Distribution and Clinical Profile of Human Parainfluenza Viruses in Hospitalized Patients With Acute Febrile Illness.

Introduction: Human parainfluenza viruses (HPIVs) are significant causes of respiratory infections, particularly in children, yet their epidemiology remains poorly understood in low- and middle-income countries. HPIVs contribute to 20%-40% of pediatric lower respiratory tract infections (LRTIs) and are a leading cause of croup and hospitalizations. This study was aimed at determining the incidence, distribution, and clinical and laboratory characteristics of HPIV in hospitalized acute febrile illness (AFI) patients. Methods: A total of 12,409 AFI cases from 2016 to 2018 were tested for HPIVs via molecular methods. RNA was extracted from throat swab samples and tested via multiplex real-time RT-PCR for HPIV Serotypes 1-4. The demographic, clinical, and laboratory data of HPIV-positive patients were analyzed statistically. Results: HPIVs were detected in 217 (1.75%) patients, with HPIV-3 (49.77%) being the most prevalent, followed by HPIV-4 (18.90%), HPIV-2 (17.52%), and HPIV-1 (13.83%). HPIV-3 exhibited distinct seasonal peaks, mainly affecting children (1-9 years). Significant variations in hematological and biochemical markers were observed among serotypes and age groups. Upper and lower respiratory symptoms, along with gastrointestinal issues and systemic manifestations such as chills, myalgia, and weakness, are commonly reported. Conclusion: HPIVs contribute to respiratory illness across diverse demographics. HPIV-3 is the predominant serotype, with distinct seasonal and age-related patterns. Improved surveillance and diagnostics could aid in better management and reduce unnecessary antibiotic use.