The Indian Council of Medical Research (ICMR) has confirmed two cases of Human Metapneumovirus (HMPV) in Karnataka through routine surveillance. Both cases, detected at Bengaluru Baptist Hospital, were identified as part of ICMR’s ongoing monitoring of respiratory illnesses across the country.
Human Metapneumovirus (HMPV) is a respiratory virus that primarily infects the upper and lower respiratory tracts. It was first discovered in 2001 and is a member of the Metapneumovirus genus in the Paramyxoviridae family, which also includes other respiratory viruses such as respiratory syncytial virus (RSV) and parainfluenza viruses.
Key Features of HMPV:
- Structure: HMPV is an enveloped, single-stranded, negative-sense RNA virus.
- Transmission: The virus spreads primarily through respiratory droplets when an infected person coughs or sneezes. It can also be spread by touching contaminated surfaces and then touching the mouth, nose, or eyes.
- Incubation Period: The incubation period is usually between 3 to 6 days after exposure to the virus.
Clinical Presentation:
Infection with HMPV can cause a range of respiratory symptoms, from mild to severe. Common symptoms include:
- Fever
- Cough
- Nasal congestion
- Sore throat
- Wheezing
- Shortness of breath
- Fatigue
- Headache
In severe cases, particularly in infants, the elderly, and immunocompromised individuals, HMPV can lead to more serious respiratory conditions, such as:
- Bronchiolitis (inflammation of the small airways in the lungs)
- Pneumonia
Risk Groups:
- Infants and young children: More likely to develop severe respiratory illness.
- Elderly individuals: May experience more severe symptoms, particularly those with underlying health conditions such as cardiovascular or respiratory diseases.
- Immunocompromised individuals: People with weakened immune systems are at increased risk for severe disease.
Diagnosis:
HMPV is typically diagnosed through:
- Polymerase Chain Reaction (PCR) testing: This is the most sensitive method for detecting HMPV in respiratory samples such as nasal swabs, throat swabs, or sputum.
- Virus culture: This is a more traditional method, though it is not commonly used for routine diagnosis.
- Serology: Antibody tests can help detect past infections but are not used for acute diagnosis.
Treatment:
There is no specific antiviral treatment for HMPV infection. Treatment is generally supportive and may include:
- Hydration: To prevent dehydration due to fever and respiratory symptoms.
- Fever management: Antipyretics like acetaminophen or ibuprofen.
- Oxygen therapy: In cases of severe respiratory distress or pneumonia.
- Mechanical ventilation: In rare severe cases, when breathing support is required.
Prevention:
Preventive measures are similar to those for other respiratory viruses:
- Hand hygiene: Regular handwashing with soap and water.
- Avoiding close contact with infected individuals, especially during respiratory symptoms.
- Disinfection: Cleaning frequently touched surfaces to reduce transmission.
- Vaccines: Currently, there is no vaccine available for HMPV, although research is ongoing in this area.
Seasonality:
HMPV infections tend to occur seasonally, typically during the winter and early spring months, although it can circulate year-round, similar to RSV.
Differentiation from Other Respiratory Infections:
Because the symptoms of HMPV can overlap with those of other respiratory viruses like RSV, influenza, and rhinovirus, laboratory testing is often required to definitively diagnose HMPV and differentiate it from these other pathogens.
Conclusion:
HMPV is an important cause of respiratory illness, particularly in vulnerable populations like young children, the elderly, and immunocompromised individuals. While there is no specific antiviral treatment or vaccine, supportive care is effective for most cases, and preventive measures such as good hygiene practices can help limit transmission. Research into better diagnostic tools and vaccines is ongoing, which could improve the management and prevention of HMPV in the future.