humanparainfluenzavirus 1.pptx. .

Human para influeza.

1. Human ParaInfluenza Virus (HPIV)

2. Introduction Human parainfluenza viruses (HPIV) were first discovered in the late 1950s. They are the second most common cause of lower respiratory tract infection, especially in younger children. HPIV is genetically and antigenically divided into types 1 to 4.

3. Negative sense, single-stranded RNA virus Varies in size and shape d = 150-300 nm Major cause of croup Enveloped, pleomorphic morphology Divided into 4 types Type 1 Sendai Virus Type 2 Acute Laryngo tracheo bronchitis. Type 3 Respiratory infection in children Type 4 Respiratory infection.

4. Viral Replication V irus and host cell lipid membranes fuse together. HPIV nucleocapsid is ejected into the cytoplasm of the cell. With the help of the virus-specific RNA-dependent RNA polymerase (L protein), the transcription takes place. Viral mRNAs are translated into the viral proteins. Full-length replication of the virus genome. Positive strand. Negative strand. Produced single negative-sense strands of RNA are then encapsidated with NP. Ready for use.

5. Epidemiology Predisposing factors HPIV are common community-acquired respiratory pathogens without ethnic, socioeconomic, gender, age, or geographic boundaries. HPIV cause URI in infants, children, and adults and, to a lesser extent, LRI in the immunocompromised , those with chronic diseases (e.g., heart and lung disease and asthma) and the elderly. Malnutrition Overcrowding Vitamin A deficiency Lack of breast feeding Environmental smoke or toxins  Immunosuppression

6. Mode of transmission HPIV-1 could be recovered from only 2 of 40 infected children at a distance of 60 cm. Close-contact transmission and surface contamination. HPIV-1, HPIV-2, and HPIV-3 have all been shown to survive for up to 10 h on nonporous surfaces and 4 h on porous surfaces. Person-to-person spread by direct hand contact appears to be an unlikely. The amount of virus excreted from an acutely infected child may be more than 10 times. Can be efficiently removed from surfaces with most common detergents, disinfectants, or antiseptic agents. 

7. Pathogenesis HPIV infection in the respiratory tract leads to secretion of high levels of inflammatory cytokines such as interferon (IFN)–alpha, interleukin (IL)–2, IL-6, and tumor necrosis factor (TNF)–alpha. The peak duration of secretion is 7-10 days after initial exposure. Increasing levels of certain chemokines such as RANTES (regulated upon activation, normal T-cell expressed and secreted), macrophage inflammatory protein (MIP)–K are detected in the nasal secretion of paediatric patients.

8. Symptoms Symptoms of a common head cold nasal congestion runny nose sore throat cough Inflammation of nasal cavity mucous membrane Inflammation of the larynx and upper airway Results in narrowing of the airway Inspiratory stridor (a sound heard in inspiration through a spasmodically closed glottis) Intercostal retractions (retractions of the chest cavity) Diffused inflammation with erythema and edema in the tracheal walls (because the subglottic region of a child’s upper airway is narrow, a small amount of edema can significantly restrict airflow)

9. Clinical conditions that can be caused by HPIV Causes 10% of the respiratory infections CROUP (acute laryngotracheobronchitis ) Bronchitis Bronchiolitis Pneumonia Minor respiratory tract infections Flu-like tracheobronchitis Nosocomial infections

10. Diagnosis Pulse Oximetry Used to evaluate the severity of the illness. Laryngoscopy Used in severe cases of parainfluenza virus infection. Radiogrpahy Posteroanterior (PA) radiography of the neck (o nly confirms 50% of cases)

11. Lab tests: Isolation and identification of the virus in cell culture or by direct detection of the virus in respiratory secretions (usually, collected within one week of onset of symptoms) using immunofluorescence , enzyme immunoassay, or polymerase chain reaction assay Demonstration of a significant rise in specific IgG antibodies between appropriately collected paired serum specimens or specific IgM antibodies in a single serum specimen CBC: Complete Blood Count measures: Red blood cell (RBC), white blood cell (WBC), total hemoglobin in blood, hematocrit (fraction of blood composed of RBCs), and mean corpusular volume (MCV, which measures size of RBCs), ESR

12. Treatment No vaccine to date Instead, treatment is focused on managing the symptoms. Based on the severity of symptoms, mainly of croup: Croup severity ranges from mild or moderate, to severe Severity of the infection is based upon five factors ( Level of consciousness, Cyanosis, Stridor , Air Entry and Retractions)

13. Diet Analgesics Ribavirin Cool mist and oral intake of fluids (for soothing the inflamed mucosa) Nebulized epinephrine (for symptom alleviation) Corticosteroids ( orally, for inflammation and edema) Heliox (b reathing gas, mixture of helium + oxygen) Intubation (in severe cases)

14. Case-HPIV-3 and Pneumonia Patient Profile:

Age: 3 years
Gender: Female
Medical History: Recurrent wheezing episodes, no other significant history
Presentation:
High fever (39.5°C)
Persistent cough
Shortness of breath
Crackles heard on lung auscultation

15. Diagnosis: Chest X-ray showed patchy infiltrates consistent with viral pneumonia. Nasopharyngeal swab confirmed HPIV-3. Management: Hospitalization due to respiratory distress Intravenous fluids for dehydration Supplemental oxygen to maintain adequate saturation Broad-spectrum antibiotics initiated until bacterial pneumonia was ruled out Corticosteroids to reduce airway inflammation Outcome: Significant improvement after seven days Discharged with a tapering dose of oral corticosteroids and instructions for follow-up

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