Respiratory Syncytial Virus-associated hospitalization in premature infants who did not receive palivizumab prophylaxis in Italy: a retrospective analysis from the Osservatorio Study

Abstract

BackgroundDue to different social and epidemiological factors, the eligibility criteria to receive palivizumab prophylaxis may be different between countries, especially in “otherwise healthy” late preterm infants.MethodsWe analyzed an Italian database of young children referred to emergency departments for acute lower respiratory tract infection (ALRI) during the RSV season over a four year period, when the use of palivizumab as prophylaxis for RSV disease was not widespread in premature infants. The demographic and environmental characteristics and the RSV positivity (RSV+) in hospitalized and not-hospitalized patients were compared. In the data analysis we divided children according to their chronologic age (age) and their week gestational age (wGA).ResultsOut of the 100 children evaluated, 68 were infants (≤12 month-age): 7.5 and 20.6 % were in the <29 and 29- < 32 wGA groups respectively, and 72.0 % in the 32- < 35 wGA group. Positive hospitalized-to-not-hospitalized ratios were found in all three wGA groups, progressively decreasing (from 4.0 to 1.2), with increasing wGA (p = 0.35). The percentage of hospitalized infants that were also RSV+ was also progressively decreasing (from 40.0 to 28.6 % and 18.4 %) with increasing wGA (p = 0.43). In the >12 month-age group (N = 32), there was positive hospitalized-to-not-hospitalized ratio only in the <29 wGA group with a low RSV+ frequency (<29 %) in all wGA groups. In the ≤12 month-age group, 41 infants were evaluated with a ≤6 month-age and 27 with a >6–12 month-age. A positive hospitalized-to-not-hospitalized ratios was found in all wGA groups in ≤6 month-age infants, despite a low RSV+ frequency in the 29- < 32 and 32- < 35 wGA group. In the >6-12 month-age group, all infants with a <29 and 29- < 32 wGA were hospitalized with a relatively high RSV+ frequency whilst the 32- < 35 wGA group showed a negative hospitalized-to-not-hospitalized ratio with a lower RSV+ frequency.ConclusionsThe hospitalized-to-not-hospitalized ratios and RSV+ frequency in the first 12 months of age in infants born prematurely confirm the vulnerability of these children for clinically important RSV infection, most notably in the <32 wGA category.

Respiratory Syncityal Virus A and B: three bronchiolitis seasons in a third level hospital in Italy

“…This result confirms the literature data that highlights aggressiveness of RSV in premature infants. [2, 28, 30, 33]. In 2017, a large retrospective work on prematures [13] identified an oxygen supplementation rate of around 80% and a PICU admission rate of 22%, while in our work emerged a lower rate both for O2 supplementation (62%) and PICU admission (16,1%), but a raising trend for both parameters.…”

Defining the Risk and Associated Morbidity and Mortality of Severe Respiratory Syncytial Virus Infection Among Preterm Infants Without Chronic Lung Disease or Congenital Heart Disease

“…After 18 months of age, however, RSVH was rare [59]. A recent retrospective analysis from the Osservatorio Study in Italy [60], which enrolled three different gestational age group infants (<29, 29 to <32 and 32–35 wGA), found that the percentage of hospitalized preterm infants ≤12 months old that were RSV positive progressively decreased from 40.0% to 28.6% and 18.4% with increasing wGA ( P  = 0.43). These data suggest that, at least in the first year of life, the most premature infants were more vulnerable and prone to RSV infection [60].…”

The impact of the recent AAP changes in palivizumab authorization on RSV-induced bronchiolitis severity and incidence

“…However, following the most recent modification by the American Academy of Pediatrics based on American studies on RSV epidemiology [ 4 ], in September 2016, the Italian Drug Agency (AIFA) decided the total financial coverage of the palivizumab prescription to the healthy preterms by the National Health Service, should be limited to the < 29 wGA group and age ≤ 12 months at the beginning of the RSV epidemic season (RES) [ 5 ]. However, the vulnerability of otherwise healthy premature infants, and most notably in the < 32 wGA category was demonstrated by an Italian retrospective analysis on RSV-associated hospitalization during the RSV epidemic season, over a 4 year period, when the use of prophylaxis palivizumab was not widespread in premature infants [ 6 ]. Moreover, a recent study on total costs for hospitalizations and emergency room and/or outpatient visits in infants in the first 3 years of life in Lombardy (Italy) showed that extending palivizumab prophylaxis to 29–32 wGA infants appeared to be a cost-effective strategy [ 7 ].…”