Journal of Hospital Infection (1992) 22 ( S u p p l e m e n t A), 75-87

The management of acute, serous and chronic otitis m e d i a : t h e r o l e o f a n a e r o b i c b a c t e r i a I. Brook a n d P. Burke*

Georgetown University School of Medicine, Washington DC, USA and *St Bartholomew's Medical Centre, Oxford, UK Summary: Otitis m e d i a ( O M ) is a c o m m o n c h i l d h o o d disease a n d one w h i c h can cause significant m o r b i d i t y . A knowledge of the p a t h o g e n s responsible for O M enables the m o s t a p p r o p r i a t e t r e a t m e n t r e g i m e n to be selected a n d thus m i n i m i z e s f u r t h e r c o m p l i c a t i o n s w h i c h m a y require hospital admission and surgery. T h e m i c r o b i o l o g y of acute, serous a n d c h r o n i c O M is reviewed, with particular r e g a r d to the role of anaerobic bacteria. Anaerobes, m a i n l y G r a m - p o s i t i v e cocci, have been recovered f r o m 2 5 % of the ear aspirates of patients with acute otitis media. I n a s t u d y of serous O M , anaerobic bacteria were recovered in 1 2 % of the c u l t u r e - p o s i t i v e aspirates. T h e p r e d o m i n a n t anaerobes were G r a m - p o s i t i v e cocci a n d p i g m e n t e d Prevotella. Several studies have r e p o r t e d the recovery of a n a e r o b e s f r o m a b o u t 5 0 % of patients with chronic O M a n d those with cholesteatoma. T h e p r e d o m i n a n t anaerobes were G r a m - p o s i t i v e cocci, p i g m e n t e d Prevotetla, Porphyromonas sp., Bacteroides spp. and Fusobacterium spp. M a n y of these o r g a n i s m s p r o d u c e [3lactamase w h i c h m i g h t have c o n t r i b u t e d to the failure of the patients to r e s p o n d to penicillins. T h e a p p r o p r i a t e a n t i m i c r o b i a l t h e r a p y for acute, serous and chronic otitis m e d i a is discussed.

Key words: Otitis media; anaerobic bacteria; a n t i m i c r o b i a l therapy.

Introduction Otitis media ( O M ) f r e q u e n t l y occurs in chi l dhood and can cause significant m o r b i d i t y in this age group. Patients can suffer f r o m complications such as p e r m a n e n t ear damage, a decrease in hearing, and sometimes serious sequelae such as extension of the infection to the intracranial space. Recent d e v e l o p m e n t s in microbiological techniques have increased awareness of the i m p o r t a n t role of anaerobic bacteria in ear infections. A naerobi c organisms p r e d o m i n a t e in the nor m a l flora of the oral cavity, w here they o u t n u m b e r the aerobic bacteria by a ratio of 10 to 1. Recognition of the role of anaerobes in these infections has i m p o r t a n t implications for their m a n a g e m e n t , since m a n y of these organisms are resistant to some f r e q u e n t l y used antimicrobial agents.

Correspondence to: Professor I. Brook, 4431 Albcrmarle Street NW, W~shington DC 20016, USA. 0195 6701/92/0A0075+ 13 $0800/0

g~ 19!)2 The Ilospital Infection Society

75

76

I. Brook a n d P. B u r k e Acute

otitis media

Acute otitis media (AOM) is one of the most c o m m o n diseases of early childhood. In the T h i r d National M o r b i d i t y Survey carried out by the Royal College of General Practitioners in 1981, the overall episode rate of 'acute suppurative otitis media' was 27-6 per 1000.1 More recent data suggest that this figure is rising. T h e highest incidence is probably at 6-12 m o n t h s of age with a second peak around the time of school entry. A prospective s t u d y carried out in Boston 2 showed that by 1 year of age, 62% of children had experienced at least one episode of acute otitis media and 17% had had three or more episodes. By age 7 years, these figures had risen to 93 % and 74% respectively. Particular risk factors appear to be male sex, bottle feeding, overcrowding, season (winter) and exposure to upper respiratory tract infections. In m a n y cases, recurrent A O M is followed by chronic inflammation.

Clinical features. A child may present with earache following 5-7 days of upper respiratory symptoms. In children aged 3 years or less, the only s y m p t o m s may be constitutional upset, fever, loss of appetite, vomiting or even diarrhoea. T h e e a r d r u m may be dull, pink, injected, bulging or even perforated. T h e appearance depends on the severity of the infection and the stage in the evolution of the illness when the child is seen. Usually the pain settles over 24 h, with about 90% of children being pain free after 48 h. However, it takes several weeks for the e a r d r u m to return to normal. In the interim, there continues to be an effusion in the middle ear with i m p a i r m e n t of hearing. Microbiology. M a n y studies 3 6 have established that two organisms, Streptococcus pneumoniae and Haemophilus influenzae, are the principal pathogens in A O M . Of the two, S. pneumoniae was recovered more frequently, with its predominance tending to increase with the patient's age. H. influenzae was previously t h o u g h t to be an infrequent cause of A O M in older children; however, reports have d o c u m e n t e d the continued importance of this pathogen in such patients. 4 Of particular concern is an increase in the incidence of ampicillin-resistant isolates from infected ears; this may reach up to 30% in some areas. Other organisms that are less frequently recovered in A O M include Moraxella catarrhalis, group A ~-haemolytic streptococcus, Staphylococcus aureus, and various Gram-negative bacilli, s G r a m - n e g a t i v e bacilli and staphylococci are c o m m o n l y implicated in A O M of neonates. However, recent studies have established that, even among this age group, S. pneumoniae and H. influenzae are c o m m o n pathogens. In most of these early studies, microorganisms were recovered in only about two-thirds of aspirates, and no growth was generally found in the other thirdfl '~ A later study ~ used techniques for cultivating both anaerobic and aerobic bacteria; 186 children with A O M were investigated. Aerobic

77

M a n a g e m e n t of otitis m e d i a

bacteria alone, p r e d o m i n a n t l y S. pneumoniae and H. influenzae, were isolated from 118 patients (63%), and anaerobic organisms alone, mostly anaerobic cocci, were isolated from 24 (13%). T w e n t y - s i x aspirates (14%) yielded mixtures of aerobes and anaerobes, and several had multiple aerobic or anaerobic organisms. Overall, anaerobes were recovered from 50 patients (27%). T h e results of this analysis are summarized in Figure 1. T h e s e techniques resulted in the isolation of bacteria from 90% of the patients studied. T h e predominant aerobic and anaerobic organisms isolated in this s t u d y 6 are shown in T a b l e I.

Treatment options. T h e aims of treatment are to relieve pain, to eliminate any bacterial infection, to avoid relapse and recurrence and to prevent short- and long-term complications. Adequate analgesia, preferably paracetamol, is obviously needed. T h e role of antibiotics is m o r e controversial 9 M o s t of the evidence in favour of

I00

80

63%

.~_

60

iiiii!i!iiiiiil

iiiiiiiiiiiiiil

o

g o

g

40

ii!Ni : gggggggggggg!

20

Eiiiiiiiiiiiiil

Aerobes only

27%

13%

N

Anoerobes only

14%

N Mixed

Anoerobes

oerobes and onoerobes

(whether olone or combined)

Figure 1. D i s t r i b u t i o n of bacteria isolated from ear aspirates of 186 c h i l d r e n with acute otitis media. A d a p t e d from reference 6.

78

I. B r o o k a n d P. B u r k e

Table I. The predominant aerobes and anaerobes isolated from aspirates obtained from 186 children with acute otitis media*

Organism

% Patients

Aerobes 37 30

Streptococcus pneumoniae Haemophilus influenzae Haemophilus parainfluenzae Straphylococcus aureus Staphylococcus epidermidis

Anaerobes (mainly Gram-positive cocci) Propionibacterium spp. (chiefly P. acnes) Peptostreptococcus spp. Veilonella sp. Bifidobaeterium sp. Eubacterium sp. CIostridium ramosum

Micro-aerophilic streptococci

1

8 5

One One One One One

7 4 isolate isolate isolate isolate isolate

*Adapted from reference6.

antibiotics concer ns s h o r t - t e r m outcomes. N o study has been done which was of sufficient size to show an effect on complications such as mastoiditis, which are n ow u n c o m m o n even in u n t r e a t e d children. N o n e of the m a n y p l a c e b o - c o n t r o l l e d trials show a b e t t e r o u t c o m e with placebo. In general, N o r t h A m er i c a n aut hors strongly favour antibiotics. T h e earlier studies used ampicillin and penicillin 7'8 while m o r e recent ones have used amoxycillin. 9 A recent U K trial 1~ in chi l dren aged 3-10 years, showed t r e a t m e n t failure in two of 114 children given amoxycillin but in 19 of 118 m a t c h e d chi l dr e n given placebo. An Israeli study tl used amoxycillin plus clavulanic acid and achieved c o m p a r a b l e results. Against this evidence, it is sometimes argued that antibiotic use, particularly if inadequate, p r o m o t e s m i d d l e ear effusion and r e c u r r e n t otitis m e d i a l 2 H o w e v e r , this has yet to be convi nci ngl y d e m o n s t r a t e d in any large trial. T h e r e are some studies showing only m o d e s t differences bet w een o u t c o m e with antibiotic and that with placebo. Van B u c h e m et al., 13 in the N e t h e r l a n d s , used amoxycillin while M y g i n d et al. used penicillin V. 14 Most recently, A p p e l m a n et al. is used amoxycillin plus clavulanic acid. Such studies have been highly influential, particularly in the N e t h e r l a n d s , where d ef er r ed antibiotic t r e a t m e n t has b e c o m e n o r m a l practice. 16 G i v e n the n u m b e r s of chi l dr e n in these trials (100-200 in each trial), and the overall balance of the evidence, it seems possible that their failure to find a significant difference is attributable to a statistical type 2 error. On balance, the case for antibiotic use seems strong, particularly in high-risk groups, n a m e l y those children aged u n d e r 2 years, 15 those with

Management of otitis media

79

bulging tympanic m e m b r a n e s 7 and those whose pain has been present for over 48 h. F r o m our own data, u* even when these groups are excluded, illness does seem to be shortened by antibiotics.

Choice of antimicrobial therapy. Since the most c o m m o n pathogens are S. pneumoniae and H. influenzae, it is no surprise that most patients respond favourably to ampicillin or amoxycillin. In patients allergic to penicillin, e r y t h r o m y c i n and/or sulphonamides may be prescribed. Second-generation oral cephalosporins (i.e. cefaclor, cefuroxime, cefprozil) have also been effective in the t r e a t m e n t of this disease, mostly because of their activity against Haemophilus. C o m b i n a t i o n therapy has also gained popularity, chiefly due to the growing n u m b e r of ampicillin-resistant H. influenzae. T h e combinations used successfully are amoxycillin-clavulanic acid, penicillin and sulphonamide, t r i m e t h o p r i m - s u l p h a m e t h o x a z o l e and erythromycin-sulfisoxazole. Since the anaerobes recovered in A O M are susceptible to penicillins and other antimicrobials c o m m o n l y used to treat A O M , no change in the r e c o m m e n d e d therapy is advised. However, the combination of t r i m e t h o p r i m - s u l p h a m e t h o x a z o l e is effective against only 50% of anaerobic Gram-positive cocci. S e r o u s ( s e c r e t o r y ) otitis m e d i a

Serous otitis media ( S O M ) is a c o m m o n cause of mild hearing loss in children, most often between 2 and 7 years of age. Middle-ear effusion was found to persist for at least one m o n t h in up to 40% of children who had suffered from A O M , and for at least 3 m o n t h s in 10% of these children. 17 T h e middle ear fluid in patients can vary from a thin transudate to a very thick consistency ('glue ear'). Factors favouring Eustachian tube obstruction include p r i m a r y congenital tube dysfunction, allergic rhinitis, adenoidal hyperplasia and a supine feeding position.

Microbiology. At one time, persistent or chronic middle-ear effusions were assumed to be sterile. However, in 1958, Senturia et al. 18 examined 130 patients with S O M using smears and cultures; bacteria were identified in 33% of ears with serous effusions: in 25% with mucoid effusions, in 51% with m u c o p u r u l e n t effusions and 29% with p u r u l e n t effusions. Later studies included attempts to recover anaerobes from ear aspirates of patients with SOM. Brook et al. 19 recovered bacteria from 23 of the 57 patients investigated (40%). T h e proportions of aerobic, anaerobic and mixed organisms f o u n d in these patients are shown in Figure 2 and the species of bacteria isolated in Table II. It is of particular interest that the anaerobes recovered from these patients with S O M were similar to anaerobic organisms previously recovered from children with acute 6 and chronic 2~ OM.

I. Brook a n d P. Burke

8O I00

80

-~ 60

57% \\NNNX\ \ \ \ \ \ \ \ NXNNNN\ \ \ \ \ \ \ \ \NNNXX\

O

g gu 40 U O.

\\NNNN\ \\\\N\\ \\\\XN\ \\\\\\N

35% 26'~

\\\\\N\

20

~\\\\',)

\NNNNNXX

X\\\\\'~ ~\\\\\x ~\\\\\\\

- -.- -.-.-.-.

\\NX\\X'

\\\\\\\

~\\\\\\\

~\\\\\N \\\\NNN\ \\\\\\\~

\\\\\\\ \xxx\\\ \\\\\\\

\\NNNNN\

Aerobes

Anaerobes

only

only

Mixed aerobes and anaerobes

~-Ioctomose-

producing organisms

Figure 2. Distribution of bacteria isolated from ear aspirates of 23 patients with positive ear cultures who had serous otitis media. A d a p t e d from reference 19.

T a b l e I1. Bacteria isolated from ear aspirates of 23 children with serous otitis media* Organism

A e r o b e s ( N = 31 ) Staphylococcus aureus Staphylococcus epidermidis

Total

13-1actamase p r o d u c i n g

5 4 5 4

5 0 0 0

8 5

1 0

Propionibacterium acnes

5 3

3 0

Gram-positive cocci

6

0

45

9

Streptococcus pneumoniae Streptococcus viridans Haemophilus influenzae Others

Anaerobes (N = 14) Pigmented Prevotella

Total * Adapted from reference 19.

M a n a g e m e n t of otitis m e d i a

81

Antimicrobial therapy. T h e role of bacteria in the pathogenesis of S O M is unclear at present; however, antimicrobial agents are often used in an attempt to clear the ear effusion of microorganisms. T h e r e is some evidence to support this approach. Marks et al. carried out a trial using co-trimoxazole and f o u n d that 64% of the 25 children randomized to this drug showed i m p r o v e m e n t in 6 weeks compared with 27% of the 26 children randomized to decongestant/antihistamine treatment. 21 However, this difference had largely disappeared at 1 year follow-up (28% vs. 18~ 22 Mandel et al. randomized 318 children to amoxycillin treatment for 2 weeks. 23 At the end of this time, 29% were effusion-free compared to 14% of the 156 control subjects. T h e antibiotic chosen should arguably be effective against anaerobic as well as aerobic bacteria, including the ~-lactamase-producing organisms. F u r t h e r controlled studies need to be undertaken in order to define the value of antimicrobial t r e a t m e n t alone in patients with S O M . A persistent effusion will generally require drainage by m y r i n g o t o m y , and the insertion of a g r o m m e t ( t y m p a n o s t o m y tube) may be indicated to ventilate the middle ear. Chronic otitis media

Chronic otitis media ( C O M ) can be insidious, persistent and very often destructive, with sometimes irreversible sequelae, such as a hearing deficit and subsequent learning difficulties. T h e perforation of the t y m p a n i c m e m b r a n e that occurs during A O M can persist into the chronic stage. In m a n y cases of C O M , a cholesteatoma can develop. T h e C O M with cholesteatoma tends to be persistent and progressive; it very often causes destructive, irreversible changes in the bony structure of the ear.

Microbiology. Although, in the past, studies reported the recovery of anaerobic organisms from m a n y cases of C O M , aerobic organisms were considered to be the major pathogens. Brook, 2~ however, recovered anaerobic bacteria from 51% of ear aspirates of 68 children suffering from C O M . T h e m e t h o d o l o g y employed in this study ensured that the ear aspirates were inoculated immediately into enriched media that supported the growth of anaerobes. T h e media were incubated for 14 days, thus allowing some of the slowly-growing organisms sufficient time to multiply. T h e majority of anaerobic isolates found in this study were Gram-positive cocci, pigmented Prevotella and Porphyromonas sp., Bacteroides spp. (including B. fragilis groups), and Fusobacterium nucleatum. T h e p r e d o m i n a n t aerobic bacteria isolated were enteric Gram-negative bacilli (mostly P. aeruginosa) and S. aureus. Anaerobic isolates were usually mixed with other anaerobic or aerobic bacteria, and the n u m b e r of isolates ranged between two and four per specimen, thereby demonstrating the polymicrobial aetiology of C O M .

82

I. B r o o k a n d P. B u r k e

A further study evaluated the incidence of ~-lactamase-producing organisms (BLPO) in 48 children with C O M . 24 Eighty-three aerobic and 93 anaerobic isolates were recovered. As shown in Figure 3, aerobic bacteria alone were involved in 22 patients (46%) and anaerobic organisms alone in five (10%). Mixed aerobic and anaerobic isolates were recovered from 21 cases (44%) and B L P O were recovered in two-thirds of patients. There were 40 B L P O (24 anaerobes and 16 aerobes) recovered from 31 patients. These included all 10 isolates of S. aureus and the B./ragilis group, 11 of 19 (58%) of the pigmented Prevotella and Porphyromonas sp., three of six (50%) Prevotella oralis, four of six (67%) H. influenzae, two of three (67%) ~. epidermid~s and two of four (50%) M. catarrhalis. Furthermore, it was possible to detect the ~-lactamase enzyme in 84% of the ear aspirates that contained B L P O in excess of 104 colony-forming units (cfu) ml 1.2s T h e high rate of recovery of B L P O in C O M is not surprising, since most of the patients had received multiple courses of antimicrobial agents, including penicillins, which might have selected out resistant organisms.

IO0

80

66% .= c

e

60

o.

46%

g

44%

o

=

40

#_

:::::::::::::: =l====lll====l

~i!!illlliiiiii ==::l===l::=:::

iilliiiiiiiiii

iiiiiiiiiiiiill

!gggigigg!ggg!

aaaa~aaaaaaaaa~

:::==:==::::=l

...............

:::::::::::::~

i!!~ili~iiiii~i :::::::==::=::=

IIII=IIIIIII=I III=~IIIIIII~I :III====I=II=I

EO

:II~III:II=:=:: III~IIIIII:~I:= I==~==I=I=====~

==l=====l====l ==::====:::=:l ==g=====g==g=1

i~iii~i~iiiii

............... ===g======g====

,0%

!~il!illlli~ill :==!:1:=====I=: Aerobes only

iiiiiiiiiiiiiii iiii~i~iiiiiii ...............

Anaerobes only

Mixed aerobes and anaerobes

~ -Ioctornaseproducing orgonisrns

Figure 3. D i s t r i b u t i o n of bacteria isolated from ear aspirates of 48 children w i t h chronic otitis m e d i a . A d a p t e d from reference 24.

M a n a g e m e n t of otitis m e d i a

83

In-vitro and in-vivo studies have d o c u m e n t e d the synergistic effects of mixtures of anaerobic and aerobic bacteria w h e r e b y the polymicrobial infections are more pathogenic. 26 Another important virulence factor for the anaerobes present in C O M is encapsulation. T h e presence of encapsulated Gram-negative anaerobic bacilli and anaerobic Gram-positive cocci was investigated in 48 patients with C O M , and c o m p a r e d to those found in the pharynx of 26 control subjects. 27 In the patients with C O M , 45 (60%) of the 60 isolates of p i g m e n t e d Prevotella and Porphyromonas sp., B. fragilis group, B. oralis and anaerobic cocci were found to be encapsulated, compared to only 34 of 96 (35%) controls ( P < 0 - 0 0 1 ; S t u d e n t ' s t-test). Early and vigorous antimicrobial therapy, directed at both aerobic and anaerobic bacteria present in these mixed infections, may abort the infection before the emergence of encapsulated bacterial strains that contribute to the chronicity of the infection. T h e polymicrobial bacteriology of cholesteatomas present in chronically infected ears provides further support for the role of anaerobes in C O M . Cholesteatoma specimens were obtained from 28 patients undergoing surgery for C O M and cholesteatoma; bacterial growth was present in specimens from 24 of the 28 patients. 2s A total of 74 bacterial isolates were present (40 aerobes and 34 anaerobes). Aerobes alone were isolated from eight (33%) of culture-positive patients, 27% yielded only anaerobes and 50% had both aerobic and anaerobic bacteria. Fifty isolates (27 aerobes and 23 anaerobes) were present in a concentration greater than 106 cfu g - l . T h e most c o m m o n l y isolated aerobic organisms were P. aeruginosa (nine isolates), Proteus spp. (seven), Klebsiella pneumoniae (five), 5;. aureus (five), and E. coli (four). T h e anaerobic bacteria most c o m m o n l y isolated were Gram-positive cocci (12), Bacteroides spp. (eight including five B. fragilis group), Prevotella sp. (four), Clostridium spp. (three), and Bifidobacterium spp. (three). Various theories have been proposed for the process of expansion of cholesteatoma and the collagen degradation that occurs in its vicinity. 29'3~ Production of organic acid by the anaerobic bacteria may be involved in the destructive process seen in cholesteatoma, and further studies to ascertain their effects on the s u r r o u n d i n g bone and collagen are warranted. F u r t h e r proof of the importance of anaerobes in C O M is suggested by their recovery in cases that present with complications. Anaerobes were recovered from 23 (96%) specimens from patients with chronic mastoiditis, 31 and the bacterial species were similar to those recovered in C O M . Anaerobes were also recovered from most of the patients who presented with intracranial abscesses complicating C O M . 32

Antimicrobial therapy. Until recently, most of the anaerobic strains recovered from respiratory tract and orofacial infections were considered to be susceptible to penicillins. Staphylococcus aureus and B. fragilis group are known to be resistant to penicillins due to [3-1actamase production.

84

I. Brook and P. Burke

However, an alarming n u m b e r of other Bacteroides spp., Prevotella and Porphyromonas sp. and Fusobacterium spp. formerly susceptible to penicillins, have increased resistance to these drugs by p r o d u c i n g the enzyme ~-lactamase. 33 T h e appearance of penicillin resistance among m a n y Gram-negative anaerobic bacteria has important implications for the choice of treatment. Such organisms can release the ]3-1actamase enzyme and degrade penicillins or cephalosporins in the area of the infection. In this way, the organisms not only protect themselves but also other, penicillin-sensitive, pathogens. Penicillin therapy directed against a susceptible pathogen might therefore be rendered ineffective by the presence of a ]3-1actamase-producing organism) 4 T h e isolation of B L P O from two-thirds of chronically inflamed ears and the ability to detect the free enzyme in the middle-ear fluid 24'2s raises the question of w h e t h e r the treatment of C O M with penicillins is adequate and whether therapy should be directed at the eradication of B L P O which might also be present. Surgical drainage and correction of any pathology is still the treatment of choice in C O M . H o w e v e r , the presence of penicillin-resistant aerobic and anaerobic b a c t e r i a m a y warrant the administration of appropriate antimicrobial agents that are effective against these organisms, e.g. clindamycin, metronidazole, chloramphenicol, ticarcillin, cefoxitin or the combination of amoxycillin and clavulanic acid, when P. aeruginosa is recovered from the middle ear, an aminoglycoside or quinolone would be the treatment of choice. Conclusions

Recent studies have pointed to the role of anaerobic bacteria in acute, recurrent, serous and chronic otitis media. T h e increased recovery rate of ~-lactamase-producing organisms in these infections warrants the administration of appropriate antimicrobial agents that are also directed against these organisms. These considerations will aid the choice of a suitable empirical treatment; in chronic O M , however, treatment should be tailored to the unique microbiology of each patient. Discussion

and audience

opinions

What are the main objectives for the management of a 5-year-old child with acute otitis media and how would you choose to treat the patient? Audience response. T h e prevention of acute complications, e.g. mastoiditis, and the curtailment of pain, were indicated as the main objectives by the audience, followed by the prevention of deafness due to middle ear effusion. Antibiotic therapy, alone or in combination, was

M a n a g e m e n t of otitis m e d i a

85

advocated by 73% of the audience, other popular options were analgesics (51%) and decongestants (34%). Although no strong trends were apparent in relation to the respondents' country of origin, early m y r i n g o t o m y and specialist referral may be more popular in the Netherlands, Belgium and Germany. The consensus was to use antibiotics at first presentation rather than wait. W h a t would be your drug of first choice for acute otitis media? Audience response. Amoxycillin plus clavulanic acid was indicated as the drug of choice by 4 5 % of the respondents, with amoxycillin alone as the second choice (26%). Amoxycillin plus clavulanic acid was the first choice for antibiotic therapy across all professional specialities. W h a t duration of antibiotic therapy is required? Dr Burke. In general practice, the treatment of A O M often entails a compromise between bacteriological considerations and patient compliance. However, if treatment is continued for at least 48 h, most children will respond and remain pain free. This has been confirmed in two U K studies with amoxycillin at standard and high dose. 3s'36 I f after 2 days treatment the patient returns with continuing symptoms, what management would you propose? Audience response. W i t h this scenario, antibiotics and referral to a specialist were in equal first place (36%), with m y r i n g o t o m y (18%) and analgesics (17%) in third and fourth place. T h e antibiotic of choice was again indicated as amoxycillin-clavulanic acid (43%), with cephalosporins chosen by 21% and macrolides by 11% of respondents. T h e increased likelihood of [3-1actamase-producing organisms or anaerobic bacteria, in a patient who fails to respond to initial treatment, was reflected in the decrease in the selection of amoxycillin and penicillin V. W h a t would be the recommended treatment for malignant otitis media which has been well described in diabetics? Dr Brook. In this condition, the pathogens are usually Pseudomonas or S. aureus, with less than 5% anaerobes. Obtaining cultures of the infected area is of great importance. Empirical treatment will usually consist of parenteral anti-pseudomonal antibiotics, along with surgical debridement. W h a t is the aetiology of otitis media and is prevention possible? Dr Brook. T h e r e is a definite physiological element to this disease; some races are more c o m m o n l y affected, e.g. the Eskimos, and a family history is sometimes found. A viral infection of the upper respiratory tract is

86

I. Brook a n d P. B u r k e

f r e q u e n t l y p r e s e n t b e f o r e t h e p r e s e n t a t i o n o f o t i t i s m e d i a a n d m a y set t h e stage for a s u b s e q u e n t bacterial infection. V a c c i n e s a g a i n s t S. pneumoniae a n d H. influenzae are n o t very h el p f u l a g a i n s t the b a c t e r i a i m p l i c a t e d in o t i t i s m e d i a a n d so a n t i m i c r o b i a l t h e r a p y r e m a i n s t h e o n l y o p t i o n at p r e s e n t . I t is i m p o r t a n t i n e a c h case to d e t e r m i n e w h e t h e r t h e p a t i e n t h a s a c u t e o r c h r o n i c i n f e c t i o n . S i n c e it is n o t a l w a y s p o s s i b l e to p e r f o r m a c u l t u r e , a n a c c u r a t e h i s t o r y o f p r e v i o u s t h e r a p y s h o u l d b e o b t a i n e d to e n a b l e a n assessment of the most likely causative organisms and allow appropriate e m p i r i c a l t r e a t m e n t to b e i n i t i a t e d .

References

1. Royal College of General Practitioners. Morbidity Statistics from General Practice: third National Study 1981-1982. London: HMSO 1986. 2. Teele DW, Klein JO, Rosner Bet al. Epidemiology of otitis media during the first seven years of life in children in greater Boston: a prospective cohort study. J Infect Dis 1989; 160: 83-94. 3. Howie VM, Ploussard JH. The otitis prone condition. Am J Dis Child 1975; 129: 675-678. 4. Schwartz RH, Rodriguez WJ, Khan WN et al. The increasing incidence of ampicillin-resistant Hemophilus influenzae. A cause of otitis media. J Am Med Assoc 1978; 239: 320-323. 5. Schwartz RH, Brook I. Gram-negative rod bacteria as a cause of acute otitis media in children. Ear Nose Throat J 1981; 60:9-11. 6. Brook I. Otitis media in children: a prospective study of aerobic and anaerobic bacteriology. Laryngoscope 1979; 89:992 997. 7. Halstead C, Lepow ML, Balassanian N e t al. Otitis media: clinical observations, microbiology and evaluation of therapy. Am J Dis Child 1968; 115: 542--587. 8. Laxdal OE, Merida J, Jones RT. Treatment of acute otitis media: a controlled study of 142 children. Can Med A s s J 1970; 102:263 268. 9. Kaleida PH, Casselbrandt ML, Rockette HE et al. Amoxycillin or myringotoray or both for acute otitis media: results of a randomized clinical trial. Paediatrics 1991; 87: 466474. 10. Burke P, Bain J, Robinson D et al. Acute red ear in children: controlled trial of non-antibiotic treatment in general practice. Br M e d J 1991; 303: 558-562. 11. Engelhard D, Strauss N, Jorczak-Sarni L et al. Randomised study of myringotomy, amoxycillin/clavulanicor both for acute otitis media in infants. Lancet 1989; 2: 141-143. 12. Diamant M, Diamant B. Abuse and timing of use of antibiotics in acute otitis media. Arch Otolaryngol 1974; 100:226 232. 13. Van Buchem FL, Dunk JHM, Van't Hof MA. Therapy of acute otitis media: myringotomy, antibiotics or neither? Lancet 1981; 2:883 887. 14. Mygind N, Meistrup-Larsen K-I, Tomsen J e t al. Penicillin in acute otitis media: a double-blind, placebo-controlled trial. Clin Otolaryngol 198l; 6 : 5 13. 15. Appelman CLM, Claessen JQPJ, Touw-Otten F W M M et al. Co-amoxiclav in recurrent acute otitis media: placebo-controlled study. Br Med J 1991; 303:1450 1452. 16. Van Buchem FL, Peeters MF, Van't Hof MA. Acute otitis media: a new treatment strategy. Br M e d J 1985; 290:1033 1038. 17. Bluestone CO. Recent advances in the pathogenesis, diagnosis and management of otitis media. Pediatr Clin North Am 1981; 28: 727-755. 18. Senturia BH, Gessert CF, Cart CD et al. Studies concerned with tubotympanitis. Prac Oto-Rhinol-Laryngol 1956; 67: 440-467. 19. Brook I, Yocum P, Shah K et al. Aerobic and anaerobic bacteriological features of serous otitis media in children. Am J Otolarvngol 1983; 4: 389-392. 20. Brook I. Chronic otitis media in children: microbiological studies. Am J Dis Child 1980; 134: 564-566. 21. Marks J, Mills RP, Shaeen OH. A controlled trial of co-trimoxazole therapy in serous otitis media, ff Laryngol Otol 1981; 95:1003 1009.

M a n a g e m e n t of otitis m e d i a

87

22. Marks J, Mills RP, Shaeen OH. Co-trimoxazole in the treatment of serous otitis media: a follow-up report. J Laryngol Otol 1983; 97:213-215. 23. Mandel EM, Rockette HE, Bluestone CD et al. Efficacy of amoxycillin with and without decongestant antihistamine for otitis media with effusion in children. N Engl J Med 1987; 316: 4324-37. 24. Brook I. Prevalence of 13-1actamase-producing bacteria in chronic otitis media. A m J Dis Child 1985; 139: 280-283. 25. Brook I., Yocum P. Quantitative bacterial cultures and [3-1actamase activity in chronic suppurative otitis media. Ann Otol Rhinol Laryngol 1989; 98:293 297. 26. Brook I, Hunter V, Walker RI. Synergistic effects of anaerobic cocci, Bacteroides, clostridia, fusobacteria, and aerobic bacteria on mouse mortality and induction of subcutaneous abscess. J Infect Dis 1984; 149: 924-928. 27. Brook I. Recovery of encapsulated bacteria from orofacial abscesses. J Med Microbiol 1986; 22: 171-176. 28. Brook I. Aerobic and anaerobic bacteriology of cholesteatoma. Laryngoscope 1981; 91: 250-253. 29. Fernandez C, Lindsay JR, Moskowitz M. Some observations on the pathogenesis of the middle ear cholesteatoma. Arch Otolaryngol 1952; 69: 537-546. 30. Juers AL. Cholesteatoma genesis. Arch Otolaryngol 1965; 81: 5-8. 31. Brook I. Aerobic and anaerobic bacteriology of chronic mastoiditis in children. Am J Dis Child 1981; 135: 4784-79. 32. Brook I. Bacteriology of intracranial abscess in children. J Neurosurg 1981; 54: 484-488. 33. Brook I, Calhoun L, Yocum P. Beta-lactamase producing isolates of Bacteroides species in children. Antimicrob Agents Chemother 1980; 18: 164-166. 34. Brook I, Pazzaglia G, Coolbaugh JC et al. In vivo protection of Group A beta-haemolytic streptococci from penicillin by beta-lactamase producing Bacteroides species. J Antimicrob Chemother 1983; 12: 599-696. 35. Bain J, Murphy E, Ross F. Acute otitis media: clinical course among children who received a short course of high dose antibiotic. Br Med J 1985; 291:1243-1246. 36. Chaput de Saintonge DM, Levine DF, Temple Savage I e t al. Trial of three-day and ten-day courses of amoxycillin in otitis media. Br M e d J 1982; 284: 1078-1081.

The management of acute, serous and chronic otitis media: the role of anaerobic bacteria.

Otitis media (OM) is a common childhood disease and one which can cause significant morbidity. A knowledge of the pathogens responsible for OM enables...
716KB Sizes 0 Downloads 0 Views