Evaluation of three influenza neuraminidase inhibition assays for use in a public health laboratory setting during the 2011-2012 influenza season

OBJECTIVES

We evaluated the implementation of three commercially available neuraminidase inhibition assays in a public health laboratory (PHL) setting. We also described the drug susceptibility patterns of human influenza A and B circulating in Maryland during the 2011-2012 influenza season.

METHODS

From January to May 2012, 169 influenza virus isolates were tested for phenotypic susceptibility to oseltamivir, zanamivir, and peramivir using NA-Fluor(TM), NA-Star®, and NA-XTD(TM) concurrently. A 50% neuraminidase inhibitory concentration (IC50) value was calculated to determine drug susceptibility. We used the standard deviation based on the median absolute deviation of the median analysis to determine the potential for reduced drug susceptibility. We evaluated each assay for the use of resources in high- and low-volume testing scenarios.

RESULTS

One of the 25 2009 influenza A (H1N1) pandemic isolates tested was resistant to oseltamivir and peramivir, and sensitive to zanamivir, on all three platforms. Eighty-two influenza A (H3N2) and 62 B isolates were sensitive to all three drugs in all three assays. For a low-volume scenario, NA-Star and NA-XTD took 120 minutes to complete, while NA-Fluor required 300 minutes to complete. The lowest relative cost favored NA-Star. In a high-volume scenario, NA-Fluor had the highest throughput. Reagent use was most efficient when maximizing throughput. Cost efficiency from low- to high-volume testing improved the most for NA-Star.

CONCLUSIONS

Our evaluation showed that both chemiluminescent and fluorescent neuraminidase inhibition assays can be successfully implemented in a PHL setting to screen circulating influenza strains for neuraminidase inhibitor resistance. For improved PHL influenza surveillance, it may be essential to develop guidelines for phenotypic drug-resistance testing that take into consideration a PHL's workload and available resources.

A survey of U.S. obstetrician-gynecologists' clinical and epidemiological knowledge of cryptosporidiosis in pregnancy

Although cryptosporidiosis is frequently diagnosed in the U.S., there has been very little assessment of obstetrician-gynaecologist knowledge about this disease. In 2010, we surveyed U.S. obstetricians about the diagnosis, treatment and epidemiology of cryptosporidiosis. Data were examined through univariable analysis and multivariable regression models. Of 1000 obstetrician-gynaecologists surveyed, 431 (43.1%) responded. Only 44.4% of respondents correctly identified that prolonged, intermittent diarrhoea would lead them to consider cryptosporidiosis in a differential diagnosis. Routine ova and parasites (O&P) testing was incorrectly chosen to identify Cryptosporidium in stool by 30.4% of respondents. Questions about nitazoxanide, the only drug approved by the U.S. Food & Drug Administration (FDA) for treatment of cryptosporidiosis, were the most frequently missed questions. Only 9.0% of respondents correctly classified nitazoxanide as an FDA pregnancy Category B drug, and only 5.6% of respondents correctly indicated that FDA approved nitazoxanide for immunocompetent patients aged ≥1 years. Regarding prevention- and control-related knowledge, only 14.1% of respondents correctly indicated that alcohol-based hand sanitizers were not effective at inactivating Cryptosporidium spp., and <10% correctly indicated that cryptosporidiosis is a reportable disease in their state of practice. Multivariable analysis found that ≥19 years in practice was positively associated with O&P diagnostic testing knowledge, while rural and urban non-inner city practice location, compared with suburban practice location, was positively associated with nitazoxanide knowledge. The low level of knowledge among obstetrician-gynaecologists about cryptosporidiosis indicates a need to develop resources for physicians about all aspects of cryptosporidiosis, particularly on diagnosis, treatment and prevention strategies.

Endogenous synthesis of n-3 PUFA modifies fatty acid composition of kidney phospholipids and eicosanoid levels in the fat-1 mouse

The goal of the present study was to determine whether endogenous synthesis of n-3 polyunsaturated fatty acids (PUFA) in the fat-1 mouse is comparable to fish oil feeding with respect to kidney n-3 PUFA composition and eicosanoid levels. Wild-type and heterozygous fat-1 mice, capable of synthesizing n-3 PUFA endogenously, were given diets enriched in either n-3 or n-6 PUFA in a 2×2 factorial design and terminated after 12 weeks. Kidney phospholipid fatty acids were analysed by gas chromatography. Kidney eicosanoids were analysed by liquid chromatography tandem mass spectrometry. Relative to control mice fed n-6 PUFA, n-3 PUFA fed and fat-1 mice had higher levels of kidney phospholipid n-3 PUFA, and lower levels of n-6 PUFA and eicosanoids. However, mice fed n-3 PUFA mice had higher levels of n-3 PUFA and lower levels of eicosanoids as compared to fat-1 mice. In conclusion, diet feeding had a greater impact on kidney fatty acid composition and eicosanoid levels than the genetic effect of the fat-1 gene. However, the fat-1 mouse remains a close approximation that can be used as a complementary model to study the role of n-3 PUFA in the kidney.

Assessing diabetes-related quality of life of youth with type 1 diabetes in routine clinical care: the MIND Youth Questionnaire (MY-Q)

AIM

It is recommended to assess health-related quality of life (HRQoL) in teenagers with diabetes as part of their ongoing medical care. Here, we describe the development and psychometric evaluation of the Monitoring Individual Needs in Diabetes Youth Questionnaire (MY-Q), a multi-dimensional self-report HRQoL questionnaire designed for use in pediatric diabetes care.

DESIGN AND METHODS

In expert meetings, characteristics and domains of interest were defined. Existing questionnaires were reviewed, topics selected, and new items added, resulting in the 36-item MY-Q. To test face validity, we interviewed 22 teenagers. In addition, 84 teenagers with type 1 diabetes (age 10-18 yr) completed the MY-Q and Pediatric Quality of Life Inventory (PedsQL) generic and diabetes-modules to examine psychometric properties. Hemoglobin A1c (HbA1c) values were obtained by chart audit.

RESULTS

The MY-Q consists of seven subscales (social impact, parents, diabetes control perceptions, responsibility, worries, treatment satisfaction, and body image and eating behavior) as well as general HRQoL and emotional well-being. Cronbach's alpha for the total scale was 0.80. Strong correlations between MY-Q total and PedsQL generic and diabetes-module scores (r = 0.58 and r = 0.71, p < 0.001) confirmed concurrent validity. Higher HbA1c was associated with lower diabetes control perceptions (r = -0.35, p = 0.001), worries (r = -0.24, p = 0.029), and body image and eating behavior (r = -0.26, p = 0.019) scores. Younger age was associated with higher diabetes control perceptions (r = -0.26, p = 0.020) and body image and eating behavior (r = -0.23, p = .038), and lower responsibility (r = 0.25, p = 0.027) scores.

CONCLUSION

The MY-Q is the first HRQoL questionnaire designed for use in clinical care. It has acceptable measurement properties and seems suitable for implementation in routine care of teenagers with diabetes.

Sticky plant captures prey for symbiotic bug: is this digestive mutualism?

Many plants capture and kill insects but, until relatively recently, only carnivorous plants with digestive enzymes were known to gain directly from the nutrients of those insects. Recent studies show that some carnivorous plants lack digestive enzymes and have evolved digestive mutualisms with symbiotic insects that digest their prey for them. Rhododendron macrosepalum, a plant with sticky leaves that captures insects, has an association with symbiotic Mirid bugs that consume the insects captured. Here, we determine what the nature of the relationship is between Mirid and plant. We find that R. macrosepalum has no digestive enzymes of its own but that it does not seem to have the ability to absorb hemipteran faeces through its leaf cuticle. Naturally occurring levels of (15) N and (14) N were used to determine that R. macrosepalum gains no nitrogen through its association with the Mirid bugs and that it obtains all of its nitrogen from the soil. The Mirids, on the other hand, seem to obtain nitrogen from insects captured by the plant, as well as from plant tissues. The relationship between plant and Mirid is not a digestive mutualism but more likely an antagonistic relationship. This study adds to our understanding of how digestive mutualisms evolve and shows that insect capture alone, or in combination with a symbiotic insect relationship does not necessarily make a plant 'carnivorous'.

A formative evaluation of shared family mealtime for parents of toddlers and young children

Shared family mealtime offers numerous health benefits for young children. Unfortunately, only a few studies examine the benefits and barriers to eating together as a family. The present study seeks to fill this gap in the literature by applying the health belief model to understand parents' perceptions about the challenges of preparing and executing family mealtime for toddlers and young children. Six focus groups were conducted with parents of toddlers and/or young children (n = 24). Results revealed that parents identified several benefits to shared family mealtime, including good teaching moments for their children, enhanced family connectedness, and encouraging nutritious meals. Parents also identified barriers to eating together as a family, including child behavioral issues, scheduling difficulties, and ill-prepared husbands. The risks associated with not eating together as a family were seldom mentioned; however, parents highlighted several issues related to self-efficacy, such as difficulty in selecting meals and challenges with cooking. Potential cues to action include print materials encouraging parents by emphasizing the benefits of eating together as a family. Results are discussed with an emphasis on message design strategies for health practitioners interested in advocating this important yet under-studied phenomenon.

Insulin delivery by injection in children and adolescents with diabetes

Type 1 diabetes is treated with insulin, which has traditionally been delivered by vial and syringe. However, for many patients, dosing inaccuracy, pain, anxiety, inconvenience, and social acceptability present barriers to this method of administration (1-5). This has contributed to the increased popularity of alternative insulin delivery systems, including pen delivery devices (4, 6). Evidence suggests that discreet devices, such as insulin pens, facilitate adherence to intensive insulin therapy regimens, help improve lifestyle flexibility, and reduce injection pain compared with the conventional syringe-based regimens, as shown in studies in adults and adolescents (7). In addition, compared with the vial and syringe method of insulin administration, pens may provide more accurate dosing - which is particularly important in children - thereby improving short-term blood glucose control and potentially improving long-term outcomes (5, 8). Children, in particular, may benefit from insulin pens that are simple to use as adherence issues may be more evident in this patient group (9). Pens for insulin delivery in children with type 1 diabetes have been used for a long time in Europe, and have recently gained in popularity in many other places around the world (4, 10). Furthermore, the conventional vial and syringe method of insulin delivery is beginning to be considered as obsolete (11). Moreover, there is a continued drive to improve insulin pen technology, to refine and enhance the functionality and usability of these pens. However, despite recent advances in pen design and function, the selection of pens available especially for children is limited.