ORTHOMYXOVIRUSES,BUNYAVIRALES

virus: Influenza virus, family: Orthomyxoviridae

An epidemic is a disease outbreak that is rapidly spreading in a limited region. A pandemic is an epidemic that is actively spreading to multiple regions across the globe

Reassortment is the mixing of the genetic material of a species into new combinations in different individuals.

• in the Nucleus

= endosomal release

A threshold of acidic pH triggers the HA protein to undergo an irreversible conformational change, exposing the fusion peptide. This critical process initiates virus-host fusion, uncoating, and release of the viral genome into the cytoplasm

threshold: 5.5 pH.

in nucleus

—> This is a target for the major antiviral agents for influenza

Antigenic drift creates influenza viruses with slightly modified antigens, while antigenic shift generates viruses with entirely new antigens.

• The Reservoir of Influenza A Diversity Resides in Aquatic Birds

• Transfer of Segments From Avian Influenza Strains Leads to Pandemic Human Strains

aka “Bird flu”

Important: there does not

seem to be a simple answer to

how avian flu strains adapt to

humans

• das Virus wird ab 70 °C

• in the Cytoplasm

Arenaviral ambisense-genome replication strategy: due to the

ambisense coding strategy of the arenaviruses, the NP (and L)

genes are transcribed directly from the viral genomic segments

into mRNAs, whereas the GP (and Z) mRNAs must be

transcribed from the antigenomic strands after genome

replication.

Hemorrhagic fever, West-Africa:

- deafness in 25% of patients who survive the disease

- death usually occurs within 14 days of onset in fatal cases

- early treatment: Ribaviri

in cytroplasm

Vertical transmission: Passage of a disease-causing agent (pathogen) from mother to baby during the period immediately before and after birth. Transmission might occur across the placenta, in the breast milk, or through direct contact during or after birth. For example, HIV can be a vertically transmitted pathogen.

Perinatal

Horizontal everything else like droplet smear parenteral