An R.S.V.P. to R.S.V. (respiratory syncytial virus): declining mortality rates

Incidence and clinical features of hospitalization because of respiratory syncytial virus lower respiratory illness among children less than two years of age in a rural Asian setting

BACKGROUND

Lower respiratory illness is the leading cause of child death in the developing world. Despite this few reports on respiratory syncytial virus (RSV) lower respiratory illness disease burden exist from rural areas of the developing world, and none exist for Indonesia.

METHODS

We evaluated children living in any of 83 villages on Lombok Island, Indonesia who were <2 years of age when hospitalized for severe lower respiratory illness during 2000 and 2001. All hospitals on Lombok were included in the evaluation. We obtained the number of births and deaths that occurred within the study villages and time frame, allowing for incidence determination.

RESULTS

Of 2677 children hospitalized for severe lower respiratory illness whose RSV status was determined, 23% had a positive test; this percentage varied from 50% at the end of the rainy season to 0% shortly before the start of the rainy season. Among children <2 years of age, the confirmed and estimated incidences of severe RSV lower respiratory illness hospitalization were 10 and 14 per 1000 child-years, respectively; values for children <1 year of age were 17 and 25 per 1000 child-years. The confirmed case-fatality percentage among RSV-positive cases was 1.9%; however, 84% of children who died were dead before RSV status could be determined, suggesting the actual case fatality percentage was higher.

CONCLUSIONS

Lombok has a large burden of severe childhood RSV lower respiratory illness, and death occurs frequently. Novel RSV vaccines thus could have a substantial positive impact on lower respiratory illness morbidity and mortality.

[Is the use of ribavirin aerosols in respiratory syncytial virus infections justified? Clinical and economic evaluation]

The controversy about the use of ribavirin aerosol for children at risk (cardiopathy, pneumopathy, premature and immunodeficient patients), in case of respiratory syncytial virus (RSV) infection, led us to stop its prescription in 1993 and study prospectively the patients admitted during the following winters.

METHODS

Criterias of inclusion for this study were those of the Committee on Infectious Diseases of the American Academy of Pediatrics concerning the use of ribavirin aerosol. Two cohorts of patients were studied: the first group included treated patients (ribavirin group: n = 22, ribavirin and support treatment: salbutamol aerosols, respiratory physiotherapy and oxygen-therapy; winters 1989-1990 to 1992-1993); the second group included patients with support treatment only (control group: n = 22; winters 1993-1994 and 1994-1995).

RESULTS

The clinical gravity score at admission (4.55 vs 5.23, P = 0.46) and the risk factor scores (3.05 vs 3.27, P = 0.69) of the two groups were identical. Results showed that the children of the ribavirin group stayed much longer in hospital (14.2 vs 8.2 days, P = 0.002) and in the intensive care unit (7.2 vs 0.2 days, P < 0.001) than those of the control group. More support treatment was necessary for the ribavirin group as regard respiratory physiotherapy (3.8 vs 2.7 sessions a day, P = 0.026), the duration of oxygen-therapy (7.3 vs 3.7 days, P = 0.030) and the number of children requiring respiratory assistance (4 vs 0 children, P = 0.116). Administration of ribavirin aerosols (480 US$ a dose) and the way in which such treatment was carried out meant high daily costs for the ribavirin group (1,076 vs 604 US$, P < 0.001). As hospitalization was longer for children treated with ribavirin, the global cost was therefore much higher (15,552 vs 5,156 US$, P < 0.001).

CONCLUSION

The antiviral effect of ribavirin is undeniable. However ribavirin is known to be the cause of severe bronchospasms (two cases in our study) and can also cause moderate and long term bronchospasms, aggravating therefore the clinical evolution of the disease. Our experience shows that administration of ribavirin aerosols in case of RSV infection of inferior respiratory airways seems not to be justified.

Effectiveness of ribavirin in otherwise well infants with respiratory syncytial virus-associated respiratory failure. Pediatric Critical Study Group

OBJECTIVE

To examine ribavirin's effectiveness in otherwise well infants with respiratory syncytial virus (RSV)-associated respiratory failure.

DESIGN

Prospective multicenter cohort study.

SETTING

Pediatric critical care units affiliated with the Pediatric Critical Care Study Group; 38 centers from the United States and Canada participated.

PATIENTS

Infants with RSV-associated respiratory failure undergoing mechanical ventilation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Data collected included demographic information; dates of hospitalization, intensive care, and mechanical ventilation; all patient diagnoses; reason for tracheal intubation; dates of ribavirin use before and during mechanical ventilation; time in hours after intubation until ribavirin administration; Pediatric Risk of Mortality (PRISM) score; and outcome. A total of 439 patients received mechanical ventilation for RSV-associated respiratory failure; 223 were classified as previously well and met entry criteria. Ninety-one infants (41%) received ribavirin during mechanical ventilation. The PRISM scores during the initial 24 hours of intensive care and blood gas measurements before intubation were similar for patients who received ribavirin versus those who did not. Use of ribavirin during mechanical ventilation was associated with prolonged duration of mechanical ventilation (p < 0.01) in a multivariate model that controlled for patient age, gender, prematurity status, and use of ribavirin before intubation. Subgroup analysis of mechanical ventilation days for previously well patients was 5.0 +/- 4.2 in the no-ribavirin group versus 6.4 +/- 5.0 in the ribavirin group (p < 0.05) and for well premature infants was 6.3 +/- 4.9 in the no-ribavirin group versus 9.0 +/- 6.3 in the ribavirin group (p < 0.01). The mortality rates for the term and the premature groups were similar for treated and untreated patients.

CONCLUSIONS

Ribavirin administration during mechanical ventilation to previously well infants with RSV infection was not associated with reductions in either mortality rates or duration of mechanical ventilation. Additional clinical effectiveness studies are required to define specific groups in which the use of aerosolized ribavirin is indicated.

Respiratory syncytial virus triggered adult respiratory distress syndrome in infants: a report of two cases

Two infants with severe respiratory syncytial virus infection which resulted eventually in classical adult respiratory distress syndrome (ARDS) are presented. Both infants had severe apneic spells, necessitating intubation and mechanical ventilation (MV). Chest radiographs changed after a few days after institution of MV from initial bronchopneumonia like pattern to severe ARDS. Assessment of respiratory system mechanics (single breath occlusion technique) revealed severe restrictive disease in both cases. The first patient recovered with residual restrictive changes determined during a follow-up 2.5 months later, whereas the second infant died because of ARDS, pulmonary interstitial emphysema and hypoxemic hypoxia.