Transcript Viral Respiratory Tract Infection

Viral Respiratory Tract
Infection-Part 2
Prof. Dr Asem Shehabi
Faculty of Medicine, University of
Jordan
Rhinoviruses
Rhinoviruses part Picorna virus Group.. have positivesense 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.
2/
Incub. 2-3 days.. Mild /Severe .. Acute
Inflammation Nasal & Throat mucosa.. Mild
sore throat, watery nasal discharge, cough..
Children often develop sinusitis, otitis media..
Serotype–specific Immunity for short time.. Reinfection is common.. Rare Lower RT infection.
Complications: Bacterial infections.. Sinusitis,
Pneumonia (Pneumococcus, H.influenzae,
S.aureus)..antibiotic treatment. No vaccine
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 animalsbirds (chicken) infect both Gut & RT.. May affects liver
and CNS.
Coronavirus
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.
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.
Rubella Rash
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)
Rubellavirus -3
• Risk of birth defects drops after the first trimester/20week 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.
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.
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.
Adenoviruses (ds-DNA).. non-enveloped,
The capsid is built up 252 capsomers with
apical Surface Fibers
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.
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.