Human Metapneumovirus (hMPV) |

 

Human Metapneumovirus (hMPV)

Definition

Human metapneumovirus (hMPV) is a single-stranded RNA virus belonging to the Paramyxoviridae family. It is a leading cause of respiratory infections in humans, affecting individuals across all age groups, particularly young children, the elderly, and immunocompromised individuals.

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History

• Discovery: hMPV was first identified in 2001 in the Netherlands.

• Relation: It is closely related to avian metapneumovirus, suggesting a zoonotic origin.

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Transmission

1. Mode of Spread:

   • Respiratory droplets from coughing or sneezing.

   • Direct contact with contaminated surfaces or infected individuals.

2. Seasonality:

   • Common in late winter and early spring.

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Epidemiology

• hMPV is a global pathogen, with nearly universal exposure by age 5.

• It accounts for a significant proportion of respiratory illnesses in both outpatient and inpatient settings.

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Pathophysiology

• Infection Site: Primarily infects the epithelial cells of the respiratory tract.

• Immune Response: Triggers inflammation and cytokine release, leading to airway obstruction and respiratory symptoms.

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Clinical Manifestations

1. Mild Infections:

   • Nasal congestion

   • Cough

   • Fever

2. Severe Infections:

   • Bronchiolitis

   • Pneumonia

   • Wheezing and shortness of breath

3. High-Risk Groups:

   • Infants and young children

   • Elderly individuals

   • Immunocompromised patients

   • Individuals with underlying respiratory or cardiac conditions

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Diagnosis

1. Clinical Assessment:

   • Based on symptoms and exposure history.

2. Laboratory Tests:

   • RT-PCR: Gold standard for detecting hMPV RNA.

   • Antigen Detection: Rapid diagnostic tests.

   • Serology: Measures specific antibodies, though less commonly used.

3. Imaging:

   • Chest X-rays in severe cases may show interstitial infiltrates or hyperinflation.

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Treatment

1. Supportive Care:

   • Hydration

   • Antipyretics for fever

   • Oxygen therapy for hypoxemia

2. Antiviral Therapy:

   • Currently, no specific antiviral drugs are approved for hMPV.

3. Hospitalization:

   • Required for severe cases with respiratory distress.

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Prevention

1. Hygiene Practices:

   • Frequent handwashing

   • Avoiding close contact with infected individuals

2. Infection Control:

   • Use of personal protective equipment in healthcare settings

3. Vaccination:

   • Vaccines are under development but not yet commercially available.

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Complications

1. Acute:

   • Respiratory failure

   • Secondary bacterial infections

2. Chronic:

   • Potential exacerbation of asthma or chronic obstructive pulmonary disease (COPD).

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Global Impact

• hMPV causes a significant healthcare burden due to hospitalizations and outpatient visits, especially among vulnerable populations.

• Research continues to focus on vaccine development and effective antiviral therapies.

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