Ebola Update: a Reemerging Infectious Disease

Ebola Update: a Reemerging Infectious Disease

Ebola Update: a ReEmerging Infectious Disease Global-to-Local Info for Health Care Professionals October 2014 Robert Ball, MD MPH FACP Adjunct Professor: MUSC Dep’t. Public Health Sciences Adjunct Professor: MUSC Dep’t. Medicine, Division of Infectious Diseases Adjunct Professor, Department of Public Health: CofC many thanks to Eric Brenner, MD, et al for some slidesR. Ball, MD MPH FACP Global Perspective: Emerging Infectious Diseases (EIDs) “The microbe that felled one child in a distant continent yesterday can reach yours today and seed a global pandemic tomorrow.” HENCE, TRAVEL Hx IS IMPERATIVE ! -Dr. Joshua Lederberg (1925-2008), Nobel Laureate- Medicine: 1958 R. Ball, MD, MPH FACP R. Ball, MD, MPH FACP R. Ball, MD, MPH FACP ”Spanish Influenza” 1917-1919: type A, subtype H1N1 21st century concerns re: “bird flu” A-H5N1 R. Ball, MD, MPH Global Air Travel- 1 day, mid-2009 Thanks to Mike Schmidt, PhD- MUSC for this graph R. Ball, MD MPH FACP EIDs: HIV-AIDS: A Retrospective slide courtesy of Charles Bryan, MD, MACP, FRCP (retired Chair, Dep’t. Medicine, USC; Editor, J.SCMA: President American Osler Society, etc…) HIV-AIDS is THE prototype of an Emerging Infectious Disease becoming a pandemic Influenza and Coronavirus Virions Segmented ssRNA(- sense) genome, 13-14 kb ssRNA(+ sense) genome, 27-32 kb Nuclear + cytoplasmic Cytoplasmic replication. replication. 4+ mutations !!! Eg: SARS, MERS-CoV 2012… MERS: Middle East Respiratory Syndrome (Saudi Arabia global) Penttinen et al., Euro Surveill, online 9.26.2013 CDC. Emerging Infectious Diseases. June 2011 Eg, Nipah (75% CFR), Hendra (70-100% CFR, etc… R. Ball, MD, MPH Many mammals (eg, bats) may be long-term carriers of many viruses, whereas most primates seldom become long-term carriers. R. Ball, MD, MPH R. Ball, MD, MPH Outbreak: 1995 Film from Warner Brothers 1995 1995 Film Film ‘Outbreak’ Outbrea k 1995 Film Outbreak “Today’s science fiction is tomorrow’s science fact.” - Isaac Asimov (1920-1992) At the CDC, Dr. Ally Hextall finds that the 2011 Film: Contagion virus is a mix of genetic material from Gwyneth Paltrow Succumbing to the Mysterypig and bat viruses. Investigations into Killer Virus cures via treatment protocols or vaccines initially stall as scientists can't find a cell culture in which to grow the newly identified Meningoencephalitis Virus One (MEV-1). UCSF professor Dr. Ian Sussman violates orders from Cheever (relayed through Hextall) to destroy his samples and identifies a usable line of bat cells. Hextall then uses this breakthrough to begin to investigate possible vaccines. The virus turns out to spread via fomites with a basic reproductive number of two; that is, each patient infects two more patients on average — increasing to four after the virus mutates, with one in twelve of the population catching the virus, and a 25-30% mortality rate for Virus ‘Hybrid + Virus = MEV-1 those infected. www.vershatutorials.org/virus-classification-and-structure/ Structure of the Ebola Virus NEJM 5.7.2014 The glycoprotein spikes attach to numerous mammalian dendritic cells & macrophages, enter our cells, & multiply by the millions within 1-3 days! Time Magazine Cover October 13, 2014 Ebola mutations are frequent ~ to HIV & HCV & other RNA exotic viruses. Simple virus: only 6 structural proteins: 18,959 codons. Very fragile too. RAPID multiplication! - Richard Preston, author: The Hot Zone Robert Ball, MD MPH FACP 8.20.2014 R. Ball, MD, MPH FACP EM photo of the Ebola virus showing typical filovirus morphology Could this be a Current W. African Ebola strain filovirus is ~5-8% genetically mutated “treble clef” ?? from original Zaire (DRC) strain http://www.huffingtonpost.com/2014/08/17/ www.cdc.gov/vhf/ebola/resources/virus-ecology.html 1. Ebola Virus (EVO Disease= EVD) 2. Ebola Hemorrhagic Fever (EHF): complication 3.Other names… Mathematical view of disease propagation: The Reproductive Rate (R0) • R0 = Average no. of new infections resulting from each case • R0 < 1 outbreak will eventually die-out • R0 = 1 continuing “endemic” spread • R0 > 1 outbreak may progress to “epidemic” or even “pandemic” proportions0 Emerging Pathogen Transmission Scenarios • Multiple introductions risk of adaptation to R0>1 Chauchemez et al., Euro Surveillance 13 June 2013 Robert Ball, MD MPH FACP CDC. MMWR 10.3.14 Robert Ball, MD MPH FACP Ebola in West Africa: Spring – www.nytimes.com/interactive/2014 /07/31/world/africa/ebola-virus- Summer 2014 outbreak-qa.html Cases to date (through August 27, This showing to date: 2014) 1427 deaths & 2615 cases CFR = 1427 / 2615 = 55% CFR = 51% of lab+ cases. Many more cases exist! R. Ball, MD, MPH FACP “The west African Ebola epidemic is spiraling out of control” In 10.2014, Frieden ordered Epi response teams to every US hospital with an Ebola case. R. Ball, MD, MPH FACP R. Ball, MD, MPH FACP 8.20.2014 R. Ball, MD, MPH FACP R. Ball, MD, MPH FACP 8.20.2014 R. Ball, MD, MPH FACP 8.20.2014 R. Ball, MD, MPH FACP “As of 27 August 2014, the cumulative number of Ebola cases in the affected countries stands at more than 3000, with over 1400 deaths, making this the largest 28 August 2014 Ebola outbreak ever recorded, despite significant gaps in reporting Globally, as of 10.22.2014: in some intense transmission areas. > 10,000 known lab (+) cases An unprecedented number of health > prob. over 10-15 K suspected etc care workers have also been > 4800 known lab (+) dead (~50% CFR) infected and died due to this outbreak.” BUT CFR (mortality) rate is prob. MUCH US cases as of 10.24.2014: 9 HIGHER (~70%) per recent reports ! 1 died, 4 released, 4 under Tx Globally, as of 10.16.2014: # HCWs infected > 427 # HCWs died > 236 R. Ball, MD, MPH FACP Ebola Case Count - 1 (From CDC.GOV October 23, 2014) CFR (Case Fatality Rate) ~ 46-83% Ebola Case Count -2 (From CDC.GOV October 23, 2014) R. Ball, MD, MPH FACP R. Ball, MD, MPH FACP R. Ball, MD, MPH FACP Estimated range: R. Ball, MD, MPH FACP R. Ball, MD, MPH FACP R. Ball, MD, MPH FACP R. Ball, MD, MPH FACP R. Ball, MD, MPH FACP 9.23.2014 Primary source of info: www.cdc.gov/ebola CDC infographics for citizens Q: do people really read & understand these? OR….. 10.16.2014 CDC infographics for citizens Q: do people really read & understand these? OR….. 1st US Case & cases as of 10.22.2014, now = 9 • 1 Liberian-American- front line HCW, exposed & infected in Liberia, flew to US (Dallas 9.20.2014) w/ fatigue, then developed Sx 9.24.14 (fever, etc)- Texas Hosp. ED missed Dx 9.25, sent home on Anbx! He returned critically ill Sun. 9.28.14. Developed EHF 9.29, ventilated & dialysis… He died on 10.8.2014 with a DNR order in place. • Texas Pres. Hospital HCWs took all precautions (eg, PPE, etc) as CDC had recommended to date. • Nonetheless, 2 direct-care nurses, under quasi- quarantine, temp-taking, etc contracted Ebola within 2-3 weeks, tested +, on Tx (IVF, Ab’s+), isolated, doing OK… Robert Ball, MD MPH FACP Great news: 10.24.14 Nurse Nina Pham released from Tx/ quarantine, then met with Pres. Obama in Oval Office, & will soon be reunited with her dog Bentley (still in quarantine). Nurse Vinson soon to follow. Use of the statistical properties of the “normal distribution” to think through important public health issues relating to the incubation period for Ebola Virus Disease Oops! In any case data Might this suggest that from this study suggest “contacts” to Ebola cases ought that a certain small to be quarantined and observed proportion (e.g. ~2-4%) of for > 21 days!? For example for Ebola cases may have perhaps as much as 25 days just incubation periods longer to be safe!? than 21 days !! 34% 34% How to decide? (Actually ~2.5% in And on what each “tail” of the basis? curve. 14% 14% 4.3 d 2.5% 4.3 d 4.3 d 4.3 d 2.5% 4.1 d 8.4 d 12.7 d 17.0 d 21.3 d Chronology of the ‘Liberian Dallas Ebola Case’ Sunday Monday Tuesday Wednesday Thursday Friday Saturday Sept 14 15 16 17 18 19 20 Monrovia -> Brussels- > Washington DC- Arrival in Dallas >Dallas 21 22 23 24 (PECT) 25 (PECT) 26 (PECT) 27 (PECT) Initial hospital visit… Onset of symptoms sent home (!?) Oct 28 (PECT) 29 (1) 30 (2) 1 (3) 2 (4) 3 (5) 4 (6) Hospitalized and Media frenzy re "contacts being traced" ============> Dx made 5 (7) 6 (8) 7 (9) 8 (10) 9 (11) 10 (12) 11 (13) Patient dies 12 (14) 13 (15) 14 (16) 15 (17) 16 (18) 17 (19) 18 (20*) PECT = “Possible Ebola (N) = no. of days (#) =quarantine policy ~21 days ! Community Transmission” since last PECT Est quarantine time > 21 days, but ranges from 0.1% - 12% beyond 21 days Amber Vinson As of Thurs. 10.23.2014, none of Duncan’s community contacts have become ill, and all are now released from 21-day quarantine. Robert Ball, MD MPH FACP Recommendations similar to BSL 3: PPE with gloves, masks, gowns, & footwear, + decon. upon exit. Robert Ball, MD MPH FACP R. Ball, MD, MPH FACP 10.23.2014 (WHO): 2yoF from Guinea WHO as of 10.22.2014 Robert Ball, MD MPH FACP WHO as of 10.22.2014 Robert Ball, MD MPH FACP Ebola cases globally> W. Africa 10.23.2014 Source: New York Times, Thurs. 10.23.2014pm Robert Ball, MD MPH FACP Robert Ball, MD MPH FACP Ebola Update: Clinical Considerations Much info via CDC webinar Mon.

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