Age‐specific incidence rates and risk factors for respiratory syncytial virus‐associated lower respiratory tract illness in cohort children under 5 years old in the Philippines

Abstract

Background Respiratory syncytial virus (RSV) is one of the main viral causes of lower respiratory tract illness (LRTI), especially in young children. RSV vaccines, including maternal and infant vaccines, are under development; however, more epidemiological studies are needed to develop effective vaccination strategies. Objectives To estimate detailed age‐specific incidence rates and severity of RSV‐associated LRTI (RSV‐LRTI) using data from a community‐based prospective cohort study in the Philippines. Patients/Methods Cohort children who visited health facilities due to acute respiratory symptoms were identified, and nasopharyngeal swabs were collected to detect RSV. The severity of RSV‐LRTI was assessed using the severity definition proposed by the World Health Organization. Risk factors for developing RSV‐LRTI and contribution of SpO 2 measurement were also evaluated. Results A total of 395 RSV episodes which occurred in children aged 2‐59 months were categorised as 183 RSV‐LRTI, 72 as severe RSV‐LRTI and 29 as very severe RSV‐LRTI. Children aged 3‐5 months had the highest incidence rate of RSV‐LRTI, at 207.4 per 1000 child‐years (95% CI: 149.0‐279.5). Younger age group, place of living and low educational level of caregivers were associated with developing RSV‐LRTI. Clinical manifestations had low levels of agreement with hypoxaemia as measured by pulse oximeter. Conclusion The highest burden of RSV was observed in young infants aged 3‐5 months, whereas the burden was also high in those aged 12‐20 months. Future vaccination strategies should consider the protection of older children, especially those aged one year, as well as young infants.

Epidemiology and Seasonality of Childhood Respiratory Syncytial Virus Infections in the Tropics

“…Excellent surveillance across the Philippines consistently shows RSV ranking as one of the top two most commonly detected respiratory viruses each year, and as the leading cause of hospitalization among infants and young children [ 25 , 26 , 27 , 37 , 38 , 39 , 40 ]. Furuse et al found that nearly 24% of all RSV-infected children visit a medical facility during their infection, with 2% requiring hospitalization [ 38 ].…”

“…Reported RSV positivity rates range between 12 and 27% by location, but the highest rates of detection and incidence of severe disease are consistently seen among children less than 2 years of age [ 25 , 26 , 27 , 37 , 38 ]. In addition to young age, other risk factors for the development of severe RSV included a lower educational level of caregivers and underlying malnutrition [ 26 , 39 ]. Like other parts of the world, transmission of RSV infection within households is well documented.…”

Respiratory syncytial virus acute respiratory infection‐associated hospitalizations in preterm Mexican infants: A cohort study

“…However, questions still remain regarding the optimal approach for RSV prophylaxis with palivizumab, and the need for additional epidemiological data regarding the incidence of RSV hospitalizations has been identified . The incidence of ARI‐ and RSV‐associated hospitalizations varies in different countries . This could be the result of diverse factors, including social conditions, environmental factors, or healthcare systems.…”

“…11,12 The incidence of ARI-and RSV-associated hospitalizations varies in different countries. [13][14][15][16] This could be the result of diverse factors, including social conditions, environmental factors, or healthcare systems. The incidence of severe RSVassociated infections in preterm infants in Mexico has not been defined.…”

Reducing childhood respiratory morbidity and mortality in low and middle income countries: a current challenge

“…However, this revision did not deal with the problem of underdiagnosis of obstructive airway disease. Only a few studies have analysed the impact of its implementation, especially in Southeast Asia [14][15][16][17].…”