Skin Antisepsis before Surgical Fixation of Extremity Fractures.

BACKGROUND: Studies evaluating surgical-site infection have had conflicting results with respect to the use of alcohol solutions containing iodine povacrylex or chlorhexidine gluconate as skin antisepsis before surgery to repair a fractured limb (i.e., an extremity fracture). METHODS: In a cluster-randomized, crossover trial at 25 hospitals in the United States and Canada, we randomly assigned hospitals to use a solution of 0.7% iodine povacrylex in 74% isopropyl alcohol (iodine group) or 2% chlorhexidine gluconate in 70% isopropyl alcohol (chlorhexidine group) as preoperative antisepsis for surgical procedures to repair extremity fractures. Every 2 months, the hospitals alternated interventions. Separate populations of patients with either open or closed fractures were enrolled and included in the analysis. The primary outcome was surgical-site infection, which included superficial incisional infection within 30 days or deep incisional or organ-space infection within 90 days. The secondary outcome was unplanned reoperation for fracture-healing complications. RESULTS: A total of 6785 patients with a closed fracture and 1700 patients with an open fracture were included in the trial. In the closed-fracture population, surgical-site infection occurred in 77 patients (2.4%) in the iodine group and in 108 patients (3.3%) in the chlorhexidine group (odds ratio, 0.74; 95% confidence interval [CI], 0.55 to 1.00; P = 0.049). In the open-fracture population, surgical-site infection occurred in 54 patients (6.5%) in the iodine group and in 60 patients (7.3%) in the chlorhexidine group (odd ratio, 0.86; 95% CI, 0.58 to 1.27; P = 0.45). The frequencies of unplanned reoperation, 1-year outcomes, and serious adverse events were similar in the two groups. CONCLUSIONS: Among patients with closed extremity fractures, skin antisepsis with iodine povacrylex in alcohol resulted in fewer surgical-site infections than antisepsis with chlorhexidine gluconate in alcohol. In patients with open fractures, the results were similar in the two groups. (Funded by the Patient-Centered Outcomes Research Institute and the Canadian Institutes of Health Research; PREPARE ClinicalTrials.gov number, NCT03523962.).

Five-Year Outcomes After Implementing a Pain, Agitation, and Delirium Protocol in a Mixed Intensive Care Unit.

Objective: Assess for continued improvements in patient outcomes after updating our institutional sedation and analgesia protocol to include recommendations from the 2013 Society of Critical Care Medicine (SCCM) Pain, Agitation, and Delirium (PAD) guidelines. Methods: Retrospective before-and-after study in a mixed medical/surgical intensive care unit (ICU) at an academic medical center. Mechanically ventilated adults admitted from September 1, 2011 through August 31, 2012 (pre-implementation) and October 1, 2012 through September 30, 2017 (post-implementation) were included. Measurements included number of mechanically ventilated patients, APACHE IV scores, age, type of patient (medical or surgical), admission diagnosis, ICU length of stay (LOS), hospital LOS, ventilator days, number of self-extubations, ICU mortality, ICU standardized mortality ratio, hospital mortality, hospital standardized mortality ratio, medication data including as needed (PRN) analgesic and sedative use, and analgesic and sedative infusions, and institutional savings. Results: Ventilator days (Pre-PAD = 4.0 vs. Year 5 post = 3.2, P < .0001), ICU LOS (Pre-PAD = 4.8 days vs. Year 5 post = 4.1 days, P = .0004) and hospital LOS (Pre-PAD = 14 days vs. Year 5 post = 12 days, P < .0001) decreased after protocol implementation. Hospital standardized mortality ratio (Pre-PAD = 0.69 vs. Year 5 post = 0.66) remained constant; while, APACHE IV scores (Pre-PAD = 77 vs. Year 5 post = 89, P < .0001) and number of intubated patients (Pre-PAD = 1146 vs. Year 5 post = 1468) increased over the study period. Using the decreased ICU and hospital LOS estimates, it is projected the institution saved $4.3 million over the 5 years since implementation. Conclusions: Implementation of an updated PAD protocol in a mixed medical/surgical ICU was associated with a significant decrease in ventilator time, ICU LOS, and hospital LOS without a change in the standardized mortality ratio over a five-year period. These favorable outcomes are associated with a significant cost savings for the institution.

Evaluation of a Multidisciplinary Pain, Agitation, and Delirium Guideline in Mechanically Ventilated Critically Ill Adults.

Background: A multidisciplinary team updated an institution-specific pain, agitation, and delirium (PAD) guideline based on the recommendations from the Society of Critical Care Medicine (SCCM) PAD guidelines. This institution-specific guideline emphasized protocolized sedation with increased as needed boluses, and nonbenzodiazepine infusions, daily sedation interruption, and pairing of spontaneous awakening (SAT) and breathing trials (SBT). Objective: The purpose of this study was to evaluate the impact of implementation of a PAD guideline on clinical outcomes and medication utilization in an academic medical center intensive care unit (ICU). It was hypothesized that implementation of an updated guideline would improve clinical outcomes and decrease usage of benzodiazepine infusions. Methods: Pre-post retrospective chart review of 2417 (1147 pre, 1270 post) critically ill, mechanically ventilated adults in a medical/surgical ICU over a 2-year period (1 year pre and post guideline implementation). Results: After guideline implementation, average ventilation days was reduced (3.98 vs 3.43 days, P = .0021), as well as ICU and hospital length of stay (LOS) (4.79 vs 4.34 days, P = .048 and 13.96 vs 12.97 days, P = .045, respectively). Hospital mortality (19 vs 19%, P = .96) and acute physiology and chronic health evaluation (APACHE) IV scores (77.28 vs 78.75, P = .27) were similar. After guideline implementation, the percentage of patients receiving midazolam infusions decreased (422/1147 [37%] vs 363/1270 patients [29%], P = .0001). The percentage of patients receiving continuous infusion propofol (679/1147 [59%] vs 896/1270 [70%], P = .0001) and dexmedetomidine (78/1147 [7%] vs 147/1270 [12%], P = .0001) increased. Conclusions: Implementing a multidisciplinary PAD guideline utilizing protocolized sedation and daily sedation interruption decreased ventilation days and ICU and hospital LOS while decreasing midazolam drip usage.

A 454 sequencing approach to dipteran mitochondrial genome research.

The availability of complete mitochondrial genome (mtgenome) data for Diptera, one of the largest metazoan orders, in public databases is limited. The advent of high throughput sequencing technology provides the potential to generate mtgenomes for many species affordably and quickly. However, these technologies need to be validated for dipterans as the members of this clade play important economic and research roles. Illumina and 454 sequencing platforms are widely used in genomic research involving non-model organisms. The Illumina platform has already been utilized for generating mitochondrial genomes without using conventional long range PCR for insects whereas the power of 454 sequencing for generating mitochondrial genome drafts without PCR has not yet been validated for insects. Thus, this study examines the utility of 454 sequencing approach for dipteran mtgenomic research. We generated complete or nearly complete mitochondrial genomes for Cochliomyia hominivorax, Haematobia irritans, Phormia regina and Sarcophaga crassipalpis using a 454 sequencing approach. Comparisons between newly obtained and existing assemblies for C. hominivorax and H. irritans revealed no major discrepancies and verified the utility of 454 sequencing for dipteran mitochondrial genomes. We also report the complete mitochondrial sequences for two forensically important flies, P. regina and S. crassipalpis, which could be used to provide useful information to legal personnel. Comparative analyses revealed that dipterans follow similar codon usage and nucleotide biases that could be due to mutational and selection pressures. This study illustrates the utility of 454 sequencing to obtain complete mitochondrial genomes for dipterans without the aid of conventional molecular techniques such as PCR and cloning and validates this method of mtgenome sequencing in arthropods.

An evaluation of sampling methods used to produce insect growth models for postmortem interval estimation.

Many authors produced carrion insect development data for predicting the age of an insect from a corpse. Under some circumstances, this age value is a minimum postmortem interval. There are no standard protocols for such experiments, and the literature includes a variety of sampling methods. To our knowledge, there has been no investigation of how the choice of sampling method can be expected to influence the performance of the resulting predictive model. We calculated 95 % inverse prediction confidence limits for growth curves of the forensically important carrion flies Chrysomya megacephala and Sarconesia chlorogaster (Calliphoridae) at a constant temperature. Confidence limits constructed on data for entire age cohorts were considered to be the most realistic and were used to judge the effect of various subsampling schemes from the literature. Random subsamples yielded predictive models very similar to those of the complete data. Because taking genuinely random subsamples would require a great deal of effort, we imagine that it would be worthwhile only if the larval measurement technique were especially slow and/or expensive. However, although some authors claimed to use random samples, their published methods suggest otherwise. Subsampling the largest larvae produced a predictive model that performed poorly, with confidence intervals about an estimate of age being unjustifiably narrow and unlikely to contain the true age. We believe these results indicate that most forensic insect development studies should involve the measurement of entire age cohorts rather than subsamples of one or more cohorts.

Population genetic structure of an invasive forensically important insect.

The forensic utility of an insect can depend in part on its population structure. Although some native North American species have been characterized in this fashion, information is lacking for species that were introduced from elsewhere and that might have lower genetic diversity and less geographic differentiation. We surveyed Chrysomya megacephala, an Asian fly present in the continental USA since the 1980s. Amplified Fragment Length Polymorphism profiles were generated from adult insects collected across Florida and in Mobile, Alabama. Analysis of Molecular Variance on 151 polymorphic loci found significant but very small variation among samples. STRUCTURE and principal coordinate analyses produced the same two clusters in the population, consistent with C. megacephala in Florida having originated from two separate source populations. A weak negative correlation between genetic and geographic distances probably reflected the geographic arrangement of the genetic clusters. A positive relative relatedness coefficient for each sample indicated that flies arriving at a bait within a short time were likely to be close relatives, consistent with the earlier results for native North American carrion flies. However, genetic diversity estimated for the introduced Florida C. megacephala was lower than for native species or for published data on Malaysian C. megacephala, perhaps reflecting the genetic effects of being introduced to a new geographic region. Genetic assignment, a method that has been proposed as a way to infer corpse postmortem relocation, was much less successful for C. megacephala compared to the native species, possibly reflecting a history of admixture.

Molecular systematics of the Calliphoridae (Diptera: Oestroidea): evidence from one mitochondrial and three nuclear genes.

Approximately 8% of calyptrate species diversity comes from the Calliphoridae, which includes flies of medical, veterinary, and forensic importance. The status of family Calliphoridae has for years been the central systematic problem of the superfamily Oestroidea, and phylogenetic relationships between the key groups of the Calliphoridae are unresolved and controversial. We reconstructed phylogenies of the Calliphoridae within the larger context of the other Oestroidea based on 5,189 bp of combined data from one mitochondrial (cytochrome oxidase subunit one) and three nuclear (carbamoylphosphate synthetase, elongation factor one alpha, and 28S ribosomal RNA) genes using maximum parsimony, maximum likelihood, and Bayesian methods. Trees obtained from the different phylogenetic methods were almost identical. Calliphoridae is polyphyletic, with the phylogenetic position of Mesembrinellinae still uncertain but clearly outside the lineage that includes other Calliphoridae and some noncalliphorids, and Polleniinae is the sister group of the family Tachinidae. Strong support for a sister group relationship between Rhiniinae and traditional calliphorid subfamilies conflicts with a recent proposal to give Rhiniinae family status. All calliphorid subfamilies (except Calliphorinae) for which we had more than one species were monophyletic. Melanomyinae was nested within Calliphorinae. Toxotarsinae was more closely related to Calliphorinae rather than, as indicated by morphology, to Chrysomyinae. Efforts to resolve the relationships of the Oestroid families were largely inconclusive, although the monophyly of the superfamily was strongly supported.

Pragmatic design and inclusion of patient-partner representatives improves participant experience in clinical research.

Objectives: Patient engagement in the design and implementation of clinical trials is necessary to ensure that the research is relevant and responsive to patients. The PREP-IT trials, which include 2 pragmatic trials that evaluate different surgical preparation solutions in orthopaedic trauma patients, followed the patient-centered outcomes research (PCOR) methodology throughout the design, implementation, and conduct. We conducted a substudy within the PREP-IT trials to explore participants' experiences with trial participation. Methods: At the final follow-up visit (12 months after their fracture), patients participating in the PREP-IT trials were invited to participate in the substudy. After providing informed consent, participants completed a questionnaire that asked about their experience and satisfaction with participating in the PREP-IT trials. Descriptive statistics are used to report the findings. Results: Four hundred two participants participated in the substudy. Most participants (394 [98%]) reported a positive experience, and 376 (94%) participants felt their contributions were appreciated. The primary reasons for participation were helping future patients with fracture (279 [69%]) and to contribute to science (223 [56%]). Two hundred seventeen (46%) participants indicated that their decision to participate was influenced by the minimal time commitment. Conclusions: Most participants reported a positive experience with participating in the PREP-IT trials. Altruism was the largest motivator for participating in this research. Approximately half of the participants indicated that the pragmatic, low-participant burden design of the trial influenced their decision to participate. Meaningful patient engagement, a pragmatic, and low-burden protocol led to high levels of participant satisfaction.

Use of Iatrogenic Lipid Emulsion and Subsequent Plasmapheresis for the Treatment of Amitriptyline Overdose.

Plasmapheresis for the treatment of hypertriglyceridemia is relatively uncommon and mostly reported either in patients experiencing hypertriglyceridemia-induced acute pancreatitis or patients with therapy-resistant familial hypercholesterolemia. Standard therapies for hypertriglyceridemia include dietary modification and lipid-lowering medication. For severe hypertriglyceridemia, the risk of pancreatitis increases significantly as triglyceride levels increase above 1000 mg/dL, and current therapies are unable to reduce triglyceride levels rapidly enough. Here, we report a case of a 48-year-old male patient who presented to the emergency department due to an amitriptyline overdose. In addition to being started on IV sodium bicarbonate therapy, an intravenous 20% fat emulsion bolus at 1.5 mL/kg was administered followed by 0.25 mL/kg/min infusion for 4 hours as a strategy to absorb lipophilic amitriptyline. Two days posttreatment, he was noted to have substantial hypertriglyceridemia (serum triglycerides: 6,475 mg/dL). His amylase was within the normal range at 37 U/L (reference range: 20-100 U/L), his lipase was low at 40 U/L (reference range: 75-390 U/L), and he was without evidence of any clinical sequelae secondary to hypertriglyceridemia (e.g., pancreatitis). Due to the severity of his hypertriglyceridemia, plasmapheresis was initiated urgently for rapid reduction in serum triglyceride levels to prevent pancreatitis and end-organ damage. He underwent a 1-plasma volume exchange with 5% albumin as the replacement fluid. This reduced his triglyceride levels to 185 mg/dL (reference range: 3-149 mg/dL). His symptoms secondary to his amitriptyline overdose were also resolved. Here, we report a 2-step process of intravenous lipid emulsion followed by plasmapheresis for amitriptyline overdose.

Range-wide persistence of the endangered arroyo toad (Anaxyrus californicus) for 20+ years following a prolonged drought.

Prolonged drought due to climate change has negatively impacted amphibians in southern California, U.S.A. Due to the severity and length of the current drought, agencies and researchers had growing concern for the persistence of the arroyo toad (Anaxyrus californicus), an endangered endemic amphibian in this region. Range-wide surveys for this species had not been conducted for at least 20 years. In 2017-2020, we conducted collaborative surveys for arroyo toads at historical locations. We surveyed 88 of the 115 total sites having historical records and confirmed that the arroyo toad is currently extant in at least 61 of 88 sites and 20 of 25 historically occupied watersheds. We did not detect toads at almost a third of the surveyed sites but did detect toads at 18 of 19 specific sites delineated in the 1999 Recovery Plan to meet one of four downlisting criteria. Arroyo toads are estimated to live 7-8 years, making populations susceptible to prolonged drought. Drought is estimated to increase in frequency and duration with climate change. Mitigation strategies for drought impacts, invasive aquatic species, altered flow regimes, and other anthropogenic effects could be the most beneficial strategies for toad conservation and may also provide simultaneous benefits to several other native species that share the same habitat.

The impact of COVID-19 restrictions on participant enrollment in the PREPARE trial.

Background: At the initiation of the COVID-19 pandemic, restrictions forced researchers to decide whether to continue their ongoing clinical trials. The PREPARE (Pragmatic Randomized Trial Evaluating Pre-Operative Alcohol Skin Solutions in Fractured Extremities) trial is a pragmatic cluster-randomized crossover trial in patients with open and closed fractures. PREPARE was enrolling over 200 participants per month at the initiation of the pandemic. We aim to describe how the COVID-19 research restrictions affected participant enrollment. Methods: The PREPARE protocol permitted telephone consent, however, sites were obtaining consent in-person. To continue enrollment after the initiation of the restrictions participating sites obtained ethics approval for telephone consent scripts and the waiver of a signature on the consent form. We recorded the number of sites that switched to telephone consent, paused enrollment, and the length of the pause. We used t-tests to compare the differences in monthly enrollment between July 2019 and November 2020. Results: All 19 sites quickly implement telephone consent. Fourteen out of nineteen (73.6%) sites paused enrollment due to COVID-19 restrictions. The median length of enrollment pause was 46.5 days (range, 7-121 days; interquartile range, 61 days). The months immediately following the implementation of restrictions had significantly lower enrollment. Conclusion: A pragmatic design allowed sites to quickly adapt their procedures for obtaining informed consent via telephone and allowed for minimal interruptions to enrollment during the pandemic.

Randomized evaluation of the trabecular micro-bypass stent with phacoemulsification in patients with glaucoma and cataract.

OBJECTIVE: To assess the safety and efficacy of the iStent trabecular micro-bypass stent (Glaukos Corporation, Laguna Hills, CA) in combination with cataract surgery in subjects with mild to moderate open-angle glaucoma. DESIGN: Prospective, randomized, open-label, controlled, multicenter clinical trial. PARTICIPANTS: A total of 240 eyes with mild to moderate open-angle glaucoma with intraocular pressure (IOP) ≤24 mmHg controlled on 1 to 3 medications were randomized to undergo cataract surgery with iStent implantation (treatment group) or cataract surgery only (control). Fifty additional subjects were enrolled to undergo cataract surgery with iStent implantation under protocol expansion. Data in this report are based on the first 240 eyes enrolled. INTERVENTION: Implantation of the iStent trabecular micro-bypass stent in conjunction with cataract surgery or cataract surgery only. MAIN OUTCOME MEASURES: The primary efficacy measure was unmedicated IOP ≤21 mmHg at 1 year. A secondary measure was unmedicated IOP reduction ≥20% at 1 year. Safety measures included best-corrected visual acuity (BCVA), slit-lamp observations, complications, and adverse events. RESULTS: The study met the primary outcome, with 72% of treatment eyes versus 50% of control eyes achieving the criterion (P<0.001). At 1 year, IOP in both treatment groups was statistically significantly lower from baseline values. Sixty-six percent of treatment eyes versus 48% of control eyes achieved ≥20% IOP reduction without medication (P = 0.003). The overall incidence of adverse events was similar between groups with no unanticipated adverse device effects. CONCLUSIONS: Pressure reduction on fewer medications was clinically and statistically significantly better 1 year after stent plus cataract surgery versus cataract surgery alone, with an overall safety profile similar to that of cataract surgery alone.

Forensic entomology when the evidence is "no insect." Best carrion fly species for predicting maximum postmortem interval in the United Arab Emirates.

The carrion insect species that most quickly deposit offspring on a corpse are, when available, likely to yield a more useful estimate of postmortem interval (PMI) compared to later arrivals. This is in part because the age of the oldest larva will be as close as possible to the PMI when doing a development analysis, and because the preappearance interval (PAI), the time the corpse was exposed before insect colonization, corresponds to the narrowest window of time since death for an insect-free corpse when doing a succession analysis. Given replicated training data a prediction of exposure time for a corpse can be in the form of a confidence set, and the maximum value of that set for an insect-free corpse is a probabilistic version of PAI. To discover the insect species likely to be useful in the early postmortem period in the United Arab Emirates we exposed 216 rat carcasses outdoors at two sites in Dubai over three-day periods during winter. Rats were sampled twice each day without replacement and kept in the lab to allow carrion insects to complete development to the adult stage. The fly species produced in this way were Sarcophaga dux, S. ruficornis, Wohlfahrtia nuba, W. indigens (Sarcophagidae), Chrysomya albiceps (Calliphoridae), and Musca domestica (Muscidae). To the best of our knowledge this is the first record of W. indigens larvae feeding on carrion. While adult C. albiceps and M. domestica were abundant on the carcasses, C. albiceps colonized too slowly to be useful for this type of succession analysis within this time frame, and M. domestica emerged from a single rat. The Sarcophagidae were rapid colonizers, and under these conditions the probability is>90% that a carcass would remain free of S. dux larvae not more than 57 h and free of W. nuba larvae for not more than 51 h.

Implementing stakeholder engagement to explore alternative models of consent: An example from the PREP-IT trials.

INTRODUCTION: Cluster randomized crossover trials are often faced with a dilemma when selecting an optimal model of consent, as the traditional model of obtaining informed consent from participant's before initiating any trial related activities may not be suitable. We describe our experience of engaging patient advisors to identify an optimal model of consent for the PREP-IT trials. This paper also examines surrogate measures of success for the selected model of consent. METHODS: The PREP-IT program consists of two multi-center cluster randomized crossover trials that engaged patient advisors to determine an optimal model of consent. Patient advisors and stakeholders met regularly and reached consensus on decisions related to the trial design including the model for consent. Patient advisors provided valuable insight on how key decisions on trial design and conduct would be received by participants and the impact these decisions will have. RESULTS: Patient advisors, together with stakeholders, reviewed the pros and cons and the requirements for the traditional model of consent, deferred consent, and waiver of consent. Collectively, they agreed upon a deferred consent model, in which patients may be approached for consent after their fracture surgery and prior to data collection. The consent rate in PREP-IT is 80.7%, and 0.67% of participants have withdrawn consent for participation. DISCUSSION: Involvement of patient advisors in the development of an optimal model of consent has been successful. Engagement of patient advisors is recommended for other large trials where the traditional model of consent may not be optimal.

Effectiveness of Iodophor vs Chlorhexidine Solutions for Surgical Site Infections and Unplanned Reoperations for Patients Who Underwent Fracture Repair: The PREP-IT Master Protocol.

Importance: The risk of developing a surgical site infection after extremity fracture repair is nearly 5 times greater than in most elective orthopedic surgical procedures. For all surgical procedures, it is standard practice to prepare the operative site with an antiseptic solution; however, there is limited evidence to guide the choice of solution used for orthopedic fracture repair. Objective: To compare the effectiveness of iodophor vs chlorhexidine solutions to reduce surgical site infections and unplanned fracture-related reoperations for patients who underwent fracture repair. Design, Setting, and Participants: The PREP-IT (Program of Randomized Trials to Evaluate Pre-operative Antiseptic Skin Solutions in Orthopaedic Trauma) master protocol will be followed to conduct 2 multicenter pragmatic cluster randomized crossover trials, Aqueous-PREP (Pragmatic Randomized Trial Evaluating Pre-Operative Aqueous Antiseptic Skin Solution in Open Fractures) and PREPARE (Pragmatic Randomized Trial Evaluating Pre-Operative Alcohol Skin Solutions in Fractured Extremities). The Aqueous-PREP trial will compare 4% aqueous chlorhexidine vs 10% povidone-iodine for patients with open extremity fractures. The PREPARE trial will compare 2% chlorhexidine in 70% isopropyl alcohol vs 0.7% iodine povacrylex in 74% isopropyl alcohol for patients with open extremity fractures and patients with closed lower extremity or pelvic fractures. Both trials will share key aspects of study design and trial infrastructure. The studies will follow a pragmatic cluster randomized crossover design with alternating treatment periods of approximately 2 months. The primary outcome will be surgical site infection and the secondary outcome will be unplanned fracture-related reoperations within 12 months. The Aqueous-PREP trial will enroll a minimum of 1540 patients with open extremity fractures from at least 12 hospitals; PREPARE will enroll a minimum of 1540 patients with open extremity fractures and 6280 patients with closed lower extremity and pelvic fractures from at least 18 hospitals. The primary analyses will adhere to the intention-to-treat principle and account for potential between-cluster and between-period variability. The patient-centered design, implementation, and dissemination of results are guided by a multidisciplinary team that includes 3 patients and other relevant stakeholders. Discussion: The PREP-IT master protocol increases efficiency through shared trial infrastructure and study design components. Because prophylactic skin antisepsis is used prior to all surgical procedures and the application, cost, and availability of all study solutions are similar, the results of the PREP-IT trials are poised to inform clinical guidelines and bring about an immediate change in clinical practice. Trial Registration: ClinicalTrials.gov Identifiers: NCT03385304 and NCT03523962.

A Forensic Entomological Analysis Can Yield an Estimate of Postmortem Interval, and Not Just a Minimum Postmortem Interval: An Explanation and Illustration Using a Case.

Several authors claimed that a forensic entomological analysis can never be interpreted as the postmortem interval (PMI), but that it can be interpreted as a minimum postmortem interval (PMImin ), or dead for not less than X amount of time. Because in most instances, a PMI estimate should be a range, that is, the set of values from maximum postmortem interval (PMImax ) to PMImin , objections to PMI estimation are objections to PMImax estimation. The arguments for this position did not address the substantial body of literature describing estimation of both PMImax and PMImin using insect succession analysis. This report reviews the scientific issues and presents a recent homicide investigation in which several forensic entomology experts used the absence of carrion insects on the corpse, a kind of succession analysis, to estimate PMI or PMImax .

Amplified fragment length polymorphism analysis supports the valid separate species status of Lucilia caesar and L. illustris (Diptera: Calliphoridae).

Common DNA-based species determination methods fail to distinguish some blow flies in the forensically and medically important genus Lucilia Robineau-Desvoidy. This is a practical problem, and it has also been interpreted as casting doubt on the validity of some morphologically defined species. An example is Lucilia illustris and L. caesar, which co-occur in Europe whilst only L. illustris has been collected in North America. Reports that these species shared both mitochondrial and nuclear gene sequences, along with claims that diagnostic morphological characters are difficult to interpret, were used to question their separate species status. We report here that amplified fragment length polymorphism profiles strongly support the validity of both species based on both assignment and phylogenetic analysis, and that traditional identification criteria based on male and female genital morphology are more reliable than has been claimed.