Viral metagenomics of aphids present in bean and maize plots on mixed-use farms in Kenya reveals the presence of three dicistroviruses including a novel Big Sioux River virus-like dicistrovirus.

BACKGROUND: Aphids are major vectors of plant viruses. Common bean (Phaseolus vulgaris L.) and maize (Zea mays L.) are important crops that are vulnerable to aphid herbivory and aphid-transmitted viruses. In East and Central Africa, common bean is frequently intercropped by smallholder farmers to provide fixed nitrogen for cultivation of starch crops such as maize. We used a PCR-based technique to identify aphids prevalent in smallholder bean farms and next generation sequencing shotgun metagenomics to examine the diversity of viruses present in aphids and in maize leaf samples. Samples were collected from farms in Kenya in a range of agro-ecological zones. RESULTS: Cytochrome oxidase 1 (CO1) gene sequencing showed that Aphis fabae was the sole aphid species present in bean plots in the farms visited. Sequencing of total RNA from aphids using the Illumina platform detected three dicistroviruses. Maize leaf RNA was also analysed. Identification of Aphid lethal paralysis virus (ALPV), Rhopalosiphum padi virus (RhPV), and a novel Big Sioux River virus (BSRV)-like dicistrovirus in aphid and maize samples was confirmed using reverse transcription-polymerase chain reactions and sequencing of amplified DNA products. Phylogenetic, nucleotide and protein sequence analyses of eight ALPV genomes revealed evidence of intra-species recombination, with the data suggesting there may be two ALPV lineages. Analysis of BSRV-like virus genomic RNA sequences revealed features that are consistent with other dicistroviruses and that it is phylogenetically closely related to dicistroviruses of the genus Cripavirus. CONCLUSIONS: The discovery of ALPV and RhPV in aphids and maize further demonstrates the broad occurrence of these dicistroviruses. Dicistroviruses are remarkable in that they use plants as reservoirs that facilitate infection of their insect replicative hosts, such as aphids. This is the first report of these viruses being isolated from either organism. The BSRV-like sequences represent a potentially novel dicistrovirus infecting A. fabae.

Genetic diversity of Kenyan native oyster mushroom (Pleurotus).

Members of the genus Pleurotus, also commonly known as oyster mushroom, are well known for their socioeconomic and biotechnological potentials. Despite being one of the most important edible fungi, the scarce information about the genetic diversity of the species in natural populations has limited their sustainable utilization. A total of 71 isolates of Pleurotus species were collected from three natural populations: 25 isolates were obtained from Kakamega forest, 34 isolates from Arabuko Sokoke forest and 12 isolates from Mount Kenya forest. Amplified fragment length polymorphism (AFLP) was applied to thirteen isolates of locally grown Pleurotus species obtained from laboratory samples using five primer pair combinations. AFLP markers and internal transcribed spacer (ITS) sequences of the ribosomal DNA were used to estimate the genetic diversity and evaluate phylogenetic relationships, respectively, among and within populations. The five primer pair combinations generated 293 polymorphic loci across the 84 isolates. The mean genetic diversity among the populations was 0.25 with the population from Arabuko Sokoke having higher (0.27) diversity estimates compared to Mount Kenya population (0.24). Diversity between the isolates from the natural population (0.25) and commercial cultivars (0.24) did not differ significantly. However, diversity was greater within (89%; P > 0.001) populations than among populations. Homology search analysis against the GenBank database using 16 rDNA ITS sequences randomly selected from the two clades of AFLP dendrogram revealed three mushroom species: P. djamor, P. floridanus and P. sapidus; the three mushrooms form part of the diversity of Pleurotus species in Kenya. The broad diversity within the Kenyan Pleurotus species suggests the possibility of obtaining native strains suitable for commercial cultivation.

The Influence of Weather on the Occurrence of Aflatoxin B1 in Harvested Maize from Kenya and Tanzania.

A study was conducted using maize samples collected from different agroecological zones of Kenya (n = 471) and Tanzania (n = 100) during the 2013 maize harvest season to estimate a relationship between aflatoxin B1 concentration and occurrence with weather conditions during the growing season. The toxins were analysed by the ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. Aflatoxin B1 incidence ranged between 0-100% of samples in different regions with an average value of 29.4% and aflatoxin concentrations of up to 6075 µg/kg recorded in one sample. Several regression techniques were explored. Random forests achieved the highest overall accuracy of 80%, while the accuracy of a logistic regression model was 65%. Low rainfall occurring during the early stage of the maize plant maturing combined with high temperatures leading up to full maturity provide warning signs of aflatoxin contamination. Risk maps for the two countries for the 2013 season were generated using both random forests and logistic regression models.

Metagenomic Analysis of Plant Virus Occurrence in Common Bean (Phaseolus vulgaris) in Central Kenya.

Two closely related potyviruses, bean common mosaic virus (BCMV) and bean common mosaic necrosis virus (BCMNV), are regarded as major constraints on production of common bean (Phaseolus vulgaris L.) in Eastern and Central Africa, where this crop provides a high proportion of dietary protein as well as other nutritional, agronomic, and economic benefits. Previous studies using antibody-based assays and indicator plants indicated that BCMV and BCMNV are both prevalent in bean fields in the region but these approaches cannot distinguish between these potyviruses or detect other viruses that may threaten the crop. In this study, we utilized next generation shotgun sequencing for a metagenomic examination of viruses present in bean plants growing at two locations in Kenya: the University of Nairobi Research Farm in Nairobi's Kabete district and at sites in Kirinyaga County. RNA was extracted from leaves of bean plants exhibiting apparent viral symptoms and sequenced on the Illumina MiSeq platform. We detected BCMNV, cucumber mosaic virus (CMV), and Phaseolus vulgaris alphaendornaviruses 1 and 2 (PvEV1 and 2), with CMV present in the Kirinyaga samples. The CMV strain detected in this study was most closely related to Asian strains, which suggests that it may be a recent introduction to the region. Surprisingly, and in contrast to previous surveys, BCMV was not detected in plants at either location. Some plants were infected with PvEV1 and 2. The detection of PvEV1 and 2 suggests these seed transmitted viruses may be more prevalent in Eastern African bean germplasm than previously thought.

Ultrasound assessment of spleen size in collegiate athletes.

OBJECTIVES: To determine normal spleen dimensions in a healthy collegiate athletic population. METHODS: 631 Division I collegiate athletes from one university participated in the study. During pre-participation examinations, demographic data collected were collected from volunteer athletes including sex, race, measurement of height and weight, and age. Subjects also completed a medical history form to determine any history of mononucleosis infection, platelet disorder, sickle cell disease (or trait), thalassaemia, or recent viral symptoms. Subjects then underwent a limited abdominal ultrasound examination, where splenic length and width were recorded. RESULTS: Mean (SD) splenic length was 10.65 (1.55) cm and width, 5.16 (1.21) cm. Men had larger spleens than women (p<0.001). White subjects had larger spleens than African-American subjects (p<0.001). A previous history of infectious mononucleosis or the presence of recent cold symptoms had no significant affect on spleen size. In more than 7% of athletes, baseline spleen size met current criteria for splenomegaly. CONCLUSIONS: There is a wide range of normal spleen size among collegiate athletes. Average spleen size was larger in men and white athletes than in women and black athletes. A single ultrasound examination for determination of splenomegaly is of limited value in this population.

Tools for Defusing a Major Global Food and Feed Safety Risk: Nonbiological Postharvest Procedures To Decontaminate Mycotoxins in Foods and Feeds.

Mycotoxin contamination of foods and animal feeds is a worldwide problem for human and animal health. Controlling mycotoxin contamination has drawn the attention of scientists and other food and feed stakeholders all over the world. Despite best efforts targeting field and storage preventive measures, environmental conditions can still lead to mycotoxin contamination. This raises a need for developing decontamination methods to inactivate or remove the toxins from contaminated products. At present, decontamination methods applied include an array of both biological and nonbiological methods. The targeted use of nonbiological methods spans from the latter half of last century, when ammoniation and ozonation were first used to inactivate mycotoxins in animal feeds, to the novel techniques being developed today such as photosensitization. Effectiveness and drawbacks of different nonbiological methods have been reported in the literature, and this review examines the utility of these methods in addressing food safety. Particular consideration is given to the application of such methods in the developing world, where mycotoxin contamination is a serious food safety issue in staple crops such as maize and rice.

In vitro experimental environments lacking or containing soil disparately affect competition experiments of Aspergillus flavus and co-occurring fungi in maize grains.

In vitro experimental environments are used to study interactions between microorganisms, and to predict dynamics in natural ecosystems. This study highlights that experimental in vitro environments should be selected to match closely the natural environment of interest during in vitro studies to strengthen extrapolations about aflatoxin production by Aspergillus and competing organisms. Fungal competition and aflatoxin accumulation were studied in soil, cotton wool or tube (water-only) environments, for Aspergillus flavus competition with Penicillium purpurogenum, Fusarium oxysporum or Sarocladium zeae within maize grains. Inoculated grains were incubated in each environment at two temperature regimes (25 and 30°C). Competition experiments showed interaction between the main effects of aflatoxin accumulation and the environment at 25°C, but not so at 30°C. However, competition experiments showed fungal populations were always interacting with their environments. Fungal survival differed after the 72-h incubation in different experimental environments. Whereas all fungi incubated within the soil environment survived, in the cotton wool environment none of the competitors of A. flavus survived at 30°C. With aflatoxin accumulation, F. oxysporum was the only fungus able to interdict aflatoxin production at both temperatures. This occurred only in the soil environment and fumonisins accumulated instead. Smallholder farmers in developing countries face serious mycotoxin contamination of their grains, and soil is a natural reservoir for the associated fungal propagules, and a drying and storage surface for grains on these farms. Studying fungal dynamics in the soil environment and other environments in vitro can provide insights into aflatoxin accumulation post-harvest.

Bean Common Mosaic Virus and Bean Common Mosaic Necrosis Virus: Relationships, Biology, and Prospects for Control.

The closely related potyviruses Bean common mosaic virus (BCMV) and Bean common mosaic necrosis virus (BCMNV) are major constraints on common bean (Phaseolus vulgaris) production. Crop losses caused by BCMV and BCMNV impact severely not only on commercial scale cultivation of this high-value crop but also on production by smallholder farmers in the developing world, where bean serves as a key source of dietary protein and mineral nutrition. In many parts of the world, progress has been made in combating BCMV through breeding bean varieties possessing the I gene, a dominant gene conferring resistance to most BCMV strains. However, in Africa, and in particular in Central and East Africa, BCMNV is endemic and this presents a serious problem for deployment of the I gene because this virus triggers systemic necrosis (black root disease) in plants possessing this resistance gene. Information on these two important viruses is scattered throughout the literature from 1917 onward, and although reviews on resistance to BCMV and BCMNV exist, there is currently no comprehensive review on the biology and taxonomy of BCMV and BCMNV. In this chapter, we discuss the current state of our knowledge of these two potyviruses including fundamental aspects of classification and phylogeny, molecular biology, host interactions, transmission through seed and by aphid vectors, geographic distribution, as well as current and future prospects for the control of these important viruses.

Prevention of brain trauma by legislation, regulation, and improved technology: a focus on motor vehicles.

More than half of all brain trauma is caused by motor vehicle crashes. Prevention strategies that reduce the likelihood of motor vehicle crashes or injuries to occupants will also prevent trauma. Many effective strategies have yet to be applied on a large scale. Roadway design improvements such as removal of fixed objects from roadsides, widening roadside recovery zones, installing dividers between opposing lanes of traffic, and replacing fixed utility poles with breakaway designs, have been effective in reducing crashes and injuries. Driver measures of documented benefit include the 55 mph speed limit, safety belt use laws, 21 year legal drinking age, administrative license suspension for drinking drivers, and driving curfews and postponement of licensure for teenagers. Motor vehicle safety has improved greatly since the National Highway Traffic Safety Administration began regulating vehicle design. Significant design requirements include lap and shoulder belts in front seat positions, and, more recently, automatic safety belts or air bags in front seat positions, head restraints in front seat positions, reinforcing side and roof beams, and the center-mounted brake light. The most significant future advance will be the provision of full front seat air bags in all passenger vehicles. As much as one-quarter of brain trauma can be prevented or reduced in severity by this measure alone. Further safety requirements should include head restraints in rear positions, a-pillar, b-pillar, and roof padding, antilock brakes, and a vehicle rollover standard.

Estimated cost of needlestick injuries for six major needled devices.

A major factor in the introduction of new products designed to decrease the risk of needlesticks to healthcare workers (HCWs) is whether the increased expense of a safer device is offset by the savings of preventing needlesticks. The itemized costs of needlestick injuries associated with six major needled devices were estimated and compared to the cost of the devices causing the injuries, based on 1988 dollars. Included was the cost of treatment, prophylaxis and employee health department personnel time. The average cost of needlestick injury was $405, with a narrow range of $390 to $456 for different devices. As a percent of the cost of the devices, needlesticks cost as little as 10% of the cost of the device, for the intravenous (IV) catheter, to as much as 457%, for needles used to connect IV lines. On the average, needlesticks cost 36% of the devices' cost. These data may be used to weigh the potential economic benefits of safer needle technology or other strategies intended to reduce the incidence of needlesticks.

Evaluating sharps safety devices: meeting OSHA's intent. Occupational Safety and Health Administration.

The Occupational Safety and Health Administration (OSHA) revised the Bloodborne Pathogen Standard and, on July 17, 2001, began enforcing the use of appropriate and effective sharps devices with engineered sharps-injury protection. OSHA requires employers to maintain a sharps-injury log that records, among other items, the type and brand of contaminated sharps device involved in each injury. Federal OSHA does not require needlestick injury rates to be calculated by brand or type of device. A sufficient sample size to show a valid comparison of safety devices, based on injury rates, is rarely feasible in a single facility outside of a formal research trial. Thus, calculations of injury rates should not be used by employers for product evaluations to compare the effectiveness of safety devices. This article provides examples of sample-size requirements for statistically valid comparisons, ranging from 100,000 to 4.5 million of each device, depending on study design, and expected reductions in needlestick injury rates.

An outbreak of needlestick injuries in hospital employees due to needles piercing infectious waste containers.

OBJECTIVES: To investigate the cause of an outbreak of needlestick injuries (NSIs) in hospital employees. SETTING: A 700-bed university hospital. DESIGN: Outbreak investigation, laboratory evaluation of a medical waste disposal device, cost analysis. METHODS: Employee health department records were reviewed of workers suffering sticks from needles piercing fiberboard-contaminated material containers (CMCs). A laboratory evaluation of needle-puncture resistance properties of the CMCs was performed using a testing apparatus. The cost of a hospital waste disposal program using fiberboard CMCs was compared with the cost of a program using rigid plastic (polypropylene) boxes. RESULTS: During 40 months of surveillance in 1986 and from 1989 to 1991, only one NSI had occurred from a needle piercing a CMC. During 9 months in 1993, 13 NSIs occurred due to needles piercing CMCs (P < .001). No clinical illness resulted from the NSIs. The outbreak was halted by a temporary change to plastic (polypropylene) boxes for sharps disposal ($4.92 to $23.33/cu ft) until receipt of a box with a newly designed solid fiberboard liner ($1.25/cu ft). CMC liners used during the epidemic had a mean needle puncture resistance of 527 g, as compared with 660 g for liners used before the outbreak (P < .001). The new solid fiberboard liner has a mean puncture resistance of 1,765 g. A program of waste disposal using fiberboard CMCs was found to cost approximately one-seventh the cost of a program using plastic boxes for disposal of infectious waste. CONCLUSION: A program for infectious waste disposal using fiberboard CMCs can be safe and cost-effective if appropriate standards for puncture resistance are met.

Sharp object injuries in the hospital: causes and strategies for prevention.

We identified characteristics of items causing sharp object injuries in hospital personnel during a 10-month interval. Sharp objects were defined as items that were not hollow-bore needles, that cause lacerations or puncture wounds. Workers reporting sharp object injuries were interviewed to determine what items caused injury and the circumstances of their injuries. Of 89 incidents, 51% were surgical instrument injuries, 19% were lancet injuries, 16% were glass injuries, and 15% were caused by other sharp items. A frequent feature of sharp objects causing injuries was the necessity of disengaging a disposable sharp item from a reusable holder. The application of manual force to fragile glass items also caused many injuries. Opportunities for safer product design and improved materials are discussed to reduce this common occupational hazard.

The risks of occupational exposure and infection by human immunodeficiency virus, hepatitis B virus, and hepatitis C virus in the dialysis setting. Italian Multicenter Study on Nosocomial and Occupational Risk of Infections in Dialysis.

BACKGROUND: The dialysis setting has been recognized as a high-risk environment for transmission to both patients and health care personnel of blood-borne infections, such as hepatitis B virus, hepatitis C virus, and HIV. METHODS: A seroprevalence survey of HIV, hepatitis B virus, and hepatitis C virus infection among 1002 patients and a subsequent 1-year surveillance study of percutaneous injuries and skin and mucous membrane contaminations were carried out among 527 health care workers in nine Italian dialysis units. The risks of occupational acquisition of HIV, hepatitis B virus, and hepatitis C virus infections among health care workers were calculated according to a deterministic model. RESULTS: HIV antibody, hepatitis B surface antigen, and hepatitis C antibody prevalences among patients were 0.1%, 5.1%, and 39.4%, respectively. A total of 67 percutaneous injuries, 29 mucous membrane contaminations, and 271 skin contaminations were reported by health care workers. The risk of acquiring infection was calculated to be 4000 and 8000 times lower for HIV than for hepatitis B and C, respectively. CONCLUSIONS: The risks of infection with HIV, hepatitis B, and hepatitis C for health care workers at dialysis units differ greatly and depend on the demographic profile and medical history of patients undergoing dialysis. To minimize the risk of exposure to HIV and other blood-borne pathogens, efforts must continue to increase compliance with universal precautions. Needle designs incorporating safety features and improvements in dialysis equipment design are also needed to avoid potential exposure.

Risk of needle stick and sharp object injuries among medical students.

BACKGROUND: Much is known about sharp object and needle stick injuries among employee health care workers, but relatively little attention has been directed to exposures among medical students. METHOD: The frequency and mechanisms of needle stick and sharp object injuries were determined retrospectively by surveying students in their fourth year of medical school. Students were questioned about the number of percutaneous injuries that they had sustained during their clinical years. Descriptive information was collected on their most recent injury. RESULTS: Of 137 students in the class, 106 (77%) responded. Thirty-five (33%) of the students who responded sustained one or more injuries; 24 (69%) were injured while on a surgical service, and 60% of the injuries occurred in an operating room. Suturing was the procedure most frequently associated with injury. In 34% of cases, the injury was caused by a needle or device being used by another person. The most frequent site of injury was the hand (97%). Ninety-four percent of students were wearing gloves at the time of the injury. None of the injuries was associated with recapping needles. Only 43% of students reported their injuries to proper authorities. CONCLUSION: Medical students frequently sustain needle stick and sharp object injuries during their clinical training. Concerted efforts are needed to protect them.

The epidemiology of Tourette's syndrome: a pilot study.

A new, precoded, self-report questionnaire was used to collect information on 75 patient members of the Tourette Syndrome Association. This diverse group of Tourette's syndrome (TS) patients supplied by mail detailed medical, symptom, developmental, family, and personal history information. Analysis of these data supported the usefulness and validity of the questionnaire, and also indicated that the diagnosis of TS is being made earlier; attentional difficulties may be basic to the disorder; haloperidol is an effective treatment for many patients, but alternative treatments are needed because unpleasant side effects of haloperidol often lead to discontinued use, and TS is disabling for many with most patients reporting serious problems in one or more areas of functioning.

Air bags: reducing the toll of brain trauma.

Motor vehicle crashes account for approximately one-half of all hospitalized patients with brain injury. Therefore, measures to reduce the frequency and severity of injuries from motor vehicle crashes have the potential for making a substantial impact on the incidence and severity of brain trauma. Occupant restraints, including seat belts and air bags, have been proven highly effective in preventing injuries, yet the specific benefits for the brain, the face, and the cervical spine provided by air bags have not been widely publicized. Air bags prevent the violent whiplash motion of the head in a frontal crash, resulting in a more controlled deceleration of the brain. Wrenching forces exerted on the cervical spine are attenuated, and the face is protected from contact with hard or lacerating surfaces. Furthermore, compliance is not a problem with air bags. When a car is equipped with air bags, they are in effect 100% of the time, which is important for the protection of high risk groups, such a teenage boys, who tend to wear seat belts less often than other groups. It is estimated from national data and from epidemiological studies that air bags could have prevented or reduced brain injury for 25% of the hospitalized, brain-injured population. If provided as standard equipment on both the driver and the passenger side, air bags could do more to reduce the toll of brain trauma than any other available intervention. Air bags were ready for introduction into the marketplace 15 years ago. Since then, approximately 150,000 preventable deaths and more than 1,500,000 preventable brain injuries have occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of alcohol intoxication on the diagnosis and apparent severity of brain injury.

Because alcohol intoxication is common among brain-injured patients, we performed this study to determine the extent to which alcohol alters the initial assessment of brain injury severity in these patients by depressing the level of consciousness. The Glasgow coma scale was used to measure the level of consciousness of 257 brain-injured adults admitted to the University of Virginia Hospital, both on arrival in the emergency room and 6 to 10 hours later. Improvement in the level of consciousness between the first and second measurements was significantly related to the blood alcohol concentration on admission. Patients with the highest blood alcohol concentrations showed the greatest improvement. Most of this effect occurred in patients with a blood alcohol concentration of 0.20% or higher. Alcohol intoxication is a potential source of bias in the clinical classification of brain injuries according to severity.