Diphtheria is an infection that has been unreported for more than two decades in Mahajanga. A child, aged 4, presented with a pseudomembranous pharyngitis was associated with a dysphagia. He was from a rural municipality of Ambato Boeny at Mahajanga province and was admitted to the Pediatric Unit of the University Hospital Center. The child was not immunized against diphtheria. A throat swab was performed and cultured, from which Corynebacterium diphtheriae was identified. The strain, of biovar Mitis, was confirmed as diphtheria toxin (DT)-gene positive and produced DT (Elek test). Unfortunately, the child developed cardiac and neurological complications and died of respiratory and heart failure.

In whole, 56 patients were included. Amidst identified microorganisms were fungus (4,7%) and bacteria (95,3%) to which Gram negative bacilli represented 72,1% (n=44), Gram positive cocci 6,4% (n=10), Gram positive bacilli 8,2% (n=5) and Gram negative cocci 3,3% (n=2). Among these bacterias, Pseudomonas aeruginosa and Proteus sp were predominant, with respectively 41% (n=25), 23% (n=14). However, three cases of S. aureus reported, six with negative coagulase Staphylococcus, one with Escherichia coli, one with Klebsiella sp, one with Haemophilus sp, two cases with Neisseria sp and four cases with Corynebacterium sp. Two types of cultures were noticed, one of them monomorphic (91,1%, n=51) and the other polymorphic (8,9%, n=5) to which 3 associations of P. aeruginosa-Proteus sp, 1 association of P. aeruginosa- coagulase negative Staphylococcus and 1 association of P. aeruginosa- E. coli. No resistance to ciprofloxacin was observed with Pseudomonas, Neisseria sp, Haemophilus, and enterobacteria except for E. coli. No resistance to rifampicin was observed with S. aureus. However, the sensitivity of S. aureus to ciprofloxacin decreased (one bacterium out of three). The use of rifampicin or fluoroquinolones should be based on the type of ear infections,

<p class="abstract"><strong>Background:</strong> Otitis externa is common in medical practice. This study aims to identify the contributing factors of otitis externa in the city of Antsiranana, Madagascar.</p><p class="abstract"><strong>Methods:</strong> This is an analytical case-control type study, concerning patients with otitis externa, seen from January to July 2019, at the university hospital of place Kabary and at the grand Pavois medical practice, all in Antsiranana. The epidemiological, behavioural and clinical parameters were evaluated.  </p><p class="abstract"><strong>Results:</strong> We included 153 patients, among which 51were cases and 102 controls. The average age was 32.9 years (±19.41). The occurrence of otitis externa was significantly associated with the existence of a history of otitis externa, as well as ear cleaning 4 to 6 times per week (p=0.00; OR=46.17; CI=5.90-361.02). The diabetes exposure ratio was 18.79 in the ‘cases’ (p=0.00; CI=2.27-154.88), this ratio was 10.71 in the event of repeated swimming in pool (p=0.00; CI=2.22-51.70), 3.94 in case of ear cleaning with the cotton swab (p=00; CI=1.34-11, 60), and 2.23 when using headphones (p=0.02; CI=1.05-4.75).  The treatment of a previous otological pathology was a protective factor against otitis externa (OR=0.1500, p=0.0159, CI=0.0259-0.8689).</p><p class="abstract"><strong>Conclusions:</strong> The occurrence of otitis externa is related to well define daily behaviours and to other associated clinical factors. Managing these risk factors is the first step in treatment of otitis externa.</p>