Viral Respiratory Tract Infection-Part 2

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Viral Respiratory Tract Infection-Part 2

• Prof. Dr Asem Shehabi
• Faculty of Medicine, University of Jordan

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Rhinoviruses

• Rhinoviruses part Picorna virus Group.. have
  positive- sense single stranded RNA
  genomes..surrounded by protein capsid composed 4
  viral protein (VP1-4)..
• Icosahedron structure without Envelop.
• A B Rhinovirus major group .. Over 100
  serotypes.. Susceptible to stomach acidity,
  infect nasal mucosa..Common incidence all year
  seasons.. Few common serotypes are highly human
  communicable .. droplet infection.. Upper
  Respiratory Tract.. Caused about 10-20 of common
  cold infections/mild Flu-like symptoms.. Epidemic
  Outbreaks in crowded meeting areas.

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• Incub. 2-3 days.. Mild /Severe .. Acute
  Inflammation Nasal Throat mucosa.. Mild sore
  throat, watery nasal discharge, cough.. Children
  often develop sinusitis, otitis media..
  Serotypespecific Immunity for short time..
  Re-infection is common.. Rare Lower RT infection.
  Complications Bacterial infections.. Sinusitis,
  Pneumonia (Pneumococcus, H.influenzae,
  S.aureus)..antibiotic treatment. No vaccine

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Corona Respiratory Viruses

• Virus structure have positive- sense single
  stranded RNA genomes, Lipoprotein envelop
  associated with characteristic ring of small
  protein structures (spikes) covers nucleocapsid..
  Crown-like structures..Multiply within cell
  cytoplasm..causing cell lysis syncytia rapidly.
  Causing up 30 of human common cold.
• Attached to Ciliary epithelium Trachea, Nasal
  mucosa.. Mostly mild URT Infections. Both
  symptomatic or asymptomatic.. Winter-Spring..
  Major symptoms Nasal discharge.. less
  pharyngitis, Fever or Cough.. Affect All Ages.
  Re-infections is common.. Mostly Sporadic
  Cases..less outbreaks.. In animals-birds
  (chicken) infect both Gut RT.. May affects
  liver and CNS.

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Coronavirus
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SARS-Coronavirus

• SARS ( Severe Acute Respiratory Syndrome) is
  caused by Corona related virus.
• First detected 2003 in China.. Later spread
  worldwide (2003-4) within weeks first in
  Asian..later numerous countries caused thousands
  cases hundred Deaths.
• In 2012-14 New SARS-Like Coronavirus strain
  caused Middle East Respiratory Syndrome.. More
  fatal cases, Saudi-Arabia, Jordan , other
  countries
• Coronaviruses affect the upper respiratory
  gastrointestinal tract human ,animal birds.
• Clinical Infection cause suddenly severe mixed
  viral bacterial pneumonia.. Symptoms include
  high fever, dry cough, dyspnea, headache,
  hypoxemia, high mortality ..more severe in middle
  ages elderly persons.. progressive respiratory
  failure liver damage..few days..No vaccine or
  specific antiviral therapy.

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Rubellavirus-1

• Rubivirus Rubella/ German measles..
• positive-ss RNA, Envelope ..carries only
  Haemaggultinins (2 glycoproteins, E1, E2), only
  one virus antigenic type.. Part of Togavirus
  /Arovirrus
• Rubella is a highly contagious viral disease,
  spread through contact with droplet discharges
  nose, throat, rarely by skin contact..
  Susceptible ultraviolet light, low pH, heat. The
  virus may also be present during active disease
  in the urine, feces, skin  
• Rubella virus incubation 2 weeks in Respiratory
  tract mucosa.. Saliva, Lymphadenopathy, Viremia,
  Mild fever, later macular fine skin rash ..
  develops on face, neck.. then the trunk and
  extremities.. Mostly subclinical infection.. Not
  recognized.. more in Children than Adults..
  Results Rubella antibodies immunity.

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Rubella Rash
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Rubellavirus-2

• Rubella may have symptoms similar to those of
  flu.. Lymphadenopathy begins 3 days prior to the
  skin rash and lasts until 3 days after disappear
  of rash.. Infected person remain for 2 weeks
  highly Infectious to susceptible persons of all
  ages.
• Humans are the only known reservoir for disease..
  RT, Intestine, Urinary tract.
• Rubella infection spread all the year.. But more
  in late winter and spring months.
• Rubella is mostly endemic in countries who have
  less than 90 immunization.
• Infection during pregnancy Lack of Rubella
  antibodies.. Virus reach placenta fetus via
  blood.. multiply in fetal organ and cause severe
  damage, stillbirth, abortion during the
  1-trimester (3-4 months)

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Rubellavirus -3

• Risk of birth defects drops after the first
  trimester/20- week pregnancy.. rarely any
  complications in fetus.
• Rubella Intra-uterine infection during pregnancy
  Detected by presence virus IgM antibodies in
  fetus blood.. Mother should abort her fetus.
• Congenital rubella syndrome Affects the eyes of
  new born babies (cataracts), Blindness,
  congenital heart defects, Brain CNS
  abnormalities, Mental retardation, Deafness,
  Hepatitis.
• Virus may persist in the infected new born baby
  tissues for 3-4 years and can infect others up to
  one year after birth.
• Rubella infection acquired later in life of
  young women may be associated with Arthralgia /
  Arthritis.

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Rubella immunity-4

• Rubella Humoral antibodies develop soon after
  infection/vaccination (IgM, IgG).. Rubella IgG
  alone indicates immunity .. The lack of both
  antibodies or IgG indicates susceptible to
  Rubella.
• Passive prophylaxis Susceptible pregnant women
  after contact with infected Rubella case should
  given Rubella human immunoglobulin.
• Laboratory test A 4-fold increase in Rubella
  serum antibodies titer IgM or both IgG IgM is
  diagnostic for recent infection. A live
  attenuated vaccine is given in combination with
  measles and mumps (MMR) to any woman lacks enough
  Rubella Antibodies.. 2-3 months prior to becoming
  pregnant.

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Adenoviruses Group

• Virus structure linear ds-DNA, non-enveloped,
  enclosed in a cubical capsid shell with projected
  surface fibers act as specific receptors.. human
  Avian specific virus groups.. Wide
  distribution nature.
• Human Adenovirus 47 serotypes..common few types
• Pathogensis Attachment to mucosal surfaces of
  respiratory tract, GI tract, and conjunctiva..
  Produces severe cytopathic effect (CPE) in
  infected tissues.
• Transmission Respiratory droplets, Saliva,
  Blood., Fecal-oral, Urine..close contacts..
  common asymptomatic infections in medical
  professionals, Common healthy carriers.. children
  Adults can transmitted the virus.
• Virus persist in Tonsils Adenoids, Intestine
  Urinary tract , in lymphoid tissues including
  Peyer's Patches.. For short/ long live time.. may
  be reactivated by immunosuppression condition.

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Adenoviruses (ds-DNA).. non-enveloped, The capsid
is built up 252 capsomers with apical Surface
Fibers
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Adenovirus-2

• Clinical Manifestation Almost all humans acquire
  Adenovirus infection early in life.. Only a few
  percentage (1- 5) develop mild clinical
  disease.. Serious disease in Immunocompromised
  persons, Common associated with kidney
  transplant.
• Common Clinical Diseases
• 1-Acute Respiratory Infections Few serotypes..
  Common in crowded schools, military refuge
  camps .. Acute febrile pharyngitis, fever, runny
  nose, mild cough.. Rarely pneumonia/
  Pharyngo-conjunctivitis.
• 2-Conjunctivitis Epidemic keratoconjunctivitis
  with no systemic symptoms, very painful, Sporadic
  Outbreaks cases.
• 3-Acute Gastroenteritis Few serotypes.. common
  infants.. Less other children/Adults.. Mesenteric
  Adenitis.. Mild-acute Diarrhea.. chronic diarrhea
  in patient with AIDS or immunosuppressed
  conditions.

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Adenovirus-3

• 4-Acute Hemorrhagic Cystitis Children Young
  Males/Females.. Infection genital tract cause
  Cervicitis , Urethritis , Haemorrhagic cystitis,
  Hepatitis, Pneumonitis..Fatal immunosuppressant.
• Immunity Specific humoral antibodies against one
  or few serotype..Last long time and protect
  against re-infection.. Each country has endemic
  specific Adenovirus type infections.
• Diagnosis Detection a rise in specific
  antibodies by ELASA.. Viral antigen Detection DNA
  PCR .
• Treatment Antiviral drugs for eye infection
  other patients .. Cidofovir, Ribavirin.. No
  Vaccine.