rhinovirus an update
DESCRIPTION
Rhino virus an updateTRANSCRIPT
Dr.T.V.Rao MD 1
Rhinovirusan update Dr.T.V.Rao MD
Dr.T.V.Rao MD 2
Common cold Pharyng Tracheobronchitis Pneumonia
RHINOVIRUSESINFLUENZA type A
INFLUENZA type B
CORONAVIRUSESADENOVIRUSES (types 1-5,7)
EPSTEIN-BARR VIRUSRSVPARAINFLUENZA (types 1-3)
COXSACKIE (group A & B)ECHOVIRUS
+++
±
±
++
±
-
±
±
±
±
+
+
+
±
±
±
±
+
±
±
±
++
+
±
±
-
±
±
±
±
±
+
+
±
±
±
-
-
±
±
Viral Organisms in U.R.I.Adults
Dr.T.V.Rao MD 3
Coryza Pharyngitis Croup Tr.bronchitis PneumoniaRSVPARAINFLUENZA (type 3)PARAINFLUENZA (type 2)PARAINFLUENZA (type 1)RHINOVIRUSESINFLUENZA type AINFLUENZA type BADENOVIRUSES (types 1-3,5)CORONAVIRUSESEPSTEIN-BARR VIRUSCOXSACKIE (group A & B)ECHOVIRUS
++
++
++
++
++
±
±
+
++
-
±
±
+
+
+
+
+
+
+
+
±
±
+
+
+
+
±
+++
±
+
±
±
±
-
±
±
++
++
-
+
±
+
+
±
±
-
±
±
+++
++
±
+
+
+
±
±
±
-
±
±
Viral Organisms in U.R.I.Children
Dr.T.V.Rao MD 4
Rhinoviruses • Rhinoviruses (from the Greek (gen.) "nose")
are the most common viral infective agents in humans and are the predominant cause of the common cold. Rhinovirus infection proliferates in temperatures between 33–35 °C (91–95 °F), and this may be why it occurs primarily in the nose. Rhinovirus is a species in the genus Enterovirus of the Picornaviridae family of viruses.
Dr.T.V.Rao MD 5
Viral Rhinitis sites infected
Rhinovirus nose > pharynx > saliva
90% 70% 50%
Coronavirus ?nose
Parainfluenza, RSV, adenovirus U & L.RT
Influenza extensive destruction of U & L.RT (ciliated, intermediate and basal
cells of epithelium)
Ebisava et al, 1969)
Dr.T.V.Rao MD 6
Rhinoviruses are the most commonly isolated viruses from persons with mild upper respiratory illness.
Rhinoviruses are a genus of picornaviridae
In contrast to enteroviruses they do not replicate in the intestinal tract, they have an extreme species specificity and more fastidious growth requirements
Rhinoviruses are ..
Dr.T.V.Rao MD 7
RHINOVIRUS GROUP
• Produces Common Cold.• Mild respiratory Illness.
• More than 100 serotypes• Nasal secretions are infective. Mistaken with Infections with Corona viruses, Adenovirus. Para influenza viruses. Influenza viruses
Dr.T.V.Rao MD 8
Properties of Rhinoviruses.
• Gross appearance like Entero viruses,• Acid Labile destroyed at 3.0 pH.• Grown in Human Cell lines, WI – 38 MRC -5• Cultivated at 330 c
Dr.T.V.Rao MD 9
Rhinovirus
• Picornoviridae family• Size• Single stranded• Incubation period of 1
to 3 days• Optimum growth occurs
between 33 and 34 deg Celsius (93 deg F)
• Not stable below the pH of 5-6
Dr.T.V.Rao MD 10
Rhino Virus
Dr.T.V.Rao MD 11
Structure
Dr.T.V.Rao MD 12
Entering a Cell
Rhinovirus bonded to a CAM 1 receptor
Antibodies bonded to a rhinovirus
Dr.T.V.Rao MD 13
Understanding – Common cold
• leading cause of doctor visits and lost hours both at school and the workplace over >100 different viruses found to cause symptoms of the common cold responsible for about 70% of the cases where a virus has been found one of the most common illnesses to man 35 to 50% of the total number of common colds
Hand to hand contact
Dr.T.V.Rao MD 14
Transmission of Rhinoviruses
• There are two modes of transmission: via aerosols of respiratory droplets and from contaminated surfaces, including direct person-to-person contact.
Dr.T.V.Rao MD 15
Pathogenesis - Rhinoviruses• Entry through Respiratory tract.• Nasal Mucosa, can infect Lower Respiratory
tract.• Chilling, wearing wet cloths do not produce
infection.• But common cold starts with chills.• Local inflammation and cytokines may be
responsible for the symptoms of common cold.
• Interferon production occurs early and specific antibody appears in nasal secretions
Dr.T.V.Rao MD 16
PathogenesisEpithelial destruction hypothesis:
intact nasal epithelium (Winther et al)
rhinovirus replication in extremely small number of cells (Arrunda et al)
viral quantity does not influence duration nor severity of colds (Arrunda et al)
Dr.T.V.Rao MD 17
Pathogenesis
• Inflammatory cascade hypothesis:
Common cold symptoms result from an inflammatory cascade triggered by a viral infection
Dr.T.V.Rao MD 18
Cytokines initiate pathogenic process
Small number of virus infected cells elaborate a variety of cytokines initiating a host inflammatory response, which orchestrate chemotaxis and expression of endothelial adhesion receptor molecules resulting in the typical common cold symptoms.
Dr.T.V.Rao MD 19
Interleukin-1• T-cell activation
• B-cell profileration, antibody synthesis
• up-regulation adhesion molecule expression
• mediator, cytokine, growth factor induction
• increased vascular permeabilitiy
• up-regulation kinin receptor expression
• hematopoietic progenitor cell stimulation
• neuro-endocrine interactions
Dr.T.V.Rao MD 20
Clinical Findings.• Incubation 2-4 days,• Last for 7 days.• Sneezing, Nasal
Obstruction, Sore throat,
• May lead to secondary infection with Bacteria.
Dr.T.V.Rao MD 21
The common cold, nasal congestion is caused by a vasodilation of the subepithelial capillaries and of the cavernous sinuses, by
edema in the lamina propria and by inflammatory processes in which neutrophils
and kinins play an important role.
o Histamine plays only a minor role in the symptoms of common cold
o Little is known about the role of prostaglandins and leukotrienes in the common cold.
Dr.T.V.Rao MD 22
Clinical Findings.• Incubation 2-4 days,• Last for 7 days.• Sneezing, Nasal
Obstruction, Sore throat,
• May lead to secondary infection with Bacteria.
Dr.T.V.Rao MD 23
Laboratory Diagnosis
• Isolation of virus may be obtained from nasal or throat swabs collected early in infection.
• Culturing on MRC5 or W 138
• Appearing of CPE
Dr.T.V.Rao MD 24
Immunity – Rhinoviruses.• Antibodies in
Nose • Recurrent
infections with antigenic variants, may be 2-3 attacks a year.
Dr.T.V.Rao MD 25
Prevention and Control• No specific
treatment.• Vaccines are
unsuccessful.• Intranasal spray of Gamma
Interferon for 5 Days
Dr.T.V.Rao MD 26
Epidemiology - Rhinoviruses.
• Prevalent all over the world.
• Close Contact.• Fingers and Hand
- Hand washing.• High rate of
infection in Infants and Children.
Dr.T.V.Rao MD 27
CDC Recommends • The CDC recommends
that children with symptoms lasting more than 10 days who are unresponsive to over-the-counter medications or with fevers over 100.4 degrees Fahrenheit seek medical attention.
Dr.T.V.Rao MD 28
Dr.T.V.Rao MD 29
Stop Spreading the Virus
Dr.T.V.Rao MD 30
Use Tissue Paper• Use
paper :Instead of shared cloth towels. Individuals with colds should always sneeze or cough into a facial tissue, and promptly throw it away.
Dr.T.V.Rao MD 31
Hand washing• Hand washing is the
simplest and most effective way to keep from getting rhinovirus colds. Children and adults should wash hands at key moments after nose-wiping, after diapering or toileting, before eating, and before preparing food.
Dr.T.V.Rao MD 32
Treatments are Still Experimental
• DRACO, a broad-spectrum antiretroviral therapy being developed at the Massachusetts Institute of Technology, has shown preliminary effectiveness in treating rhinovirus, as well as a number of other infectious viruses
Dr.T.V.Rao MD 33
Preventing Common Cold• There is no vaccine to protect you against
the common cold. However, you may be able to reduce your risk of getting a cold by taking these steps:
• wash your hands often with soap and water do not touch your eyes, nose, or mouth with unwashed hands stay away from people who are sick
Dr.T.V.Rao MD 34
Prospects of Vaccine• There are no vaccines against these viruses as
there is little-to-no cross-protection between serotypes. At least 99 serotypes of Human rhinoviruses affecting humans have been sequenced. However, recent study of the VP4 protein has shown it to be highly conserved amongst many serotypes of Human rhinovirus, opening up the potential for a future pan-serotype Human rhinovirus vaccine.
Dr.T.V.Rao MD 35
• The Programme Created by Dr.T.V.Rao MD for Medical and
Health care Workers in the Developing World