Respiratory syncytial virus and influenza are the key viral pathogens in children <2 years hospitalized with bronchiolitis and pneumonia in Islamabad Pakistan

Abstract

Pneumonia remains a leading cause of morbidity and mortality in developing countries. Comprehensive surveillance data are needed to review the prevention and control strategies. We conducted active surveillance of acute lower respiratory infections among children aged <2 years hospitalized at two hospitals of Islamabad, Pakistan. Viral etiology was determined using real-time PCR on respiratory specimens collected during March 2011-April 2012. The overall mean age was 7.83 ± 5.25 months while no statistical difference between age or sex distribution of patients with positive and negative viral etiology (p > 0.05). The average weight of the study group was 6.1 ± 2.25 kg. ≥1 viral pathogens were detected in 75% cases. Major respiratory viruses included RSV-A: 44%, RSV-B: 23%, Influenza-A: 24.5%, Influenza-B: 7%, Adenovirus: 8.4% and HmPV: 5.2%. A single, dual or multiple viral pathogens were detected in 43%, 27% and 5.2% patients respectively. Common symptoms were cough (95%), apnoea (84%), fever (78%), wheeze (64.5%), nasal congestion (55%) and rhinorrhea (48%). Among the RSV positive cases, 2-6 months age group had highest detection rate for RSV-A (30%, n = 21/69) and RSV-B (20%, n = 14/69) while patients infected with Influenza-A were in 2.1-6 months age group (61%, 23/38). Statistically significant difference was observed between RSV-positive and negative cases for nutrition status (p = 0.001), cigarette/wood smoke exposure (p = 0.001) and concomitant clinical findings. Most patients had successful outcome on combination therapy with bronchodilators, inhaled steroids and antibiotics. Our findings underscore high burden of ALRI in Pakistan. Interventions targeting viral pathogens coupled with improved diagnostic approaches are critical for better prevention and control.

Etiology of acute viral respiratory infections common in Pakistan: A review

“…Twenty four percent of samples were positive, and out of these positive, 22% were subtyped RSV‐B. Three genotypes of RSV‐B—BA‐9, BA‐10, and BA‐13—were isolated . Throat swabs were tested by RT‐PCR.…”

“…Major pathogens included 44% RSV‐A, 23% RSV‐B, 24.5% influenza A, 7% influenza B, 8.4% adenovirus, and 5.2% HMPV. RSV‐A and RSV‐B association was detected more commonly during 2 to 6 months of age, while influenza A was estimated as more common in 2.1 to 6‐month age group . RSV association with kids between the ages of one and 5 years old suffering from pneumonia and asthma was the most widely recognized finding of a 3‐year study conducted in Karachi from August 2009 to June 2012.…”

“…Every year, almost 200 million cases of viral pneumonia occur, which affects children and adults equally . Common symptoms include cough, high‐temperature fever, wheeze, runny nose, and nasal congestion . In 2017, UNICEF assessed 64% of children under age 5 indicating the symptoms of pneumonia in Pakistan…”

“…Major pathogens involved were RSV‐A, RSV‐B, influenza A, influenza B, adenovirus, and HMPV. Cases involving dual and even multiple pathogens were also identified . Children less than 5 years of age conceded with intense respiratory contaminations (ARI) were enlisted for another study conducted at Aga Khan University Hospital, Karachi.…”

Immunological Features of Respiratory Syncytial Virus-Caused Pneumonia—Implications for Vaccine Design

“…Pneumonia is primarily due to infectious agents, such as viruses, bacteria and fungi. Streptococcus pneumoniae and Klebsiella pneumoniae are the most common bacterial etiology, whereas the human respiratory syncytial virus (hRSV), influenza and rhinovirus are the more frequent viral causal agents of pneumonia [5,6]. Furthermore, virus and bacteria co-infections are usually observed in about 40% of patients with community-acquired pneumonia [7].…”