ORTHOMYXOVIRIDAERNA virus

orthos, Greek "straight"

myxo, Greek "mucus"

Mode of Transmission: Airborne Respiratory Droplets

Virulence Factors:

Glycoprotein spike contains:

Hemagglutinin (HA) - binds to cell surface receptors ( neuramidic acid/sialic acid)

Neuramidase (NA) – cleaves neuramidic acid, exposing sialic acid binding sites.

The Orthomyxovirus/Influenza viruses:

1. Influenza A- pandemics and epidemics; humans and animals

2. Influenza B- epidemics; human virus3. Influenza C- mild respiratory tract infection

Clinical Manifestation:

The Flu: Fever, runny nose, cough, myalgias(muscle pain), arthralgias (joint pain).

Complications:Secondary bacterial pneumonias in the elderly.

Reyes Syndrome in children who use aspirin; get liver and brain disease.

Increased mortality in the elderly and in those with underlying pulmonary and cardiac disease.

References: http://pathmicro.med.sc.edu/mhunt/RNA10.jpg http://pathmicro.med.sc.edu/mhunt/RNA14.jpgM. Gladwin and B. Trattler, Clinical Microbiology Made Ridiculously Simple

PARAMYXOVIRIDAERNA virus

para, Greek “beyond”

myxo, Greek “mucus”

Mode of Transmission: Airborne Respiratory Droplets

Virulence Factors:

HA and NA are a part of the same glycoprotein spike, not two different spikes.

Possess a fusion (F) protein (not present in the orthomyxoviridae) that causes the infected host cells to fuse together into multinucleated giant cells.

The Paramyxoviruses:

1. Parainfluenza virus - Upper respiratory tract Infection in adults; bronchitis, pharyngitis, rhinitis.- Viral pneumonia in children, elderly and immunocompromised.- Croup: Children develop a barking cough.

2. Respiratory Syncytial virus- Most common cause of pneumonia in infants less than 6 months of age.

3. Mumps virus- Parotid gland swelling- Testicular inflammation

4. Measles virus (rubeola)- Prodrome: high fever, cough and conjunctivitis.- Koplik’s spots: small red based blue-white centered lesion in the mouth.- Rash: from head, then to neck and torso, then to feet.