Challenges Associated with Investigating Salmonella Enteritidis with Low Genomic Diversity in New York State: The Impact of Adjusting Analytical Methods and Correlation with Epidemiological Data.

Defining investigation-worthy genomic clusters among strains of Salmonella Enteritidis is challenging because of their highly clonal nature. We investigated a cluster identified by core genome multilocus sequence typing (cgMLST) consisting of 265 isolates with isolation dates spanning two and a half years. This cluster experienced chaining, growing to a range of 14 alleles. The volume of isolates and broad allele range of this cluster made it difficult to ascertain whether it represented a common-source outbreak. We explored laboratory-based methods to subdivide and refine this cluster. These methods included using cgMLST with a narrower allele range, whole genome multilocus sequence typing (wgMLST) and high-quality single-nucleotide polymorphism (hqSNP) analysis. At each analysis level, epidemiologists retroactively reviewed exposures, geography, and temporality for potential commonalities. Lowering the threshold to 0 alleles using cgMLST proved an effective method to refine this analysis, resulting in this large cluster being subdivided into 34 smaller clusters. Additional analysis by wgMLST and hqSNP provided enhanced cluster resolution, with the majority of clusters being further refined. These analysis methods combined with more stringent allele thresholds and layering of epidemiologic data proved useful in helping to subdivide this large cluster into actionable subclusters.

Placental levels of polycyclic aromatic hydrocarbons (PAHs) and their association with birth weight of infants.

As an alarming group of pollutants, polycyclic aromatic hydrocarbons (PAHs) gather much public health concern not only because of their carcinogenic or co-carcinogenic risk but also by interfering with hormone systems or by causing oxidative damage, henceforth liable to toxic actions on reproduction. Accordingly, the present study was aimed to explore the association between in-utero exposure to PAHs by evaluating their placental levels and infant birth weight among 110 healthy and nonsmoking pregnant women. Placental tissue samples were collected instantly after delivery and were analyzed for the presence of sixteen Environmental Protection Agency (EPA) listed PAHs with the help of Gas chromatography equipped with flame ionization detector (GC-FID). Chrysene and benzo(k)fluoranthene were the predominant PAHs detected in tissue samples. To assess the source of origin of PAHs in placenta tissue samples, the ratio of low molecular weight PAHs to high molecular weight (∑LMW/∑HMW PAHs) was calculated, showing the predominance of pyrogenic sources of PAHs possibly responsible for the exposure of the studied population. Results of regression analysis demonstrated the inverse although not significant association of naphthalene (Nap), acenaphthylene (Acy), anthracene (Anth), pyrene (Pyr), benzo(b)fluoranthene (BbF), benzo(k)Fluoranthene (BkF), benzo(a)pyrene (BaP), indeno (123 cd pyrene (IcdP), dibenzo(ah)anthracene (DahA) and benzo(ghi)Perylene (BghiP) with birth weight of neonates. Additionally, the regression model lay light upon the significant association of fluoranthene (Fla) (coefficient= -1.41 gram, p < 0.05) to the depletion trend of birth weight after adjusting for potential covariates. These findings suggest the possible role of an environmental contaminants like PAHs on impairment of fetal growth.

Environmental toxic metals in placenta and their effects on preterm delivery-current opinion.

Preterm birth is a significant public reproductive health concern globally; Furthermore, preterm birth has long-lasting medical and pecuniary burdens on the society. Moreover, preterm birth is well-established as the underlying cause of low birth weight in infants as well as neonatal mortality. A growing body of literature suggests that the etiology of preterm delivery in women is elusive; however, countless environmental factors are considered responsible for preterm birth. Environmental contaminants that are toxic metals such as lead, cadmium, arsenic, and mercury are familiar confounding factors for preterm birth globally. Recent studies have indicated that these toxic heavy metals induce oxidative stress in the trophoblastic placental tissue by producing reactive oxygen species that alter the mechanism of antioxidants possibly leading to preterm birth. Moreover, no obvious mechanism underlying metal-induced oxidative stress in the placenta has been identified until date. Consequently, this review offers an outline of the currently existing scientific information on the association of toxic metals and redox status of the placental tissue with preterm birth. Furthermore, this study critically recognizes the gaps related to the deleterious effect of metals on the gestation period in scientific literature.

Association Between Placental Polycyclic Aromatic Hydrocarbons (PAHS), Oxidative Stress, and Preterm Delivery: A Case-Control Study.

Polycyclic aromatic hydrocarbons are known to disturb the antioxidant defense system, which may indirectly contribute to induction of early pregnancy in women. Therefore, the present investigation was designed to offer preliminary information about exposure to PAHs by estimating their placental levels and its association with oxidative stress as well as with preterm birth. Placenta tissue samples were drawn after delivery from 84 healthy pregnant women, recruited at a local nursing home of Agra, India, and levels of PAHs were quantified by gas chromatograph equipped with flame ionization detector. To evaluate redox status biomarkers, malondialdehyde (MDA) and glutathione (GSH) were determined in placenta tissue. Significantly elevated levels of benzo(a)pyrene and MDA while decreasing trend of GSH was found in women with preterm delivery group (study) than women with a full-term delivery group (control). Results demonstrated higher, but statistically insignificant (p > 0.05), levels of naphthalene, anthracene, fluorene, pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, indeno[1,2,3-cd]pyrene, dibenzo(ah)anthracene, and benzo(ghi)perylene in the study group than the control group. However, higher and lower molecular weight PAHs showed significant correlation for the depletion trend of GSH sights upon an example of oxidative stress mechanism. Because of limited statistical power and absence of controlled confounders, this study does not provide an ample involvement of PAHs with preterm delivery but increased MDA and decreased GSH in cases than controls gives the possible contribution of PAHs to early delivery.

Giardiasis Outbreak Associated with Asymptomatic Food Handlers in New York State, 2015.

Giardia duodenalis is a protozoan that causes a gastrointestinal illness called giardiasis. Giardiasis outbreaks in the United States are most commonly associated with waterborne transmission and are less commonly associated with food, person-to-person, and zoonotic transmission. During June to September 2015, an outbreak of 20 giardiasis cases occurred and were epidemiologically linked to a local grocery store chain on Long Island, New York. Further investigation revealed three asymptomatic food handlers were infected with G. duodenalis, and one food handler and one case were coinfected with Cryptosporidium spp. Although G. duodenalis was not detected in food samples, Cryptosporidium was identified in samples of spinach dip and potato salad. The G. duodenalis assemblage and subtype from one of the food handlers matched two outbreak cases for which genotyping could be performed. This outbreak highlights the potential role of asymptomatically infected food handlers in giardiasis outbreaks.

Outbreak of Salmonella Newport infections linked to cucumbers--United States, 2014.

In August 2014, PulseNet, the national molecular subtyping network for foodborne disease surveillance, detected a multistate cluster of Salmonella enterica serotype Newport infections with an indistinguishable pulse-field gel electrophoresis (PFGE) pattern (XbaI PFGE pattern JJPX01.0061). Outbreaks of illnesses associated with this PFGE pattern have previously been linked to consumption of tomatoes harvested from Virginia's Eastern Shore in the Delmarva region and have not been linked to cucumbers or other produce items. To identify the contaminated food and find the source of the contamination, CDC, state and local health and agriculture departments and laboratories, and the Food and Drug Administration (FDA) conducted epidemiologic, traceback, and laboratory investigations. A total of 275 patients in 29 states and the District of Columbia were identified, with illness onsets occurring during May 20-September 30, 2014. Whole genome sequencing (WGS), a highly discriminating subtyping method, was used to further characterize PFGE pattern JJPX01.0061 isolates. Epidemiologic, microbiologic, and product traceback evidence suggests that cucumbers were a source of Salmonella Newport infections in this outbreak. The epidemiologic link to a novel outbreak vehicle suggests an environmental reservoir for Salmonella in the Delmarva region that should be identified and mitigated to prevent future outbreaks.

Pandemic 2009 influenza A(H1N1) virus illness among pregnant women in the United States.

CONTEXT: Early data on pandemic 2009 influenza A(H1N1) suggest pregnant women are at increased risk of hospitalization and death. OBJECTIVE: To describe the severity of 2009 influenza A(H1N1) illness and the association with early antiviral treatment among pregnant women in the United States. DESIGN, SETTING, AND PATIENTS: Surveillance of 2009 influenza A(H1N1) in pregnant women reported to the Centers for Disease Control and Prevention (CDC) with symptom onset from April through December 2009. MAIN OUTCOME MEASURES: Severity of illness (hospitalizations, intensive care unit [ICU] admissions, and deaths) due to 2009 influenza A(H1N1) among pregnant women, stratified by timing of antiviral treatment and pregnancy trimester at symptom onset. RESULTS: We received reports on 788 pregnant women in the United States with 2009 influenza A(H1N1) with symptom onset from April through August 2009. Among those, 30 died (5% of all reported 2009 influenza A[H1N1] influenza deaths in this period). Among 509 hospitalized women, 115 (22.6%) were admitted to an ICU. Pregnant women with treatment more than 4 days after symptom onset were more likely to be admitted to an ICU (56.9% vs 9.4%; relative risk [RR], 6.0; 95% confidence interval [CI], 3.5-10.6) than those treated within 2 days after symptom onset. Only 1 death occurred in a patient who received treatment within 2 days of symptom onset. Updating these data with the CDC's continued surveillance of ICU admissions and deaths among pregnant women with symptom onset through December 31, 2009, identified an additional 165 women for a total of 280 women who were admitted to ICUs, 56 of whom died. Among the deaths, 4 occurred in the first trimester (7.1%), 15 in the second (26.8%), and 36 in the third (64.3%); CONCLUSIONS: Pregnant women had a disproportionately high risk of mortality due to 2009 influenza A(H1N1). Among pregnant women with 2009 influenza A(H1N1) influenza reported to the CDC, early antiviral treatment appeared to be associated with fewer admissions to an ICU and fewer deaths.

Comparison of polycyclic aromatic hydrocarbon levels in placental tissues of Indian women with full- and preterm deliveries.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants formed from combustion products of fossil fuels, cigarette smoking and in grilled/smoked foods. They are reported to alter trophoblast proliferation in placenta, in addition to disturbing its endocrine functions, which may be able to increase the risk of preterm delivery in pregnant women. The present study was planned to assess possible involvement of PAHs exposure of pregnant women (measured as placental PAHs concentrations) with preterm delivery cases among women of Lucknow city (India). We performed a case-control study and a total of 60 mothers (n=31 full term and n=29 preterm deliveries) were recruited at a local nursing home of Lucknow, for the period of August 2005-February 2006. Subsequent to parturition, placental tissues from each participant were immediately collected and kept at -20 degrees C until PAHs analyses. Placental tissue PAHs concentrations were determined by HPLC, using a fluorescence detector. Mean+/-SD placental level (61.91+/-12.43ppb) of benzo(b)fluoranthene, a carcinogenic PAH, was found significantly elevated (p<0.05) among women with preterm delivery when compared with the level (23.84+/-7.01) in women having full-term deliveries. In the same way, non-carcinogenic fluoranthene level (325.91+/-45.14ppb) was also detected to be higher in the preterm delivery group compared to 208.6+/-21.93ppb level from the full-term delivery group of women. Additionally naphthalene, acenaphthylene, phenanthrene, anthracene, benzo(a)pyrene and dibenzo(a,h)anthracene levels in placental tissue were also found to be higher in the preterm delivery group of women but the difference did not reach statistically significant levels. This foremost study from India with modest samples size and limited statistical power does not show a substantial involvement of PAHs with preterm delivery, but higher concentrations of placental PAHs detected among preterm delivery group of women could show some possible association with these environmental toxicants. Further study with large sample size, controlled for confounders and great statistical power, is reasonable to elucidate the association of PAHs exposure with preterm delivery of women in India.

Finely controlled size-selective precipitation and separation of CdSe/ZnS semiconductor nanocrystals using CO2-gas-expanded liquids.

A technique was developed to size-selectively separate polydisperse dispersions of CdSe/ZnS nanocrystals into distinct color fractions using only the tunable solvent properties of CO2-expanded hexane. This size-selective precipitation of semiconductor nanoparticles is achieved by finely tuning the solvent strength of the CO2/hexane medium by simply adjusting the applied CO2 pressure. These subtle changes affect the balance between osmotic repulsive and van der Waals attractive forces, thereby allowing fractionation of the nanocrystals into multiple narrow size populations.

West Nile virus surveillance in mosquitoes in New York State, 2000-2004.

A West Nile virus (WNV) surveillance system was created and implemented in New York State (NYS) in 2000 and described previously (White et al. 2001). We examine and evaluate the results of mosquito and virus surveillance for 2000 through 2004 exclusive of New York City. Forty-nine counties submitted 1,095,426 mosquitoes in 35,280 pools for WNV assay. Specimens of 47 species were tested, with Culex species accounting for 47.6% of all pools tested. WNV was detected in 814 pools from 10 species, with combined Culex pipiens/Culex restuans pools accounting for 90.8% of all detections. Pools submitted from gravid traps were 5.7 times more likely to be positive than submissions from carbon dioxide-baited light traps. Most human WNV cases resided in counties that conducted mosquito surveillance. Local health departments' use of mosquito surveillance information often led to an enhanced disease prevention response. In NYS, Cx. pipiens/Cx. restuans groups are most likely vectors of WNV. Future efforts to improve system efficacy are discussed.

Synthesis and steric stabilization of silver nanoparticles in neat carbon dioxide solvent using fluorine-free compounds.

The adjustable solvent properties, vanishingly low surface tensions, and environmentally green characteristics of supercritical carbon dioxide present certain advantages in nanoparticles synthesis and processing. Unfortunately, most current techniques employed to synthesize and disperse nanoparticles in carbon dioxide use environmentally persistent fluorinated compounds as metal precursors and/or stabilizing ligands. This paper illustrates a one-step process for synthesis and stabilization of silver nanoparticles in carbon dioxide using only fluorine-free compounds. Isostearic acid coated silver nanoaparticles were formed and stably dispersed through arrested precipitation. Silver bis(3,5,5-trimethyl-1-hexyl)sulfosuccinate (Ag-AOT-TMH) was reduced in the presence of isostearic acid as a capping ligand in carbon dioxide solvent to form silver nanoparticles. The addition of cyclohexane as cosolvent or an increase in carbon dioxide solvent density enhances the dispersibility of the particles due to an increase in solvent strength. The dispersibility of the isostearic acid capped silver nanoparticles diminished with time until a stable dispersion was achieved due to the precipitation of a fraction of particle sizes too large to be stabilized by the solvent medium, thereby leaving a smaller size fraction of nanoparticles stably dispersed in the CO2 mixtures. This paper presents the one-step synthesis and stabilization of metallic nanoparticles in neat carbon dioxide without the aid of any fluorinated compounds.

Synthesis and extraction of beta-D-glucose-stabilized Au nanoparticles processed into low-defect, wide-area thin films and ordered arrays using CO2-expanded liquids.

This letter presents a straightforward and economic strategy to create aqueous Au nanoparticle dispersions using small amounts of beta-D-glucose as a "green" alternative to the conventional phase-transfer catalyst approach. Furthermore, this new process provides for efficient extraction of these monodisperse Au nanoparticles into an organic phase that was successfully processed into wide-area, locally ordered nanoparticle arrays and thin films using a precisely controlled CO2-expanded liquid particle deposition technique. This CO2-based technique allows for pressure-tunable particle deposition while eliminating the detrimental surface tension and dewetting effects common to normal solvent-evaporation techniques.

Stable dispersions of silver nanoparticles in carbon dioxide with fluorine-free ligands.

Iso-stearic acid, a short, stubby compound with branched, methylated tails has been shown to have high solubility in carbon dioxide. Tail solvation by carbon dioxide makes iso-stearic acid a good choice for use as a ligand to sterically stabilize metallic nanoparticles. Iso-stearic acid coated silver nanoparticles have been stably dispersed in carbon dioxide with hexane cosolvent. Neat carbon dioxide has successfully dispersed iso-stearic acid coated silver nanoparticles that had been deposited on either quartz or polystyrene surfaces. These results are the first reports of sterically stabilized nanoparticles in carbon dioxide without the use of any fluorinated compounds.

Dead crow density and West Nile virus monitoring, New York.

New York State used the health commerce system to monitor the number of West Nile virus (WNV) human disease cases and the density of dead crows. In each year from 2001 to 2003 and for the 3 years combined, persons living in New York counties (excluding New York City) with elevated weekly dead crow densities (above a threshold value of 0.1 dead crows per square mile) had higher risk (2.0-8.6 times) for disease caused by WNV within the next 2 weeks than residents of counties reporting fewer dead crows per square mile. This type of index can offer a real-time, relatively inexpensive window into viral activity in time for prevention and control. Changes in reporting, bird populations, and immunity may require that thresholds other than 0.1 be used in later years or in other areas.

Babesia microti, upstate New York.

Five cases of human babesiosis were reported in the Lower Hudson Valley Region of New York State in 2001. An investigation to determine if Babesia microti was present in local Ixodes scapularis ticks yielded 5 positive pools in 123 pools tested, the first detection of B. microti from field-collected I. scapularis in upstate New York.

Precise and rapid size selection and targeted deposition of nanoparticle populations using CO2 gas expanded liquids.

This paper demonstrates the rapid and precise size selection of nanoparticle populations using the pressure tunable solvent properties of CO2-expanded liquids. Specifically, by pressurizing and expanding a single organic solution with carbon dioxide gas, ligand-stabilized silver particles of desired mean size were size selectively precipitated at desired locations. Compared to current techniques, this CO2-expanded liquid approach provides for faster and more efficient particle size separation, reduction in organic solvent usage, and pressure tunable size selection.

Tunable solvation effects on the size-selective fractionation of metal nanoparticles in CO2 gas-expanded solvents.

This paper presents an environmentally friendly, inexpensive, rapid, and efficient process for size-selective fractionation of polydisperse metal nanoparticle dispersions into multiple narrow size populations. The dispersibility of ligand-stabilized silver and gold nanoparticles is controlled by altering the ligand tails-solvent interaction (solvation) by the addition of carbon dioxide (CO2) gas as an antisolvent, thereby tailoring the bulk solvent strength. This is accomplished by adjusting the CO2 pressure over the liquid, resulting in a simple means to tune the nanoparticle precipitation by size. This study also details the influence of various factors on the size-separation process, such as the types of metal, ligand, and solvent, as well as the use of recursive fractionation and the time allowed for settling during each fractionation step. The pressure range required for the precipitation process is the same for both the silver and gold particles capped with dodecanethiol ligands. A change in ligand or solvent length has an effect on the interaction between the solvent and the ligand tails and therefore the pressure range required for precipitation. Stronger interactions between solvent and ligand tails require greater CO2 pressure to precipitate the particles. Temperature is another variable that impacts the dispersibility of the nanoparticles through changes in the density and the mole fraction of CO2 in the gas-expanded liquids. Recursive fractionation for a given system within a particular pressure range (solvent strength) further reduces the polydispersity of the fraction obtained within that pressure range. Specifically, this work utilizes the highly tunable solvent properties of organic/CO2 solvent mixtures to selectively size-separate dispersions of polydisperse nanoparticles (2 to 12 nm) into more monodisperse fractions (+/-2 nm). In addition to providing efficient separation of the particles, this process also allows all of the solvent and antisolvent to be recovered, thereby rendering it a green solvent process.

Multiple-year experience in the diagnosis of viral central nervous system infections with a panel of polymerase chain reaction assays for detection of 11 viruses.

BACKGROUND: Polymerase chain reaction (PCR) is becoming more common in diagnostic laboratories. In some instances, its value has been established. In other cases, assays exist, but their beneficial use has not been determined. This article summarizes findings from 3485 patients who underwent testing over a 6-year period in our laboratory. METHODS: A panel of PCR assays was used for the detection of a range of viruses associated with central nervous system (CNS) infections. PCR results were analyzed in conjunction with information about patient age and sex, the time between onset and specimen collection, and other variables. Medical chart review was conducted for 280 patients to gain diagnostic and epidemiologic insight with regard to cases of unresolved encephalitis. RESULTS: A total of 498 PCR-positive samples (14.3%) were detected. Enteroviruses accounted for the largest number (360 [72.3%]) of positive PCR results, followed by herpes simplex virus (76 [15.3%]), varicella-zoster virus (29 [5.82%]), and West Nile virus (WNV) (18 [3.61%]). Of 360 patients who tested positive for enterovirus, only 46 met the Centers for Disease Control and Prevention's encephalitis definition. It resulted in the greatest decrease (87.2%) in positive PCR results. Overall, the PCR positivity rate for specimens collected within 5 days after illness onset was 17.2%, compared with 8.6% for specimens collected > or =6 days after onset. CONCLUSIONS: The value of PCR in the diagnosis of viral infections has been established. PCR is of lower value in the detection of WNV in CNS, compared with serological testing, but is of greater value in the detection of other arboviruses, particularly viruses in the California serogroup. Medical chart reviews indicated that apparent CNS infection resolves in approximately 50% of cases.