Climate Change and the Epidemiology of Infectious Diseases in the United States.

The earth is rapidly warming, driven by increasing atmospheric carbon dioxide and other gases that result primarily from fossil fuel combustion. In addition to causing arctic ice melting and extreme weather events, climatologic factors are linked strongly to the transmission of many infectious diseases. Changes in the prevalence of infectious diseases not only reflect the impacts of temperature, humidity, and other weather-related phenomena on pathogens, vectors, and animal hosts but are also part of a complex of social and environmental factors that will be affected by climate change, including land use, migration, and vector control. Vector- and waterborne diseases and coccidioidomycosis are all likely to be affected by a warming planet; there is also potential for climate-driven impacts on emerging infectious diseases and antimicrobial resistance. Additional resources for surveillance and public health activities are urgently needed, as well as systematic education of clinicians on the health impacts of climate change.

Broad Antibody and Cellular Immune Response From a Phase 2 Clinical Trial With a Novel Multivalent Poxvirus-Based Respiratory Syncytial Virus Vaccine.

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of severe respiratory disease in young children and the elderly. Protective immunity is not generated after repeated infections, but vaccination may hopefully prove effective. METHODS: This phase 2 clinical study investigated a multivalent RSV vaccine (MVA-BN-RSV) designed to induce broad antibody and cellular immune responses by encoding RSV surface proteins F, G (for both A and B subtypes), and internal antigens (M2, N). This study evaluated the immune response in adults aged ≥55 years to identify the optimal MVA-BN-RSV dose and vaccination schedule. RESULTS: A single dose increased the levels of neutralizing (plaque reduction neutralization test to RSV A and B) and total (IgG and IgA ELISA) antibodies (1.6 to 3.4-fold increase from baseline) and induced a broad Th1-biased cellular immune response (interferon-γ ELISPOT) to all 5 vaccine inserts (5.4 to 9.7-fold increases). Antibody responses remained above baseline for 6 months. A 12-month booster dose elicited a booster effect in antibody and T-cell responses (up to 2.8-fold from preboost levels). No drug-related serious adverse events were reported. CONCLUSIONS: MVA-BN-RSV induces a broad immune response that persists at least 6 months and can be boosted at 12 months, without significant safety findings. CLINICAL TRIALS REGISTRATION: NCT02873286.

DAS181 Treatment of Severe Lower Respiratory Tract Parainfluenza Virus Infection in Immunocompromised Patients: A Phase 2 Randomized, Placebo-Controlled Study.

BACKGROUND: There are no antiviral therapies for parainfluenza virus (PIV) infections. DAS181, a sialidase fusion protein, has demonstrated activity in in vitro and in animal models of PIV. METHODS: Adult immunocompromised patients diagnosed with PIV lower respiratory tract infection (LRTI) who required oxygen supplementation were randomized 2:1 to nebulized DAS181 (4.5 mg/day) or matching placebo for up to 10 days. Randomization was stratified by need for mechanical ventilation (MV) or supplemental oxygen (SO). The primary endpoint was the proportion of patients reaching clinical stability survival (CSS) defined as returning to room air (RTRA), normalization of vital signs for at least 24 hours, and survival up to day 45 from enrollment. RESULTS: A total of 111 patients were randomized to DAS181 (n = 74) or placebo (n = 37). CSS was achieved by 45.0% DAS181-treated patients in the SO stratum compared with 31.0% for placebo (P = .15), whereas patients on MV had no benefit from DAS181. The proportion of patients achieving RTRA was numerically higher for SO stratum DAS181 patients (51.7%) compared with placebo (34.5%) at day 28 (P = .17). In a post hoc analysis of solid organ transplant, hematopoietic cell transplantation within 1 year, or chemotherapy within 1 year, more SO stratum patients achieved RTRA on DAS181 (51.8%) compared with placebo (15.8%) by day 28 (P = .012). CONCLUSIONS: The primary endpoint was not met, but post hoc analysis of the RTRA component suggests DAS181 may have clinical activity in improving oxygenation in select severely immunocompromised patients with PIV LRTI who are not on mechanical ventilation. Clinical Trials Registration. NCT01644877.

Diagnostic Performance of Multiplex Nucleic Acid Testing of Bronchoalveolar Lavage and Bronchial Wash Specimens for Respiratory Viral Pathogens.

There is limited knowledge on the yield of performing multiplex nucleic acid testing (NAT) on multiple lower respiratory tract specimens from a single patient with a single instance of infection. We evaluated the performance characteristics of multiplex NAT assays performed concurrently on bronchoalveolar lavage (BAL) and bronchial wash (BW) specimens to detect respiratory pathogens. A retrospective study of admitted patients from March 2013 through December 2016 was performed. Individual performance characteristics of BAL and BW specimens were compared to positive results from either set of specimens. Only contemporaneous BAL and BW specimens (received by the laboratory within 4 h of each other) were included. The final cohort included 170 patients, with 184 contemporaneous BAL and BW specimens submitted for multiplex NAT (median age, 58 years; 62% male). Of the patients with positive NAT results, 38 of 40 BW specimens tested positive (overall percent agreement with combined testing, 98.9%; 95% confidence interval [CI], 95.5 to 98.9%), and 34 of 40 BAL specimens tested positive (overall percent agreement with combined testing, 96.7%; 95% CI, 93.0 to 96.7%). Assays performed on BW specimens identified 4 additional specimens and had a higher positive percent agreement (95.0%) with combined testing results compared to those performed on BAL specimens (85.0%). There was exact concordance in 174 specimens (94.6%; negative and positive for respiratory pathogens, 144 and 34 specimens, respectively). We observed high concordance (95%) between multiplex NAT results from contemporaneous BAL and BW specimens. Performance characteristics of BW specimen testing were equivalent to those of BAL specimen testing. The benefit of performing additional testing should be carefully considered against the potential complications and health care costs.

Epidemiology of infections following haploidentical peripheral blood hematopoietic cell transplantation.

BACKGROUND: The use of T-cell replete haploidentical hematopoietic cell transplant (haplo-HCT) has increased substantially since the introduction of post-transplant cyclophosphamide (PTCy) regimens. Limited data exist concerning infectious complications of haplo-HCT utilizing mobilized peripheral blood (PB) hematopoietic cells. METHODS: This retrospective cohort study included all adult patients at our institution undergoing PB haplo-HCT with PTCy between June 2009 and June 2015. Infections were microbiologically confirmed. Invasive fungal infections (IFI) classified as "proven" or "probable" by standard definitions were included. RESULTS: In total, 104 patients were identified. Median follow-up was 218 days (range: 6-1576). A total of 322 episodes of infection were recorded. Eighty-nine percent of patients experienced at least one infection. Median time to first infection was 22 days. Patients experiencing at least one bacterial, viral, and IFI were 62%, 72%, and 6%, respectively. The majority (69%) of bacterial infections were caused by enteric organisms. Seven cases of Staphylococcus aureus infection were recorded, with one bacteremia case. Cytomegalovirus (CMV) viremia occurred in 54/71 (76%) at-risk patients at a median time of 24 days. Sixteen (15%) patients developed CMV disease. Nineteen percent (20/104) of patients developed BK polyomavirus-associated cystitis. Six (6%) patients experienced a total of seven IFI. Infection was the primary cause of death for 12% (6/51) of patients and was a secondary cause for 41%. CONCLUSION: In PB haplo-HCT patients, a high incidence of CMV viremia and disease was observed. Infections with enteric bacteria were common. Fungal and staphylococcal infections were uncommon. Further studies are needed to compare infectious complications in haplo-HCT with other transplant modalities.

Precise dissection of an Escherichia coli O157:H7 outbreak by single nucleotide polymorphism analysis.

The current pathogen-typing methods have suboptimal sensitivities and specificities. DNA sequencing offers an opportunity to type pathogens with greater degrees of discrimination using single nucleotide polymorphisms (SNPs) than with pulsed-field gel electrophoresis (PFGE) and other methodologies. In a recent cluster of Escherichia coli O157:H7 infections attributed to salad bar exposures and romaine lettuce, a subset of cases denied exposure to either source, although PFGE and multiple-locus variable-number tandem-repeat analysis (MLVA) suggested that all isolates had the same recent progenitor. Interrogation of a preselected set of 3,442,673 nucleotides in backbone open reading frames (ORFs) identified only 1 or 2 single nucleotide differences in 3 of 12 isolates from the cases who denied exposure. The backbone DNAs of 9 of 9 and 3 of 3 cases who reported or were unsure about exposure, respectively, were isogenic. Backbone ORF SNP set sequencing offers pathogen differentiation capabilities that exceed those of PFGE and MLVA.

Predicting severe disease in patients diagnosed with seasonal influenza in the emergency department.

Objectives: We sought to develop an evidence-based tool to risk stratify patients diagnosed with seasonal influenza in the emergency department (ED). Methods: We performed a single-center retrospective cohort study of all adult patients diagnosed with influenza in a large tertiary care ED between 2008 and 2018. We evaluated demographics, triage vital signs, chest x-ray and laboratory results obtained in the ED. We used univariate and multivariate statistics to examine the composite primary outcome of death or need for intubation. We validated our findings in patients diagnosed between 2018 and 2020. Results: We collected data from 3128 subjects; 2196 in the derivation cohort and 932 in the validation cohort. Medical comorbidities, multifocal opacities or pleural effusion on chest radiography, older age, elevated respiratory rate, hypoxia, elevated blood urea nitrogen, blood glucose, blood lactate, and red blood cell distribution width were factors associated with intubation or death. We developed the Predicting Intubation in seasonal Influenza Patients diagnosed in the ED (PIIPED) risk-stratification tool from these factors. The PIIPED tool predicted intubation or death with an area under the receiver operating characteristic curve (AUC) of 0.899 in the derivation cohort and 0.895 in the validation cohort. A version of the tool including only factors available at ED triage, before laboratory or radiographic evaluation, exhibited AUC of 0.852 in the derivation cohort and 0.823 in the validation cohort. Conclusion: Clinical findings during an ED visit predict severe outcomes in patients with seasonal influenza. The PIIPED risk stratification tool shows promise but requires prospective validation.

Understanding and Addressing Bias in Grading: Progress at Washington University School of Medicine.

In 2020, the authors published work examining disparities in clerkship grading and found students who identify as White were more likely to receive honors grades compared with students from races/ethnicities traditionally underrepresented in medicine. Through a quality improvement approach, the authors identified the following 6 areas where improvements could mitigate grading disparities and, therefore, put processes in place to: ensure equitable access to examination preparation resources, change student assessment, develop medical student curriculum interventions, improve the learning environment, change house staff and faculty recruitment and retention practices, and provide ongoing program evaluation and continuous quality improvement processes to monitor for success. While the authors cannot yet be sure that they have achieved their goal of promoting equity in grading, they believe this evidence-based, multipronged intervention is a clear step in the right direction and encourage other schools to consider a similar approach to tackling this critically important problem at their own institutions.

Student Response Initiatives: A Case Study of COVID-19 at Washington University.

The COVID-19 pandemic disrupted medical education worldwide, leading medical students to organize response initiatives. This paper summarizes the Washington University Medical Student COVID-19 Response (WUMS-CR) and shares lessons to guide future initiatives. We used a three-principle framework of community needs assessment, faculty mentorship, and partnership with pre-existing organizations to address needs in St. Louis, including contact tracing and childcare. In total, over 12,000 h were volunteered across 15+ projects. Overall, student response initiatives should use appropriate frameworks to guide projects and should capitalize on volunteer participation, speed and flexibility, and the diversity of student interests and skills for maximal impact.

A randomized phase II trial to compare safety and immunogenicity of the MVA-BN smallpox vaccine at various doses in adults with a history of AIDS.

Traditional replicating smallpox vaccines are associated with serious safety concerns in the general population and are contraindicated in immunocompromised individuals. However, this very population remains at greatest risk for severe complications following viral infections, making vaccine prevention particularly relevant. MVA-BN was developed as a non-replicating smallpox vaccine that is potentially safer for people who are immunocompromised. In this phase II trial, 3 MVA-BN dosing regimens were evaluated for safety, tolerability, and immunogenicity in persons with HIV (PWH) who had a history of AIDS. Following randomization, 87 participants who were predominately male and African American received either 2 standard doses on weeks 0 and 4 in the standard dose (SD) group (N = 27), 2 double-standard doses on the same schedule in the double dose (DD) group (N = 29), or 3 standard doses on weeks 0, 4 and 12 in the booster dose (BD) group (N = 31). No safety concerns were identified, and injection site pain was the most commonly reported solicited adverse event (AE) in all groups (66.7%), with no meaningful differences between groups. The incidence of severe (Grade 3) AEs was low across groups and no serious AEs or AEs of special interest considered related to study vaccine were reported. Doubling the standard MVA-BN dose had no significant effect on induction of neutralizing antibodies, with 100% seroconversion and comparable GMTs at week 6 in the SD and DD groups (78.9 and 100.3, respectively). A booster dose significantly increased peak neutralizing titers in the BD group (GMT: 281.1), which remained elevated at 12 months (GMT: 45.3) compared to the SD (GMT: 6.2) and DD (GMT: 10.6) groups. However, based on the immune response previously reported for healthy participants, a third dose (booster) does not appear necessary, even for immunocompromised participants. Clinical Trial Registry Number: NCT02038881.

Washington University School of Medicine in St. Louis Case Study: A Process for Understanding and Addressing Bias in Clerkship Grading.

In 2018, in response to a news story featuring the Icahn School of Medicine's decision to eliminate its chapter of Alpha Omega Alpha (AOA) due to perceived racial inequities, students at Washington University School of Medicine in St. Louis (WUSM) brought similar concerns to leadership. WUSM leadership evaluated whether students' race, ethnicity, and gender were associated with their receipt of honors in the 6 core clerkships, key determinants of AOA selection. In preliminary analysis of the school's data, statistically significant racial and ethnic disparities were associated with receipt of honors in each clerkship. Leaders shared these findings with the WUSM community along with a clear message that such discrepancies are unacceptable to the school. An effort to further analyze what lay behind the findings as well as to identify steps to resolve the problem was launched. Using a quality improvement framework, data from focus groups and student surveys were analyzed and 2 overarching themes emerged. Students perceived that both assessment and the learning environment impacted racial/ethnic disparities in clerkship grades. In multivariable logistic regression models, shelf exam scores (a part of student assessment) were found to be associated with receipt of honors in each clerkship; in some (but not all) clerkships, shelf exam scores attenuated the effect of race/ethnicity on receipt of honors, so that when the shelf scores were added to the model, the race/ethnicity effect was no longer significant. This case study describes WUSM's process to understand and address bias in clerkship grading and AOA nomination so that other medical schools might benefit from what has been learned.

Importance of routine public health influenza surveillance: detection of an unusual W-shaped influenza morbidity curve.

Seasonal influenza causes excess morbidity and mortality at the extremes of age: It disproportionately affects the very young and the very old, typically resulting in "U"-shaped age-distributed curves. By means of a well-established public health department surveillance system using positive influenza tests submitted from sentinel sites, the authors generated annual influenza-specific morbidity curves over a 10-year period (1998-2008) for St. Louis County, Missouri. The authors detected an unusually high incidence of cases of medically attended test-positive influenza, particularly in young adults, during the 2007-2008 season, resulting in an unexpected "W"-shaped age-distributed morbidity curve that was distinctly unique in comparison with the prior 9 influenza seasons. Public health influenza surveillance programs are useful tools for detecting emerging epidemiologic trends that may have clinical importance.

Treatment of select open calcaneus fractures with reduction and internal fixation: an intermediate-term review.

BACKGROUND: Open calcaneal fractures are devastating, high-energy injuries frequently occurring in multiply-injured patients. Unsatisfactory outcomes with significant complications rates are frequently reported. Our purpose was to assess outcomes of delayed ORIF for open calcaneal fractures with medial hindfoot wounds and limited posterior facet comminution. MATERIALS AND METHODS: Following acute management of the open fractures, seven patients were determined to have stable medial hindfoot wounds and posterior facet comminution of three or fewer fracture fragments. The average age was 32.5 years. These patients were treated with operative management with a plate-and-screw construct using the extensile lateral approach. RAND-36 Item Health, AOFAS Ankle-Hindfoot Survey, and physical examinations were undertaken to access outcomes. RESULTS: All open calcaneal injuries were initially treated with irrigation and debridement, intravenous antibiotics, and plaster immobilization. Definitive fixation was performed at an average of 11.7 days. Six of seven patients were multiply injured. Prior to injury, five were employed on a full-time basis. Four returned to their original or a comparable job. The results of the RAND-36 Item Health Survey and the AOFAS Ankle-Hindfoot scores were 56.7 and 71, respectively. There were no postoperative infections. No patients required additional operative hindfoot procedures. Five continued to use tobacco products. None reported chronic narcotic usage. CONCLUSION: Aggressive treatment of select open calcaneal fractures with delayed ORIF produced satisfactory functional results. Most patients were able to return to gainful employment. There were no infections or wound complications.

Immunogenicity and safety of three consecutive production lots of the non replicating smallpox vaccine MVA: A randomised, double blind, placebo controlled phase III trial.

BACKGROUND: Modified Vaccinia Ankara (MVA) is a live, viral vaccine under advanced development as a non-replicating smallpox vaccine. A randomised, double-blind, placebo-controlled phase III clinical trial was conducted to demonstrate the humoral immunogenic equivalence of three consecutively manufactured MVA production lots, and to confirm the safety and tolerability of MVA focusing on cardiac readouts. METHODS: The trial was conducted at 34 sites in the US. Vaccinia-naïve adults aged 18-40 years were randomly allocated to one of four groups using a 1:1:1:1 randomization scheme. Subjects received either two MVA injections from three consecutive lots (Groups 1-3), or two placebo injections (Group 4), four weeks apart. Everyone except personnel involved in vaccine handling and administration was blinded to treatment. Safety assessment focused on cardiac monitoring throughout the trial. Vaccinia-specific antibody titers were measured using a Plaque Reduction Neutralization Test (PRNT) and an Enzyme-Linked Immunosorbent Assay (ELISA). The primary immunogenicity endpoint was Geometric Mean Titers (GMTs) after two MVA vaccinations measured by PRNT at trial visit 4. This trial is registered with ClinicalTrials.gov, number NCT01144637. RESULTS: Between March 2013 and May 2014, 4005 subjects were enrolled and received at least one injection of MVA (n = 3003) or placebo (n = 1002). The three MVA lots induced equivalent antibody titers two weeks after the second vaccination, with seroconversion rates of 99·8% (PRNT) and 99·7% (ELISA). Overall, 180 (6·0%) subjects receiving MVA and 29 (2·9%) subjects in the placebo group reported at least one unsolicited Adverse Event (AE) that was considered trial-related. Vaccination was well tolerated without significant safety concerns, particularly regarding cardiac assessment. CONCLUSIONS: The neutralizing and total antibody titers induced by each of the three lots were equivalent. No significant safety concerns emerged in this healthy trial population, especially regarding cardiac safety, thus confirming the excellent safety and tolerability profile of MVA. TRIAL REGISTRATION: ClinicalTrials.gov NCT01144637.

Clostridium difficile in the intensive care unit: epidemiology, costs, and colonization pressure.

OBJECTIVE: To evaluate the epidemiology, outcomes, and importance of Clostridium difficile colonization pressure (CCP) as a risk factor for C. difficile-associated disease (CDAD) acquisition in intensive care unit (ICU) patients. DESIGN: Secondary analysis of data from a 30-month retrospective cohort study. SETTING: A 19-bed medical ICU in a midwestern tertiary care referral center. PATIENTS: Consecutive sample of adult patients with a length of stay of 24 hours or more between July 1, 1997, and December 31, 1999. RESULTS: Seventy-six (4%) of 1,872 patients were identified with CDAD; 40 (53%) acquired CDAD in the ICU, for an incidence of 3.2 cases per 1,000 patient-days. Antimicrobial therapy, enteral feeding, mechanical ventilation, vancomycin-resistant enterococci (VRE) colonization or infection, and CCP (5.5 vs 2.0 CDAD case-days of exposure for patients with acquired CDAD vs no CDAD; P=.001) were associated with CDAD acquisition in the univariate analysis. Only VRE colonization or infection (45% of patients with acquired CDAD vs 16% of patients without CDAD; adjusted odds ratio, 2.76 [95% confidence interval, 1.36-5.59]) and a CCP of more than 30 case-days of exposure (20% with acquired CDAD vs 2% with no CDAD; adjusted odds ratio, 3.77 [95% confidence interval, 1.14-12.49]) remained statistically significant in the multivariable analysis. Lengths of stay (6.1 vs 3.0 days; P<.001 by univariate analysis) and ICU costs ($11,353 vs $6,028; P<.001 by univariate analysis) were higher for patients with any CDAD than for patients with no CDAD. CONCLUSIONS: In this nonoutbreak setting, the CCP was an independent risk factor for acquisition of CDAD in the ICU at the upper range of exposure duration. Having CDAD in the ICU was a marker of excess healthcare use.

Open hindfoot injuries.

Successful management of open talar and calcaneal injuries of the hindfoot is a formidable orthopaedic challenge. The soft-tissue disruption associated with these high-energy traumatic injuries adds to treatment complexity. Extensive fracture comminution and cartilage damage are often present with calcaneal fracture. Osteonecrosis is commonly associated with talar injury. Treatment may be divided into acute and reconstructive phases. Successful outcome is dependent on several variables--accurate fracture reduction, timing of intervention, prevention of infection, and meticulous soft-tissue handling. Anatomic fracture or joint reconstruction may not be possible. Joint stiffness and posttraumatic arthritis are common and may be debilitating. Complications, such as infection and osteonecrosis, also can be devastating. Long-term outcomes are frequently unsatisfactory. Chronic ambulatory dysfunction and persistent neurogenic pain may result despite appropriate management. With severe complex open fractures and extended soft-tissue injury, limb amputation may be the best treatment option.

Safety and immunogenicity of inactivated varicella-zoster virus vaccine in adults with hematologic malignancies receiving treatment with anti-CD20 monoclonal antibodies.

BACKGROUND: Immunocompromised patients can experience significant morbidity and occasional mortality from complications associated with herpes zoster (HZ), but live attenuated HZ vaccine is contraindicated for these patients. Inactivated zoster vaccine (ZVIN) is in development for prevention of HZ in immunocompromised patients. However, there are limited data in the literature regarding the effect of anti-CD20 monoclonal antibodies on vaccine-related cell-mediated immune response. This study evaluated safety and immunogenicity of ZVIN in patients with hematologic malignancies (HM) receiving anti-CD20 monoclonal antibodies (alone or in combination chemotherapy regimens) and not likely to undergo hematopoietic cell transplant (HCT) (n=80). METHODS: This was an open-label, single-arm, multicenter Phase I study (NCT01460719) of a 4-dose ZVIN regimen (∼30days between doses) in patients ⩾18years old. Blood samples were collected prior to dose 1 and 28days Postdose 4 to measure varicella zoster virus (VZV)-specific T-cell responses using interferon-γ enzyme-linked immunospot (IFN-γ ELISPOT). The primary hypothesis was that ZVIN would elicit significant VZV-specific immune responses at ∼28days Postdose 4, with a geometric fold rise (GMFR) >1.0. All vaccinated patients were evaluated for adverse events (AE) through 28days Postdose 4. RESULTS: ZVIN elicited a statistically significant VZV-specific immune response measured by IFN-γ ELISPOT at 28days Postdose 4 (GMFR=4.34 [90% CI:3.01, 6.24], p-value<0.001), meeting the pre-specified success criterion. Overall, 85% (68/80) of patients reported ⩾1 AE, 44% (35/80) reported ⩾1 injection-site AE, and 74% (59/80) reported ⩾1 systemic AE. The majority of systemic AEs were non-serious and considered unrelated to vaccination by the investigator. Frequencies of AEs did not increase with subsequent doses of vaccine. No recipient of ZVIN had rash polymerase chain reaction (PCR) positive for VZV vaccine strain. CONCLUSIONS: In adults with HM receiving anti-CD20 monoclonal antibodies, ZVIN was well-tolerated and elicited statistically significant VZV-specific T-cell responses ∼28days Postdose 4. CLINICALTRIALS.GOV identifier: NCT01460719.