Risk Assessment and Management of COVID-19 Among Travelers Arriving at Designated U.S. Airports, January 17-September 13, 2020.

In January 2020, with support from the U.S. Department of Homeland Security (DHS), CDC instituted an enhanced entry risk assessment and management (screening) program for air passengers arriving from certain countries with widespread, sustained transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19). The objectives of the screening program were to reduce the importation of COVID-19 cases into the United States and slow subsequent spread within states. Screening aimed to identify travelers with COVID-19-like illness or who had a known exposure to a person with COVID-19 and separate them from others. Screening also aimed to inform all screened travelers about self-monitoring and other recommendations to prevent disease spread and obtain their contact information to share with public health authorities in destination states. CDC delegated postarrival management of crew members to airline occupational health programs by issuing joint guidance with the Federal Aviation Administration.* During January 17-September 13, 2020, a total of 766,044 travelers were screened, 298 (0.04%) of whom met criteria for public health assessment; 35 (0.005%) were tested for SARS-CoV-2, and nine (0.001%) had a positive test result. CDC shared contact information with states for approximately 68% of screened travelers because of data collection challenges and some states' opting out of receiving data. The low case detection rate of this resource-intensive program highlighted the need for fundamental change in the U.S. border health strategy. Because SARS-CoV-2 infection and transmission can occur in the absence of symptoms and because the symptoms of COVID-19 are nonspecific, symptom-based screening programs are ineffective for case detection. Since the screening program ended on September 14, 2020, efforts to reduce COVID-19 importation have focused on enhancing communications with travelers to promote recommended preventive measures, reinforcing mechanisms to refer overtly ill travelers to CDC, and enhancing public health response capacity at ports of entry. More efficient collection of contact information for international air passengers before arrival and real-time transfer of data to U.S. health departments would facilitate timely postarrival public health management, including contact tracing, when indicated. Incorporating health attestations, predeparture and postarrival testing, and a period of limited movement after higher-risk travel, might reduce risk for transmission during travel and translocation of SARS-CoV-2 between geographic areas and help guide more individualized postarrival recommendations.

Travel and Border Health Measures to Prevent the International Spread of Ebola.

During the 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa, CDC implemented travel and border health measures to prevent international spread of the disease, educate and protect travelers and communities, and minimize disruption of international travel and trade. CDC staff provided in-country technical assistance for exit screening in countries in West Africa with Ebola outbreaks, implemented an enhanced entry risk assessment and management program for travelers at U.S. ports of entry, and disseminated information and guidance for specific groups of travelers and relevant organizations. New and existing partnerships were crucial to the success of this response, including partnerships with international organizations, such as the World Health Organization, the International Organization for Migration, and nongovernment organizations, as well as domestic partnerships with the U.S. Department of Homeland Security and state and local health departments. Although difficult to assess, travel and border health measures might have helped control the epidemic's spread in West Africa by deterring or preventing travel by symptomatic or exposed persons and by educating travelers about protecting themselves. Enhanced entry risk assessment at U.S. airports facilitated management of travelers after arrival, including the recommended active monitoring. These measures also reassured airlines, shipping companies, port partners, and travelers that travel was safe and might have helped maintain continued flow of passenger traffic and resources needed for the response to the affected region. Travel and border health measures implemented in the countries with Ebola outbreaks laid the foundation for future reconstruction efforts related to borders and travel, including development of regional surveillance systems, cross-border coordination, and implementation of core capacities at designated official points of entry in accordance with the International Health Regulations (2005). New mechanisms developed during this response to target risk assessment and management of travelers arriving in the United States may enhance future public health responses. The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

US college and university student health screening requirements for tuberculosis and vaccine-preventable diseases, 2012.

OBJECTIVE: Colleges are at risk for communicable disease outbreaks because of the high degree of person-to-person interactions and relatively crowded dormitory settings. This report describes the US college student health screening requirements among US resident and international students for tuberculosis (TB) and vaccine-preventable diseases (VPDs) as they relate to the American College Health Association (ACHA) guidelines. Methods/Participants: In April 2012, US college health administrators (N = 2,858) were sent online surveys to assess their respective school's TB screening and immunization requirements. RESULTS: Surveys were completed by 308 (11%) schools. Most schools were aware of the ACHA immunization (78%) and TB screening (76%) guidelines. Schools reported having policies related to immunization screening (80.4%), immunization compliance (93%), TB screening (55%), and TB compliance (87%). CONCLUSION: Most colleges were following ACHA guidelines. However, there are opportunities for improvement to fully utilize the recommendations and prevent outbreaks of communicable diseases among students in colleges.

Airport exit and entry screening for Ebola--August-November 10, 2014.

In response to the largest recognized Ebola virus disease epidemic now occurring in West Africa, the governments of affected countries, CDC, the World Health Organization (WHO), and other international organizations have collaborated to implement strategies to control spread of the virus. One strategy recommended by WHO calls for countries with Ebola transmission to screen all persons exiting the country for "unexplained febrile illness consistent with potential Ebola infection." Exit screening at points of departure is intended to reduce the likelihood of international spread of the virus. To initiate this strategy, CDC, WHO, and other global partners were invited by the ministries of health of Guinea, Liberia, and Sierra Leone to assist them in developing and implementing exit screening procedures. Since the program began in August 2014, an estimated 80,000 travelers, of whom approximately 12,000 were en route to the United States, have departed by air from the three countries with Ebola transmission. Procedures were implemented to deny boarding to ill travelers and persons who reported a high risk for exposure to Ebola; no international air traveler from these countries has been reported as symptomatic with Ebola during travel since these procedures were implemented.

Impact of port of entry referrals on initiation of follow-up evaluations for immigrants with suspected tuberculosis: Illinois.

US-bound immigrants with suspected non-infectious TB are encouraged to be medically re-evaluated after arrival in the United States. We evaluated the Centers for Disease Control and Prevention's immigrant referral process, designed to facilitate timely post-arrival evaluations. Over 1,200 immigrants with suspected TB arriving during October 1, 2008-September 30, 2010 were identified. In 2011, differences in days to evaluation initiation were assessed by referral type using survival analysis and Cox proportional hazard models. Among those receiving any referral, median time to post-arrival evaluation was significantly lower compared with immigrants receiving no referral (16 vs. 69 days, respectively; p < 0.0001). After adjusting for the covariates, immigrants receiving any referral initiated follow-up at 4 times the rate (adjusted hazard ratio = 4.0; p < 0.0001) of those receiving no referral. Implementing a referral system at US ports of entry will improve timeliness and increase the proportion of immigrants initiating domestic evaluation.

Mass screening for fever in children: a comparison of 3 infrared thermal detection systems.

OBJECTIVES: Infrared thermal detection systems (ITDSs) have been used with limited success outside the United States to screen for fever during recent outbreaks of novel infectious diseases. Although ITDSs are fairly accurate in detecting fever in adults, there is little information about their utility in children. METHODS: In a pediatric emergency department, we compared temperatures of children (<18 years old) measured using 3 ITDSs (OptoTherm Thermoscreen, FLIR ThermoVision 360, and Thermofocus 0800H3) to standard, age-appropriate temperature measurements (confirmed fever defined as ≥38.0°C [oral or rectal], ≥37.0°C [axillary]). Measured temperatures were compared with parental reports of fever using descriptive, multivariate, and receiver operating characteristic analyses. RESULTS: Of 855 patients, 400 (46.8%) had parent-reported fever, and 306 (35.8%) had confirmed fever. At optimal fever thresholds, OptoTherm and FLIR had sensitivity (83.0% and 83.7%, respectively) approximately equal to parental report (83.9%) and greater than Thermofocus (76.8%), and specificity (86.3% and 85.7%) greater than parental report (70.8%) and Thermofocus (79.4%). Correlation coefficients between traditional thermometry and ITDSs were 0.78 (OptoTherm), 0.75 (FLIR), and 0.66 (Thermofocus). CONCLUSIONS: Compared with traditional thermometry, FLIR and OptoTherm were reasonably accurate in detecting fever in children and better predictors of fever than parental report. These findings suggest that ITDSs could be a useful noninvasive screening tool for fever in the pediatric age group.

Malaria prevention knowledge, attitudes, and practices (KAP) among international flying pilots and flight attendants of a US commercial airline.

BACKGROUND: In 2010, malaria caused approximately 216 million infections in people and 655,000 deaths. In the United States, imported malaria cases occur every year, primarily in returning travelers and immigrants from endemic countries. In 2010, five Plasmodium falciparum malaria cases occurred among crew members of one US commercial airline company (Airline A). This investigation aimed to assess the malaria prevention knowledge, attitudes, and practices (KAP) of Airline A crew members to provide information for potential interventions. METHODS: The web link to a self-administered on-line survey was distributed by internal company communications to Airline A pilots and flight attendants (FA) eligible for international travel. The survey collected demographic information as well as occupation, work history, and malaria prevention education. RESULTS: Of approximately 7,000 nonrandomly selected crew members, 220 FA and 217 pilots completed the survey (6%). Respondents correctly identified antimalarial medication (91% FA, 95% pilots) and insect repellents (96% FA, 96% pilots) as effective preventive measures. While in malaria-intense destinations, few FA and less than half of pilots always took antimalarial medication (4% FA, 40% pilots) yet many often spent greater than 30 minutes outdoors after sundown (71% FA, 66% pilots). Less than half in both groups always used insect repellents (46% FA, 47% pilots). Many respondents were unaware of how to get antimalarial medications (52% FA, 30% pilots) and were concerned about their side effects (61% FA, 31% pilots). CONCLUSION: Overall, FA and pilots demonstrated good knowledge of malaria prevention, but many performed risky activities while practicing only some recommended malaria preventive measures. Malaria prevention education should focus on advance notification if traveling to a malaria-endemic area, how to easily obtain antimalarial medications, and the importance of practicing all recommended preventive measures.

Comparison of 3 infrared thermal detection systems and self-report for mass fever screening.

Despite limited evidence regarding their utility, infrared thermal detection systems (ITDS) are increasingly being used for mass fever detection. We compared temperature measurements for 3 ITDS (FLIR ThermoVision A20M [FLIR Systems Inc., Boston, MA, USA], OptoTherm Thermoscreen [OptoTherm Thermal Imaging Systems and Infrared Cameras Inc., Sewickley, PA, USA], and Wahl Fever Alert Imager HSI2000S [Wahl Instruments Inc., Asheville, NC, USA]) with oral temperatures (≥ 100 °F = confirmed fever) and self-reported fever. Of 2,873 patients enrolled, 476 (16.6%) reported a fever, and 64 (2.2%) had a confirmed fever. Self-reported fever had a sensitivity of 75.0%, specificity 84.7%, and positive predictive value 10.1%. At optimal cutoff values for detecting fever, temperature measurements by OptoTherm and FLIR had greater sensitivity (91.0% and 90.0%, respectively) and specificity (86.0% and 80.0%, respectively) than did self-reports. Correlations between ITDS and oral temperatures were similar for OptoTherm (ρ = 0.43) and FLIR (ρ = 0.42) but significantly lower for Wahl (ρ = 0.14; p < 0.001). When compared with oral temperatures, 2 systems (OptoTherm and FLIR) were reasonably accurate for detecting fever and predicted fever better than self-reports.

Identifying Shiga toxin-producing Escherichia coli: results of a laboratory evaluation.

Laboratory procedures for identifying Escherichia coli O157 and other Shiga toxin-producing E. coli (STEC) strains vary considerably, causing concern that these infections may be underdiagnosed. E. coli O157 may be screened for by culture on sorbitol-containing selective media; however, no selective medium is available for isolation of non-O157 STEC. Shiga toxins may be detected using enzyme immunoassay or real-time polymerase chain reaction; however, the organism is not isolated for subsequent characterization. The Centers for Disease Control and Prevention (CDC) recommends using both routine bacterial culture on sorbitol-containing medium and an assay for Shiga toxins to identify STEC. An evaluation of laboratories revealed limited compliance with these recommendations. Enhancing laboratory procedures to comply with the CDC guidelines is essential for public health surveillance.