RNA Virus

What are some respiratory virus

Mumps, Rhinovirus, COVID19, Influenza, Parainfulenza, Adenovirus, Respiratoday syncytial virus

What is mumps parotitis

SsRNA paramyxovirus; airborne droplets, salivary secretion, urine; close contact is necessary

What is the clinical presentation and manifestation of Mumps parotitis

Fever + swelling with tenderness of salivary gland (parotid); complication can be meningitis, encephalitis etc as result of virus spread

Pathogenesis mumps parotitis

Enter into respiratory tract → Lymph node → primary viremia → spread to salivary gland/testes/orvaries/pancreas/CNS → viremia → spread to other places → viremia

Lab Diag for mumps parotitis

Clinically diagnosed; can be done by throat swab, CSF, urine detection, cell culture isolation, Mumps IgM

Mumps parotitis treatment and prevention

No specific treatment; prevent with MMR vaccine

Rhinitis, common cold is sign of what viruses

Rhinovirus, COVID, Influenza

Pharyngitis/Larygitis/Sore throat is sign of what viruses

Adenovirus, parainfluenza, influenza

Croup/Laryngotracheo-bonchitis is sign of what virus

Parainfluenza and influenza

Bronchitis is sign of what virus

Parainfluenza, influenza, adenovirus, COVID

Bronchiolitis is sign of what virus

RSV, influenza, adenovirus

Pneumonia is sign of what virus

All, esp influenza

What is rhinovirus

Picornavirus; small naked capsid, ssRNA, positive sense; A-C serotype; bind to ICAM-1r

What is the association of rhinovirus infection

Major cause of upper repiratory infection in all age groups; major cause of common cold

Rhinovirus pathogenesis

Upper repiratory tract that may be localized or spread to lower respiratory tract; minimal cell injury

Rhinovirus clinical presentation

2-3 incubation, acute symptoms last 3-7 days; mucosal cell damage is minimal

Epidemiology of rhinovirus

Transmit by droplet, contact; asthma at risk; found worldwide common early autumn, late spring

Rhinovirus Diag

NP specimen, throat swab, VTM; NAAT, immunofluoresence

What is SARS-CoV-2

Coroniaviridae, beta coronavirus; enveloped, + sense ssRNA

What coronavirus is human

Alpha coronavirus

What is betacoronavirus

Murine corona, SARS-COV, MERS-CoV

What is gammacoronavirus

Avian coronavirus

What is the variant of concern for COVID

SARS-CoV-2 variant: mutates spike protein receptor binding domain; change virulence, transmissibility

COVID viral transmission

Airborne: droplet and aerosol; contaminated surface; stool/feces; urine

SARS-CoV-2 life cycle

Expose to host cell → Bind to ACE2 And TMPRSS2 and enter cell → Viral membrane fusion → translate and assemble

What is ACE2 receptor

Expressed in rectum, GI, urinary system, respiratory, circulatory

COVID transmission duration

14 day incubation; case develop between 4-5 days; infectious 2-3 days before symptoms

COVID clinical manifestation

Asymptomatic phase → Invasion/infection of upper respiratory tract → Lower respiratory involvement (ARDS)

Common COVID symptoms

Fever, cough, tiredness, loss of taste/smell

Less common COVID symptoms

Sore throat, headache, aches and pain, diarrhea, rash on skin, red/irratated eyes

Disease course and complication of COVID

Respiratory failure (ARCS, dyspnea); hypoxemia in COVID pneumonia; thrombosis and endothelialitis

Complication of COVID

Thromboembolism; arrthymia, myocarditis, shock; stroke, encephalopathy; renal failure, inflammatory complication

What is the presentation of multisystem inflammatory syndrome in children and adolescent (MIS-C)

0-19 yr old >3 day fever; Evidence of COVID; ESR, CRP, procalcitonin elevated; no other apparent cause

Symptoms of MIS-C

Rash/conjuncitivitis/oral, hand feet inflammation; hypotension/shocl; heart problems; coagulopathy; GI problem

What is common post COVID condition

Fatigue; dyspnea, memory/concentration/sleep problem; cough; chest pain; trouble speaking, muscle ache; loss of smell/taste; fever

COVID Diag

NP and throat swab; VTM is bronchial wash or bronchi-alveolar lavage; NAAT, Ab detection

What does influenza cause

Acute febrile respiratory tract infection; primary viral pneumonia; Reye’s syndrome

What is influenza

Orthomyxovirus; 3 main types (A-C); subtypes based on hemagglutinin and neuraminidase variation

What is the transmission of influenza

Human influenza A and influenza B spread by droplets, surface and aerosol

Pathogenesis of influenza

Infect upper and lower respiratory tract→ Susceptiblity to bacterial superinfection → Cytokine response to infection make systemic symptoms

What is the clinical presentation of uncomplicated influenza

Classic signs appear abruptly (chill/haedache/dry cough then high fever, muscle ache, malaise, anorexia); fever; cough and weakness

Pneumonia complicating influenza infection clinical presentation

Increased mucous secretion carry agent to lower respiratory tract; loss of ciliary clearance, phagocyte dysfunction; infect with S aureus, S pneumoniae

What is pneumonia

Primary influenza pneumonia → Respiratory failure; secondary = prime lung tissue for infection, S. Aureus, S pneumoniae etc

What is Reye Syndrome

Acute encephalopathy; RARE complication; salicylate use may cause Reye

Avian Flu (H5N1) and Swine flu (H1N1) clinical manifestation

High fever, respiratory symptoms, neurological symptoms, lymphopenia, diarrhea; replicate in lower lung; no bacterial infection = primary pneumonia

What is the epidemiology of the influenza types

Influenza A → Pandemic; Influenza B → Pandemic; Influenza C → least significant

Influenza lab Diag

RT-pCR; serology; isolation from NP and throat swab

What is parainfluenza

Common cause of acute respiratory infection; severe croup and tracheobronchitis; mild upper respiratory infection

Pathogenesis of parainfluenza

Replicate in repiratory epithelia → Involve nose and throat ONLY (common cold) → Croup → Pneumonia/bronchiolitis

Croup pathogenesis

Invade and destroy epithelia in larynx and upper trachea → Inflammatory reaction → blood permeability → fluid thick’ens wall

Parainfluenza clinical presentation

Mild upper respiratory infection → Variable progression in middle/lower respiratory tract

What is respiratory syncytial virus infection

Causes severe infection in infants (bronchiolitis and pneumonia); BRONCHIOLITIS

What is RSV

Paramyxovirus, negative sense RNA, enveloped, spikes; cause syncytial formation in cell culture

RSV pathogenesis

207 day incubation → Spread to lower respiratory tract (bronchiolitis and pneumonia) → Viral antigen found in UPPER respiratory tract

Pathological finding of RSV

Epithelial cell necrosis, high IgE, plugged airways in BRONCHI, BRONCHIOLES, ALVEOLI; multinucleated syncytial cell with intracytoplasmic inclusion

Bronchiolitis clinical manifestation

Rhinitis onset → Infant have bronchiolitis, pneumonitis with productive cough, wheezing, respiratory distress

Bronchiolitis clinical finding

Hyper expansion of lung; hypoxemia; hyper apnea

RSV Diag

Largely clinical (age, symptoms); Diag from RT PCR and ELISA; serodiag and virus isolation

RSV treatment

Palivizumab against F protein prevent severe disease; used a prophylaxis

What virus is associated with gastroenteritis

Rotavirus, Norovirus, Adenovirus

What is rotavirus

Classified into groups; Group A infect human; G1-4 and G9 detected worldwide; fecal oral; common cause of winter gastroenteritis in children <5 and serious diarrheal disease

What is caliciviruses

Norovirus and sapovirus; called Norwalk agent; GI, GIi and GIV infect human; fecal oral; gastroenteritis common in older people

Caliciviruses illness

Vomiting, diarrhea with abdominal cramp, nausea and low grade fever

What is Astro virus

Mild gastroenteritis outbreak; fecal oral; virus shed in feces

What is picornaviridae

Naked, small; mRNA, replicate in cytoplasm

What are the members of picornavirus

Enterovirus family, rhinovirus

What is the difference between enterovirus and rhinovirus

Entero: res to pH 3-9; Rhinovirus labile at acidic pH; if capsid stable at pH3 = enterovirus

What is enterovirus infection

Infect intestinal tract epithelial and lymphoid tissue and shed into feces

What is poliovirus infection

Polio; affect children <5; vaccine: IPV/OPV; fecal-oral

What is polio

Abortive poliomyelitis: NO signs of CNS and flu like symptoms; Aseptic meningitis: meningeal irritation; paralytic poliomyelitis: meningeal irritation

What are important enteroviruses

Enterovirus, Coxsackievirus virus, echovirus

How is enterovirus transmitted

Resistant to sewage treatment, salt water, detergent and temp changes; FECAL ORAL

What is echovirus infection

Echovirus 9-16: exanthem and fever (start on face to trunk and extremities); Echovirus 9: cause umbellifrom (discrete) rash

What is hand food and mouth disease (HFMD)

Fever, anorexia and malaise; sore throat buccal mucosa vesicle on tongue; lesion on hand and sometimes palm; encephalitis and myocarditis

What is herpangina

Infection of palate and tonsil; acute fever, sore throat, odynophagia

Lab Diag of HFMD

Virus isolation, RT PCR, serodiag