RSV and Influenza Knowledge Quiz

Respiratory Syncytial Virus (RSV)

• RSV is a highly contagious respiratory virus
• Leading cause of lower respiratory tract infections in infants and young children
• Significant public health burden, resulting in substantial hospitalizations and medical costs annually worldwide
• High-risk groups include infants, young children, older adults, and individuals with compromised immune systems or chronic medical conditions

RSV Seasonal Patterns

• Peak RSV season is November through March in most areas
• RSV infections typically decline in April
• RSV transmission accelerates nationwide in late Fall
• Low RSV activity during warm months (Summer)
• RSV cases dwindle after the winter surge (Early Spring)

RSV Properties

• RSV belongs to the Paramyxoviridae family, genus Orthopneumovirus
• Negative-sense, single-stranded RNA virus
• Categorized into RSV-A and RSV-B (based on genetic and antigenic differences)
• Enveloped virus with a helical nucleocapsid
• Encodes for 11 viral proteins, including fusion (F) and attachment (G) glycoproteins, crucial for viral entry and pathogenesis
• Pleomorphic in shape, appearing as spherical or filamentous particles under electron microscopy
• Replicates in the cytoplasm of host cells; viral RNA is transcribed into mRNAs, translated into viral proteins; new viral genomes are synthesized and packaged into progeny virions, released through budding.

RSV Pathogenesis

• Host immune response to RSV infection plays a critical role in disease severity, with excessive inflammation contributing to respiratory symptoms and lung damage
• In severe cases, RSV infection leads to bronchiolitis, pneumonia, and respiratory failure, particularly in infants, young children, and older adults.

RSV Transmission Pathways

• Droplet transmission: Respiratory droplets containing RSV particles expelled through coughing or sneezing can transmit virus when inhaled by susceptible individuals
• Contact transmission: RSV can spread through direct or indirect contact with contaminated surfaces or objects, followed by touching the mouth, nose, or eyes.
• Aerosol transmission: RSV may be transmitted through smaller respiratory particles or aerosols which remain suspended in the air for an extended period, leading to airborne transmission over short distances
• Contaminated fomites: RSV can survive on various surfaces and objects, facilitating indirect transmission when touched by susceptible individuals
• Close personal contact, like kissing or sharing utensils, can transmit RSV through the exchange of respiratory secretions.

High-Risk Groups for RSV

• Premature infants (born before 29 weeks of gestation)
• Children under 2 years old with chronic lung disease or congenital heart disease
• Adults aged 65 years and older with weakened immune systems
• Individuals with chronic conditions such as asthma, COPD, or diabetes

RSV Clinical Manifestations

• Infants: Symptoms may include cough, wheezing, difficulty breathing, fever, and poor feeding
• Adults and older children: RSV often presents as mild cold symptoms but can progress to more severe respiratory illness in individuals with underlying health conditions

RSV Diagnosis and Testing

• Diagnosing RSV typically involves analyzing patient symptoms, conducting laboratory tests on respiratory samples
• Common methods include rapid antigen testing, molecular testing (RT-PCR), and virus culture
• Chest X-rays may be used to evaluate the extent of lung involvement in severe cases

RSV Management and Treatment

• Mild cases: Oral hydration, pain relievers, rest, and monitoring for worsening symptoms
• Severe cases: Supportive care (supplemental oxygen, intravenous fluids, respiratory support, including mechanical ventilation if needed)
• Severe cases (Antivirals): Ribavirin (an antiviral medication) may be considered but effectiveness is limited
• Monoclonal antibody treatment: Palivizumab may be given to high-risk infants to prevent severe RSV disease.
• Preventing the spread of RSV: Frequent handwashing, avoiding close contact with infected individuals, and keeping surfaces clean

RSV Prevention Strategies

• Handwashing and Hygiene
• Respiratory Etiquette
• Avoiding close contact with others
• Potential maternal RSV vaccine
• Monoclonal antibody prophylaxis
• Development of a pediatric RSV vaccine

Rhinovirus: A Common Cold Culprit

• Rhinovirus is a highly contagious respiratory virus that spreads easily through coughing, sneezing, or touching contaminated surfaces
• Leading cause of the common cold, responsible for a significant number of respiratory infections worldwide
• Diverse strains (over 100 different strains), making effective vaccines or treatments challenging

Rhinovirus Properties

• Rhinovirus is a small, non-enveloped, positive-sense single-stranded RNA virus in the Picornaviridae family
• Genome consists of a single-stranded RNA molecule (approximately 7,200 nucleotides long) encoding a single polyprotein
• Rhinovirus particles are icosahedral in shape, with a diameter of around 30 nanometers; composed of 60 copies of each of the four structural proteins VP1, VP2, VP3, and VP4
• Exhibit extensive genetic and antigenic diversity (over 100 serotypes)

Rhinovirus Receptor Binding

• Primarily binds to intercellular adhesion molecule 1 (ICAM-1) or the low-density lipoprotein receptor (LDLR) family on respiratory epithelial cells

Rhinovirus Replication

• Occurs in the cytoplasm of host cells, utilizes cellular machinery and enzymes
• Viral RNA is translated into proteins, followed by genome replication and assembly of new viral particles

Rhinovirus Transmission

• Primarily transmitted through respiratory droplets from infected individuals or by direct contact with contaminated surfaces

Rhinovirus Clinical Manifestations

• Runny or stuffy nose (rhinorrhea)
• Sore throat (pharyngitis)
• Cough.
• Fever (may occur)
• Headache and body aches (may occur)

Immunity to Rhinovirus

• Serotype-specific; infection with one serotype doesn't confer immunity to other serotypes

Rhinovirus Diagnosis

• Polymerase Chain Reaction (PCR)
• Viral culture
• Serology (Antibody testing)

Rhinovirus Management and Treatment

• Adequate fluid intake
• Rest and symptom relief medications
• Antibiotics for secondary bacterial infections

Coronavirus: An Overview

• Coronaviruses are a family of enveloped RNA viruses
• Can infect various animal species, including humans
• Cause a range of illnesses, from mild respiratory infections to severe diseases

Coronavirus Classification

• Four genera of coronaviruses: Alphacoronavirus, Betacoronavirus, Gammacoronavirus, Deltacoronavirus

• Alphacoronavirus: Human coronaviruses (HCoV-229E, HCoV-NL63), some animal coronaviruses (TGEV)

• Betacoronavirus: Severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, cause of COVID-19)

• Gammacoronavirus: Primarily infects birds but includes some mammalian coronaviruses

• Deltacoronavirus: Mainly infects birds and mammals

Coronavirus Timeline of Outbreaks

• 2003: SARS-CoV outbreak
• 2012: MERS-CoV outbreak
• 2019: SARS-CoV-2 outbreak leading to the COVID-19 pandemic
• 2021: COVID-19 vaccines widely available

COVID-19 (SARS-CoV-2)

• Identified in December 2019
• Highly transmissible
• Caused millions of infections worldwide
• Significantly impacted global morbidity and mortality

COVID-19 Virology

• Spherical enveloped virus with distinctive spike proteins (crucial for binding to ACE2 receptors on human cells)

COVID-19 Transmission

• Primarily transmitted through respiratory droplets

COVID-19 Clinical Presentation

• Variety of symptoms from asymptomatic to mild, severe, respiratory illnesses, pneumonia, ARDS, and multi-organ failure

COVID-19 Diagnosis

• Confirmation using RT-PCR

COVID-19 Management and Treatment

• Supportive care, including oxygen therapy, fluid management, and monitoring for complications
• Antiviral medications (like remdesivir or molnupiravir) may be considered
• Corticosteroids like dexamethasone are sometimes considered in serious cases
• Monoclonal antibodies

COVID-19 Prevention and Control

• Vaccination
• Physical distancing
• Wearing face masks
• Frequent hand hygiene

Influenza Viruses

• Belong to the Orthomyxoviridae family
• Categorized into types A, B, C, and D

Influenza A viruses

• Cause seasonal epidemics and occasional pandemics in humans and various animal species
• Undergo frequent genetic mutations

Influenza B viruses

• Primarily infect humans
• Cause seasonal outbreaks

Influenza C viruses

• Cause mild illness in humans

Influenza D viruses

• Primarily infect livestock and have been isolated in humans.

Influenza Virus Timeline

• 1918: Spanish Flu pandemic
• 1957: Asian Flu pandemic
• 1968: Hong Kong Flu pandemic
• 2009: H1N1 Swine Flu pandemic

Influenza viral structure

• Segmented negative-sense RNA genome
• Enveloped with HA and NA glycoproteins

Influenza Virus Genetic Reassortment

• Influenza viruses posses a segmented genome
• Genetic reassortment can create new viral combinations

Influenza Clinical Manifestations

• Fever, cough, sore throat, muscle aches, fatigue, and severe cases leading to pneumonia, respiratory failure, and death