P. Karma

PNEUMOCOCCAL VACCINE AND OTITIS MEDIA

After an acute attack of otitis media 827 children aged 3 months to 6 years were assigned randomly to receive either 14-valent pneumococcal polysaccharide vaccine or a control vaccine (Haemophilus influenzae type b capsular polysaccharide). In children older than 6 months serum antibody responses to most of the vaccine polysaccharides were satisfactory. The response to type 6A was poor. Correspondingly, no clinical protection was seen below 6 months of age or against otitis media caused by group 6 pneumococci. Among the children more than 6 months old, the first 6 months after vaccination saw significantly (p < 0.001) fewer attacks caused by the pneumococal types represented in the vaccine (group 6 excepted) in those who received the pneumococcal vaccine than in those who received the control vaccine. Protection against type 19F was statistically significant (p < 0.01). The overall protective efficacy was 58%--somewhat better in children older than 2 years than in those younger. Previous attacks of otitis caused by pneumococci did not influence the protective efficacy of the vaccine.

Otoscopic diagnosis of middle ear effusion in acute and non-acute otitis media. I. The value of different otoscopic findings

To determine the value of different pneumotoscopic findings in diagnosing the middle ear effusion (MEE) of acute (AOM) and non-acute otitis media, 11,804 ear-related visits of 2,911 unselected children at ages 0.5-2.5 years were analysed. About half of these were examined by an otolaryngologist in one, and half by a pediatrician in another, urban area. Myringotomy was always performed when MEE was suspected, and it confirmed the presence of MEE in 85% (otolaryngologist) and 82% (pediatrician) of altogether 5,462 acute and in 69% (both doctors) of 1,092 non-acute cases suspected. Redness of the tympanic membrane (TM) was found in only 18% and 27% of the visits with AOM, and it predicted MEE with only 60% and 51% probability, if seen in acute visits. Cloudiness of the TM was noticed in 81% and 67% of the visits with AOM; its specificity and the other calculated variables were good in regard to the diagnosing of MEE, especially in acute cases in both groups. Distinctly impaired mobility of the TM was of about the same diagnostic value, but its position reliably indicated MEE only when bulging. In AOM the colour or mobility of the TM was normal very rarely, but the position was normal in a third of the cases. Thus, although there were differences in the incidences of different otoscopic findings in the two study groups, the diagnostic value of certain pneumatic otoscopic findings, especially cloudiness and distinct hypomobility of the TM, seemed to be good in both groups.

Risk Factors Affecting the Occurrence of Acute Otitis Media among 2-3-Year-Old Urban Children

The factors affecting the occurrence and recurrence of acute otitis media (AOM) were studied among 471 2-3-year-old children in two cities in Finland. Of these children, 188 had experienced greater than or equal to 3 attacks of AOM, 76 had had 1-2 attacks and 207 no otitis attacks (= control group). The study showed that the risk of recurrent AOM was increased among those children attending day-care nurseries as well as among those who had several siblings. Proneness to rhinorrhea and exposure to passive smoking at home was associated with an increased risk of AOM, while prolonged breast-feeding (greater than 6 months) seemed to reduce it. No correlation was found between the risk of recurrent AOM and the place of residence or type of housing, the parental otitis history, or atopic diathesis of a child. Thus the study suggested that to protect a young child from AOM we should promote breast-feeding and home-care for babies as well as avoid smoking in the home.

The bayesian approach to the evaluation of risk factors in acute and recurrent acute otitis media

A multivariant modelling method was used to analyse the risk, associated with 22 different factors, of contracting acute otitis media (AOM) in a prospective cohort of 1294 urban children followed up to the age of 17-32 (mean 25) months. By far the most important risk factor was the caring of the child at a day-care centre. The importance of this factor further increased with increasing recurrence of the attacks. Next in order came the existence of sibling(s) with AOM attacks during the follow-up. Prolongation of breastfeeding increased the protection against AOM during the first year of life. The frequency of AOM attacks was lowest around midsummer and highest in early winter.

Incidence of Acute Otitis Media

The occurrence of acute otitis media was studied over a one-year period in a total population of 146822 persons living in different parts of Finland. Of these 146822 persons, 4583 experienced a total of 6518 otitis attacks giving an annual incidence rate of 4.44% (4.48% in males and 4.07% in females, P less than 0.001). Acute otitis media was strikingly concentrated in the youngest age groups, with the highest annual incidence rates, in the order of 50%, found in infants younger than 2 years. Half of all the episodes occurred before the age of 33 months. The relative risk of getting acute otitis media was about 200 times higher during the first 2 years of life than as an adult. The occurrence of otitic episodes followed seasonal variations, and in urban areas the incidence was significantly (P less than 0.001) higher than in the countryside.

Bacteriology of the Chronically Discharging Middle Ear

Suitable bacteriological techniques revealed anaerobic bacteria in 38 (33%) of 114 chronically discharging middle ears. The genus Bacteroides was cultured from 25 ears. Aerobic bacteriology showed the predominance of staphylococci, facultative enteric gramnegative rods, diphtheroid bacilli and Pseudomonas species. Anaerobic bacterial cultures were always mixed with aerobic bacteria. 12 ears were culture-negative, and 9 of the 108 Gram-stained smers revealed no bacteria. No significant difference in bacteriology was noted between ears with or without local antimicrobial treatment, or between profusely draining or only moist ears. The ears with postoperative recurrent infection or with clinical suspicion of cholesteatoma grew anaerobes significantly more often, and were seldom sterile. Because anaerobic bacteria are frequently associated with chronic otitis media, their characteristics with regard to susceptibility to antimicrobials and to air must be remembered in the choice of therapy.

Incidence of Acute Otitis Media up to the Age of 1 1/2 Years in Urban Infants

The object of this prospective cohort investigation of 1,642 infants was to study the incidence of acute otitis media (AOM) in urban children during the first 18 months of life. The monthly incidence of AOM was greatest at the age of 10 months, and the largest proportion of children with AOM was also found in this 10-month age group. Before the age of 18 months, 56.7% of the infants had had at least one episode of AOM, while 26.9% had had one or two episodes and 29.8% three or more. The corresponding figures before the age of 12 months were: 45.3%; 26.8%; 18.5%, and before the age of 9 months: 30.5%; 22.1%; 8.4%. The AOM incidence, particularly as regards recurrent AOM, was rather higher in boys than in girls.

OCCURRENCE AND RECURRENCE OF ACUTE OTITIS MEDIA AMONG CHILDREN

The occurrence and recurrence of acute otitis media among 37 570 Finnish children at risk who were under 15 years of age were studied. During a one-year period, 4 337 of the children experienced a total of 6 249 attacks of acute otitis media, giving an annual incidence rate of 16.6%. The highest incidence, 75.5%, was found among infants 6--11 months old. 50% of Finnish children had experienced at least one ear infection before their third birthday and 75% before the age of 10, and among this latter group the total number of otitis attacks per child-year during a lifetime was 0.71. Among children under 10, half of the index attacks were recurrences, and among children under 16, 28% of the index attacks were followed by recurrences during the study year. The highest relative recurrence rate was found during the second year of life. Before the second birthday both incidence and recurrence rates were significantly (p less than 0.001) higher among boys. Acute otitis media was most common in the higher social class families and the lowest incidence and recurrence rates were found among children of farmers.

Bacteria in the middle ear and ear canal of patients with secretory otitis media and with non-inflamed ears.

Aerobic and anaerobic semiquantitative bacteriological cultures were taken from 110 mucoid middle ear effusions and the respective ear canals of 74 patients with secretory otitis media (SOM). Additionally, mucosal pieces from 20 non-inflamed middle ears and swabs from the ear canals were cultured similarly. Bacteria were found in 35 effusions and 65 ear canals with SOM; in both sites the most frequent species were S. epidermidis and S. aureus, and the species distributions were not significantly different in the sites. Ten effusions grew bacteria not culturable in the respective ear canal samples. Anaerobes were found in one effusion only. Nine non-inflamed middle ears revealed bacteria; the species distribution was no different from SOM, and four of the bacteria were not found in the ear canal of the same ear. In conclusion, there may be bacteria in the middle ear in the absence of inflammation and in SOM, but the role of viable bacteria seems to be nil in an established secretory otitis media.

Sensorineural Hearing Loss and Acute Otitis Media in Children

Sensorineural hearing of 359 otoscopically and tympanometrically normal 5-year-old children with known otitis-history was studied under ideal conditions. In the subgroups of children with a different number (0, 1-2, 3-7, greater than or equal to 8) of attacks of acute otitis media (AOM) in their history, the mean bone conduction thresholds unregularly varied from 0.1 dB to 7.4 dB, depending on the frequency and the subgroup studied. The proportion of the ears with a bone conduction threshold greater than 10 dB at 0.5, 1, 2 or kHz ranged, also unregularly, from 10.8% to 0.5%, the greatest percentages being found at 0.5 and 1 kHz in the children without a history of AOM. Thus, neither AOM nor its treatment, even if frequently occurring, seem to cause permanent sensorineural hearing loss in children.