1 / 11

Agents (5) – Viral Haemorrhagic Fevers

Agents (5) – Viral Haemorrhagic Fevers. Part 8 of 13 Comments and contributions are encouraged: please e-mail DRcomments@hpa.org.uk. HPA Centre for Infections. Reviewed April 2009. Viral Haemorrhagic Fevers: Viruses. Several virus families: Filoviruses (Ebola, Marburg) Arenaviruses

valin
Télécharger la présentation

Agents (5) – Viral Haemorrhagic Fevers

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Agents (5) – Viral Haemorrhagic Fevers Part 8 of 13 Comments and contributions are encouraged: please e-mail DRcomments@hpa.org.uk HPA Centre for Infections Reviewed April 2009

  2. Viral Haemorrhagic Fevers: Viruses Several virus families: • Filoviruses (Ebola, Marburg) • Arenaviruses (eg Lassa, Junin, Machupo) • Bunyaviruses (eg Crimean-Congo and Hanta HF, Rift Valley fever) • Flaviviruses (eg Yellow Fever, dengue) (CDC Public Health Image Library)

  3. Viral Haemorrhagic Fevers • Not all VHF viruses are transmissible by aerosol,or they are unlikely to be produced in high enough concentrations to be used as likely biological agents

  4. Viral Haemorrhagic Fevers:Signs & Symptoms • Variety of possible clinical manifestations and incubation periods depending on VHF agent • Incubation period varies from 2-21 days • Symptom onset may be abrupt (filoviruses) or more gradual (arenoviruses)

  5. Viral Haemorrhagic Fevers:Early Signs & Symptoms • Non-specific prodrome for up to 7 days, including: •  high fever  headache •  malaise  myalgia •  arthralgia  abdo pain •  nausea & vomiting +/or diarrhoea

  6. Viral Haemorrhagic Fevers:Clinical course • Initial • Cutaneous flushing or rash, conjunctival injection • Periorbital oedema • Positive tourniquet test • Hypotension • Later • Prostration • Pain (throat, chest, abdomen) • Bleeding & Shock

  7. Viral Haemorrhagic Fevers:Bleeding Manifestations • Ecchymoses (shown here in a patient with CCHF) are often accompanied by haemorrhage in other locations, e.g. epistaxis, haematemesis, melaena, haematuriaand atpuncture sites (Image courtesy of Professor R Swanepoel, NICD, South Africa)

  8. Viral Haemorrhagic Fevers:Outcome • Usually improving or moribund within a week (except Haemorrhagic Fever with renal syndrome [Hantavirus], arenaviruses) • Bleeding, CNS involvement, SGOT indicate poor prognosis • Mortality 10-90% (depends on virus)

  9. Viral Haemorrhagic Fevers: Differential Diagnosis • Bacterial • - Typhoid fever, meningococcaemia, rickettsioses, leptospirosis, toxic shock syndrome • Protozoal • - Falciparum malaria • Other • - Vasculitis, TTP, Haemolytic Uraemic Syndrome (HUS), heat stroke

  10. Viral Haemorrhagic Fevers: Diagnosis • Primarily clinical • Laboratory confirmation: • Enteric Respiratory and Neurological Virus Laboratory (ERNVL) HPA CfI or • Special Pathogens Reference Unit (SPRU) HPA CEPR • Antigen detection by PCR • Virus isolation • Acute (& convalescent) serum • Tissue

  11. Viral Haemorrhagic Fevers: Management • Negative pressure isolation if possible (but would depend on numbers affected) • Supportive care • Correct coagulopathies • No antiplatelet drugs or IM injections • Ribavirin possibly for • Arenaviruses (Lassa fever) • Bunyaviruses (CCHF)

More Related