Contact tracing performance during the Ebola epidemic in Liberia, 2014-2015.

BACKGROUND: During the Ebola virus disease (EVD) epidemic in Liberia, contact tracing was implemented to rapidly detect new cases and prevent further transmission. We describe the scope and characteristics of contact tracing in Liberia and assess its performance during the 2014-2015 EVD epidemic. METHODOLOGY/PRINCIPAL FINDINGS: We performed a retrospective descriptive analysis of data collection forms for contact tracing conducted in six counties during June 2014-July 2015. EVD case counts from situation reports in the same counties were used to assess contact tracing coverage and sensitivity. Contacts who presented with symptoms and/or died, and monitoring was stopped, were classified as "potential cases". Positive predictive value (PPV) was defined as the proportion of traced contacts who were identified as potential cases. Bivariate and multivariate logistic regression models were used to identify characteristics among potential cases. We analyzed 25,830 contact tracing records for contacts who had monitoring initiated or were last exposed between June 4, 2014 and July 13, 2015. Contact tracing was initiated for 26.7% of total EVD cases and detected 3.6% of all new cases during this period. Eighty-eight percent of contacts completed monitoring, and 334 contacts were identified as potential cases (PPV = 1.4%). Potential cases were more likely to be detected early in the outbreak; hail from rural areas; report multiple exposures and symptoms; have household contact or direct bodily or fluid contact; and report nausea, fever, or weakness compared to contacts who completed monitoring. CONCLUSIONS/SIGNIFICANCE: Contact tracing was a critical intervention in Liberia and represented one of the largest contact tracing efforts during an epidemic in history. While there were notable improvements in implementation over time, these data suggest there were limitations to its performance-particularly in urban districts and during peak transmission. Recommendations for improving performance include integrated surveillance, decentralized management of multidisciplinary teams, comprehensive protocols, and community-led strategies.

Salmonella enterica Serotype Newport Infections in the United States, 2004-2013: Increased Incidence Investigated Through Four Surveillance Systems.

Newport is the third most common Salmonella enterica serotype identified among the estimated 1.2 million human salmonellosis infections occurring annually in the United States. Risk factors for infection and food items implicated in outbreaks vary by antimicrobial resistance pattern. We conducted a descriptive analysis of data from four enteric disease surveillance systems capturing information on incidence, demographics, seasonality, geographic distribution, outbreaks, and antimicrobial resistance of Newport infections over a 10-year period from 2004 through 2013. Incidence increased through 2010, then declined to rates similar to those in the early years of the study. Incidence was highest in the South and among children <5 years old. Among isolates submitted for antimicrobial susceptibility testing, 88% were susceptible to all antimicrobials tested (pansusceptible) and 8% were resistant to at least seven agents, including ceftriaxone. Rates of pansusceptible isolates were also highest in the South and among young children, particularly in 2010. Pansusceptible strains of Newport have been associated with produce items and environmental sources, such as creek water and sediment. However, the role of environmental transmission of Newport in human illness is unclear. Efforts to reduce produce contamination through targeted legislation, as well as collaborative efforts to identify sources of contamination in agricultural regions, are underway.

Outbreak of influenza and rhinovirus co-circulation among unvaccinated recruits, U.S. Coast Guard Training Center Cape May, NJ, 24 July-21 August 2016.

Military and Coast Guard recruits are particularly susceptible to respiratory infections. Although seasonal influenza vaccinations are mandatory for recruits, the vaccine expires annually in June. On 29 July 2016, the U.S. Coast Guard Training Center Cape May, NJ, identified an increase in febrile respiratory illness (FRI) among recruits. During 24 July-21 August, a total of 115 recruits reported symptoms. A total of 74 recruits tested positive for respiratory infections: influenza A (H3) (n=34), rhinovirus (n=28), influenza/rhinovirus co-infection (n=11), and adenovirus/rhinovirus co-infection (n=1), while 41 recruits had no laboratory-confirmed specimen but were considered suspected cases. Only one recruit reported receiving the seasonal influenza vaccine within the previous 12 months. Influenza predominated during 24 July-6 August, whereas rhinovirus predominated during 7 August-20 August. Most (92.2%) cases were identified in four of 10 recruit companies; incidence rates were highest among recruits in weeks 2-4 of an 8-week training cycle. Key factors for outbreak control included rapid detection through routine FRI surveillance, quick decision-making and streamlined response by using a single chain of command, and employing both nonpharmaceutical and pharmaceutical interventions.