parainfluenssat

Parainfluenssat, or human parainfluenza viruses (HPIV), are a group of enveloped, negative-sense RNA viruses in the family Paramyxoviridae. They include four serotypes, HPIV-1 through HPIV-4, which are organized into two genera: HPIV-1 and HPIV-3 belong to Respirovirus, while HPIV-2 and HPIV-4 belong to Rubulavirus. These viruses are among the common causes of acute respiratory infections worldwide, particularly in young children, though they can affect people of any age.

Transmission occurs primarily via respiratory droplets and direct contact with contaminated surfaces. The incubation period is typically 2 to 7 days. Clinical presentations range from mild upper respiratory symptoms to more severe diseases such as croup (laryngotracheobronchitis), bronchiolitis, pneumonia, and feverish pharyngitis. HPIV-1 is a frequent cause of croup in toddlers; HPIV-3 is commonly associated with bronchiolitis and pneumonia in infants. HPIV-2 and HPIV-4 often cause milder illnesses but can contribute to significant disease in young children and older adults. In temperate regions, infections occur year-round with seasonal peaks that vary by serotype and location.

Diagnosis is usually based on clinical presentation and can be supported by laboratory testing, most commonly reverse-transcription PCR on nasopharyngeal specimens. Viral culture is less commonly used in routine care. Treatment is mainly supportive, as there are no widely approved antiviral drugs for HPIVs. In severe cases or among immunocompromised patients, antiviral therapy such as ribavirin may be considered in expert centers; corticosteroids may be used for severe croup when indicated. Prevention relies on standard infection-control measures, including hand hygiene and avoidance of contact with sick individuals. There are currently no licensed vaccines for HPIVs, though several candidates and approaches are under investigation.