P. Marchisio, S. Esposito, M.Picca, E. Baggi, PROSPECTIVE EVALUATION OF THE ETIOLOGY AND PATHOGENESIS OF ACUTE OTTIS MEDIA WITH SPONTANEOUS TYMPANIC MEMBRANE PERFORATION P. Marchisio, S. Esposito, M.Picca, E. Baggi, A. Orenti, E. Biganzoli, N. Principi Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Fondazione IRCSS Cà Granda Ospedale Maggiore University of Milan, Milan, Italy

BACKGROUND Spontaneous tympanic membrane perforation (STMP) can occur during an episode of acute otitis media (AOM) and complicate the clinical course of the disease. Incidence of AOM with STMP varies between 5% and 30%. Several studies have suggested that AOM with STMP could have some specific characteristics and be differentiated from uncomplicated AOM.

OBJECTIVES To evaluate the microbiology of acute otitis media with otorrhea due to spontaneous tympanic membrane perforation in children living in Italy To evaluate pneumococcal serotypes

prospective, single-center study, Italy METHODS (1) prospective, single-center study, Italy enrollment for 12 months: May 1, 2015 to April 30, 2016 previously healthy children (6 m – 7 yrs) diagnosis of AOM with spontaneous otorrhea: (a) middle ear effusion + signs of acute inflammation of the tympanic membrane + acute symptoms and (b) otorrhea (within 12 hours of spontaneous rupture of TM)

METHODS (2) excluded: tubes, midfacial abnormalities, chronic middle ear conditions, including chronic perforation, immunodeficiency, antibiotics in the previous 2 weeks, topical treatment purulent fluid removed and MEE collected close to the perforation using an extra-thin flexible wire swab (Copan eNAT transport and preservation medium, Brescia, Italy). bacterial genomic DNA was extracted by clinical specimens by semi-automatic DNA extraction system. The presence of Streptococcus pneumoniae (S.pn) (and its serotypes) , Haemophilus influenzae (Hi), Moraxella catarrhalis (M.cat), group A beta hemolyticus Streptocccus (GABHS) and Staphylococcus aureus was evaluated by means of real-time PCR using specific oligos-probe sets. S.pn. cases were serotyped using primers and probes designed on the basis of the GenBank database sequences (www.ncbi.nlm.nih.gov)

STUDY POPULATION Children N = 177 (%) Sex (males) Age (group) < 2 years 2 - 4 years > 5 years mean age ± SD (years) History of rAOM PCV13 fully vaccinated 103 (58.2) 65 (36.7) 70 (39.6) 42 (23.7) 3.5 ± 2.7 100 (56.5) 162 (91.5)

PATHOGENS DETECTED ALONE OR AS CO-PATHOGENS Il patogeno identificato più frequentemente è risultato essere H. influenzae (90 campioni, 50,8% del totale), seguito da M. catarrhalis, S. pneumoniae, S. pyogenes e infine S. aureus. All H.influenzae strains were non typeable

How many children had a positive sample for one or more pathogens?

Non typeable H.Influenzae  the most frequent pathogen (70%) in co-infections (M.catarrhalis  GAS  S.pneumoniae)

COMPARISON BETWEEN TIME AND DETECTION METHODS Il patogeno identificato più frequentemente è risultato essere H. influenzae (90 campioni, 50,8% del totale), seguito da M. catarrhalis, S. pneumoniae, S. pyogenes e infine S. aureus. PCR – Italian data 2015 to 2016 Marchisio P et al., CMI, epub 2017 Culture – Italian data 2001 to 2011 Marchisio P et al., Infection, 2013

Streptococcus pneumoniae positive cases: age distribution

Streptococcus pneumoniae positive cases: PCV13 versus non-PCV13 serotypes

Streptococcus pneumoniae serotypes PCV7 PCV13 non PCV13

CONCLUSIONS - 1 Non typeable H.influenzae , which is the most frequently pathogen associated with biofilm formation, is predominant in spontaneous otorrhea Group A Strep is confirmed to be a main cause of otorrhea, especially in older children M. catharralis seems to be a relevant pathogen Co-infections are common , especially in children with recurrent AOM and especially for NTHi The therapeutic approach should be different from that which is usually reported for uncomplicated AOM, taking into account the possible formation of biolfim and the presence of betalactamase producers

CONCLUSIONS - 2 S. pneumoniae is still one of the main pathogens despite full immunization with PCV13 most of the pneumococcal cases are associated with serotypes not included in the vaccine. This finding suggests that a significant replacement phenomenon has developed, reducing the potential effect of PCV13 on AOM incidence periodical monitoring of pneumococcal ST circulation after introduction of PCV with a defined number of ST is needed in order to evaluate replacement phenomenon and the need for new vaccines with greater protective activity

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