Mary R Reichler1, Dana Bruden2, Harold Thomas3, Bobbie Rae Erickson4, Barbara Knust4, Nadia Duffy5, John Klena4, Thomas Hennessy2. 1. Division of Tuberculosis Elimination, National Center for HIV/AIDS, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA. 2. Division of Preparedness and Emerging Infections, National Center for Emerging and Zoonotic diseases, Centers for Disease Control and Prevention, Anchorage, Alaska, USA. 3. Directorate of Disease Prevention and Control, Ministry of Health and Sanitation, Freetown, Sierra Leone. 4. Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Diseases , Centers for Disease Control and Prevention, Atlanta, Georgia, USA. 5. Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Abstract
BACKGROUND: Identifying risk factors for household transmission of Ebola virus (EBOV) is important to guide preventive measures during Ebola outbreaks. METHODS: We enrolled all confirmed persons with EBOV disease who were the first case patient in a household from December 2014 to April 2015 in Freetown, Sierra Leone, and their household contacts. Index patients and contacts were interviewed, and contacts were followed up for 21 days to identify secondary cases. Epidemiologic data were linked to EBOV real-time reverse-transcription polymerase chain reaction cycle threshold (Ct) data from initial diagnostic specimens obtained from enrolled index case patients. RESULTS: Ct data were available for 106 (71%) of 150 enrolled index patients. Of the Ct results, 85 (80%) were from blood specimens from live patients and 21 (20%) from oral swab specimens from deceased patients. The median Ct values for blood and swab specimens were 21.0 and 24.0, respectively (P = .007). In multivariable analysis, a Ct value from blood specimens in the lowest quintile was an independent predictor of both increased risk of household transmission (P = .009) and higher secondary attack rate among household contacts (P = .03), after adjustment for epidemiologic factors. CONCLUSIONS: Our findings suggest the potential to use Ct values from acute EBOV diagnostic specimens for index patients as an early predictor of high-risk households and high-risk groups of contacts to help prioritize EBOV disease investigation and control efforts. Published by Oxford University Press for the Infectious Diseases Society of America 2019.
BACKGROUND: Identifying risk factors for household transmission of Ebola virus (EBOV) is important to guide preventive measures during Ebola outbreaks. METHODS: We enrolled all confirmed persons with EBOV disease who were the first case patient in a household from December 2014 to April 2015 in Freetown, Sierra Leone, and their household contacts. Index patients and contacts were interviewed, and contacts were followed up for 21 days to identify secondary cases. Epidemiologic data were linked to EBOV real-time reverse-transcription polymerase chain reaction cycle threshold (Ct) data from initial diagnostic specimens obtained from enrolled index case patients. RESULTS: Ct data were available for 106 (71%) of 150 enrolled index patients. Of the Ct results, 85 (80%) were from blood specimens from live patients and 21 (20%) from oral swab specimens from deceased patients. The median Ct values for blood and swab specimens were 21.0 and 24.0, respectively (P = .007). In multivariable analysis, a Ct value from blood specimens in the lowest quintile was an independent predictor of both increased risk of household transmission (P = .009) and higher secondary attack rate among household contacts (P = .03), after adjustment for epidemiologic factors. CONCLUSIONS: Our findings suggest the potential to use Ct values from acute EBOV diagnostic specimens for index patients as an early predictor of high-risk households and high-risk groups of contacts to help prioritize EBOV disease investigation and control efforts. Published by Oxford University Press for the Infectious Diseases Society of America 2019.
Authors: Nadezhda Duffy; Dana Bruden; Harold Thomas; Erin Nichols; Barbara Knust; Thomas Hennessy; Mary R Reichler Journal: Int J Epidemiol Date: 2022-10-13 Impact factor: 9.685
Authors: Andrew Fox-Lewis; Shivani Fox-Lewis; Jenna Beaumont; Dragana Drinković; Jay Harrower; Kevin Howe; Catherine Jackson; Fahimeh Rahnama; Blair Shilton; Helen Qiao; Kevin K Smith; Susan C Morpeth; Susan Taylor; Matthew Blakiston; Sally Roberts; Gary McAuliffe Journal: Pathology Date: 2021-03-20 Impact factor: 5.306