Can the UNAIDS modes of transmission model be improved? A comparison of the original and revised model projections using data from a setting in west Africa.

OBJECTIVE: The UNAIDS modes of transmission model (MoT) is a user-friendly model, developed to predict the distribution of new HIV infections among different subgroups. The model has been used in 29 countries to guide interventions. However, there is the risk that the simplifications inherent in the MoT produce misleading findings. Using input data from Nigeria, we compare projections from the MoT with those from a revised model that incorporates additional heterogeneity. METHODS: We revised the MoT to explicitly incorporate brothel and street-based sex-work, transactional sex, and HIV-discordant couples. Both models were parameterized using behavioural and epidemiological data from Cross River State, Nigeria. Model projections were compared, and the robustness of the revised model projections to different model assumptions, was investigated. RESULTS: The original MoT predicts 21% of new infections occur in most-at-risk-populations (MARPs), compared with 45% (40-75%, 95% Crl) once additional heterogeneity and updated parameterization is incorporated. Discordant couples, a subgroup previously not explicitly modelled, are predicted to contribute a third of new HIV infections. In addition, the new findings suggest that women engaging in transactional sex may be an important but previously less recognized risk group, with 16% of infections occurring in this subgroup. CONCLUSION: The MoT is an accessible model that can inform intervention priorities. However, the current model may be potentially misleading, with our comparisons in Nigeria suggesting that the model lacks resolution, making it challenging for the user to correctly interpret the nature of the epidemic. Our findings highlight the need for a formal review of the MoT

Assessing changes to ecosystem structure and function following invasion by Spartina alterniflora and Phragmites australis: a meta-analysis [Supplemental Files]

Includes data and R codeBiological invasions resulting from anthropogenic activities are one of the greatest threats to maintaining ecosystem functioning and native biodiversity. Invasions are especially problematic when the invading species behaves as an ecosystem engineer that is capable of transforming ecosystem structure, function, and community dynamics. Of particular concern is the spread of emergent wetland grasses whose root systems alter hydrology and structural stability of soils, modify ecosystem functions, and change community dynamics and species richness. To address the threats posed to ecosystems across the globe, management practices focus on the control and removal of invasive grasses. However, it remains unclear how severely invasive grasses alter ecosystem functions and whether alterations persist after invasive grass removal, limiting our ability to determine if management practices are truly sufficient to fully restore ecosystems. Here, we conducted a meta-analysis to quantify ecological alterations and the efficacy of management following the invasion of Spartina alterniflora and Phragmites australis, two common and pervasive invaders in coastal wetlands. Our results indicate that S. alterniflora and P. australis significantly alter measures of ecosystem functioning and organismal abundance. Invaded ecosystems had significant elevations in abiotic carbon and nitrogen fixation and uptake in areas with invasive grasses, with differential photosynthetic pathways of these two grass species further explaining carbon fluxes. Moreover, evidence from our analyses indicates that management practices may not adequately promote recovery from invasion, but more data are needed to fully assess management efficacy. We call for future studies to conduct pairwise comparisons between uninvaded, invaded, and managed systems and provide research priorities

Validation of the American Association for the Surgery of Trauma Emergency General Surgery Grading System for Colorectal Resection: An EAST Multicenter Study

BACKGROUND: The American Association for the Surgery of Trauma (AAST) has developed a grading system for emergency general surgery (EGS) conditions. We sought to validate the AAST EGS grades for patients undergoing urgent/emergent colorectal resection. METHODS: Patients enrolled in the Eastern Association for the Surgery of Trauma Multicenter Colorectal Resection in EGS-to anastomose or not to anastomose study undergoing urgent/emergent surgery for obstruction, ischemia, or diverticulitis were included. Baseline demographics, comorbidity severity as defined by Charlson comorbidity index (CCI), procedure type, and AAST grade were prospectively collected. Outcomes included length of stay (LOS) in-hospital mortality, and surgical complications (superficial/deep/organ-space surgical site infection, anastomotic leak, stoma complication, fascial dehiscence, and need for further intervention). Multivariable logistic regression models were used to describe outcomes and risk factors for surgical complication or mortality. RESULTS: There were 367 patients, with a mean (± SD) age of 62 ± 15 years. 39% were women. The median interquartile range (IQR) CCI was 4 (2-6). Overall, the pathologies encompassed the following AAST EGS grades: I (17, 5%), II (54, 15%), III (115, 31%), IV (95, 26%), and V (86, 23%). Management included laparoscopic (24, 7%), open (319, 87%), and laparoscopy converted to laparotomy (24, 6%). Higher AAST grade was associated with laparotomy ( = .01). The median LOS was 13 days (8-22). At least 1 surgical complication occurred in 33% of patients and the mortality rate was 14%. Development of at least 1 surgical complication, need for unplanned intervention, mortality, and increased LOS were associated with increasing AAST severity grade. On multivariable analysis, factors predictive of in-hospital mortality included AAST organ grade, CCI, and preoperative vasopressor use (odds ratio (OR) 1.9, 1.6, 3.1, respectively). The American Association for the Surgery of Trauma emergency general surgery grade was also associated with the development of at least 1 surgical complication (OR 2.5), while CCI, preoperative vasopressor use, respiratory failure, and pneumoperitoneum were not. CONCLUSION: The American Association for the Surgery of Trauma emergency general surgery grading systems display construct validity for mortality and surgical complications after urgent/emergent colorectal resection. These results support incorporation of AAST EGS grades for quality benchmarking and surgical outcomes research

Colorectal resection in emergency general surgery: An EAST multicenter trial

OBJECTIVE Evidence comparing stoma creation (STM) versus anastomosis after urgent or emergent colorectal resection is limited. This study examined outcomes after colorectal resection in emergency general surgery patients. METHODS This was an Eastern Association for the Surgery of Trauma-sponsored prospective observational multicenter study of patients undergoing urgent/emergent colorectal resection. Twenty-one centers enrolled patients for 11 months. Preoperative, intraoperative, and postoperative variables were recorded. ?2, Mann-Whitney U test, and multivariable logistic regression models were used to describe outcomes and risk factors for surgical complication/mortality. RESULTS A total of 439 patients were enrolled (ANST, 184; STM, 255). The median (interquartile range) age was 62 (53-71) years, and the median Charlson Comorbidity Index (CCI) was 4 (1-6). The most common indication for surgery was diverticulitis (28%). Stoma group was older (64 vs. 58 years, p \u3c 0.001), had a higher CCI, and were more likely to be immunosuppressed. Preoperatively, STM patients were more likely to be intubated (57 vs. 15, p \u3c 0.001), on vasopressors (61 vs. 13, p \u3c 0.001), have pneumoperitoneum (131 vs. 41, p \u3c 0.001) or fecal contamination (114 vs. 33, p \u3c 0.001), and had a higher incidence of elevated lactate (149 vs. 67, p \u3c 0.001). Overall mortality was 13%, which was higher in STM patients (18% vs. 8%, p = 0.02). Surgical complications were more common in STM patients (35% vs. 25%, p = 0.02). On multivariable analysis, management with an open abdomen, intraoperative blood transfusion, and larger hospital size were associated with development of a surgical complication, while CCI, preoperative vasopressor use, steroid use, open abdomen, and intraoperative blood transfusion were independently associated with mortality. CONCLUSION This study highlights a tendency to perform fecal diversion in patients who are acutely ill at presentation. There is a higher morbidity and mortality rate in STM patients. Independent predictors of mortality include CCI, preoperative vasopressor use, steroid use, open abdomen, and intraoperative blood transfusion. Following adjustment by clinical factors, method of colon management was not associated with surgical complications or mortality. LEVEL OF EVIDENCE Therapeutic study, level IV