OBJECTIVE: To describe epidemiologic and genomic characteristics of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak in a large skilled nursing facility (SNF), and the strategies that controlled transmission. DESIGN, SETTING, AND PARTICIPANTS: Cohort study during March 22-May 4, 2020 of all staff and residents at a 780-bed SNF in San Francisco, California. METHODS: Contact tracing and symptom screening guided targeted testing of staff and residents; respiratory specimens were also collected through serial point prevalence surveys (PPS) in units with confirmed cases. Cases were confirmed by real-time reverse transcription-polymerase chain reaction testing for SARS-CoV-2; whole genome sequencing (WGS) characterized viral isolate lineages and relatedness. Infection prevention and control (IPC) interventions included restricting from work any staff who had close contact to a confirmed case; restricting movements between units; implementing surgical face masking facility-wide; and recommended PPE (isolation gown, gloves, N95 respirator and eye protection) for clinical interactions in units with confirmed cases. RESULTS: Of 725 staff and residents tested through targeted testing and serial PPS, twenty-one (3%) were SARS-CoV-2-positive; sixteen (76%) staff and 5 (24%) residents. Fifteen (71%) were linked to a single unit. Targeted testing identified 17 (81%) cases; PPS identified 4 (19%). Most (71%) cases were identified prior to IPC intervention. WGS was performed on SARS-CoV-2 isolates from four staff and four residents; five were of Santa Clara County lineage and the three others were distinct lineages. CONCLUSIONS: Early implementation of targeted testing, serial PPS, and multimodal IPC interventions limited SARS-CoV-2 transmission within the SNF.

BACKGROUND: Burkholderia cepacia complex (Bcc) has caused healthcare-associated outbreaks, often in association with contaminated products. The identification of 4 Bcc bloodstream infections in patients residing at a single skilled nursing facility (SNF) within 1 week led to an epidemiological investigation to identify additional cases and the outbreak source. METHODS: A case was initially defined via a blood culture yielding Bcc in a SNF resident receiving intravenous therapy after 1 August 2016. Multistate notifications were issued to identify additional cases. Public health authorities performed site visits at facilities with cases to conduct chart reviews and identify possible sources. Pulsed-field gel electrophoresis (PFGE) was performed on isolates from cases and suspect products. Facilities involved in manufacturing suspect products were inspected to assess possible root causes. RESULTS: An outbreak of 162 Bcc bloodstream infections across 59 nursing facilities in 5 states occurred during September 2016-January 2017. Isolates from patients and pre-filled saline flush syringes were closely related by PFGE, identifying contaminated flushes as the outbreak source and prompting a nationwide recall. Inspections of facilities at the saline flush manufacturer identified deficiencies that might have led to the failure to sterilize a specific case containing a partial lot of the product. CONCLUSIONS: Communication and coordination among key stakeholders, including healthcare facilities, public health authorities, and state and federal agencies, led to the rapid identification of an outbreak source and likely prevented many additional infections. Effective processes to ensure the sterilization of injectable products are essential to prevent similar outbreaks in the future.

Skilled nursing facilities (SNFs) are focal points of the coronavirus disease 2019 (COVID-19) pandemic, and asymptomatic infections with SARS-CoV-2, the virus that causes COVID-19, among SNF residents and health care personnel have been described (1-3). Repeated point prevalence surveys (serial testing of all residents and health care personnel at a health care facility irrespective of symptoms) have been used to identify asymptomatic infections and have reduced SARS-CoV-2 transmission during SNF outbreaks (1,3). During March 2020, the Detroit Health Department and area hospitals detected a sharp increase in COVID-19 diagnoses, hospitalizations, and associated deaths among SNF residents. The Detroit Health Department collaborated with local government, academic, and health care system partners and a CDC field team to rapidly expand SARS-CoV-2 testing and implement infection prevention and control (IPC) activities in all Detroit-area SNFs. During March 7-May 8, among 2,773 residents of 26 Detroit SNFs, 1,207 laboratory-confirmed cases of COVID-19 were identified during three periods: before (March 7-April 7) and after two point prevalence surveys (April 8-25 and April 30-May 8): the overall attack rate was 44%. Within 21 days of receiving their first positive test results, 446 (37%) of 1,207 COVID-19 patients were hospitalized, and 287 (24%) died. Among facilities participating in both surveys (n = 12), the percentage of positive test results declined from 35% to 18%. Repeated point prevalence surveys in SNFs identified asymptomatic COVID-19 cases, informed cohorting and IPC practices aimed at reducing transmission, and guided prioritization of health department resources for facilities experiencing high levels of SARS-CoV-2 transmission. With the increased availability of SARS-CoV-2 testing, repeated point prevalence surveys and enhanced and expanded IPC support should be standard tools for interrupting and preventing COVID-19 outbreaks in SNFs.

Insect saliva induces significant antibody responses associated with the intensity of exposure to bites and the risk of disease in humans. Several salivary biomarkers have been characterized to determine exposure intensity to Old World Anopheles mosquito species. However, new tools are needed to quantify the intensity of human exposure to Anopheles bites and understand the risk of malaria in low-transmission areas in the Americas. To address this need, we conducted proteomic and bioinformatic analyses of immunogenic candidate proteins present in the saliva of uninfected Anopheles albimanus from two separate colonies-one originating from Central America (STECLA strain) and one originating from South America (Cartagena strain). A ~65 kDa band was identified by IgG antibodies in serum samples from healthy volunteers living in a malaria endemic area in Colombia, and a total of five peptides were designed from the sequences of two immunogenic candidate proteins that were shared by both strains. ELISA-based testing of human IgG antibody levels against the peptides revealed that the transferrin-derived peptides, TRANS-P1, TRANS-P2 and a salivary peroxidase peptide (PEROX-P3) were able to distinguish between malaria-infected and uninfected groups. Interestingly, IgG antibody levels against PEROX-P3 were significantly lower in people that have never experienced malaria, suggesting that it may be a good marker for mosquito bite exposure in naive populations such as travelers and deployed military personnel. In addition, the strength of the differences in the IgG levels against the peptides varied according to location, suggesting that the peptides may able to detect differences in intensities of bite exposure according to the mosquito population density. Thus, the An. albimanus salivary peptides TRANS-P1, TRANS-P2, and PEROX-P3 are promising biomarkers that could be exploited in a quantitative immunoassay for determination of human-vector contact and calculation of disease risk.

Exophiala (Wangiella) dermatitidis is a dematiaceous fungus that can grow in yeast or mold forms and is typically found in decaying organic matter. It can cause central nervous system disease, particularly in immunocompromised patients, and has been implicated as a respiratory pathogen in cystic fibrosis patients [1,2]. It has also been identified as a colonizer in the gastrointestinal tract [3]. However, bloodstream infections with this organism are exceedingly rare.

On May 24, 2016, the New York City Department of Health and Mental Hygiene notified CDC of two cases of Exophiala dermatitidis bloodstream infections among patients with malignancies who had received care from a single physician at an outpatient oncology facility (clinic A). Review of January 1-May 31, 2016 microbiology records identified E. dermatitidis bloodstream infections in two additional patients who also had received care at clinic A. All four patients had implanted vascular access ports and had received intravenous (IV) medications, including a compounded IV flush solution containing saline, heparin, vancomycin, and ceftazidime, compounded and administered at clinic A.

The mcr-1 gene confers resistance to the polymyxins, including the antibiotic colistin, a medication of last resort for multidrug-resistant infections. The mcr-1 gene was first reported in 2015 in food, animal, and patient isolates from China and is notable for being the first plasmid-mediated colistin resistance mechanism to be identified. Plasmids can be transferred between bacteria, potentially spreading the resistance gene to other bacterial species. Since its discovery, the mcr-1 gene has been reported from Africa, Asia, Europe, South America, and North America, including the United States, where it has been identified in Escherichia coli isolated from three patients and from two intestinal samples from pigs. In July 2016, the Pathogen Detection System at the National Center for Biotechnology Information (Bethesda, Maryland) identified mcr-1 in the whole genome sequence of an E. coli isolate from a Connecticut patient; this is the fourth isolate from a U.S. patient to contain the mcr-1 gene.

On September 17, 2015, the Pennsylvania Department of Health (PADOH) notified CDC of a cluster of three potentially health care-associated mucormycete infections that occurred among solid organ transplant recipients during a 12-month period at hospital A. On September 18, hospital B reported that it had identified an additional transplant recipient with mucormycosis. Hospitals A and B are part of the same health care system and are connected by a pedestrian bridge. PADOH requested CDC's assistance with an on-site investigation, which started on September 22, to identify possible sources of infection and prevent additional infections.

Since November 2015, Puerto Rico has reported active mosquito-borne transmission of Zika virus (1). Because of the potential for Zika virus to be transmitted through transfusion of blood components, and because a high percentage of persons infected with Zika virus are asymptomatic (2), the Food and Drug Administration (FDA) recommended that blood collections cease in areas of the United States affected by active vector-borne transmission of Zika virus until laboratory screening of blood donations or pathogen reduction technology (PRT)* for treatment of blood components can be implemented (3). To inform efforts to maintain the safety and availability of the blood supply in Puerto Rico, CDC, in collaboration with the Puerto Rico Department of Health, conducted a rapid assessment of blood collection and use on the island. A total of 139,369 allogeneic red blood cell (RBC) units,(dagger) 45,243 platelet units, and 56,466 plasma units were collected in or imported to Puerto Rico during 2015, and 135,966 allogeneic RBC units, 13,526 therapeutic platelet units,( section sign) and 25,775 plasma units were transfused. Because of the potential for local Zika virus transmission in areas with a competent mosquito vector (4), other areas of the United States should develop plans to ensure local blood safety and adequacy. Blood collection organizations and public health agencies should collaborate to maintain the safety and availability of local blood supplies in accordance with FDA guidance.