Meta-analysis of antibiotics for simple hand injuries requiring surgery.

BACKGROUND: Simple hand trauma is very common, accounting for 1·8 million emergency department visits annually in the USA alone. Antibiotics are used widely as postinjury prophylaxis, but their efficacy is unclear. This meta-analysis assessed the effect of antibiotic prophylaxis versus placebo or no treatment on wound infection rates in hand injuries managed surgically. METHODS: Embase, MEDLINE, PubMed, Cochrane Central, ClinicalTrials.gov and the World Health Organization International Clinical Trials Portal were searched for published and unpublished studies in any language from inception to September 2015. The primary outcome was the effect of antibiotic prophylaxis on wound infection rates. Open fractures, crush injuries and bite wounds were excluded. Study quality was assessed using the Cochrane risk-of-bias tool. Data were pooled using random-effects meta-analysis, and risk ratios (RRs) and 95 per cent c.i. obtained. RESULTS: Thirteen studies (2578 patients) were included, comprising five double-blind randomized clinical trials, five prospective trials and three cohort studies. There was no significant difference in infection rate between the antibiotic and placebo/no antibiotic groups (RR 0·89, 95 per cent c.i. 0·65 to 1·23; P = 0·49). Subgroup analysis of the five double-blind randomized clinical trials (864 patients) again found no difference in infection rates (RR 0·66, 0·36 to 1·21; P = 0·18). CONCLUSION: There was moderate-quality evidence that routine use of antibiotics does not reduce the infection rate in simple hand wounds that require surgery.

Assessment of the severity of Ebola virus disease in Sierra Leone in 2014-2015.

The current Ebola virus disease (EVD) epidemic in West Africa is unprecedented in scale, and Sierra Leone is the most severely affected country. The case fatality risk (CFR) and hospitalization fatality risk (HFR) were used to characterize the severity of infections in confirmed and probable EVD cases in Sierra Leone. Proportional hazards regression models were used to investigate factors associated with the risk of death in EVD cases. In total, there were 17 318 EVD cases reported in Sierra Leone from 23 May 2014 to 31 January 2015. Of the probable and confirmed EVD cases with a reported final outcome, a total of 2536 deaths and 886 recoveries were reported. CFR and HFR estimates were 74·2% [95% credibility interval (CrI) 72·6-75·5] and 68·9% (95% CrI 66·2-71·6), respectively. Risks of death were higher in the youngest (0-4 years) and oldest (⩾60 years) age groups, and in the calendar month of October 2014. Sex and occupational status did not significantly affect the mortality of EVD. The CFR and HFR estimates of EVD were very high in Sierra Leone.

Systematic review of molecular mechanism of action of negative-pressure wound therapy.

BACKGROUND: Negative-pressure wound therapy (NPWT) promotes angiogenesis and granulation, in part by strain-induced production of growth factors and cytokines. As their expression profiles are being unravelled, it is pertinent to consider the mode of action of NPWT at the molecular level. METHODS: MEDLINE (January 1997 to present), Embase (January 1997 to present), PubMed (no time limit), the Cochrane Database of Systematic Reviews and the Cochrane Controlled Trials Register were searched for articles that evaluated the influence of NPWT on growth factor expression quantitatively. RESULTS: Sixteen studies met the inclusion criteria. Tumour necrosis factor expression was reduced in acute and chronic wounds, whereas expression of interleukin (IL) 1ß was reduced in acute wounds only. Systemic IL-10 and local IL-8 expression were increased by NPWT. Expression of vascular endothelial growth factor, fibroblast growth factor 2, transforming growth factor ß and platelet-derived growth factor was increased, consistent with mechanoreceptor and chemoreceptor transduction in response to stress and hypoxia. Matrix metalloproteinase-1, -2, -9 and -13 expression was reduced but there was no effect on their enzymatic inhibitor, tissue inhibitor of metalloproteinase 1. CONCLUSION: Cytokine and growth factor expression profiles under NPWT suggest that promotion of wound healing occurs by modulation of cytokines to an anti-inflammatory profile, and mechanoreceptor and chemoreceptor-mediated cell signalling, culminating in angiogenesis, extracellular matrix remodelling and deposition of granulation tissue. This provides a molecular basis for understanding NPWT.

Genome-wide analysis of transcriptomic divergence between laboratory colony and field Anopheles gambiae mosquitoes of the M and S molecular forms.

Our knowledge of Anopheles gambiae molecular biology has mainly been based on studies using inbred laboratory strains. Differences in the environmental exposure of these and natural field mosquitoes have inevitably led to physiological divergences. We have used global transcript abundance analyses to probe into this divergence, and identified transcript abundance patterns of genes that provide insight on specific adaptations of caged and field mosquitoes. We also compared the gene transcript abundance profiles of field mosquitoes belonging to the two morphologically indistinguishable but reproductively isolated sympatric molecular forms, M and S, from two different locations in the Yaoundé area of Cameroon. This analysis suggested that environmental exposure has a greater influence on the transcriptome than does the mosquito's molecular form-specific genetic background.

Commensal ecology, urban landscapes, and their influence on the genetic characteristics of city-dwelling Norway rats (Rattus norvegicus).

Movement of individuals promotes colonization of new areas, gene flow among local populations, and has implications for the spread of infectious agents and the control of pest species. Wild Norway rats (Rattus norvegicus) are common in highly urbanized areas but surprisingly little is known of their population structure. We sampled individuals from 11 locations within Baltimore, Maryland, to characterize the genetic structure and extent of gene flow between areas within the city. Clustering methods and a neighbour-joining tree based on pairwise genetic distances supported an east-west division in the inner city, and a third cluster comprised of historically more recent sites. Most individuals (approximately 95%) were assigned to their area of capture, indicating strong site fidelity. Moreover, the axial dispersal distance of rats (62 m) fell within typical alley length. Several rats were assigned to areas 2-11.5 km away, indicating some, albeit infrequent, long-distance movement within the city. Although individual movement appears to be limited (30-150 m), locations up to 1.7 km are comprised of relatives. Moderate F(ST), differentiation between identified clusters, and high allelic diversity indicate that regular gene flow, either via recruitment or migration, has prevented isolation. Therefore, ecology of commensal rodents in urban areas and life-history characteristics of Norway rats likely counteract many expected effects of isolation or founder events. An understanding of levels of connectivity of rat populations inhabiting urban areas provides information about the spatial scale at which populations of rats may spread disease, invade new areas, or be eradicated from an existing area without reinvasion.

Asbestiform amphibole minerals: detection and measurement of high concentrations in municipal water supplies.

Ashestiform amphibole minerals, which have been demonstrated to be associated with human health problems, have been detected in substantial quantities in municipal water supplies taken from western Lake Superior Water. The total concentrationl of amphibole minerals in the Duluth, Minnesota, water supply, as measured by x-ray diffraction for daily samples of suspended solids averages 0.19 milligram per liter with large fluctuations due to seasonal and climatological effects on lake circulation. Electron microscopic examination of these water samples confirms the presence of asbestiform amphibole fibers. A conservatiue estimate of the fiber count for 1973 Duluth water supply samples is (1 to 30) x 10(6) amphibole fibers identifiable by electron diffraction per liter of water with a mass concentration of 1 to 30 micrograms per liter.

A survey of rodent-borne pathogens carried by wild-caught Norway rats: a potential threat to laboratory rodent colonies.

Unintentional infection of laboratory rodents can compromise scientific research as well as the health of the animals and animal handlers. The source of contamination often is unknown, but may be introduced by wild rats from surrounding environments. To determine whether rats in Baltimore, Maryland, USA carry infectious agents commonly found in laboratory rodent colonies, we live-trapped 162 rats during 2005 to 2006 and screened them for a panel of viruses, bacteria and parasites. Antibodies against rat coronavirus/sialodacryoadenitis virus (91.7%), Mycoplasma pulmonis (72.9%), cilia-associated respiratory bacillus (52.1%), rat parvovirus/rat minute virus (29.2%), Kilham rat virus (10.4%), Toolan's H-1 virus (10.4%), Sendai virus (4.2%) and Theiler's mouse encephalomyelitis virus (4.2%), were detected in wild-caught Norway rats. Antibodies against reovirus and pneumonia virus of mice were not detected in wild Norway rats. Endoparasites, including Nippostrongylus braziliensis (71.6%), Rodentolepis nana or Hymenolepis diminuta (34.4%), Hetarakis spumosa (24.1%) and Trichuris muris (14.8%), as well as ectoparasites (14.8%), were identified in wild-caught rats. The risk of pathogen transmission from wild-caught rats to laboratory colonies needs to be mitigated by minimizing exposures rather than assuming wild animals represent a minimal hazard.

Nasal tip necrosis--an unusual presentation of rheumatoid vasculitis.

We describe an unusual case of cutaneous necrosis of the nasal tip presenting to a facial reconstructive surgeon. The patient had developed this painless necrosis over a period of about 10 days. Her past medical history included rheumatoid arthritis. She described an exacerbation of her arthritic symptoms in the weeks preceding the development of the nasal tip necrosis. Her rheumatoid arthritis had been managed with corticosteroid and immunosuppressive therapy for more than 3 years. She had not previously experienced extra-articular manifestations (EAMs). A biopsy was taken and histological analysis identified a lymphocytic vasculitis. She was referred to her rheumatologist, and surgical management of her necrotic nasal tip commenced.

A correlation analysis of metacarpal & phalangeal injury pattern from improvised explosive devices amongst armed force personnel.

Injuries to the hand during military combat operations, particularly from improvised explosive devices (IEDs) have a significant impact on form, function, mental health and future employment but remain underreported amidst the life and limb-threatening emergencies that garner more attention. An understanding the patterns of hand injuries encountered from IEDs is crucial to optimizing reconstruction and rehabilitation. The aim of this study was to re-evaluate hand injury sustained from IED in order to understand the clinical burden for reconstruction and direct the focus for future hand protection. We identified 484 hand injuries in 380 patients sustained as a result of IEDs among military personnel service in Afghanistan between 2006 and 2013. 53% of all surviving military personnel injured by IEDs sustain injuries to the hand. Analysis of the 103 patients who sustained injury to the metacarpal, phalanges or digital amputation revealed that the middle and ring fingers are most commonly injured. Amputation to the ring finger is strongly associated with injury to the adjacent fingers and amputations to the middle, ring and little fingers concurrently is a commonly observed pattern. The proximal phalanges of the middle and ring fingers had a strong correlation for fracture together. These findings disprove the conventional belief in an ulnar focus of injury and support the quest for a development of combat hand protection that addresses the injury pattern seen.

Hilotherapy for the management of perioperative pain and swelling in facial surgery: a systematic review and meta-analysis.

Hilotherapy is the application of cold compression at a regulated temperature through a face mask. Studies that have evaluated its efficacy have focused on postoperative oedema, pain, and the patient's comfort. However, there is no clear consensus in favour of its use, so we have made a systematic review and meta-analysis to evaluate relevant published reports. We searched PubMed, EMBASE, MEDLINE, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials to identify studies. Sixty-one records were screened, six of which met the inclusion criteria and four of which were suitable for meta-analysis. All data suitable for meta-analysis were derived from studies of elective and traumatic facial skeletal surgery. Hilotherapy was associated with significant reductions in facial pain on postoperative day 2 (p<0.00001), and facial oedema on days 2 (p=0.0004) and 3 (p=0.02). Patients reported more comfort and satisfaction with hilotherapy than with cold compression (p<0.00001). The effect of hilotherapy on ecchymosis and formation of haematomas remains uncertain. Well-designed, randomised, controlled trials of its use after aesthetic facial surgery are required.

Necrotising soft tissue infection in a UK metropolitan population.

INTRODUCTION: Necrotising soft tissue infection (NSTI) is a rare but life threatening diagnosis. Geographic, economic and social variances influence presentation and prognosis. As the current literature does not reflect a UK metropolitan population, we conducted a retrospective chart review to establish pertinent features relevant to our practice. METHODS: Patients with histologically confirmed diagnoses of NSTI presenting to two London teaching hospitals between January 2007 and July 2013 were included in the study. Features of presentation, surgical and medical management, microbiological findings and outcome were evaluated. RESULTS: Twenty-four patients with histologically confirmed NSTI were included. Two age clusters were identified, with means of 46 years (standard deviation [SD]: 10 years) and 80 years (SD: 6 years). Pain, erythema and sepsis were common findings. Hypertension, hypercholesterolaemia and type II diabetes mellitus were common co-morbidities. A third of younger patients had human immunodeficiency virus or hepatitis C, with a quarter dependent on drugs and/or alcohol. The mean Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC) score was 5.8 (SD: 3.3). The lower extremities, groin and perineum were common sites of infection. Fourteen patients required inotropic support and seventeen required transfusions. The median number of surgical procedures was 5 (range: 1-17). Group A Streptococcus was the most frequently identified pathogen. Five patients died. Being elderly, female sex and failure to use clindamycin as a first-line antibiotic were associated with significantly higher mortality. CONCLUSIONS: In contrast to other recent series, group A streptococcal monomicrobial NSTI remains the most common presentation in our population. Survival is anticipated in young patients, regardless of premorbid status. Elderly patients have a poor prognosis. The negative predictive value of the LRINEC score is questioned. Use of clindamycin as a first-line antibiotic is supported.

Isolation of lactate dehydrogenase-elevating viruses from wild house mice and their biological and molecular characterization.

Lactate dehydrogenase-elevating virus (LDV) was first identified as a contaminant of transplantable mouse tumors that were passaged in laboratory mice. It has been assumed that these LDVs originated from LDVs endemic in wild house mouse populations. In order to test this hypothesis and to explore the relationships between LDVs from wild house mice among each other and to those isolated from laboratory mice, we have isolated LDVs from wild house mice and determined their biological and molecular properties. We have screened for LDV tissues of 243 wild house mice that had been caught in various regions of North, Central and South America between 1985 and 1994. We were able to isolate LDVs from the tissues of four mice, three had been caught in Baltimore, MD and one in Montana. We demonstrate that the phenotypic properties (ability to establish a long-term viremic infection, low immunogenicity of the neutralization epitope, high resistance to antibody neutralization and lack of neuropathogenicity) of the four wild house mouse LDVs are identical to those of the primary LDVs isolated from transplantable tumors (LDV-P and LDV-vx), which are distinct from those of the neuropathogenic LDV-C. Furthermore, ORF 5 and ORF 2 and their protein products (the primary envelope glycoprotein VP-3P, and the minor envelope glycoprotein, respectively) of the wild house mouse LDVs were found to be closely related to those of LDV-P and LDV-vx. The LDVs caught in Baltimore, MD were especially closely related to each other, whereas the LDV isolated in Montana was more distantly related, indicating that it had evolved independently. The ectodomain of VP-3P of all four wild house mouse LDVs, like those of LDV-P and LDV-vx, possess the same three polylactosaminoglycan chains, two of which are lacking in the VP-3P ectodomain of LDV-C. These results further strengthen the conclusion that the three polylactosaminoglycan chains are the primary determinants of the phenotypic properties of LDV-P/vx.

Sex differences in immune responses and viral shedding following Seoul virus infection in Norway rats.

In the field, male rodents are more frequently infected with hantaviruses than females. This study examined whether patterns of immune responses against hantavirus differed between the sexes. Male and female Long Evans rats (Rattus norvegicus) were inoculated with Seoul virus, and antibody and cytokine responses, as well as virus shedding were assessed. Males were more likely to shed virus in saliva, to shed virus through multiple routes (saliva, urine, and feces), and to have viral RNA in the spleen than females. Anti-Seoul virus IgG responses were higher in males than females. In both sexes, splenic IFNgamma and IL-4 production increased following infection. After infection, males had higher Th1 immune responses (i.e., IgG2a, IFNgamma, and IL-2) than females; in contrast, Th2 immune responses (i.e., IgG1, IL-4, and IL-10) were similar between the sexes. These data suggest that immune responses to Seoul virus differ between the sexes.

Prospective seroepidemiology of hantaviruses and population dynamics of small mammal communities of Baltimore, Maryland.

We used a prospective seroepidemiological study, in conjunction with a mark-release-recapture protocol, to investigate the transmission of hantaviruses in four rodent species from Baltimore, Maryland, from June 1984 to June 1986. A total of 1,208 captures of 762 rodents provided 984 individual blood samples. The antibody prevalence, as determined by frequency of reciprocal indirect fluorescent antibody (IFA) titers greater than or equal to 32, was 33.9% in rats (Rattus norvegicus, n = 466), 28.3% in meadow voles (Microtus pennsylvanicus, n = 67), 1.4% in house mice (Mus musculus, n = 146), and 1.2% in white-footed mice (Peromyscus leucopus, n = 83). Populations of all rodents were maximal during the fall and winter months, but population trends were not clearly associated with periods of virus transmission. The mean incidence of seroconversion to a Hantavirus for rats was 12.06/100 rats/month, but incidence rates could not be established for other species. Rats which seroconverted were generally sexually mature animals, and there was evidence of transmission throughout the year. Animals which seroconverted to a Hantavirus achieved high IFA titers, and remained seropositive for the duration of the study.

Predicting Ixodes scapularis abundance on white-tailed deer using geographic information systems.

We collected 1,410 Ixodes scapularis from 139 white-tailed deer in Kent County, Maryland during the 1990 hunting season. A geographic information system was used to extract 41 environmental variables in the areas surrounding the collection sites of the deer. Stepwise linear regression was used to evaluate the association between the abundance of ticks on deer and the environmental data. A significant statistical association was observed between the abundance of I. scapularis and seven environmental variables (R = 0.69). Tick abundance was negatively correlated with urban land use patterns, wetlands, the amount of privately owned land, soils that tended to be saturated with water, and one drainage system. Tick abundance was positively correlated with well-drained, sandy soils having low water tables. These results indicate that geographically referenced environmental data may be useful in anticipating the risk of exposure to vectors over large areas.

Serologic evidence of hantaviral infections within small mammal communities of Baltimore, Maryland: spatial and temporal patterns and host range.

Serologic evidence was used to investigate the spatial and temporal distribution and host range of hantaviruses in small mammal communities in Baltimore, MD. Immunofluorescent antibody (IFA) reactive to a Baltimore rat isolate of Seoul virus was detected in 44% of 404 Norway rats captured at 4 park or residential locations; 21% of 121 meadow voles captured at 4 park locations possessed significant IFA titers to Prospect Hill virus. Evidence from plaque neutralization assay of rodent sera suggested that Seoul virus and Prospect Hill virus circulated concurrently in voles and rats, respectively, at 1 park. No cross infection of virus between these primary reservoir species was observed, as determined by higher specific neutralizing antibody titers to the characteristic virus for each host species. Only 4% of 449 house mice and 1% of 94 white-footed mice captured at the same sites as the primary host species were seropositive to hantaviruses, despite extensive demonstrated overlap in time and space with the primary host species.

Lymphocytic choriomeningitis virus infection and house mouse (Mus musculus) distribution in urban Baltimore.

Four hundred eighty house mice (Mus musculus) were trapped primarily from urban sites in Baltimore, Maryland from 1984 to 1989 and tested for antibody to lymphocytic choriomeningitis virus (LCMV). The majority of mice (95%) were trapped in residences at two city locations (n = 260), or in an urban park (n = 196); five additional sites were sampled. Overall, 9.0% of the mice were LCMV antibody positive and infected animals were obtained from six of eight sites, including all three of the primary city sites, where the prevalence varied significantly (3.9-13.4%). The location with the highest prevalence was an inner city residential site where positive mice were found significantly clustered within blocks and households. In this location, LCMV antibody prevalence was also significantly correlated with estimates of mouse density within individual blocks. The focal nature of LCMV infection in house mice may result from contact or vertical transmission of virus in conjunction with the highly structured social system of mice, which promotes inbreeding and limited dispersal.

Longitudinal study of infection with Borrelia burgdorferi in a population of Peromyscus leucopus at a Lyme disease-enzootic site in Maryland.

The maintenance of Borrelia burgdorferi in a population of Peromyscus leucopus was investigated from 202 mark and recapture mice and 61 mice that were removed from a site in Baltimore County, Maryland. Borrelia burgdorferi infection was detected by culture and polymerase chain reaction (PCR) of ear tissue, and exposure to the spirochete was quantified by serology. Overall prevalence of B. burgdorferi, as determined by culture and PCR of ear tissue at first capture, was 25% in the longitudinal sample and 42% in the cross-sectional sample. Significantly more juvenile mice were captured in the longitudinal sample (18%) than in the cross-sectional sample (0%). Among 36 captured juvenile mice, only one was infected with B. burgdorferi; this contributed to a significant trend for infection with B. burgdorferi with age. Recovery from infection with B. burgdorferi was not detected among 77 mice followed for an average of 160 days. The incidence rate of infection with B. burgdorferi was 10 times greater in mice captured during two periods of high risk of exposure to nymphal Ixodes scapularis ticks compared with a period of low risk. Maintenance of B. burgdorferi in this population was dependent on indirect transmission of the organism from infected ticks to susceptible mice and development of chronic infection with the spirochete, which had no measurable effect on the survival of infected mice.

Experimental evaluation of rodent exclusion methods to reduce hantavirus transmission to humans in rural housing.

An experimental assessment of methods to reduce rodent infestations in rural housing was conducted in Yosemite National Park, California, Sequoia/Kings Canyon National Parks, California, and Shenandoah National Park, Virginia. During pretreatment surveys, nearly all (63 of 68) selected units had past or ongoing rodent activity inside. Active infestations were found in 58.8% of the units. Peromyscus spp. represented 91.2% of all animals caught inside housing units. Despite little harborage, rodent activity was common near housing (290 animals/2,254 trap nights). The most common species present was Peromyscus maniculatus (43-50% of all captures). This species was especially frequent (49-87% of Peromyscus captures) around the foundations of housing units. Habitat had little effect on captures. There were 1.8 Peromyscus caught per unit along the foundations of housing in modified rural settings with grass lawns compared with 1.2 Peromyscus caught per unit in sites located in mature woodlands. During autumn of 1994, randomly selected housing units were rodent proofed by sealing openings associated with chases, roof eaves, and attics with insulation and wire mesh. Housing was examined and the fauna was resampled in the spring-summer of 1995. Rodent-proofed houses were infested significantly less often (3 of 28) than control houses (13 of 36) (P = 0.02) and the intensity of infestation was lower in experimental houses (6 versus 23 mice/treatment). More than 25% of the mice trapped inside the houses had been marked outside the houses during the three-day surveys, demonstrating movement of mice adjacent to the buildings into not rodent-proofed housing. As in the previous autumn, most of the animals captured in (98.9%) and along the foundations of the houses (77.5%) were Peromyscus spp. These results demonstrate that Peromyscus frequently invade rural housing but rodent-proofing effectively eliminates or substantially reduces rodent activity.