Chronic suppurative otitis media in indigenous populations: The Australian Aborigine.

Approximately 100,000 Aboriginal people live in Australia. Children account for somewhere between 30,000 and 40,000 of this figure. Regardless of whether they live in an urban, rural, or remote area, the Aborigines' access to medical care is inadequate. As many as 50% of these children have otorrhea and chronic perforations (figure). Between the ages of 2 and 20 years, the average Aborigine experiences approximately 32 weeks of middle ear disease and hearing loss, compared with an average of 2 weeks for non-Aborigines.

Aboriginal children in urban areas do have somewhat better nutrition, hygiene, and medical care, and they have a higher incidence of otitis media with effusion and cholesteatoma--just as we see in non-Aboriginal children.

Finding the causes

Aboriginal people suffer from inadequate housing, poor nutrition, and a lack of hygiene and access to clean water. Another major factor that diminishes their quality of life is overcrowding. As many as 18 people might live in one home.

Exposure to cigarette smoke is a major factor in the high incidence of ear disease in these children. We are currently conducting a study in Kalgoorlie, Western Australia, in an attempt to identify and compare risk factors in Aboriginal and non-Aboriginal children younger than 2 years of age. So far, two major differences have emerged: (1) pneumococcal invasion of the nasopharynx occurs earlier in Aboriginal children and (2) there is no relationship between health problems and exposure to smoking in non-Aboriginal children. Parents of non-Aboriginal children generally smoke outdoors, whereas Aboriginal adults typically gather and smoke in a small room with children present. Our early results show an 80% correlation between ear disease and passive smoking in Aboriginal children. By the age of 12 weeks, 90% of Aboriginal children have evidence of pneumococcal invasion of the nasopharynx. We believe that if overcrowding and cigarette exposure can be reduced, the incidence of typical acute otitis media and typica l chronic suppurative otitis media (CSOM) will decrease as well.

Treatment

I am also involved in a treatment study of CSOM that is being sponsored by the National Aboriginal Community Controlled Health Organisation and carried out at eight clinics in Western Australia, the Northern Territory, and Queensland. This independent study is being conducted primarily by the Aboriginal people for the Aboriginal people. The important thing about this study is that it is not just another survey. It is a proper randomized, double-blind trial, and it is focused on curing disease rather than compiling statistics.

In this study, we are comparing the effectiveness of topical ciprofloxacin/hydrocortisone with a combination of framycetin and dexamethasone, which has long been the standard treatment for CSOM in Aboriginal children. We are looking to compare the effectiveness of the two treatments in clearing ear discharge, healing perforations, and improving hearing. We are also studying the impact that CSOM has on school attendance.

We are going to report 10-day bacteriologic cure rates, the types of bacteria, the rates of perforation healing, the incidence of recurrent and persistent CSOM, and the possible development of antibiotic resistance over time. We will also quantify the degree of hearing losses and the proportion of children who improve over 3 to 4 months, and we are addressing quality-of-life issues in children with CSOM. This is a major project.

So far we have recruited 100 children and obtained preliminary data on 82 of them. We have not unblinded the two treatments yet, but overall we have seen a clinical cure rate of 70% and a bacteriologic cure rate of 74%. Moreover, approximately 50% of the children who have not been cured clinically have been cured bacteriologically. There has been no evidence thus far of antibiotic resistance.

Comments

Dr. Croxson: Are you using povidone iodine or any other antiseptic in this study?

Dr. Coates: Yes. We are using ear toilets with 5% povidone solution followed by the use of tissue spears to dry the ear canal.

Dr. Rutka: In Toronto, I do a good deal of work in underserviced areas with North American Aboriginals. Many of them live about 2,000 km (~1,200 mi) north of our institution. We see the same problems, especially with regard to chronically draining ears. We have also noticed that cholesteatoma is usually not an issue in these patients. In fact, to a large extent, chronic ear disease appears to be indirectly related to affluence-that is, the more affluent the family situation becomes, the less likely we will see CSOM.

Another interesting finding is that once most of these young patients become teenagers, their ear discharge seems to stop. We subsequently tend to see safe central tympanic membrane perforations as the discharge stops.

Dr. Coates: A number of years ago, a group of otologists went into the central desert of Australia and operated on a lot of younger children. However, many of these operations failed. As a result, the consensus was reached that we shouldn't operate on 4- and 5-year-olds; instead, we should wait until their ear disease has burned out and then perform surgery when these patients reach adolescence.

But [do not agree with this strategy. I perform a tragal cartilage myringoplasty in these younger children because it can survive in a great deal of pus. Even if a small perforation remains, it can sometimes serve as nature's own grommet, and hearing will still improve and the ear might still be dry. What we might call a "failed" myringo-plasty--that is, one that is only 90% healed-might in fact result in better hearing than if the perforation had completely healed and fluid had recurred. So we are not too disappointed with 90% healing. We can consider that a partial success.

Dr. Rutka: Another problem we used to see is that following an operation, a patient would leave for home in a small, unpressurized aircraft. Changes in altitude and corresponding atmospheric pressure would sometime damage a newly placed patch. We therefore now advise patients not to fly for a few weeks afterward, if possible.

Dr. Coates: When I operate on a perforation that involves, say, less than 30% of the tympanic membrane, I use the tragal graft inlay method. As a result, my patients can fly the next day because the graft is quite solid and won't fall apart.

Dr. Roland: Do you use a palisading cartilage technique or an island cartilage technique?

Dr. Coates: I use an island inlay technique for most patients. I use an underlay technique for patients who have a subtotal or a total perforation. Some otologists use a postauricular approach with temporal fascia. I try to use cartilage as often as possible, even though it looks inelegant. The reason is that the graft survival rate with cartilage appears to be better than that seen with temporal fascia.

Dr. Croxson: Is there a place for tympanomastoidectomy rather than just straight tympanoplasty for these children?

Dr. Coates: This is controversial. In the Aboriginal population, mastoidectomies don't seem to have made much of an improvement. A tympanomastoidectomy might be worth considering when you're operating on a recurrence or perhaps doing a revision. Perhaps the reason that mastoidectomies haven't been all that successful has something to do with the presence of a biofilm. Perhaps we should look at this aspect before we consider a mastoidectomy. However, I am not disclaiming the fact that we should do some mastoidectomies in children.

Harvey Coates, MS, FRACS

Dr. Coates is a senior ENT surgeon at the Princess Margaret Hospital for Children in Perth, Western Australia. He specializes in pediatric otology and obstructive sleep disorders and has a particular interest in treating his country's Aborigine population.