The increasing incidence of Ampicillin-resistant Haemophilus influenzae. A cause of otitis media.

Middle ear exudate was obtained by myringotomy or aspiration from 625 suburban children, aged 1 month to 12 years, who had acute otitis media; bacterial pathogens were isolated from 71%. Haemophilus species were isolated from 212 (29%), and Streptococcus pneumoniae from 205 (28%). From 1975 to August 1977, the number of Haemophilus isolates found to be resistant to ampicillin has appreciably increased. Currently, 8% of all cases of acute otitis media in the Washington, DC, area are due to H influenzae resistant to ampicillin. Thirty-one of 35 patients with resistant H influenzae otitis were treated with an erythromycin/sulfisoxazole combination with an impressive clinical response. Twenty-six of these 31 cases had failed to have H influenzae eradicated by an average of ten days of oral ampicillin in recommended doses.