Presentation on theme: "Viral Hemorrhagic Fevers"— Presentation transcript:
1Viral Hemorrhagic Fevers The Viral Hemorrhagic Fevers are a group of illnesses which are a diverse group of RNA viruses that present with common clinical characteristics known as the viral hemorrhagic fever syndrome. These illnesses range from a mild flu-like illness to endothelial damage resulting in increased vascular permeability and bleeding complications. This picture is an Electron micrograph of the Filovirus, Ebola
2ObjectivesDescribe the natural geographic distribution of VHF and scenarios suggestive of bioterrorismDescribe the clinical manifestations of VHF in generalList exposure classification of contact for cases of VHFDescribe infection control precautions for personnel caring for patients with VHFList therapeutic options for patients with VHF
3Case Presentation38 yo business man returned from West Africa via London, ill for 3 daysnew onset feverchillssevere sore throatdiarrheaback painPE: T103.6 BP 90/60, alertSkin with diffuse ecchymosis and a maculopapular rash on the extremitiesCase presentation of an actual VHF presentation Sept in New Jersey in a businessman originally from Liberia who had resided in the US for 5 years. During the 4 months prior to his hospitalization, the patient had been in West Africa where he commuted between Liberia and Sierra Lione, where he owned some farms. In August, a month prior to presentation, he developed symptoms as described above. He traveled via London back to Newark, NJ where he took a train to Trenton, NJ and sought medical care.MMWR 2004;53(38):
4Differential Diagnosis Fever in a travelerMalariaTyphoid feverOther Differential DiagnosesMeningococcemiaRickettsial infectionLeptospirosisAcute leukemiaIdiopathic or thrombotic thrombocytopenic purpura
5Hospital Course Hospital Day #4 Despite empiric antibiotics including antimalarials, pt develops acute respiratory distress syndrome (ARDS)Required intubation
6Differential Diagnosis Fever in a travelerMalariaTyphoid feverYellow feverLassa feverNow you expand your DDx in a traveler to include the viral hemorrhagic fevers in Africa, particularly West Africa.
7Hospital Course Hospital Day #4 Hospital Day #5 Despite empiric antibiotics including antimalarials, pt develops ARDSRequired intubationHospital Day #5Local and state health departments notifiedInvestigational new drug (IND) protocol to administer IV ribavirinPatient died before administration of any drug
8Diagnosis Clinical and post-mortem specimens sent to CDC Lassa virus confirmedSerum antigen detectionImmunohistochemical staining liver tissueVirus isolation in cell cultureRT-PCR sequencing of virus
9FAMILY/GEOGRAPHY AGENT CASE-FATALITY FiloviridaeSub-saharan AfricaEbolaMarburg50-75%25%ArenaviridaeWest Africa (Lassa)South America, California (Whitewater)Old World: LassaNew World: Junin,Machupo, Guanarito Sabia, Whitewater arroyoLassa:1-2% (up to 25% in hospitalized pts)30% for New WorldBunyaviridaeEgypt, YemenSW US (Hantavirus)Phlebovirus: Rift ValleyNairovirus: Crimean CongoHantavirus: Sin NombreRift Valley: <1% overall50% in hemorrhagicFlaviviridaeCentral AsiaYellow feverDengueOmskKyasanurYellow Fever: 5-7% overallThe Viral Hemorrhagic Fevers are comprised of a number of different diseases. All are single-stranded RNA viruses and enter the bloodstream through various routes (i.e. tick, mosquito, rodent bite vectors, mucous membrane exposure. Endothelial infection occurs which leads to thrombocytopenia and endothelial dysfunction which may result in disseminated intravascular coagulation (Ebola, Marburg, Rift Valley Fever, Crimean Congo Fever) and cytokine storm (Ebola and Marburg). Vascular permeability and disregulation can occur, leading to periorbital edema, hemoconcentration and flushing, respectively. Animal models of Ebola pathogenesis suggest that the virus leads to immunosuppression and apoptosis (self-destruction) of T-lymphocytes and natural killer cells. In this table the major families of VHF are listed along with the endemic region, the specific agents and average case fatality rates for the diseases listed. For more information see the Center for Infectious Disease Reasearch and Policy and Infectious Disease Society of America (CIDRAP/IDSA) summary document on VHF which can be found on the websites: oraccessed 2/4/05
10Epidemiology Incubation period Endemic regions 2 days to 3 weeks for most VHFLassa fever: 21 daysEndemic regionsSub-saharan AfricaLassa fever causes ,000 infections and 5,000 deaths each year20 imported cases reported worldwideHuman to human transmission has occuredSouth AmericaPictured is the Mastomys rodent, the natural host of Lassa fever virus.
11Why do VHFs make good Bioweapons? Disseminate through aerosolsLow infectious doseHigh morbidity and mortalityCause fear and panic in the publicNo effective vaccineAvailable and can be produced in large quantityResearch on weaponization has been conducted
13Eccyhmosis encompassing left upper extremity one week after onset of Crimean-Congo Hemorrhagic Fever.D. Pigott, Associate Professor Dept. of Emergency Medicine, University of Alabama, Birmingham
14Patients with Korean Hemorrhagic Fever caused by the Hantaan virus with the typical “sunburn flush” of the cheeks, chin, and base of the neck. Photograph courtesy of John Huggins, PhD. in article on emedicine by David C. Pigott, MD.
15Morbiliform exanthem of Dengue fever with islands of sparing characteristic. Photo from Duane Gubler, PhD.
16Ecchymoses complicating a case of Dengue hemorrhagic fever Ecchymoses complicating a case of Dengue hemorrhagic fever. Photo from Duane Gubler, PhD.
17Transmission Direct contact with blood/body fluids/cadavers Aerosol spray (droplet v. airborne)Sexual transmissionPercutaneousBite of infected tick or mosquitoPerson to person transmission is greatest in the late stages of the illness when the patient has vomiting, diarrhea, and severe hemorrhage. VHF infection has not been reported in people whose contact with an infected patient occurred only during the incubation period (i.e. before the patient became febrile; the incubation period ranges from 2 days to 3 weeks). MMWR 1995;44(25):
18Infection Control Lassa Fever in New Jersey Investigation: 5 high risk contacts (wife, kids, visitor)183 low risk contacts9 other family members139 HCW at hospital: 42 labworkers, 32 RN, 11 MD16 labworkers in Virginia and California19 passengers on flight from London to NewarkNo additional cases occurred
19Infection Control Risk Category Description Surveillance Casual ContactsRemote contact with index case (eg, stayed in same hotel)VHF not spread by casual contact, no special surveillanceClose ContactsMore than casual (eg, living with contact, caretaker, shook hands with contact)Place under surveillance once index case confirmedHigh-Risk ContactsMucous membrane contact (eg, kissing, or penetrating injury involving contact with index case’s blood such as needlestick)Place under surveillance as soon as consider diagnosis of VHF in index caseSurveillance should be continued for 3 weeks after the person’s last contact with the index case. If a fever > than 101°F and/or symptoms develop, the patient should be immediately placed in isolation and treated as a VHF patient.CDC Update: management of patients with suspected VHF-United States MMWR 1995;44:475-79
20VHF Personal Protective Equipment Airborne and Contact isolation for patients with respiratory symptomsN-95 or PAPR maskNegative pressure isolationGlovesGownFitted eye protection and shoe covers if going to be exposed to splash body fluidsDroplet and Contact isolation for patients without respiratory symptomsSurgical maskEnvironmental surfacesCleaned with hospital approved disinfectantLinen incinerated, autoclaved, double-bagged for washIsolation precautions will depend on the degree of illness and volume and location of blood loss. If a patient has respiratory symptoms with cough or aerosol generating procedures such as med nebs, or bronchoscopy are planned then use of airborne in addition to contact precautions are warranted. However, if a patient is not coughing than droplet and contact precautions are sufficient. PAPR is powered air-purifying respirator.
21Treatment Supportive care: Fluid and electrolyte management Hemodynamic monitoringVentilation and/or dialysis supportSteroids for adrenal crisisAnticoagulants, IM injections, ASA, NSAIDS are contraindicatedTreat secondary bacterial infections
22Treatment Manage severe bleeding complications Cryoprecipitate (concentrated clotting factors)PlateletsFresh Frozen PlasmaHeparin for DICRibavirin in vitro activity vs.Lassa feverNew World Hemorrhagic feversRift Valley FeverNo evidence to support use in Filovirus or Flavivirus infections
23Vaccination Argentine and Bolivian HF Yellow Fever PASSIVE IMMUNIZATIONTreat with convalescent serum containing neutralizing antibody or immune globulinYellow FeverACTIVE IMMUNIZATIONTravelers to Africa and South AmericaSeveral vaccines are under investigational new drugs including vaccine for Rift Valley Fever, Argentine HF, DengueP. Jahrling, Chapter 29, Medical Aspects of Clinical and Biological Warfare; p
24This completes the current presentation. End presentation and distribute activity survey.