Genomic epidemiology reveals multiple introductions of Zika virus into the United States.

Zika virus (ZIKV) is causing an unprecedented epidemic linked to severe congenital abnormalities. In July 2016, mosquito-borne ZIKV transmission was reported in the continental United States; since then, hundreds of locally acquired infections have been reported in Florida. To gain insights into the timing, source, and likely route(s) of ZIKV introduction, we tracked the virus from its first detection in Florida by sequencing ZIKV genomes from infected patients and Aedes aegypti mosquitoes. We show that at least 4 introductions, but potentially as many as 40, contributed to the outbreak in Florida and that local transmission is likely to have started in the spring of 2016-several months before its initial detection. By analysing surveillance and genetic data, we show that ZIKV moved among transmission zones in Miami. Our analyses show that most introductions were linked to the Caribbean, a finding corroborated by the high incidence rates and traffic volumes from the region into the Miami area. Our study provides an understanding of how ZIKV initiates transmission in new regions.

Multicenter Evaluation of Ceftolozane/Tazobactam for Serious Infections Caused by Carbapenem-Resistant Pseudomonas aeruginosa.

A multicenter, retrospective study of patients infected with carbapenem-resistant Pseudomonas aeruginosa who were treated with ceftolozane/tazobactam was performed. Among 35 patients, pneumonia was the most common indication and treatment was successful in 26 (74%). Treatment failure was observed in all cases where isolates demonstrated ceftolozane-tazobactam minimum inhibitory concentrations ≥8 µg/mL.

Proactive risk stratification and low-risk penicillin allergy delabeling by an antimicrobial stewardship pharmacist.

Penicillin (PCN) allergy delabeling is an important component of antimicrobial stewardship; however, widespread implementation has lagged. We found that most patients had low-risk PCN allergy histories eligible for delabeling without skin testing. Pharmacist-led risk stratification and drug challenge expanded access to delabeling independently from an Allergy/Immunology service.

Clostridium difficile Bacteremia as a Rare Presentation of Polymicrobial Pyogenic Liver Abscesses and Its Management Challenges.

Extracolonic manifestations of Clostridium difficile have been rarely reported. We herein report a case of a 60-year-old immunocompetent man presenting with fever, nausea, abdominal pain, and loose stools for 2 weeks. Triple-phase liver computed tomography demonstrated pyogenic liver abscesses and portal pylephlebitis. Blood cultures grew C. difficile and Bacteroides fragilis, and liver abscess cultures grew Proteus mirabilis, Escherichia coli, and the viridans group Streptococci. Antibiotics coverage was selected to direct at all identified organisms. This demonstrates an unusual case of C. difficile bacteremia in a patient with polymicrobial pyogenic liver abscesses and pylephlebitis.

Granulomatous amoebic encephalitis caused by Acanthamoeba in a patient with AIDS: a challenging diagnosis.

INTRODUCTION: Acanthamoeba spp. is a ubiquitous free-living amoeba that causes human infections affecting predominantly the cornea and central nervous system. The diagnosis and treatment of Acanthamoeba encephalitis is very challenging. CASE SUMMARY: A 53-year-old male with HIV/AIDS was admitted for altered mental status and fever. On initial examination, he had left hemianopia with left-sided weakness and numbness. MRI revealed an inflammatory and enhancing parenchymal mass associated with leptomeningeal enhancement in the occipitoparietal lobe containing multiple punctate hemorrhages. He was treated with empiric antibiotics for presumptive toxoplasmosis, brain abscess, fungal infection and tuberculosis with an unremarkable lymphoma work up. Initial brain biopsy studies were unremarkable except for non-specific granulomas and adjacent necrotic tissue. The patient passed away 2.5 months after initial presentation with no diagnosis. Post-mortem testing by the Centers for Disease Control and Prevention (CDC) confirmed the diagnosis of granulomatous amoebic encephalitis (GAE) by visualization with immunohistochemistry staining and PCR. Recovery is rare from GAE likely due to delay in diagnosis. CONCLUSIONS: This case illustrates the importance of including GAE into the differential diagnosis of brain mass. We advocate early molecular testing of tissue specimen by the CDC to achieve an appropriate diagnosis, and a multidisciplinary approach for the management of this condition.

Development of a Standardized Data Collection Tool for Evaluation and Management of Coronavirus Disease 2019.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 ) is responsible for coronavirus disease 2019 (COVID-19), a disease that had not been previously described and for which clinicians need to rapidly adapt their daily practice. The novelty of SARS-CoV-2 produced significant gaps in harmonization of definitions, data collection, and outcome reporting to identify patients who would benefit from potential interventions. METHODS: We describe a multicenter collaboration to develop a comprehensive data collection tool for the evaluation and management of COVID-19 in hospitalized patients. The proposed tool was developed by a multidisciplinary working group of infectious disease physicians, intensivists, and infectious diseases/antimicrobial stewardship pharmacists. The working group regularly reviewed literature to select important patient characteristics, diagnostics, and outcomes for inclusion. The data collection tool consisted of spreadsheets developed to collect data from the electronic medical record and track the clinical course after treatments. RESULTS: Data collection focused on demographics and exposure epidemiology, prior medical history and medications, signs and symptoms, diagnostic test results, interventions, clinical outcomes, and complications. During the pilot validation phase, there was <10% missing data for most domains and components. Team members noted improved efficiency and decision making by using the tool during interdisciplinary rounds. CONCLUSIONS: We present the development of a COVID-19 data collection tool and propose its use to effectively assemble harmonized data of hospitalized individuals with COVID-19. This tool can be used by clinicians, researchers, and quality improvement healthcare teams. It has the potential to facilitate interdisciplinary rounds, provide comparisons across different hospitalized populations, and adapt to emerging challenges posed by the pandemic.

Occupational Exposure to the Ugandan Research Strain (MR766) of Zika Virus.

A laboratory worker suffered an accidental needle-stick resulting in an exposure to the Ugandan strain (MR766) of Zika virus, which has rarely been studied in humans. We report the clinical presentation and outcomes, molecular and serological diagnostic results, and antibody response.

Effect of class-specific therapy interruption on persistence of HIV type 1 antiretroviral resistance.

Interruption of all antiretroviral therapy for HIV-1 infection when therapy is failing and antiretroviral resistance has emerged is frequently associated with the disappearance of detectable resistance-associated protease and reverse transcriptase substitutions. However, the effect that discontinuation of treatment with a particular antiretroviral class has on resistance to that class when other antiretroviral therapy is continued is unknown. We investigated differences in detectable genotypic resistance to protease inhibitors (PI) and non-nucleoside reverse transcriptase inhibitors (NNRTI) among two populations: patients undergoing testing at the moment class-specific treatment failed (Group 1) and patients undergoing testing for varying periods after class-specific treatment failed and was discontinued but therapy with other antiretroviral classes continued with incomplete viral suppression (Group 2). We found that the prevalence of detectable resistance to the PI and NNRTI classes was similar in both groups despite the absence of class-specific selective pressure for lengthy periods of time in Group 2. We hypothesize that this finding may be due to nonspecific selective pressure (i.e., to nucleoside reverse transcriptase inhibitors) selecting out PI- and, to a lesser extent, NNRTI-resistant viral variants.

Differences in the frequency of resistance to antiretroviral drug classes among human immunodeficiency virus type 1 clinical isolates.

Genotypic resistance to all antiretroviral classes was widespread among human immunodeficiency virus type 1 isolates failing therapy. Resistance to nonnucleoside reverse transcriptase inhibitors was found most frequently and resistance to protease inhibitors was found least frequently, most likely due to differences in the number of enzymatic amino acid substitutions leading to resistance to each particular drug class.