fasting plasma insulin and HOMA-IR were positively related to HM insulin at 2-weeks (P<0.001, R2⩾0.38, n=31), and 4-months (P⩽0.005, R2⩾0.20, n=38). CONCLUSIONS: The concentrations of insulin in HM are higher than in maternal plasma and are related to maternal BMI and insulin sensitivity. With the exception of leptin, there were minimal other differences observed in HM composition across a wide range in maternal BMI.

Early infant adipose deposition is positively associated with the n-6 to n-3 fatty acid ratio in human milk independent of maternal BMI.

BACKGROUND/OBJECTIVES: Excessive infant weight gain in the first 6-month of life is a powerful predictor of childhood obesity and related health risks. In mice, omega-6 fatty acids (FAs) serve as potent ligands driving adipogenesis during early development. The ratio of omega-6 relative to omega-3 (n-6/n-3) FA in human milk (HM) has increased threefold over the last 30 years, but the impact of this shift on infant adipose development remains undetermined. This study investigated how maternal obesity and maternal dietary FA (as reflected in maternal red blood cells (RBCs) composition) influenced HM n-6 and n-3 FAs, and whether the HM n-6/n-3 ratio was associated with changes in infant adipose deposition between 2 weeks and 4 months postpartum. SUBJECTS/METHODS: Forty-eight infants from normal weight (NW), overweight (OW) and obese (OB) mothers were exclusively or predominantly breastfed over the first 4 months of lactation. Mid-feed HM and maternal RBC were collected at either transitional (2 weeks) or established (4 months) lactation, along with infant body composition assessed using air-displacement plethysmography. The FA composition of HM and maternal RBC was measured quantitatively by lipid mass spectrometry. RESULTS: In transitional and established HM, docosahexaenoic acid (DHA) was lower (P=0.008; 0.005) and the arachidonic acid (AA)/DHA+eicosapentaenoic acid (EPA) ratio was higher (P=0.05; 0.02) in the OB relative to the NW group. Maternal prepregnancy body mass index (BMI) and AA/DHA+EPA ratios in transitional and established HM were moderately correlated (P=0.018; 0.001). Total infant fat mass was increased in the upper AA/DHA+EPA tertile of established HM relative to the lower tertile (P=0.019). The amount of changes in infant fat mass and percentage of body fat were predicted by AA/EPA+DHA ratios in established HM (P=0.038; 0.010). CONCLUSIONS: Perinatal infant exposures to a high AA/EPA+DHA ratio during the first 4 months of life, which is primarily reflective of maternal dietary FA, may significantly contribute to the way infants accumulate adipose.

Maternal Beliefs Surrounding Infant Feeding, but Not Maternal BMI or Hospital Experience, Predict Breastfeeding Exclusivity and Behavior.

BACKGROUND: Overweight/Obese (OW/Ob) women are at risk for breastfeeding failure. How maternal BMI affects lactation support received in-hospital, or maternal attitudes and beliefs surrounding infant feeding remains poorly understood. We investigated 1) the impact of in-hospital lactation support and maternal attitudes and behaviors regarding infant feeding on breastfeeding exclusivity, and 2) whether these potentially modifiable attitudes and behaviors differed between normal weights (NW) versus OW/Ob women. METHODS: NW (n=18) and OW/Ob (n=20) women and their infants were followed from birth to 4-months postpartum. In-hospital experiences, problems and help received regarding breastfeeding were documented. Six maternal attitudes and behaviors surrounding infant feeding were assessed at 2-weeks and 4-months. These factors were compared between NW and OW/OB women, and in relation to breastfeeding exclusivity. RESULTS: In-hospital experiences, assistance received regarding breastfeeding difficulties, and infant breastfeeding exposure did not differ between NW and OW/Ob women. At 4-months OW/Ob women were more likely to feed their infant on a schedule (p<0.03); this was the only difference in attitudes/behaviors between BMI-groups. Feeding the infant on a schedule was predictive of lower total breastfeeding exposure (p<0.05). Maternal concern about infant under-eating/becoming underweight was associated with several negative feeding behaviors, including reduced breastfeeding exposure (p<0.02), pressuring feeding style (p<0.01), and feeding to calm fussiness (p<0.01). CONCLUSION: This hospital setting provided equitable breastfeeding support to OW/Ob and NW women. Maternal concern over infant under-eating/under-gaining and encouragement to feed on-demand are prime interventional targets to improve breastfeeding outcomes; the latter may be especially relevant to OW/Ob mothers.

Maternal diet but not gestational weight gain predicts central adiposity accretion in utero among pregnant adolescents.

BACKGROUND: Modifiable risk factors during pregnancy, such as diet and weight gain, are associated with fetal birth weight but little is known about how these factors influence fetal fat acquisition in utero among pregnant adolescents. OBJECTIVE: To determine whether maternal pre-pregnancy BMI (ppBMI), gestational weight gain (GWG) and dietary intake during pregnancy influence fetal fat accretion in utero. METHODS: Longitudinal data were obtained from 121 pregnant adolescents enrolled in a study designed to identify determinants of maternal and fetal bone changes across gestation. Adolescents (ages 13-18 years) completed up to three study visits during early, mid- and late gestation. Maternal anthropometrics, 24 h dietary recalls and measures of fetal biometry were obtained at each visit. Fetal abdominal wall thickness (abdominal subcutaneous fat thickness, AbFat), a measure of fetal subcutaneous fat, was calculated by sonography at each visit. Statistical determinants of AbFat during late pregnancy were explored using simple and multiple regression. RESULTS: During late pregnancy (34.8±2.0 weeks; range 31.0-40.6 weeks of gestation), the median (inter-quartile range) fetal AbFat and GWG were 0.44 (0.39, 0.55) cm and 14.6 (9.5, 18.3) kg, respectively. After adjusting for infant birth weight, variables significantly associated with fetal AbFat included gestational age (P<0.0001, 95% confidence interval, CI: 0.01, 0.03), maternal race (P=0.029, 95% CI: -0.04, -0.002) and dietary intake of added sugar (P=0.025, 95% CI: 1.42e-6, 2.06e-5). Fetal AbFat had a significant positive quadratic relationship with total maternal dietary sugar intake such that both low and high extremes of sugar consumption were associated with significantly higher fetal AbFat. Birth weight was not significantly associated with maternal intake of added sugars. CONCLUSION: Extreme sugar intakes among pregnant adolescents may lead to increased accumulation of fetal abdominal fat with little net effect on birth weight. This finding suggests that increased sugar consumption during pregnancy promotes shifts in fetal body composition.

Large medical databases, population-based research, and patient confidentiality.

OBJECTIVE: This article is a discussion of the use of large clinical databases in population-based research on psychiatric disorders. METHOD: The authors review uses of large clinical databases in research on the etiology, impact, and treatment of psychiatric disorders. They also describe existing privacy safeguards applicable to use of medical records data in research. RESULTS: The growth of large medical databases has prompted increasing concern about the confidentiality of patient records. Efforts to restrict access to computerized medical data, however, may preclude use of such data in important and legitimate research. Prior research using large medical databases has made important contributions across a broad range of topics, including epidemiology, genetics, treatment effectiveness, and health policy. Continued population-based research will be essential in order to preserve the accessibility and quality of treatment for people with psychiatric disorders. CONCLUSIONS: Public domain research should be distinguished from proprietary or commercial uses of health information, and existing privacy safeguards should be vigorously applied. In our efforts to protect patient privacy, however, we should take care not to endorse or reinforce prejudices against psychiatric treatment and people who suffer from psychiatric disorders. Neither should we ignore important opportunities to improve quality of care and influence public policy through population-based research.

Nursing and health care reform: implications for curriculum development.

The health care system is undergoing profound changes. Cost containment efforts and restructuring have resulted in cutbacks in registered nurse (RN) positions. These changes are often related to the increased market penetration by managed care companies. To determine how RN graduates perceive these changes and their impact on the delivery of patient care, Healthcare Environment Surveys were mailed to graduates of the classes of 1986 and 1991. Using the Survey's 5-point Likert Scale, we measured the graduates' satisfaction with their salary, quality of supervision they received, opportunities for advancement, recognition for their job, working conditions, the overall job and the changes in their careers over the previous five year period. Our study suggests that the changes in the health care system are having an impact on how health care is being delivered and the way nurses view their jobs. Respondents reported that insurance companies are exerting increased control over patient care and perceive that the quality of patient care is declining. Increased workloads and an increase in the amount of paperwork were reported. Participants perceived that there were fewer jobs available and that job security was decreasing. The percentage of nurses who see job satisfaction as remaining the same or increasing are a majority. However, the relatively high percent of nurses who see job satisfaction as declining should provide a note of warning. The major implications of this study are that the professional nursing curriculum must be modified to include content on communication, organization, legislative/policy skills, and leadership. The nation's health care system is undergoing profound changes. There are numerous forces at work that are effecting the delivery of care and, consequently, the work of health professionals. These forces include significant efforts at cost containment, restructuring and downsizing of hospitals, and the movement of health care delivery out of acute care centers and into the community. Even though cutbacks in registered nurse (RN) positions appear to have leveled off in sections of the country that have gone through restructuring and reengineering of the work place, there still remains a heavy emphasis on lowering costs by decreasing employee benefits and increasing productivity through the substitution of part-time RNs for full-time RNs and the substitution of unlicensed assistive personnel (UAP) for RNs. These changes are often related to the increased market penetration by managed care companies, which are not expected to abate any time soon. It is important to determine what impact these changes are having on the delivery of patient care since there is some evidence to suggest that reduction in nursing staff below certain levels is related to poor patient outcomes (Fridken et al, 1996). It is also important to assess the effect of system changes on the satisfaction level health professionals have in their jobs. This is particularly important since some researchers suggest that job dissatisfaction, over a period of time, can result in burnout and eventually, turnover (Cameron, Horsburgh, & Armstrong-Stassen, 1994; Cotterman, 1991). Finally, understanding the impact of these health care delivery system changes has significant implications for baccalaureate nursing education and the preparation needed by future nurses to help them adjust to the changed environment.

Determination of methyl 2-benzimidazolecarbamate in bulk fruit juice concentrates by competitive-inhibition enzyme immunoassay.

A polyclonal enzyme immunoassay (EIA) was used to quantitate methyl 2-benzimidazolecarbamate (MBC or carbendazim), a degradation product of benomyl, in bulk fruit juice concentrates. These concentrates are used by industrial producers to prepare juice or juice concentrates sold in supermarkets. Total sample analysis time was less than 18 min without cleanup or 35 min with cleanup. As many as 8 samples can be analyzed simultaneously, with a limit of quantitation of 10 ppb. The assay's dynamic range ran from 0.5 to 20 ppb MBC but was best from 0.5 to 10 ppb. Intra-assay coefficients of variation (CVs) varied from 4.0 to 13% for standards and from 4.1 to 26% for samples. Interassay CVs varied from 4.5 to 47% for standards and 5.6 to 22% for samples. Average recovery of several juice concentrates spiked at 10 to 290 ppb was 97%. A total of 140 juice concentrates comprising 20 different kinds of juice were analyzed by 2 EIA methods and one liquid chromatographic (LC) procedure. MBC-positive samples gave the following correlation coefficients: 0.954 for EIA without cleanup vs LC, 0.956 for EIA with cleanup vs LC, and 0.978 for EIA with cleanup vs EIA without cleanup. MBC concentrations in MBC-positive juice samples ranged from 5 to 2960 ppb.

Determination of thiabendazole in fruits and vegetables by competitive-inhibition enzyme immunoassay.

An enzyme immunoassay (EIA) was developed for analysis of thiabendazole (TBZ) in fruits and vegetables. A commercial kit using a polyclonal antibody for benomyl-carbendazim was used. Total analysis time, including sample preparation, was 35 min. As many as 8 samples can be analyzed simultaneously, with a limit of quantitation of 9 ppb. The assay's dynamic range ran from 9 to 304 ppb TBZ. Intra-assay coefficients of variation (CVs) ranged from 5.0 to 9.6% for standards and 11 to 30% for samples. Interassay CVs varied from 4.4 to 15% for standards and from 10 to 24% for samples. Average recovery from 29 samples spiked at 50-50,000 ppb was 116%. A total of 107 food products comprising 12 different fruits and vegetables and their processed products were analyzed for their TBZ content by EIA and liquid chromatography (LC). Of these samples, 84 were positive for TBZ by both methods, with a correlation coefficient (r) of 0.989. Eight samples had none detected by either technique, and 15 were positive for carbendazim. Concentrations of TBZ ranged from 11 to 94,000 ppb. The immunoassay with methanol sonication shows promise as a rapid screening method for TBZ in foods.

Blood parasites in birds from Monteverde, Costa Rica.

In a survey of avian blood parasites in Costa Rica, 51 (11%) of 479 birds sampled were infected by at least one species of hematozoan. Fourteen of the 60 species of birds in the survey were examined for the first time. Infections were most common in ramphastids and emberizids and infrequent in other taxa. Among resident species, infections were more commonly detected during the wet season when most birds breed than during the dry season when few birds breed. Infections caused by Haemoproteus sp. were most common, while Plasmodium sp., Leucocytozoon sp., Trypanosoma sp., and microfilarial infections were rare. The intensity of the 40 Haemoproteus infections in adult birds was low, with a mean +/- SE of 12.5 +/- 3.7 infected cells per 10,000. Haemoproteus infections did not undergo seasonal changes in intensity.

Determination of methyl 2-benzimidazolecarbamate in wine by competitive inhibition enzyme immunoassay.

A benomyl polyclonal enzyme immunoassay (EIA) commercial kit was used to quantitate methyl 2-benzimidazolecarbamate (MBC), a degradation product of benomyl in wine. Total analysis time, including sample preparation, was 30 min. As many as 8 samples can be analyzed simultaneously with a limit of quantitation of 5 ppb. The assay logarithmic response was linear from 0.4 to 26 ppb MBC. Intra-assay percent coefficients of variation (%CVs) ranged from 2.4 to 13 for standards and from 7.4 to 21 for actual wine samples. Interassay %CVs varied from 2.6 to 15 for the standards and from 6.9 to 23 for the samples. Average recovery from samples spiked at 10-10,000 ppb was 93% for evaporated red and white wines. MBC was determined in 134 different wines by immunoassay and liquid chromatography (LC). Of these samples, 98 were positive for MBC by both methods with a correlation coefficient (r) of 0.986. The other 36 samples had MBC levels that either were not detectable by either procedure or were below the 10 ppb limit of quantitation for LC. Concentrations of MBC in wine ranged from 5 to 1329 ppb, with the majority ranging from 10 to 300 ppb. Also, a mini-study was conducted using the plate EIA format.

Total diet study nutritional elements, 1982-1989.

Daily intakes of sodium, potassium, calcium, phosphorus, magnesium, iron, zinc, selenium, iodine, copper, and manganese for eight age-sex groups are presented for 1982 to 1989. Compared with the intakes recommended by the National Academy of Sciences, sodium intakes (which did not include discretionary salt) exceeded the estimated minimum requirement; intakes of potassium, phosphorus, selenium, and iodine were adequate for all groups; and copper intakes were low (less than 80% of the suggested intake) for all groups. In addition, calcium, magnesium, iron, and manganese were low in the diets of teenage girls; calcium, magnesium, and iron were low in the diets of adult women; calcium, magnesium, and zinc were low in the diets of older women; calcium and zinc were low in the diets of 2-year-olds; and magnesium was low in the diets of teenage boys and older men. The primary food group source for each element was dairy products for potassium, calcium, phosphorus, magnesium, and iodine; grain products for sodium, iron, and manganese; and animal flesh for zinc, selenium, and copper.

Breast self-examination in relation to the occurrence of advanced breast cancer.

Two hundred nine female enrollees of the Group Health Cooperative of Puget Sound who developed advanced-stage breast cancer during the period 1982-1988 were interviewed about their practice of breast self-examination (BSE), use of other breast cancer screening modalities, and medical and reproductive histories. Each subject's description of how she performed the examination was scored according to her mention of up to 10 recommended BSE techniques. A random sample of 433 women without advanced-stage breast cancer from the same population was interviewed for comparison. Relative to women not practicing BSE, the risk of advanced-stage breast cancer among BSE users was 1.15 (95% confidence interval, 0.73-1.81). Frequency of BSE did not differ between women with advanced-stage breast cancer and control subjects, whether in all subjects or in subgroups defined by age, use of mammography, or frequency of clinical breast examinations. While self-described proficiency in BSE was generally low in both case and control subjects, the small percentage of women reporting more thorough self-examinations, regardless of frequency, had about a 35% decrease in the occurrence of advanced-stage breast cancer compared to women who did not perform BSE. These results suggest that, while carefully performed BSE may avoid the development of some advanced-stage breast cancers, BSE as practiced by most Seattle-area women is of little or no benefit.

Nutritional elements in U.S. diets: results from the Total Diet Study, 1982 to 1986.

Through the Food and Drug Administration's Total Diet Study, the levels of 11 nutritional elements (sodium, potassium, calcium, phosphorus, magnesium, iron, zinc, copper, manganese, selenium, and iodine) in the diets of eight age-sex groups were determined for the 4 years between 1982 and 1986. The 234 Total Diet Study foods, which are representative of the U.S. food supply, were purchased, prepared for consumption, and analyzed for the elements four times each year. The results were combined with national food consumption data to estimate intakes for 6- to 11-month-old infants, 2-year-old children, 14- to 16-year-old boys and girls, 25- to 30-year-old men and women, and 60- to 65-year-old men and women. Six elements (calcium, magnesium, iron, zinc, copper, and manganese) were low (less than 80% of the Recommended Dietary Allowance or below the low end of the Estimated Safe and Adequate Daily Dietary Intake range) for three or more of the age-sex groups. Six elements were of concern for teenage girls and adult women, five for older women, three for 2-year-old children, two for teenage boys and older men, and only one for infants and adult men. Sodium levels (which did not include discretionary salt) were elevated for 2-year-old children and teenage boys, and iodine was elevated for all age-sex groups. A significant trend was noted only for iodine, the intake of which decreased during the 4-year period.(ABSTRACT TRUNCATED AT 250 WORDS)

Mineral content of market samples of fluid whole milk.

Results from the Food and Drug Administration's Total Diet Study on the nutrient element content of fluid whole cow's milk are presented and compared with previously published values. Whole milk was collected and analyzed yearly from 1975 through 1985. Yearly and overall means were similar for all elements except iron and iodine. The iron content of milk was generally low, but several samples had high levels. The distribution of iodine in whole milk was quite wide (0.002 to 0.094 mg/100 gm). The iodine content of milk is affected by the level of iodine added to cattle feed and by the use of iodophor sanitizing solutions used by the dairy industry. Overall mean levels of the elements in milligrams per 100 gm whole milk were: sodium, 42; potassium, 134; calcium, 106; phosphorus, 83; magnesium, 9.8; iron, 0.07; zinc, 0.37; copper, 0.009; manganese, 0.004; iodine, 0.034; and selenium, 0.001. Coefficients of variation were high (67% to 117%) for iron, copper, manganese, selenium, and iodine but ranged from 18% to 26% for the other elements. An 8-fl oz serving of whole milk is an excellent source of iodine, calcium, phosphorus, and potassium. It also provides some sodium, magnesium, zinc, and selenium but is not a reliable source of iron, copper, or manganese.

Mineral content of foods and total diets: the Selected Minerals in Foods Survey, 1982 to 1984.

The 234 foods of the FDA's Total Diet Study were collected four times per year form mid-1982 to mid-1984 and analyzed for 11 essential minerals. Daily intakes of the minerals were estimated for eight age-sex groups of the U.S. population. Levels of calcium, magnesium, iron, zinc, copper, and manganese were low (less than 80% of the RDA or below the low end of the Estimated Safe and Adequate Daily Dietary Intake range) for some or all age-sex groups. Those most at risk of low intakes were young children, teenage girls, adult women, and older women. Non-discretionary sodium intake exceeded the upper Estimated Safe and Adequate Daily Dietary Intake range for two age-sex groups, and iodine was considerably above the RDA for all age-sex groups. Levels of potassium, phosphorus, and selenium were adequate for all groups.