A person under investigation (PUI) is defined as a patient who presents with both clinical and epidemiological risk factors for a specific infectious disease. In the case of infectious diseases that present risks of transmission to healthcare workers (HCWs) and patients, the use of the identify-isolate-inform framework is essential to protect staff and patients and the delivery of safe and effective care. This includes early identification of PUIs, institution of appropriate transmission-based precautions including use of specific personal protective equipment (PPE) and isolation, and prompt notification of relevant personnel, including relevant experts and authorities.
Depending on the specific infection suspected, once appropriate infection control measures have been implemented, clinical evaluation of PUIs can vary in complexity. In the case of Ebola virus disease (EVD), the need for specialized PPE and training, well-developed procedures, and dedicated space can be extremely resource-intensive and costly for facilities. In addition, depending upon the need to reduce risks to other patients and HCWs, regular laboratory and imaging equipment may not be available (or available at the standard frequency or turnaround time) to support medical care. Lastly, diagnostic tests needed to confirm the diagnosis may not be available at the healthcare facility and may instead be accessible through public health authorities. This testing may take several days to confirm the diagnosis or rule out the presence of the suspected infection. Thus, the potential period of evaluation for a PUI can extend well beyond a typical clinic or emergency department (ED) visit. Thoughtful and coordinated planning efforts are required across the community and across the hospital to be able to adequately care for the PUI.
Person under investigation Case definition Diagnosis Laboratory investigation Clinical care HHCD Emerging pathogens Infection control
This is a preview of subscription content, log in to check access.
Cho SY, Kang JM, Ha YE, Park GE, Lee JY, Ko JH, et al. MERS-CoV outbreak following a single patient exposure in an emergency room in South Korea: an epidemiological outbreak study. Lancet (London, England). 2016;388(10048):994–1001.CrossRefGoogle Scholar
Borgundvaag B, Ovens H, Goldman B, Schull M, Rutledge T, Boutis K, et al. SARS outbreak in the greater Toronto area: the emergency department experience. CMAJ. 2004;171(11):1342–4.CrossRefPubMedPubMedCentralGoogle Scholar
Liu JW, Lu SN, Chen SS, Yang KD, Lin MC, Wu CC, et al. Epidemiologic study and containment of a nosocomial outbreak of severe acute respiratory syndrome in a medical center in Kaohsiung, Taiwan. Infect Control Hosp Epidemiol. 2006;27(5):466–72.CrossRefPubMedGoogle Scholar
Teleman MD, Boudville IC, Heng BH, Zhu D, Leo YS. Factors associated with transmission of severe acute respiratory syndrome among health-care workers in Singapore. Epidemiol Infect. 2004;132(5):797–803.CrossRefPubMedPubMedCentralGoogle Scholar
Chevalier MS, Chung W, Smith J, Weil LM, Hughes SM, Joyner SN, et al. Ebola virus disease cluster in the United States--Dallas County, Texas, 2014. MMWR Morb Mortal Wkly Rep. 2014;63(46):1087–8.PubMedPubMedCentralGoogle Scholar
Chung WM, Smith JC, Weil LM, Hughes SM, Joyner SN, Hall EM, et al. Active tracing and monitoring of contacts associated with the first cluster of Ebola in the United States. Ann Intern Med. 2015;163(3):164–73.CrossRefPubMedGoogle Scholar
Chea N, Perz J, Srinivasan A, Laufer A, et al. Identify, isolate, inform: background and considerations for Ebola virus disease preparedness in U.S. ambulatory care settings. Am J Infect Control. 2015;43(11):1244–5.CrossRefPubMedGoogle Scholar
Centers for Disease Control and Prevention. Key terms used in case classifications: Centers for Disease Control and Prevention; 2015 [updated December 17, 2015. Available from: https://wwwn.cdc.gov/nndss/terms.html.
Centers for Disease Control and Prevention. Clinical guidance on the identification and evaluation of possible SARS-CoV disease among persons presenting with community-acquired illness (version 2): Centers for Disease Control and Prevention; 2012 [updated July 7, 2012. Available from: https://www.cdc.gov/sars/clinical/guidance.html.
Centers for Disease Control and Prevention. Interim patient under investigation (PUI) guidance and case definitions: Centers for Disease Control and Prevention; 2016 [updated July 13, 2016. Available from: https://www.cdc.gov/coronavirus/mers/case-def.html.
Schneider E, Chommanard C, Rudd J, Whitaker B, Lowe L, Gerber SI. Evaluation of patients under investigation for MERS-CoV infection, United States, January 2013–October 2014. Emerg Infect Dis. 2015;21(7):1220–3.CrossRefPubMedPubMedCentralGoogle Scholar
Schwedhelm S, Msn RN, Swanhorst J, Bsn RN, Watson S, Bsn RN, et al. ED Ebola triage algorithm: a tool and process for compliance. J Emerg Nurs. 2015;41(2):165–9.CrossRefPubMedGoogle Scholar
Wadman MC, Schwedhelm SS, Watson S, Swanhorst J, Gibbs SG, Lowe JJ, et al. Emergency department processes for the evaluation and management of persons under investigation for Ebola virus disease. Ann Emerg Med. 2015;66(3):306–14.CrossRefPubMedGoogle Scholar
Le A, Biddinger P, Smith P, Herstein J, Levy D, Gibbs S, et al. A highly infectious disease care network within the United States healthcare system. Health Secur. 2017;15(3):282–7.CrossRefPubMedGoogle Scholar
Bogucki S, Isakov A. Patients under investigation for Ebola virus disease in the United States: hospital preparedness planning and alternate care facilities. Acad Emerg Med. 2015;22(5):600–4.CrossRefPubMedGoogle Scholar
Van Beneden CA, Pietz H, Kirkcaldy RD, Koonin LM, Uyeki TM, Oster AM, et al. Early identification and prevention of the spread of Ebola - United States. MMWR Suppl. 2016;65(3):75–84.PubMedGoogle Scholar
Karwowski MP, Meites E, Fullerton KE, Stroher U, Lowe L, Rayfield M, et al. Clinical inquiries regarding Ebola virus disease received by CDC–United States, July 9–November 15, 2014. MMWR Morb Mortal Wkly Rep. 2014;63(49):1175–9.PubMedPubMedCentralGoogle Scholar
Sugalski G, Murano T, Fox A, Rosania A. Development and use of mobile containment units for the evaluation and treatment of potential Ebola virus disease patients in a United States hospital. Acad Emerg Med. 2015;22(5):616–22.CrossRefPubMedGoogle Scholar
Jeon MH, Kim TH. Institutional preparedness to prevent future Middle East respiratory syndrome coronavirus-like outbreaks in Republic of Korea. Infect Chemother. 2016;48(2):75–80.CrossRefPubMedPubMedCentralGoogle Scholar
Fairley JK, Kozarsky PE, Kraft CS, Guarner J, Steinberg JP, Anderson E, et al. Ebola or not? Evaluating the ill traveler from Ebola-affected countries in West Africa. Open Forum Infect Dis. 2016;3(1):ofw005.CrossRefPubMedPubMedCentralGoogle Scholar
Davies HD, Byington CL, Committee on Infectious Diesease. Parental presence during treatment of Ebola or other highly consequential infection. Pediatrics. 2016;138(3):e20161891.CrossRefPubMedGoogle Scholar