I “NUOVI” PATOGENI RESPIRATORI

1. I “NUOVI” PATOGENI RESPIRATORI Susanna Esposito Istituto di Pediatria, Università di Milano Fondazione IRCCS “Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena” Milano

2. NEWER RESPIRATORY VIRUS INFECTIONS • Acute respiratory tract infections are responsible for considerable morbidity and mortality • A variety of viruses are associated with RTIs • Since the beginning of the millenium, the Paramyxoviridae, the Coronaviridae and Parvoviridae virus families have been expanded • In the past five years, we have also become reacquainted with several influenza A virus subtypes that crossed the species barrier

3. DISTRIBUTION OF RESPIRATORY VIRUSES DURING THE WINTER SEASON 2003-2004 (Children enrolled = 2,060) Esposito S et al. J Med Virol 2006 % cases Weeks 2003 2004

4. IN JUNE 2001 VAN DEN HOOGEN ET AL. AT THE ERASMUS MEDICAL CENTER, ROTTERDAM, REPORTED THE DISCOVERY OF A NEW RESPIRATORY PATHOGEN Van Den Hoogen et al. Nat Med 2001;7:719-24

5. hMPV EPIDEMIOLOGY • PHYLOGENETIC ANALYSIS OF STRAINS DEMONTRATED 2 MAIN LINEAGES OF hMPV (A, B) AND 4 SUBLINEAGES (A1, A2, B1,B2) • SEROLOGICAL DATA INDICATED THAT hMPV CAN CAUSE MULTIPLE INFECTIONS IN HUMAN BEINGS • STUDIES SUGGESTED A SEASONAL DISTRIBUTION • UNDERLYING CONDITIONS MAY PREDISPOSE PATIENTS TO SEVERE hMPV DISEASE • COINFECTION WITH hMPV MIGHT BE A DETERMINANT OF RSV DISEASE SEVERITY

6. DISTRIBUTION OF HMPV-INFECTIONS IN ITALY 2003-2004 • 49 (2.4%) of the cases were single hMPV infections: hMPV A in 24 (49.0%), hMPV B in 14 (28.6%) and untyped hMPV in 11 (22.4%) • 11 children (0.5%) were co-infected by hMPV and another respiratory virus Esposito S et al., 25th ESPID 2007

7. CLINICAL PRESENTATION OF THE STUDY CHILDREN WITH HMPV INFECTION WAS DIAGNOSED (from Principi et al. NEJM 2004)

8. IMPACT AMONG HOUSEHOLD CONTACTS OF THE STUDY CHILDREN IN WHOM HMPV INFECTION WAS DIAGNOSED (from Principi et al NEJM 2004)

9. CLINICAL OUTCOME OF THE STUDY CHILDREN IN WHOM HMPV INFECTION WAS DIAGNOSED Esposito S et al., 25th ESPID 2007

10. PHARMACOLOGICAL TREATMENT IN THE STUDY CHILDREN IN WHOM hMPV INFECTION WAS DIAGNOSED (%) Esposito S et al., 25th ESPID 2007

11. IMPACT AMONG HOUSEHOLD CONTACTS OF THE STUDY CHILDREN IN WHOM HMPV INFECTION WAS DIAGNOSED Esposito S et al., 25th ESPID 2007

12. VIRAL LOAD (MEAN + SD cp/mL) AND DISEASE SEVERITY IN CHILDREN WITH HMPV INFECTION Esposito S et al., 25th ESPID 2007

13. CORONAVIRUS Nidovirales Coronaviridae Coronavirus - Grp I - Grp II - Grp III RNA virus Found everywhere Cause of mild as well as severe infections sometimes with epidemic peaks that could involve mainly respiratory and gastroenteric tracts

14. CORONAVIRUS HOST AND DISEASES

15. CORONAVIRUS INFECTIONS: PATHOGENESIS Viral Immune response Organ involvement replication C° Days from the beginning of the disease

16. EPIDEMIOLOGIC RESULTS • 2,060 children < 15 yrs (1,112 males) • Mean age + SD, 3.46 + 3.30 yrs HCoVs were detected in 79 children (3.8%) as against influenza in 235 (11.4%; p<0.0001), RSV in 171 (8.3%; p<0.0001), adenovirus in 136 (6.6%; p<0.0001), rhinoviruses in 130 (6.3%; p<0.05), hMPV in 48 (2.3%; p<0.05)and parainfluenza viruses in 29 (1.4%; p<0.05) Esposito S et al. J Med Virol 2006

17. DEMOGRAPHIC AND CLINICAL CHARACTERISTICS OF CHILDREN WITH CORONAVIRUS INFECTION Esposito S et al. J Med Virol 2006

18. DIAGNOSIS, THERAPY AND CLINICAL OUTCOME IN CHILDREN WITH BOCAVIRUS INFECTION Esposito S et al. J Med Virol 2006

19. %

20. SARS in pediatric age • Under 12 years of age, SARS appears as a moderate disease clinically less aggressive than in adults • Radiographic alterations appear low and not severe • The main signs were cough and nasal congestion • No death is observed in the first 12 years of age

21. FIRST DETECTION OF CORONAVIRUS HKU1 IN AN ITALIAN INFANT WITH BRONCHIOLITIS • While studying the epidemiology of viral respiratory infections in Italy during the winter seasons from 2002-2003 to 2004-2005, we detected HCoV-HKU1 in the nasopharyngeal secretions of a pre-term infant hospitalized for bronchiolitis • This finding not only allows a better definition of the disease’s possible etiology, but also confirms that coronaviruses can cause mild, as well as moderate/severe respiratory infections Bosis S et al. J Clin Virol 2007

22. HUMAN BOCAVIRUS (hBoV) • Latest addition to the list of novel respiratory virus • Described by Allander et al. in Swedish children in 2005 • DNA virus closely related to the Bovine Parvovirus (BPV) • Classified in the genus Bocavirus within the Parvoviridae

23. FREQUENCY OF hBoV INFECTIONS

24. SYMPTOMS OF PATIENTS WITH hBoV INFECTIONS Arnold et al., CID 2006

25. FREQUENCY OF DETECTION OF RESPIRATORY VIRUSES AMONG 1,332 CHILDREN ATTENDING THE EMERGENCY ROOM % Esposito S et al., J Clin Microbiol 2008

26. AGE DISTRIBUTION OF BOCAVIRUS INFECTIONS Esposito S et al., J Clin Microbiol 2008

27. FREQUENCY OF HUMAN BOCAVIRUS (HBOV) CO-DETECTION *p< 0.0001; no other significant difference between the groups. Esposito S et al., J Clin Microbiol 2008

28. CLINICAL MANIFESTATIONS IN CHILDREN WITH HUMAN BOCAVIRUS (HBOV) INFECTIONS *p<0.05

29. CLINICAL OUTCOME IN CHILDREN WITH HUMAN BOCAVIRUS (HBOV) INFECTIONS *p<0.05

30. CLINICAL IMPACT AMONG HOUSEHOLDS OF CHILDREN WITH HUMAN BOCAVIRUS (HBOV) INFECTIONS

31. TAKE HOME MESSAGES: EMERGING RESPIRATORY VIRUSES • Respiratory viral pathogens, old and new, continue to be an important threat to human health • Diagnostic techniques remain crucial for the rapid identification of known and unknown pathogens • It will be essential to further increase our understanding of virus epidemiology, pathogenesis, clinical presentation and host defense against infection