The following article was submitted today for publication. Pitfalls in Screening for Ebola Virus Disease: The Variable Febrile and Human Subjective Response Author information: Ricketson, RA Hale Omanao Clinical and Biomedical Research Wichita, Kansas Email: robertperezmd@gmail Date of submission November 12, 2014 The purpose of screening is to contain further transmission of the disease. There is no screening checkbox for “not feeling right”. Subjective fever. Always a good topic as to what constitutes fever. We all remember the days when “normal” was 98.6 degrees F. Now, with digital read outs, Harrison’s textbook of internal medicine defines a fever as’ “a morning oral temperature of >37.2 °C (>98.9 °F) or an afternoon oral temperature of >37.7 °C (>99.9 °F) while the normal daily temperature variation is typically 0.5 °C (0.9 °F).” [10, 11,12] Additionally, so we are all on the same page, we would really like to have it as close to the “core body temperature” as possible but, in reality, most of us don’t want an esophageal probe every time we feel uneasy, so we do need another way that best approximates our own, individual core body temperature. Only you know what that is. Also the manner in which it is measured and observed by another is critical in its accuracy. A rectal thermometer is the best, then oral (mouth closed!), temporal artery (not across the forehead, not a strip), then tympanic in that order. A lot of variability. Because of that, and my soap-box statement is I am weary of “check-box” medical history taking, a blanket check box that specifies a single number to fit every single individual just does not work in every situation [12] Image 1. Clinical course of single patient found to have been infected by the Tai Forest Ebolavirus (TAFV). His temperature varies during the viremia stage. [2] For an example, consider the following general scenario of infection. On day 1, you are infected by an Ebolavirus by whatever cause. The virus then passes into human tissue. It then must specifically recognize a receptor on a cell (dendritic cell; macrophage) and attaches itself to that specific receptor on that specific cell to interact in essentially a key and lock formation. Not a random event as there are many folds in the viral glycoprotein (GP spike much smaller) that must bind with and interact with the 3d structure of its receptor (NP1). Structure of the protein is the most important. The initial virus then injects it’s RNA and, to greatly simplify the rest, makes several viral proteins after it converts it’s antisense (“backward”), single strand, RNA from 3′ -> 5′ to 5′-> 3′ . It then also must make multiple copies of its original antisense genome, reassemble the virus together and then “bud” along with taking part of the host cell to form it’s envelope. The person it infects reacts to this invasion by the production of cytokines, resulting in a fever (febrile response). This obviously is not “abrupt” and this prodromal phase where symptoms begin gradually before the full manifestation of the disease occurs, can be where inadvertent transmission can occur. People then take Tylenol, Aspirin, Ibuprofen, etc, drink water, pass it if as anxiety, and walk on. The febrile response is masked by exogenous antiinflammatories. Image 2. Febrile response of experimentally infected Rhesus Macaques via the aerosol route. [8] Denial of disease is big, especially when it can be fatal [13, 14]. We have all observed patients with cancer deny it until it’s metastasized. Human behavior cannot fit in a check box nor does It respond to rules, human declared regulations, and legislations. Anosognosia. A rise in temperature from the individual normal to the elevated stage (fever) and maintained through the viruses life cycle [1-9] Anywhere on the elevation can be contagious. It just so happens that in EVD, that rise is quick. There is still the pre-prodrome and prodromal stage of fever, headache, myalgia, and malaise that really could be anything. Throw in denial and, well, I think we see the consequences [14]. References 1. Basic Clinical and Laboratory Features of Filoviral Hemorrhagic Fever Mark G. Kortepeter, Daniel G. Bausch and Mike Brap 2. Formenty P, Hatz C, Le Guenno B, Stoll A, Rogenmoser P, Widmer A. Human infection due to Ebola virus, subtype Cote d’Ivoire: clinical and biologic presentation. J Infect Dis 1999;179 Suppl 1:S48-53. 3. Emond RT, Evans B, Bowen ET, Lloyd G. A case of Ebola virus infection. Br Med J 1977;2:541-4. 4. Gear JS, Cassel GA, Gear AJ, et al. Outbreak of Marburg virus disease in Johannesburg. Br Med J 1975;4:489- 5. Stille W, Boehle E. Clinical course and prognosis of Marburg virus (“green monkey”) disease. In: Martini GA, Siegert R, editors. Marburg virus disease. New York: Springer Verlag; 1971. p. 10-8. 6. Towner JS, Rollin PE, Bausch DG, et al. Rapid diagnosis of Ebola hemorrhagic fever by reverse transcription-PCR in an outbreak setting and assessment of patient viral load as a predictor of outcome. J Virol 2004;78:4330-41. 7. Human asymptomatic Ebola infection and strong inflammatory response. Leroy EM, Baize S, Volchkov VE, Fisher-Hoch SP, Georges-Courbot MC, Lansoud-Soukate J, Capron M, Debré P, McCormick JB, Georges AJ; Lancet. 2000 Jun 24;355(9222):2210-5 8. Lethal experimental infections of rhesus monkeys by aerosolized Ebola virus. E. Johnson, N. Jaax, J. White, and P. Jahrling; Int J Exp Pathol. Aug 1995; 76(4): 227–236. 9. Symptomless infection with Ebola virus.; Baxter AG; Lancet. 2000 Jun 24;355(9222):2178 10. Fever and Hyperthermia. Harrisons Textbook of Internal Medicine. monroe-harrison-internalmedicine.blogspot/2011/08/fever-and-hyperthermia.html 11. Harrisons Principles of Internal Medicine, 18e; Chapter 16 Fever and Hyperthermia. Dinarello CA; Dan L. Longo, Editor, Anthony S. Fauci, Editor, Dennis L. Kasper, Editor, Stephen L. Hauser, Editor, J. Larry Jameson, Editor, Joseph Loscalzo 12. Validity of Devices that Assess Body Temperature During Indoor Exercise in the Heat; Matthew S Ganio, MS, Christopher M Brown, MA ATC, [...], and Carl M Maresh, PhD FACSM; J Athl Train. 2009 Mar-Apr; 44(2): 124–135. 13. Immigration Policies and Issues on Health-Related Grounds for Exclusion Ruth Ellen Wasem, Specialist in Immigration Policy August 13, 2014 14. Patients denial of disease may pose difficulty for achieving informed consent; Gavin AT; BMJ 2002;324:974
Posted on: Wed, 12 Nov 2014 17:44:01 +0000
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