The Management of Viral Haemorrhagic Fevers in Ireland - Health ...

3. Infection Prevention and Control Guidance3.1 IntroductionFour VHFs have caused significant outbreaks of disease due to person-to-person transmission (Lassa fever,CCHF, Ebola HF and Marburg HF). They present a risk to public health and have the potential for nosocomialtransmission. Given the lack of effective therapy or preventive vaccines against most VHF agents, efforts toprevent transmission rely on careful and vigilant implementation of appropriate infection control measures.This chapter provides the infection prevention and control advice for management of patients At Risk orat High Risk of VHF, and for those with Confirmed VHF; advice on environmental decontamination andmanagement of healthcare risk waste, as well as advice on post-mortem management. It is important tonote that strict adherence to Standard and Transmission-based Precautions, including the correct useof Personal Protective Equipment (PPE), at all times during the care of At Risk or High Risk patientsand those confirmed as having VHF is of paramount importance. 47-51 All staff should be familiar with thecorrect sequence for the donning and removal of PPE in order to prevent contamination of the face, mucousmembranes and clothing.The infection control and prevention principles outlined in this chapter apply to all healthcare settingsirrespective of patient location and apply to acute Emergency Departments, Medical Assessment Units andpaediatric settings.3.2 Mode of transmissionMost of the evidence for the mode of transmission of VHF comes from endemic areas where large outbreakshave occurred, in settings with limited medical and public health infrastructure. The transmission risksassociated with various body fluids have not been well defined because most caregivers who have acquiredinfection had contacts with multiple fluids.Epidemiological investigations of outbreaks have demonstrated that the four main VHF viruses appear to bepredominantly transmitted from person-to-person in the same way: through direct contact with virus-infectedbody fluids, such as blood, saliva, vomitus, stools and possibly sweat. Cross-infection with multiple-use sharpinstruments such as lancets and needles is associated with a high infection risk and a high fatality rate.Marburg, Ebola and Lassa virus have been shown to be present in the genital secretions of convalescentpatients several weeks after illness. At least one incident of transmission from a convalescent patient to theirsexual contact has occurred with Marburg HF. 22 Evidence of Ebola virus has been detected in semen up to 91days after disease onset. 52These viruses may be transmitted over a short distance of a metre or so by droplets of body fluids from infectedpatients, if the droplets come into contact with mucous membranes. There is also a potential risk to laboratoryworkers as small clouds of aerosolised viruses can be released in laboratory accidents such as breakage ofcontainers within centrifuges.Because for some cases, no plausible alternative explanations for transmission have been considered possible,airborne transmission remains a theoretical possibility. Appendix H summarises available evidence in relationto the mode of transmission.3. Infection Prevention and Control Guidance The Management of Viral Haemorrhagic Fevers in Ireland/HPSC 2012INFECTION PREVENTIONA AND CONTROLKey Points‣ The VHF sub-committee advises, on a precautionary basis, the use of Standard and Contact,Droplet and Airborne Precautions at all times when managing patients who are High Risk cases, orconfirmed cases.‣ Standard Precautions should be used at all times when caring for patients who are classified asAt Risk of VHF.- 30 -