Parainfluenza virus infections in a tropical city: clinical and epidemiological aspects

Abstract

Human parainfluenza viruses (HPIV) are genetically and antigenically divided into types 1 to 4 [1]. HPIV-1 to HPIV-3 are major causes of acute respiratory infections (ARI), including lower respiratory tract infections, in infants and children. These three types of HPIV have been more extensively investigated than HPIV-4 [2-4]. All subtypes can cause a full spectrum of respiratory illness, including upper respiratory infections, croup, bronchiolitis and pneumonia [1,5]. Seasonal patterns of HPIV infections are distinct among the subtypes and geographic regions. In the USA, HPIV-2 can cause yearly outbreaks or biennial epidemics in cocirculation with HPIV-1 during the fall seasons, while HPIV-3 causes yearly spring and summer epidemics [5][6][7][8][9][10]. In England and Wales HPIV-3 causes yearly epidemics in the summer as shown [11]. In the northeast of England, a hospital-based study of the epidemiology of respiratory infections among pediatric inpatients over a six-year period showed that HPIV-1 and HPIV-2 epidemics occurred together, but only every 2 years [12]. In tropical countries, there have been fewer studies of HPIV and most of them do not demonstrate a seasonal pattern of HPIV infections [13,14].The purposes of the study were: (1) To determine the rate of HPIV infections among children attended at the Albert Sabin Children's Hospital (HIAS) over six consecutive years; (2) To describe the clinical and epidemiological characteristics of these infections; (3) To show the seasonal pattern of HPIV infections and its relation with the rainy season and with periods of activity of other respiratory viruses; and (4) To compare the clinical characteristics of parainfluenza infections with infections caused by respiratory syncytial virus (RSV), influenza and adenovirus. Material and Methods Site of StudyThis study was conducted at HIAS, a teaching hospital where care is provided to children from low income families living in Fortaleza and other cities in the state of Ceará. The city of Fortaleza is located at sea level, 4 o south of the equator and has a tropical climate characterized by two distinct seasons: the rainy season, that occurs in the first semester of each year, usually from January to June, and the dry season, during the rest of the year. The humidity is high (>70%), and there is little temperature variation throughout the year. During this study, the minimum and maximum daily temperatures in Fortaleza were 21.1 o C and 33.9 o C, respectively. Population of StudyThe patients included in this study were children and teenagers (0 to 16 years old) with acute respiratory symptoms. They were attended at the emergency department, outpatients' clinics and pediatric wards of HIAS from January 2000 to December 2006. Inclusion CriteriaPatients were included in the study if they had one or more of the following symptoms with or without fever (≥37.5 o C): cough, coryza, sore throat, earache, breathing difficulty, stridor and/or wheezing within seven days of onset. Epidemiological and Clinical DataThe guardians a...

Acute respiratory viral infections in children in Rio de Janeiro and Teresópolis, Brazil

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The potential influence of human parainfluenza viruses detected during hospitalization among critically ill patients in Kuwait, 2013–2015

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Comparative Dynamics, Morbidity and Mortality Burden of Pediatric Viral Respiratory Infections in an Equatorial City

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