Viral Haemorrhagic Fevers Images .

Viral Haemorrhagic Viral Haemorrhagic FeversFevers

Images www.google/images.co.za

No vaccine for killer virus


S Africa fear over killer disease More than 100 people in South Africa are under medical observation after coming into contact with people who died from suspected haemorrhagic fever.


Viral Haemorrhagic FeversViral Haemorrhagic Fevers

Group of febrile illnessesGroup of febrile illnesses RNA viruses from 4 familiesRNA viruses from 4 families Highly infectious virusesHighly infectious viruses Potential lethal syndromePotential lethal syndrome

Fever, malaise, vomiting, mucosal and GIT bleeding, Fever, malaise, vomiting, mucosal and GIT bleeding, hypotension, edemahypotension, edema

Most notorious Ebola case fatality rate 90%, 1995 Most notorious Ebola case fatality rate 90%, 1995 Kikwik, ZaireKikwik, Zaire

Contracted from infected animal or arthropod Contracted from infected animal or arthropod vector vector

International travel, nosocomial outbreaksInternational travel, nosocomial outbreaks

E b o laM a rgb u rg

F ilo v iru ses

L a ssaN e w W o rld

A re n av iru ses

C o n g o -C rim e anR ift V a lley F e ver

B u n yav iru ses

Y e llo w fe ver

F la v iv iru ses

V H FR N A se ve ra l v ira l fa m ilies


Shared featuresShared features

Lipid envelopeLipid envelope Survival and Survival and

perpetuation depend perpetuation depend on animal host: on animal host: natural reservoirnatural reservoir

Distributed all over Distributed all over the world, higher the world, higher occurrence tropical occurrence tropical areas e.g. South areas e.g. South America, Africa, America, Africa, Pacific IslandsPacific Islands


Shared featuresShared features

Transmitted 2 categories Transmitted 2 categories natural reservoirs: natural reservoirs: rodents or arthropodsrodents or arthropods

Transmission occurs Transmission occurs through contact with:through contact with: Natural reservoirs Natural reservoirs

(mosquito bites, rodent (mosquito bites, rodent bites)bites)

Excretions, secretions, Excretions, secretions, blood reservoirs, blood reservoirs, intermediate hostsintermediate hosts

Person-to-person Person-to-person nosocomial infections nosocomial infections


PathophysiologyPathophysiology Vascular bed attacked, microvascular damage and increased Vascular bed attacked, microvascular damage and increased

vascular permeabilityvascular permeability Specific pathophysiologic findings can vary depending on virus Specific pathophysiologic findings can vary depending on virus

family and speciesfamily and species Initial febrile illness, haemorrhaging skin and mucous Initial febrile illness, haemorrhaging skin and mucous

membranes, orifices, effusionsmembranes, orifices, effusions Widespread necrosis, may present any organ, modest and Widespread necrosis, may present any organ, modest and

focal to massive in extentfocal to massive in extent Liver, lymphoid system extensively involvedLiver, lymphoid system extensively involved Lung varying degrees interstitial pneumonitis, diffuse alveolar Lung varying degrees interstitial pneumonitis, diffuse alveolar

damage and haemorrhagedamage and haemorrhage ATN, microvascular thrombosisATN, microvascular thrombosis Minimal inflammatory responseMinimal inflammatory response

thromocytopaenia, leucocytosis thromocytopaenia, leucocytosis

Morbidity and MortalityMorbidity and Mortality

Ebola, Marburg Ebola, Marburg 25-100% mortality, pregnancy universally fatal 25-100% mortality, pregnancy universally fatal High infection rate, especially Zaire typeHigh infection rate, especially Zaire type

South-American HF South-American HF case-infection ratio > 50% exposedcase-infection ratio > 50% exposed Mortality rate 15-30%Mortality rate 15-30%

Lassa feverLassa fever Fatality rate 2-15%Fatality rate 2-15%

Rift Valley FeverRift Valley Fever 1% exposed infected, mortality rate 50%1% exposed infected, mortality rate 50%

Congo FeverCongo Fever Infection rate 20-100%, Fatality rate 15-30%Infection rate 20-100%, Fatality rate 15-30%

HistoryHistory Not all patients present with bleedingNot all patients present with bleeding Travel history, contact vectors, patient, Travel history, contact vectors, patient,

bioterrorist attackbioterrorist attack Incubation period 2-14 dIncubation period 2-14 d Initial symptoms non-specificInitial symptoms non-specific

Progressive fever, biphasicProgressive fever, biphasic ChillsChills MalaiseMalaise Generalized myalgias, arthralgiasGeneralized myalgias, arthralgias Headache, anorexia,coughHeadache, anorexia,cough Severe sore throatSevere sore throat Nausea, vomiting, diarrhoea, epigastric painNausea, vomiting, diarrhoea, epigastric pain

Physical examination Physical examination

Findings not distinctiveFindings not distinctive Nonspecific Nonspecific

conjunctival injectionconjunctival injection Facial/truncal flushingFacial/truncal flushing Petechiae, Petechiae,

purpura,ecchymosespurpura,ecchymoses IcterusIcterus Epistaxis;GIT,GUT Epistaxis;GIT,GUT

bleedingbleeding LymphadenopathyLymphadenopathy

Hypotension, shock, Hypotension, shock, bradycardia, pneumonitis, bradycardia, pneumonitis, pleural and pericardial effusions, pleural and pericardial effusions, haemorrhagehaemorrhage

Encephalopathy, seizures, Encephalopathy, seizures, coma, deathcoma, death


ArenaviridaeArenaviridae

Conjunctivitis, pharyngeal Conjunctivitis, pharyngeal enanthema and enanthema and petechiae, no exudatepetechiae, no exudate

Sore throatSore throat Retrosternal painRetrosternal pain Lassa fever: classic signs Lassa fever: classic signs

meningitismeningitis Swollen baby syndromeSwollen baby syndrome

Infants toddlers; Lassa Infants toddlers; Lassa fever anasarca, fever anasarca, abdominasl distension, abdominasl distension, bleeding bleeding


BunyaviridaeBunyaviridae

Retinal vasculitis, Retinal vasculitis, blindnessblindness

Cotton wool spots maculaCotton wool spots macula Severe disease bleeding, Severe disease bleeding,

icterus, anuria, shockicterus, anuria, shock EncephalitisEncephalitis Congo fever most severe Congo fever most severe

bleeding and ecchymosisbleeding and ecchymosis


FiloviridaeFiloviridae

Ebola similar clinically Ebola similar clinically more severe disease more severe disease MarburgMarburg

55thth day distinct day distinct morbiliform rash trunk, morbiliform rash trunk, expressionless ghost-like expressionless ghost-like faciesfacies

Haemorrhage mucous Haemorrhage mucous membranes, membranes, venipuncture sites, body venipuncture sites, body orificesorifices

DIC late diseaseDIC late diseaseImages www.google/images.co.za

FlaviviridaeFlaviviridae

Yellow feverYellow fever Midzone necrosis liver, Midzone necrosis liver,

jaundice d3, flushing jaundice d3, flushing face, congested face, congested conjunctivae, conjunctivae, reddening edges reddening edges tonguetongue

Heart, kidney Heart, kidney damageddamaged

Early haemorrhage, Early haemorrhage, swelling bleeding swelling bleeding gums prominentgums prominent


Differential diagnosisDifferential diagnosis

Rickettsial infectionsRickettsial infections Bacterial infectionsBacterial infections

Salmonella, shigella, gram Salmonella, shigella, gram negative infectionsnegative infections

SepticaemiaSepticaemia Meningococcal, staph, Meningococcal, staph,

strep, typhoidstrep, typhoid

LeptospirosisLeptospirosis MalariaMalaria Viral: Chikungunya, Viral: Chikungunya,

Sinbis, Herpes, influenzaSinbis, Herpes, influenza EBVEBV

Acute anemiaAcute anemia Acute Leukemia, Acute Leukemia,

promyelocytic leukemiapromyelocytic leukemia DICDIC EncephalitisEncephalitis HUSHUS TTPTTP MeningitisMeningitis SepsisSepsis Collagen vascular Collagen vascular

diseasesdiseases

Lab studiesLab studies FBCFBC Leucopenia, leucocytosis, Leucopenia, leucocytosis,

thrombocytopenia, thrombocytopenia, hemoconcentration, DIChemoconcentration, DIC

Liver enzymesLiver enzymes Alb Alb Proteinuria universalProteinuria universal Serological tests – Ab not Serological tests – Ab not

detected acute phase; detected acute phase; Direct examination Direct examination blood/tissues for viral Ag blood/tissues for viral Ag enzyme immunoassay, enzyme immunoassay, virions EM specific and virions EM specific and sensitivesensitive

PCRPCR MassTag PCRMassTag PCR


TreatmentTreatment

Supportive, ICUSupportive, ICU Blood, platelets, Blood, platelets,

plasma plasma Ribavirin – Ribavirin –

arenaviruses Congo, arenaviruses Congo, LassaLassa

Vaccination: Yellow Vaccination: Yellow feverfever

Electrolyte and fluid Electrolyte and fluid balancebalance


VHF isolation precautionsVHF isolation precautionsWHO and CDC guidelinesWHO and CDC guidelines

Wash hands as neededWash hands as needed Isolate the patientIsolate the patient Wear protective clothingWear protective clothing Dispose of needles and syringes safelyDispose of needles and syringes safely Dispose of waste safelyDispose of waste safely Use safe burial practicesUse safe burial practices

Decontamination and isolationDecontamination and isolation

Contain diseaseContain disease Appropriate barrier mechanisms and Appropriate barrier mechanisms and

negative pressure isolationnegative pressure isolation Report infection control of hospital as well Report infection control of hospital as well

as local and state public health officials, as local and state public health officials, notify laboratory directors notify laboratory directors

CDC – expedite virus specific diagnosis CDC – expedite virus specific diagnosis (beyond scope local lab) and mobilization (beyond scope local lab) and mobilization resources containment resources containment

Specific infection control Specific infection control recommendationsrecommendations

Strict adherence to hand Strict adherence to hand washingwashing

Double gloving, Double gloving, impermeable gownsimpermeable gowns

N-95 masks or air-N-95 masks or air-purifying respiratorspurifying respirators

Negative pressure Negative pressure isolation 6-12 air changes isolation 6-12 air changes per hourper hour

Leg and shoe coveringsLeg and shoe coverings Face shields or gogglesFace shields or goggles


Specific infection control Specific infection control recommendationsrecommendations

Restricted access Restricted access Dedicated equipmentDedicated equipment Point-of-care analysersPoint-of-care analysers Environmental disinfection 1:100 bleach solutionEnvironmental disinfection 1:100 bleach solution Multiple infected patients same part hospitalMultiple infected patients same part hospital Portable high-efficiency particulate air filtered forced-Portable high-efficiency particulate air filtered forced-

air equipmentair equipment Survivors remain contagious extended periods of Survivors remain contagious extended periods of

timetime Fatalities promptly buried/crematedFatalities promptly buried/cremated Contacts medical surveillance 21 dContacts medical surveillance 21 d

Lab samplesLab samples

Specially handled and packaged for Specially handled and packaged for shipment to authorized labsshipment to authorized labs

Biosafety level 3 and 4 facilities Biosafety level 3 and 4 facilities

ReferencesReferences

Clare DJ, Ricketti AJ et al. Clare DJ, Ricketti AJ et al. Viral Hemorrhagic Fevers: Currentb Status of Endemic Disease and Strategies for Control. Infect Dis Clin N Am 20 (2006) 359–393.

Marty AM,Jahrling PB, Geisbert TW. Hemorrhagic Fevers. Clin Lab Med 26 (2006) 345–386

Pigott DC.Hemorrhagic Fever Viruses. Crit Care Clin 21 (2005) 765– 783

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Viral Haemorrhagic Fevers Images .

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