The Implementation of CDC COVID-19 Recommendations for Testing, Isolation, Quarantine and Movement at Emergency Intake Sites of Unaccompanied Children in the United States, April 1-May 31, 2021.

In March 2021, Emergency Intake Sites (EIS) were created to address capacity shortfalls during a surge of Unaccompanied Children at the Mexico-United States land border. The COVID-19 Zone Plan (ZP) was developed to decrease COVID-19 transmission. COVID-19 cumulative percent (%) positivity was analyzed to evaluate the impact of the ZP, venue type and bed capacity across EIS from April 1-May 31, 2021.

Effect of Predeparture Testing on Postarrival SARS-CoV-2-Positive Test Results Among International Travelers - CDC Traveler-Based Genomic Surveillance Program, Four U.S. Airports, March-September 2022.

Beginning December 6, 2021, all international air passengers boarding flights to the United States were required to show either a negative result from a SARS-CoV-2 viral test taken ≤1 day before departure or proof of recovery from COVID-19 within the preceding 90 days (1). As of June 12, 2022, predeparture testing was no longer mandatory but remained recommended by CDC (2,3). Various modeling studies have estimated that predeparture testing the day before or the day of air travel reduces transmission or importation of SARS-CoV-2 by 31%-76% (4-7).

Using spatial and population mobility models to inform outbreak response approaches in the Ebola affected area, Democratic Republic of the Congo, 2018-2020.

The Democratic Republic of the Congo's (DRC) 10 known Ebola virus disease (EVD) outbreak occurred between August 1, 2018 and June 25, 2020, and was the largest EVD outbreak in the country's history. During this outbreak, the DRC Ministry of Health initiated traveller health screening at points of control (POC, locations not on the border) and points of entry (POE) to minimize disease translocation via ground and air travel. We sought to develop a model-based approach that could be applied in future outbreaks to inform decisions for optimizing POC and POE placement, and allocation of resources more broadly, to mitigate the risk of disease translocation associated with ground-level population mobility.

Early Detection of Severe Acute Respiratory Syndrome Coronavirus 2 Variants Using Traveler-based Genomic Surveillance at 4 US Airports, September 2021-January 2022.

We enrolled arriving international air travelers in a severe acute respiratory syndrome coronavirus 2 genomic surveillance program. We used molecular testing of pooled nasal swabs and sequenced positive samples for sublineage. Traveler-based surveillance provided early-warning variant detection, reporting the first US Omicron BA.

Public Health Actions to Control Measles Among Afghan Evacuees During Operation Allies Welcome - United States, September-November 2021.

On August 29, 2021, the United States government oversaw the emergent establishment of Operation Allies Welcome (OAW), led by the U.S. Department of Homeland Security (DHS) and implemented by the U.

Multidrug-Resistant Tuberculosis in U.S.-Bound Immigrants and Refugees.

Approximately two-thirds of new cases of tuberculosis (TB) in the United States are among non-U.S.-born persons.

Cruise Ship Travel in the Era of Coronavirus Disease 2019 (COVID-19): A Summary of Outbreaks and a Model of Public Health Interventions.

Background: Cruise travel contributed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission when there were relatively few cases in the United States. By 14 March 2020, the Centers for Disease Control and Prevention (CDC) issued a No Sail Order suspending US cruise operations; the last US passenger ship docked on 16 April.

Methods: We analyzed SARS-CoV-2 outbreaks on cruises in US waters or carrying US citizens and used regression models to compare voyage characteristics.

Reducing travel-related SARS-CoV-2 transmission with layered mitigation measures: symptom monitoring, quarantine, and testing.

Background: Balancing the control of SARS-CoV-2 transmission with the resumption of travel is a global priority. Current recommendations include mitigation measures before, during, and after travel. Pre- and post-travel strategies including symptom monitoring, antigen or nucleic acid amplification testing, and quarantine can be combined in multiple ways considering different trade-offs in feasibility, adherence, effectiveness, cost, and adverse consequences.

Use of US Public Health Travel Restrictions during COVID-19 Outbreak on Diamond Princess Ship, Japan, February-April 2020.

Public health travel restrictions (PHTR) are crucial measures during communicable disease outbreaks to prevent transmission during commercial airline travel and mitigate cross-border importation and spread. We evaluated PHTR implementation for US citizens on the Diamond Princess during its coronavirus disease (COVID-19) outbreak in Japan in February 2020 to explore how PHTR reduced importation of COVID-19 to the United States during the early phase of disease containment. Using PHTR required substantial collaboration among the US Centers for Disease Control and Prevention, other US government agencies, the cruise line, and public health authorities in Japan.

Modelling airport catchment areas to anticipate the spread of infectious diseases across land and air travel.

Air travel is an increasingly important conduit for the worldwide spread of infectious diseases. However, methods to identify which airports an individual may use to initiate travel, or where an individual may travel to upon arrival at an airport is not well studied. This knowledge gap can be addressed by estimating airport catchment areas: the geographic extent from which the airport derives most of its patronage.

Cost effectiveness analysis of implementing tuberculosis screening among applicants for non-immigrant U.S. work visas.

Background: While persons who receive immigrant and refugee visas are screened for active tuberculosis before admission into the United States, nonimmigrant visa applicants (NIVs) are not routinely screened and may enter the United States with infectious tuberculosis.

Objectives: We evaluated the costs and benefits of expanding pre-departure tuberculosis screening requirements to a subset of NIVs who arrive from a moderate (Mexico) or high (India) incidence tuberculosis country with temporary work visas.

Methods: We developed a decision tree model to evaluate the program costs and estimate the numbers of active tuberculosis cases that may be diagnosed in the United States in two scenarios: 1) "Screening": screening and treatment for tuberculosis among NIVs in their home country with recommended U.

An immunization program for US-bound refugees: Development, challenges, and opportunities 2012-present.

Background: US-bound refugees undergo required health assessments overseas to identify and treat communicable diseases of public health significance-such as pulmonary tuberculosis-before migration. Immunizations are not required, leaving refugees at risk for vaccine-preventable diseases. In response, the US Centers for Disease Control and Prevention and the US Department of State developed and co-funded a global immunization program for US-bound refugees, implemented in 2012 in collaboration with the International Organization for Migration.

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).

Coronavirus Disease 2019 (COVID-19) in Americans Aboard the Diamond Princess Cruise Ship.

Background: The Diamond Princess cruise ship was the site of a large outbreak of coronavirus disease 2019 (COVID-19). Of 437 Americans and their travel companions on the ship, 114 (26%) tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods: We interviewed 229 American passengers and crew after disembarkation following a ship-based quarantine to identify risk factors for infection and characterize transmission onboard the ship.

Tuberculosis among Newly Arrived Immigrants and Refugees in the United States.

U.S. health departments routinely conduct post-arrival evaluation of immigrants and refugees at risk for tuberculosis (TB), but this important intervention has not been thoroughly studied.

The Check and Report Ebola (CARE+) Program to Monitor Travelers for Ebola After Arrival to the United States, 2014-2016.

The 2014-2016 Ebola epidemic in West Africa influenced how public health officials considered migration and emerging infectious diseases. Responding to the public's concerns, the US government introduced enhanced entry screening and post-arrival monitoring by public health authorities to reduce the risk of importation and domestic transmission of Ebola while continuing to allow travel from West Africa. This case study describes a new initiative, the Check and Report Ebola (CARE+) program that engaged travelers arriving to the United States from countries with Ebola outbreaks.

Immigrant and Refugee Health: A Centers for Disease Control and Prevention Perspective on Protecting the Health and Health Security of Individuals and Communities During Planned Migrations.

Migration and forced displacement are at record levels in today's geopolitical environment; ensuring the health of migrating populations and the health security of asylum and receiving countries is critically important. Overseas screening, treatment, and vaccination during planned migration to the United States represents one successful model. These strategies have improved tuberculosis detection and treatment, reducing rates in the United States; decreased transmission and importation of vaccine-preventable diseases; prevented morbidity and mortality from parasitic diseases among refugees; and saved health costs.

Expanding travel medicine in the 21st century to address the health needs of the world's migrants.

The body of knowledge needed to effectively practice travel medicine has expanded since the 1990s, as migrants begin to comprise an increasing proportion of the world's population. We describe the unique needs of migrants and provide resources available to migration health practitioners. As the number of the world's migrants grows, collaboration across disciplines is key to achieving high-quality migration health practices.

International travel between global urban centres vulnerable to yellow fever transmission.

Objective: To examine the potential for international travel to spread yellow fever virus to cities around the world.

Methods: We obtained data on the international flight itineraries of travellers who departed yellow fever-endemic areas of the world in 2016 for cities either where yellow fever was endemic or which were suitable for viral transmission. Using a global ecological model of dengue virus transmission, we predicted the suitability of cities in non-endemic areas for yellow fever transmission.

Fatal Yellow Fever in Travelers to Brazil, 2018.

Yellow fever virus is a mosquito-borne flavivirus that causes yellow fever, an acute infectious disease that occurs in South America and sub-Saharan Africa. Most patients with yellow fever are asymptomatic, but among the 15% who develop severe illness, the case fatality rate is 20%-60%. Effective live-attenuated virus vaccines are available that protect against yellow fever (1).