Medical students' views on selection tools for medical school--a mixed methods study

It is important to ensure that the tools used in Medical School selection are acceptable to students and applicants. A questionnaire was administered to year 1 medical students in 2010 to determine the suitability of a variety of selection tools and the acceptability of HPAT-Ireland in particular. There were 291 respondents a 77% response rate representing approximately one third of all school leaver entrants that year. While the majority 285 (98%) were in favour of using school leaving examinations there was also support for the use of interviews 215 (74%) and other tools. Three quarters of Irish respondents 159 (76%) agreed that HPAT-Ireland is a fair test overall however section 3 (non-verbal reasoning) appeared less acceptable and relevant than other sections. A little over half had taken a preparatory HPAT-Ireland course 112 (54%). Medical school applicants appear to accept the use of non-traditional tools in the selection process.

Blood donor management in china

Despite a steady increase in total blood collections and voluntary non-remunerated blood donors, China continues to have many challenges with its blood donation system. The country's donation rate remains low at 9%o, with over 60% of donors being first-time donors. Generally there is a lack of adequate public awareness about blood donation. The conservative donor selection criteria, the relatively long donation interval, and the small donation volume have further limited blood supply. To ensure a sufficient and safe blood supply that meets the increasing clinical need for blood products, there is an urgent need to strengthen the country's blood donor management. This comprehensive effort should include educating and motivating more individuals especially from the rural areas to be involved in blood donation, developing rational and evidence-based selection criteria for donor eligibility, designing a donor follow-up mechanism to encourage more future donations, assessing the current donor testing strategy, improving donor service and care, building regional and national shared donor deferral database, and enhancing the transparency of the blood donation system to gain more trust from the general public. The purpose of the review is to provide an overview of the key process of and challenges with the blood donor management system in China.

Free-roaming kissing bugs, vectors of Chagas disease, feed often on humans in the Southwest

BACKGROUND

Kissing bugs, vectors of Trypanosoma cruzi, the parasite that causes Chagas disease, are common in the desert Southwest. After a dispersal flight in summer, adult kissing bugs occasionally gain access to houses where they remain feeding on humans and pets. How often wild, free-roaming kissing bugs feed on humans outside their homes has not been studied. This is important because contact of kissing bugs with humans is one means of gauging the risk for acquisition of Chagas disease.

METHODS

We captured kissing bugs in a zoological park near Tucson, Arizona, where many potential vertebrate hosts are on display, as well as being visited by more than 300,000 humans annually. Cloacal contents of the bugs were investigated for sources of blood meals and infection with T. cruzi.

RESULTS

Eight of 134 captured bugs were randomly selected and investigated. All 8 (100%) had human blood in their cloacae, and 7 of 8 (88%) had fed on various vertebrates on display or feral in the park. Three bugs (38%) were infected with T. cruzi. Three specimens of the largest species of kissing bug in the United States (Triatoma recurva) were captured in a cave and walking on a road; 2 of 3 (67%) had fed on humans. No T. recurva harbored T. cruzi.

CONCLUSIONS

This study establishes that free-roaming kissing bugs, given the opportunity, frequently feed on humans outside the confines of their homes in the desert Southwest and that some harbored T. cruzi. This could represent a hitherto unrecognized potential for transmission of Chagas disease in the United States.

Household model of Chagas disease vectors (Hemiptera: Reduviidae) considering domestic, peridomestic, and sylvatic vector populations

ABSTRACT Disease transmission is difficult to model because most vectors and hosts have different generation times. Chagas disease is such a situation, where insect vectors have 1-2 generations annually and mammalian hosts, including humans, can live for decades. The hemataphagous triatominae vectors (Hemiptera: Reduviidae) of the causative parasite Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae) usually feed on sleeping hosts, making vector infestation of houses, peridomestic areas, and wild animal burrows a central factor in transmission. Because of difficulties with different generation times, we developed a model considering the dwelling as the unit of infection, changing the dynamics from an indirect to a direct transmission model. In some regions, vectors only infest houses; in others, they infest corrals; and in some regions, they also infest wild animal burrows. We examined the effect of sylvatic and peridomestic vector populations on household infestation rates. Both sylvatic and peridomestic vectors increase house infestation rates, sylvatic much more than peridomestic, as measured by the reproductive number R0. The efficacy of manipulating parameters in the model to control vector populations was examined. When R0 > 1, the number of infested houses increases. The presence of sylvatic vectors increases R0 by at least an order of magnitude. When there are no sylvatic vectors, spraying rate is the most influential parameter. Spraying rate is relatively unimportant when there are sylvatic vectors; in this case, community size, especially the ratio of houses to sylvatic burrows, is most important. The application of this modeling approach to other parasites and enhancements of the model are discussed.

Portion weights of food served in English schools: have they changed following the introduction of nutrient-based standards?

BACKGROUND

Mandatory food-based and nutrient-based standards for the food provided in English schools were introduced in 2008 (primary) and 2009 (secondary) and have had a positive impact on pupils' food choice and nutrient intake at school. There are no recommendations for portion sizes in England, although anecdotal evidence suggests that portions of food and drink sold in schools have decreased since the standards were introduced.

METHODS

Data were collected from 136 primary and 80 secondary schools in 2009 and 2010/11, respectively. All food and drink items provided at lunchtime were weighed on five consecutive days at each school. The mean and median weight, SD, and 25th and 75th centile for each individual food were calculated. Data were compared with the results obtained from similar surveys in 2004 and 2005, as well as with portion size recommendations for Scottish schools.

RESULTS

The proportion of food items that differed in weight since 2004/05 varied from 13% in primary schools to 29% in secondary schools. Changes in weight were equally likely to be positive or negative, with the exception of portions of fruit and vegetables, which had decreased. Primary schools were more likely to meet portion size recommendations than secondary schools.

CONCLUSIONS

Of the items that were directly comparable over time, a limited number showed a significant change in portion size since the standards for school food were introduced. Portion weight recommendations are based on a balanced healthy diet, and pupils should eat all the components of meals offered by schools to meet dietary recommendations.

Novel polymerase chain reaction-restriction fragment length polymorphism assay to determine internal transcribed spacer-2 group in the Chagas disease vector, Triatoma dimidiata (Latreille, 1811)

Triatoma dimidiata is the most important Chagas disease insect vector in Central America as this species is primarily responsible for Trypanosoma cruzi transmission to humans, the protozoan parasite that causes Chagas disease. T. dimidiata sensu lato is a genetically diverse assemblage of taxa and effective vector control requires a clear understanding of the geographic distribution and epidemiological importance of its taxa. The nuclear ribosomal internal transcribed spacer 2 (ITS-2) is frequently used to infer the systematics of triatomines. However, oftentimes amplification and sequencing of ITS-2 fails, likely due to both the large polymerase chain reaction (PCR) product and polymerase slippage near the 5' end. To overcome these challenges we have designed new primers that amplify only the 3'-most 200 base pairs of ITS-2. This region distinguishes the ITS-2 group for 100% of known T. dimidiata haplotypes. Furthermore, we have developed a PCR-restriction fragment length polymorphism (RFLP) approach to determine the ITS-2 group, greatly reducing, but not eliminating, the number of amplified products that need to be sequenced. Although there are limitations with this new PCR-RFLP approach, its use will help with understanding the geographic distribution of T. dimidiata taxa and can facilitate other studies characterising the taxa, e.g. their ecology, evolution and epidemiological importance, thus improving vector control.

Blood safety and availability: continuing challenges in China's blood banking system

Social and economic development, along with increased health care coverage, has caused a sharp increase in the clinical demand for blood in China. Whole blood collection has increased rapidly in the past decade but has failed to keep pace with the ever-increasing demand. Overall, the country's blood safety has been improved with 99% of whole blood donations collected from voluntary unpaid donors. However, the unmet clinical demand for blood and the increasing incidence of human immunodeficiency virus and syphilis in the general population pose new challenges to China's blood banking system. To ensure a safe and adequate blood supply, continued efforts are required to recruit and retain a sufficient number of low-risk voluntary blood donors, improve donor prescreening and blood testing process, ease donor restrictions, and strengthen patient blood management.

Ecohealth interventions limit triatomine reinfestation following insecticide spraying in La Brea, Guatemala

In this study, we evaluate the effect of participatory Ecohealth interventions on domestic reinfestation of the Chagas disease vector Triatoma dimidiata after village-wide suppression of the vector population using a residual insecticide. The study was conducted in the rural community of La Brea, Guatemala between 2002 and 2009 where vector infestation was analyzed within a spatial data framework based on entomological and socio-economic surveys of homesteads within the village. Participatory interventions focused on community awareness and low-cost home improvements using local materials to limit areas of refuge and alternative blood meals for the vector within the home, and potential shelter for the vector outside the home. As a result, domestic infestation was maintained at ≤ 3% and peridomestic infestation at ≤ 2% for 5 years beyond the last insecticide spraying, in sharp contrast to the rapid reinfestation experienced in earlier insecticide only interventions.

Mechanical analysis of the effects of bacteria and aprotinin on skin wound healing in adult guinea pigs

Inhibition of wound healing by bacteria may result in part from the conversion of plasminogen to plasmin. This conversion results in dissolution of the fibrin seal in a wound or between skin graft and bed. Aprotinin blocks conversion to plasmin, preserving the fibrin clot. The current study was undertaken to determine the effects of high concentrations of bacteria on wound healing and how these effects are mitigated by aprotinin. Dorsal full-thickness skin incisions were made in 40 anesthetized guinea pigs and closed with nylon sutures. Animals were divided into four groups: (1) control wounds, (2) infected wounds, (3) wounds treated with aprotinin, and (4) infected wounds plus aprotinin (single dose). Animals were killed 3 and 4 weeks after the operation. Skin strips containing segments of the healing wounds were pulled apart by a tensiometer until rupture. Stress-strain curves were generated, and wound strength and toughness were determined. All wounds, including those inoculated with bacteria, appeared healed. The 3-week infected group healed with the least strength and toughness (p < 0.001). A single dose of aprotinin administered with the bacterial inoculum reversed this inhibition. In the 4-week groups, the strongest and toughest wounds resulted from bacterial inoculation alone. Aprotinin alone augmented wound healing when compared with controls. These data suggest that wound healing in both clean and infected wounds is augmented when the plasminogen-plasmin pathway is inhibited.