A perspective on the impacts of microplastics on mosquito biology and their vectorial capacity

Microplastics (plastic particles <5 mm) permeate aquatic and terrestrial ecosystems and constitute a hazard to animal life. Although much research has been conducted on the effects of microplastics on marine and benthic organisms, less consideration has been given to insects, especially those adapted to urban environments. Here, we provide a perspective on the potential consequences of exposure to microplastics within typical larval habitat on mosquito biology. Mosquitoes represent an ideal organism in which to explore the biological effects of microplastics on terrestrial insects, not least because of their importance as an infectious disease vector. Drawing on evidence from other organisms and knowledge of the mosquito life cycle, we summarise some of the more plausible impacts of microplastics including physiological, ecotoxicological and immunological responses. We conclude that although there remains little experimental evidence demonstrating any adverse effect on mosquito biology or pathogen transmission, significant knowledge gaps remain, and there is now a need to quantify the effects that microplastic pollution could have on such an important disease vector

Establishing the precision and robustness of farmers’ crop experiments

Precision farming technologies such as global positioning, input placement technologies and on-the-go yield monitoring now provide farmers with the means to conduct their own experiments at scales relevant to their decisions with minimal disruption. However, these experiments are generally incompatible with conventional statistical methods and alternative models of response variables (e.g. yield) must be estimated if the effect of the management decision is to be distinguished from other sources of variation. We explore the precision and robustness of such experiments using four sources of data and experimental designs of different degrees of complexity. We see that there is a trade-off between the precision of the experiment and its complexity and hence implementation cost. In yield experiments with small-grain cereals, standard errors of treatment effects in yield of less than 0.05 t/ha can potentially be achieved when the treatment is varied along the field traffic row and standard errors of less than 0.1 t/ha can potentially be achieved when single treatments are applied in each row but the experiment includes multiple disconnected repetitions of each treatment. Simpler split-field designs are less robust since it can be difficult to distinguish treatment effects from independent spatial trends and discontinuities in the response variable. In some instances, the potential precision is not realised because the data include noise or artefacts that are unrelated to crop performance. Further yield sensor developments are required to minimise these occurrences. The model-based statistical analyses of these experiments require assumptions regarding the variation of the response variable. We see that when these assumptions are inappropriate (e.g. if the correlation between response variable measurements is poorly modelled) then the inferences from the experiments can be unreliable. In particular, we see that the spatial correlation amongst yield measurements tends to be greater along the farm traffic row than perpendicular to it. Standard isotropic models of spatial correlation do not accommodate this feature and led to substantial under-estimation of the standard errors

Development of a core information set for colorectal cancer surgery: a consensus study

Objective ‘Core information sets’ (CISs) represent baseline information, agreed by patients and professionals, to stimulate individualised patient-centred discussions. This study developed a CIS for use before colorectal cancer (CRC) surgery. Design Three phase consensus study: (1) Systematic literature reviews and patient interviews to identify potential information of importance to patients, (2) UK national Delphi survey of patients and professionals to rate the importance of the information, (3) international consensus meeting to agree on the final CIS. Setting UK CRC centres. Participants Purposive sampling was conducted to ensure CRC centre representation based upon geographical region and caseload volume. Responses were received from 63/81 (78%) centres (90 professionals). Adult patients who had undergone CRC surgery were eligible, and purposive sampling was conducted to ensure representation based on age, sex and cancer location (rectum, left and right colon). Responses were received from 97/267 (35%) patients with a wide age range (29–87), equal sex ratio and cancer location. Attendees of the international Tripartite Colorectal Conference were eligible for the consensus meeting. Outcomes Phase 1: Information of potential importance to patients was extracted verbatim and operationalised into a Delphi questionnaire. Phase 2: Patients and professionals rated the importance information on a 9-point Likert scale, and resurveyed following group feedback. Information rated of low importance were discarded using predefined criteria. Phase 3: A modified nominal group technique was used to gain final consensus in separate consensus meetings with patients and professionals. Results Data sources identified 1216 pieces of information that informed a 98-item questionnaire. Analysis led to 50 and 23 information domains being retained after the first and second surveys, respectively. The final CIS included 11 concepts including specific surgical complications, short and long-term survival, disease recurrence, stoma and quality of life issues. Conclusions This study has established a CIS for professionals to discuss with patients before CRC surgery

Synthesis and summary of patient-reported outcome measures to inform the development of a core outcome set in colorectal cancer surgery

AIM: Patient-reported outcome (PRO) measures (PROMs) are standard measures in the assessment of colorectal cancer (CRC) treatment, but the range and complexity of available PROMs may be hindering the synthesis of evidence. This systematic review aimed to: (i) summarize PROMs in studies of CRC surgery and (ii) categorize PRO content to inform the future development of an agreed minimum 'core' outcome set to be measured in all trials. METHOD: All PROMs were identified from a systematic review of prospective CRC surgical studies. The type and frequency of PROMs in each study were summarized, and the number of items documented. All items were extracted and independently categorized by content by two researchers into 'health domains', and discrepancies were discussed with a patient and expert. Domain popularity and the distribution of items were summarized. RESULTS: Fifty-eight different PROMs were identified from the 104 included studies. There were 23 generic, four cancer-specific, 11 disease-specific and 16 symptom-specific questionnaires, and three ad hoc measures. The most frequently used PROM was the EORTC QLQ-C30 (50 studies), and most PROMs (n = 40, 69%) were used in only one study. Detailed examination of the 50 available measures identified 917 items, which were categorized into 51 domains. The domains comprising the most items were 'anxiety' (n = 85, 9.2%), 'fatigue' (n = 67, 7.3%) and 'physical function' (n = 63, 6.9%). No domains were included in all PROMs. CONCLUSION: There is major heterogeneity of PRO measurement and a wide variation in content assessed in the PROMs available for CRC. A core outcome set will improve PRO outcome measurement and reporting in CRC trials

Strengthening adult mosquito surveillance in Africa for disease control: Learning from the present

Mosquito surveillance is essential to successfully control and eliminate mosquito-borne diseases. Yet, it is often done by numerous organizations with little collaboration, incomplete understanding of existing gaps, and limited long-term vision. There is a clear disconnect between entomological and epidemiological indices, with entomological data informing control efforts inadequately. Here we discuss current mosquito surveillance practises across the heterogenous disease landscape in Africa. We advocate for the development of mosquito surveillance strategic plans to increase the impact and functionality of mosquito surveillance. We urge for a proactive approach to set up centralized mosquito data systems under custodian of national governments, focus on epidemiologically relevant mosquito data and increase robustness of mosquito surveillance using a more spatially explicit sampling design

Estimating malaria transmission risk through surveillance of human–vector interactions in northern Ghana

Background: Vector bionomics are important aspects of vector-borne disease control programs. Mosquito-biting risks are affected by environmental, mosquito behavior and human factors, which are important for assessing exposure risk and intervention impacts. This study estimated malaria transmission risk based on vector–human interactions in northern Ghana, where indoor residual spraying (IRS) and insecticide-treated nets (ITNs) have been deployed. Methods: Indoor and outdoor human biting rates (HBRs) were measured using monthly human landing catches (HLCs) from June 2017 to April 2019. Mosquitoes collected were identified to species level, and Anopheles gambiae sensu lato (An. gambiae s.l.) samples were examined for parity and infectivity. The HBRs were adjusted using mosquito parity and human behavioral observations. Results: Anopheles gambiae was the main vector species in the IRS (81%) and control (83%) communities. Indoor and outdoor HBRs were similar in both the IRS intervention (10.6 vs. 11.3 bites per person per night [b/p/n]; z = −0.33, P = 0.745) and control communities (18.8 vs. 16.4 b/p/n; z = 1.57, P = 0.115). The mean proportion of parous An. gambiae s.l. was lower in IRS communities (44.6%) than in control communities (71.7%). After adjusting for human behavior observations and parity, the combined effect of IRS and ITN utilization (IRS: 37.8%; control: 57.3%) on reducing malaria transmission risk was 58% in IRS + ITN communities and 27% in control communities with ITNs alone (z = −4.07, P < 0.001). However, this also revealed that about 41% and 31% of outdoor adjusted bites in IRS and control communities respectively, occurred before bed time (10:00 pm). The mean directly measured annual entomologic inoculation rates (EIRs) during the study were 6.1 infective bites per person per year (ib/p/yr) for IRS communities and 16.3 ib/p/yr for control communities. After considering vector survival and observed human behavior, the estimated EIR for IRS communities was 1.8 ib/p/yr, which represents about a 70% overestimation of risk compared to the directly measured EIR; for control communities, it was 13.6 ib/p/yr (16% overestimation). Conclusion: Indoor residual spraying significantly impacted entomological indicators of malaria transmission. The results of this study indicate that vector bionomics alone do not provide an accurate assessment of malaria transmission exposure risk. By accounting for human behavior parameters, we found that high coverage of ITNs alone had less impact on malaria transmission indices than combining ITNs with IRS, likely due to observed low net use. Reinforcing effective communication for behavioral change in net use and IRS could further reduce malaria transmission

Trial outcomes and information for clinical decision-making: a comparative study of opinions of health professionals

Background: Trials are robust sources of data for clinical practice, however, trial outcomes may not reflect what is important to communicate for decision making. The study compared clinicians’ views of outcomes to include in a core outcome set for colorectal cancer (CRC) surgery, with what clinicians considered important information for clinical practice (core information). Methods: Potential outcomes/information domains were identified through systematic literature reviews, reviews of hospital information leaflets and interviews with patients. These were organized into 6 categories, and used to design a questionnaire survey that asked surgeons and nurses from a sample of CRC centers to rate the importance of each domain as an outcome or as information on a 9-point Likert scale. Respondents were re-surveyed (round 2) following group feedback (Delphi methods). Comparisons were made by calculating the difference in mean scores between the outcomes and information domains, and paired t-tests were used to explore the difference between mean scores of the 6 outcome/information categories. Results: Data sources identified 1216 outcomes/information of CRC surgery that informed a 94 item questionnaire. First round questionnaires were returned from 63/81 (78%) of centers. Clinicians rated 76/94 (84%) domains of higher importance to measure in trials than to information to communicate to patients in Round 1. This was reduced to 24/47 (51%) in Round 2. The greatest difference was evident in domains about survival, which was rated much more highly as a trial outcome than important piece of information for decision-making (mean difference 2.3, 95% CI 1.9-2.8, p<0.0001). Specific complications and quality-of-life domains were rated similarly (mean difference 0.18, 95% CI -0.1-0.4, p=0.2 and 0.2, 95% CI -0.1-0.5, p=0.2 respectively). Conclusions: Whilst clinicians want to measure key outcomes in trials, they rate these as less important to communicate in decision-making with patients. This discrepancy needs to be explored and addressed to maximize the impact of trials on clinical practice

Core Outcomes for Colorectal Cancer Surgery: A Consensus Study

Background: Colorectal cancer (CRC) is a major cause of worldwide morbidity and mortality. Surgical treatment is common, and there is a great need to improve the delivery of such care. The gold standard for evaluating surgery is within well-designed randomized controlled trials (RCTs); however, the impact of RCTs is diminished by a lack of coordinated outcome measurement and reporting. A solution to these issues is to develop an agreed standard “core” set of outcomes to be measured in all trials to facilitate cross-study comparisons, meta-analysis, and minimize outcome reporting bias. This study defines a core outcome set for CRC surgery. Methods and Findings: The scope of this COS includes clinical effectiveness trials of surgical interventions for colorectal cancer. Excluded were nonsurgical oncological interventions. Potential outcomes of importance to patients and professionals were identified through systematic literature reviews and patient interviews. All outcomes were transcribed verbatim and categorized into domains by two independent researchers. This informed a questionnaire survey that asked stakeholders (patients and professionals) from United Kingdom CRC centers to rate the importance of each domain. Respondents were resurveyed following group feedback (Delphi methods). Outcomes rated as less important were discarded after each survey round according to predefined criteria, and remaining outcomes were considered at three consensus meetings; two involving international professionals and a separate one with patients. A modified nominal group technique was used to gain the final consensus. Data sources identified 1,216 outcomes of CRC surgery that informed a 91 domain questionnaire. First round questionnaires were returned from 63 out of 81 (78%) centers, including 90 professionals, and 97 out of 267 (35%) patients. Second round response rates were high for all stakeholders (>80%). Analysis of responses lead to 45 and 23 outcome domains being retained after the first and second surveys, respectively. Consensus meetings generated agreement on a 12 domain COS. This constituted five perioperative outcome domains (including anastomotic leak), four quality of life outcome domains (including fecal urgency and incontinence), and three oncological outcome domains (including long-term survival). Conclusion: This study used robust consensus methodology to develop a core outcome set for use in colorectal cancer surgical trials. It is now necessary to validate the use of this set in research practice