-Orthoymyxaviruses also replicated in both the nucleus and the cytoplasms.
-Bunyaviruses are circular
-Arenaviruses contain one negative sense and one antisense strandof RNA
’PAIN RESULTS FROM OUR BUNYONS ALWAYS
-Paramyxoviruse, rhabdovirus, filovirus,orthomycovirus,bunyvirus, areneviruses
RETROVIRIDAE
Important points about proteins in the HIV virus
-GAG gene: p24 capsid-Structural proteins including capsid proteins, core nucleocapsid proteins, and matrix proteins that stabilizes the envelope
-Pol Codes for RT which takes + sense RNA and turns it into DNA
Integrase takes DNA made and integrates it into host DNA
Protease: cleaves polyprotein (protease inhibitors work here)
-Env gp120: surface protein that binds to the CD4 receptor in the host cell. Responsible for genetic drift
-Virus attaches via gp 120 binding to CD4 receptor on the T helper cells
-RNA taken into the cell and envelope is lost
-RNA copied using the RT; Ds DNA with long terminal repeats is made
-The DNA and integrase mirate into the nucleus and the DNA is integrates into the host DNA forming the provirus
-Provirus remains in the host DNA
-Rate of viral replication regualated b the activity of regulated proteins (tat/ref/nef)
-Transcription produces ss (+) RNAs, some splced and some remain intact
-Spliced RNAs will be used as mRNA
-Whole RNA is used as genomic RNA
-Translation produces the proteins, some of which are polyproteins that are cleaved by the protease
-Triple treatment is two RT inhibitors and a protease inhbitor CDC CATEGORIES OF AIDS INFECTION
A
B
C
CD4 count
Asymptomatic
Acute or asymptomatic HIV infection
Generalized lymphadenopathy
Symptomatic
Conditions attributd to HIV infectionor are indicative of a defect in cell mediated immunity
AIDS
>500
A1
B1
C1
200-4999
A2
B2
C2
<200
A3
B3
C3
-Patients are asymptomatic when CD4 cell counts are in the range of 200-250
-Oral candidiasis is often the first manifestation (CDC category B)
-Other category B infections include hairly leukoplakia
-Idiopathic thrombocytic purpura
-Listerosis
-Pelvic inflammatory disease
-Category C are AIDS defining conditions like HIV related encephalopathy, precurrent pneumonia, fungal infectons like esophageal candidiasis, invasive cervical carcinoma, systemic and disseminated fungal infections, recurrent salmonella septicemia.
HIV DIAGNOSIS:
-Screening done via ELISA. Tests for the antigens including p24, gp160, gp120, gp41
-Has virion associated polymerase. Helical in shape; multiples in the cytoplasm
-Parainfluenza: causes croup. Seasonal variance.
-Mumps: causes parotitis and pancreatitis. Orchitis can result when adults are affected. Meningioencephalitis
-Measles: Rubeola. Presentation generally the three C’s with photophobia. Cough, coryza, conjunctivitis, Koplik spots, rare complication is subacute sclerosing panencephalitis
-RSV: major cause of bronchiolitis and pneumonia in infants. Includes common cold. Expensive therapy is ribavirin to target the virus.
Rabies virus
-Single stranded negative RNA
-Bullet shaped and enveloped
-Negri bodies: intracytoplasmic inclusion bodies
-Spreads to humans by bites of rapid dogs; contact with bats and skunks
-Disease contracted by the bite. Virus is neurotropic and will penetrate from the bite to the CNS
-Virus does not spread hematogenously
THERAPY:
-If rabies is suspected in a dog with an unknown vaccination history, the dog’s brain is sent to the health department for autopsy. If positive negri bodies, patients bitten need to be double vaccinated
-Passive immunization with antibody and antigen
-If patents are bitten by a skunk/wild animal, prophylactic vaccination is started immediately.
Orthomyxoviridae
INFLUENZA VIRUS IS PROTOTYPIC:
-ss negative DNA
-Segmented viral genome (eight segments)
-One piece of genome produces a hemagluttinin
-Hemagluttinin is necessary for entrance into human cell
-Neuraminidase #1 produces protein necessary for exit from host cell
-Enveloped nucleocapsids
-Three viruses included in the dead vaccine.
-Immunization with three types of influenza: H1N1 and H3N2 and type B
-Influenza A has a rare genetic shift: major changes can result from new combinations of RNA segments or recombination between the segments in co infections causing new pandemics
-Flu involves upper respiratory symptomatology
GENETIC RECOMBINATION or SHIFTS: responsible for pandemics, causef by rare genetic shifts. Involves recombination between the segments in influenza co-infection
GENETIC DRIFT: Mild changes in antigenicity due to mutations