RSV and Late Preterm Infants

**29**

**Chapter 2**

Infants

**Abstract**

Resolving the Debate on RSV

*Bosco Paes, Barry Rodgers-Gray and Xavier Carbonell-Estrany*

There is still active debate in the scientific literature about the importance of providing respiratory syncytial virus (RSV) prophylaxis to late preterm infants born at 33–35 weeks' gestational age (wGA). The American Academy of Pediatrics and the Canadian Paediatric Society position statements only advocate for RSV prophylaxis for infants <30 wGA. Several publications prove the contrary, reporting substantial morbidity and even mortality in older GA infants, following RSV infection. Consequently, other Societies, such as from Spain and Italy, have different criteria, and include as candidates 30–32 wGA infants and 33–35 wGA infants with risk factors for severe RSV disease. This chapter will systematically examine the current evidence for RSV prophylaxis in both early and late preterm infants 29–35 wGA and the cost-effectiveness of this strategy with the use of risk scoring tools. The authors will attempt to reconcile the misconception that late preterm infants do not merit RSV prophylaxis and hopefully resolve the long-standing

**Keywords:** respiratory syncytial virus, palivizumab, prematurity, cost effectiveness,

Respiratory syncytial virus (RSV) infection is a common cause of lower respiratory tract infection (LRTI) in young children and is associated with a high global burden of incurred illness. In 2015, 2.8 million new episodes of RSV-related infections were reported in children <5 years of age in high income countries [1]. Of these, at least 383,000 cases required hospital admissions with 3300 accompanying deaths [1]. These figures represent a major healthcare burden, with costs estimated

Preterm birth, those born <37 weeks' gestational age (wGA), has been associated with an increased risk for severe RSV-related disease requiring hospitalization (RSVH) [3]. Possible explanations for the increased RSV infection rates in preterm infants are incomplete airway development with reduced alveolar and bronchiolar diameter, increased air space wall thickness, immature immunologic responses, and reduced levels of maternally transmitted, RSV-specific antibodies compared to infants born at term [4]. Globally, about 15 million infants per year are estimated to be born premature, nearly 10% of all births, and thus are at potentially increased risk for RSV infection [5, 6]. Furthermore, the World Health Organization (WHO)

Prophylaxis in Late Preterm

debate that currently exists in many countries worldwide.

to be \$545 million in the United States alone in 2009 [2].

prevention, risk scoring tools

**1. Introduction**

## **Chapter 2**
