Although HPAI H7N9 and HPAI H5N1 human infections remain almost exclusively an Asian or Middle Eastern problem, the potential for seeing an imported case (as we already have with two H7N9 & 1 H5N1 cases in Canada) certainly exists, as does the possibility of infection by one of the recently arrived (and reassorted) HPAI H5 viruses in North America.
This winter’s unprecedented H5N1 outbreak in Egypt, in particular, raises the risks of seeing cases here, and so the CDC has released new, updated (Interim) guidance on the handling of patients (and their contacts) who may have been exposed to, or infected by, novel influenza A viruses.
These new guidance documents essentially consolidate, and update, earlier individual guidance documents for the handling of H5N1 and H7N9 (see H7N9: Updated CDC Guidance For Antiviral Treatment and CDC Interim Guidance On Antiviral Chemoprophylaxis For Persons With Exposure To Avian Flu).
Wth the rapid expansion of novel avian flu types over the past two years it has become unwieldy and counter productive to maintain separate guidance documents for each subtype, when the advice is essentially the same across the board.
As these are long and detailed documents, I’ve only posted the links and the opening section of each. Clinicians will want to follow the links to read them in their entirety.
This document provides guidance for antiviral treatment of human infection with novel influenza A viruses associated with severe human disease; these viruses currently include influenza A (H7N9) virus and highly pathogenic avian influenza A (H5N1) virus.1
This guidance merges and replaces the previously posted guidance on the use of antiviral agents for treatment of human infections with avian influenza A (H7N9) and avian influenza A (H5N1). This antiviral treatment guidance is consistent with current CDC and World Health Organization (WHO) recommendations, and provides updated recommendations for treatment of novel influenza A infections associated with severe human disease in the United States.
This guidance reflects recently updated novel influenza A case definitions (see H7N9 case definitions and H5N1 case definitions).This guidance recommends antiviral treatment as soon as possible for all hospitalized cases of human infection with novel influenza A viruses associated with severe human disease, and for confirmed and probable outpatient cases.2 Outpatient cases under investigation who have had recent close contact with a confirmed or probable case of human infection with a novel influenza A virus that can cause severe disease should receive antiviral treatment, whereas outpatient cases under investigation meeting only the travel exposure criteria for a case under investigation are not recommended to receive antiviral treatment. (For guidance on investigation of close contacts of confirmed or probable cases, see Interim Guidance on Follow-up of Close Contacts of Persons Infected with Novel Influenza A Viruses Associated with Severe Human Disease and the Use of Antiviral Medications for Chemoprophylaxis.)
These recommendations are based on expert opinion and available published and unpublished data on the treatment of infection caused by influenza viruses, including seasonal, pandemic, and novel viruses. This guidance will continue to be updated as additional information on virus transmissibility, epidemiology, and antiviral susceptibility patterns becomes available for novel influenza A viruses that cause severe disease.
This interim guidance is based on expert opinion and currently available published and unpublished data for antiviral treatment and chemoprophylaxis of seasonal, pandemic, and novel influenza. These recommendations are based on the following considerations:
- Novel influenza A viruses have caused severe human disease and substantial mortality among detected cases to date.
- Limited, non-sustained human-to-human transmission cannot be excluded in some case clusters.
- Sufficient supplies of antiviral agents that are expected to be effective against novel influenza A viruses are available.
The public health goal of this interim guidance is to prevent further spread of novel influenza A viruses associated with severe human disease if there is introduction/travel of infected persons into the United States. It is specific to a scenario where there are sporadic cases associated with poultry exposure and possible limited, non-sustained human-to-human virus transmission.
This guidance will be updated as additional information on epidemiology and transmissibility becomes available for novel influenza A viruses causing severe human disease.