OBJECTIVES: Historically, the most frequent cause of death reported to the Centers for Disease Control and Prevention (CDC) among travelers on conveyances has been cardiovascular disease, mirroring all-cause mortality in the US population. Infectious disease transmission, particularly during large-scale outbreaks, also poses a risk to travelers. To determine leading causes of death on conveyances and whether they were affected by the COVID-19 pandemic, we describe causes of death on conveyances reported to CDC from 2008 through 2022. METHODS: We queried CDC's Port Health Activity Reporting System for traveler deaths on, or immediately after disembarking from, an aircraft or maritime vessel or during land-border crossings reported to CDC from July 1, 2008, through December 31, 2022. We examined data on cause of death, age, travel mode, and traveler type (passenger vs crew). We also calculated crude annual mortality rates for each conveyance type. To assess factors associated with deaths due to infectious diseases (vs deaths due to noninfectious conditions), we performed logistic regression. RESULTS: During the analysis period, 2910 deaths on conveyances were reported. Across all conveyances, the most common causes were cardiovascular- or pulmonary-related conditions (2116 of 2910; 73%) for each year except 2020, when COVID-19 was the most common. Crew (vs passengers) had significant associations with death due to infectious causes (vs noninfectious causes; adjusted odds ratio = 2.12; 95% CI, 1.32-3.40). CONCLUSIONS: Travelers with cardiovascular- or pulmonary-related conditions should consult their health care providers prior to international travel. All travelers should check travel recommendations such as those currently available on CDC travel pages. Public health authorities should consider population-based mitigation measures aimed at transmission risk reduction to limit morbidity and mortality during infectious disease outbreaks.

Screening nonhuman primates (NHPs) for tuberculosis (TB) is important to protect the health of NHP colonies and people who interact with them. Screening is especially important for imported NHPs from countries where TB is prevalent and biosecurity practices may be lax. There are a variety of testing methods available for TB screening and diagnosis in NHPs; all have limitations, and their performance in different settings is incompletely characterized. The US Centers for Disease Control and Prevention (CDC) collects TB testing results as part of its regulatory oversight of NHP importation. We collated the results of tuberculin skin tests (TSTs), interferon-γ release assays (IGRAs), multiplexed fluorometric immunoassay (MFIA), Mycobacterium tuberculosis complex PCR, staining for acid-fast bacilli (AFB), and culture of bacteria from tissues for imported NHPs in CDC-mandated quarantine during fiscal years 2021 to 2024. We used these data to assess test performance and intertest agreement for the different tests used. Among 107 imported NHPs tested, TST and IGRA were the most common antemortem tests performed, but they agreed poorly with each other and with culture. AFB staining and PCR exhibited moderate agreement and high positive predictive values using culture as the gold standard. The most commonly affected tissues were lungs and tracheobronchial lymph nodes, regardless of the Mycobacterium sp. identified. Further research is needed to identify and validate additional methods for TB testing in NHPs, particularly for antemortem screening. Tissue acid-fast staining and PCR exhibited high positive predictive values and could be useful to inform policies and clinical decisions about colony management and occupational health while awaiting culture results.

Nonhuman primates (NHP) can become infected with the same species of Mycobacteria that cause human tuberculosis. All NHP imported into the United States are quarantined and screened for tuberculosis; no confirmed cases of tuberculosis were diagnosed among NHP during CDC-mandated quarantine during 2013-2020. In February 2023, an outbreak of tuberculosis caused by Mycobacterium orygis was detected in a group of 540 cynomolgus macaques (Macaca fascicularis) imported to the United States from Southeast Asia for research purposes. Although the initial exposure to M. orygis is believed to have occurred before the macaques arrived in the United States, infected macaques were first detected during CDC-mandated quarantine. CDC collaborated with the importer and U.S. Department of Agriculture's National Veterinary Services Laboratories in the investigation and public health response. A total of 26 macaques received positive test results for M. orygis by culture, but rigorous occupational safety protocols implemented during transport and at the quarantine facility prevented cases among caretakers in the United States. Although the zoonotic disease risk to the general population remains low, this outbreak underscores the importance of CDC's regulatory oversight of NHP importation and adherence to established biosafety protocols to protect the health of the United States research animal population and the persons who interact with them.