mycoses 32 (Suppl. 2) 9- 11 . accepted/angenommen: December 5,1989 . 0 Grosse Verlag Berlin 1989

Incidence of Oral Candidosis I W. Meinhof’ and R. Spring2

’Department of Dermatology, R.W.T.H., Aachen, Federal Republic of Germany ZJanssen GmbH, Neuss, FederaI Republic of Germany

Key words: Oral candidosis - incidence - prescribing habits

Summary: Although it is well known that both yeasts in general and Candida albicans in particular are frequently found in the oral cavity of ill and even of healthy individuals, the definite incidence of oral candidosis is far from being clear. Today it is, however, possible to assess the frequency of oral can- didosis in a country indirectly, judging from the frequency of prescription of drugs for this indication. Data thus obtained indicate a remarkable increase of the frequency of the disease during the last decade. While polyenes are still prescribed for oral candi- dosis about as often as ever, the prescription of azoles has gained more and more import- ance.

“The overall incidence of oral thrush in the population at large is impossible to assess”. This sentence, cited from EC. 0dds’“Can- dida and Candidosis”, 2nd Edition, 1988 [8], describes the situation as it is: Till today, we do not have any data which allow us to outline the epidemiology of oral candidosis if the word epidemiology is used in its orig- inal sense. Thereis anumber of publications dealing with the occurrence of candidoses in certain groups of individuals within the population, e.g. neonates or old people, denture wearers, diabetics or AIDS patients, to name just afew (2,4,6,8]. From these studies we learn that oral candidosis can be found more frequently in newborns than in elder children, and also more fre-

quently in patients with certain diseases than in healthy adults.

Most investigations aiming at the epi- demiology of candidosis, however, are not designed to assess the incidence of the dis- ease but the prevalence of yeasts, yeasts in general, or more specifically Candida albi- cans, in the oral cavity or thegastrointestinal tract. It is a well known, but often disre- garded, fact that candidosis is a disease with clinical signs and symptoms and not the mere presence of a yeast of the genus Can- dida at some anatomical location. Espe- cially with regard to gastrointestinal candi- dosis we should always ask ourselves what disease we are talking about when we are using this diagnosis. We should not follow the misconception which regards the isola- tion of Candida albicans from stools as the proof of candidosis.

The prevalence of yeasts or of Candida albicans in the oral cavity has been investi- gated by several authors at various times and locations [l, 3, 5, 7, 81. Odds (comp. table 1, 2) has listed the results of these studies in his monograph, and it is Erom his tables that the following figures were excerpted and condensed.

In additon to these average percentages the range should be mentioned, especially as it is avery wide one. For the occurrence of Candida albicans we find figures from around 2 ‘/o to over 60 O h in healthy individ- uals, and from 6% to almost 70% in

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W. Meinhof and R. Spring: Oral Candidosis

Figure 1 : Number of prescriptions for oral candidosis in FR Germany per year.

Figure 3: Development of the incidence of oral candidosis in the various age groups in FR Germany during the last decade.

patients (excluding those with a diagnosis of oral candidosis). The figures for yeasts of all kind are similar.

The question is if these figures are of any value at all for the study of the epidemiology of candidoses. As we all know, candidosis is the result of two conditions: the presence of the yeast and a predisposing factor allowing theyeast to overcome the host’s defenseline. Considering these two factors, one will eas- ily reach the conclusion that with such a fre- quent occurrence of yeasts in the oral cavity it must be the predisposing factors which set the pace of the incidence of oral candidosis. Thus, a study of the epidemiology of candi-

Figure 2: Development of the age distribution of patients getting prescriptions for oral candidosis in F R Germany during the last decade.

Figure 4: Number of prescriptions of polyenes and azoles for oral candidosis in FR Germany during the last decade.

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Table 1: Yeast colonization of the oral cavity of healthy individuals (adapted from (8))

Yeasts C. albicans

Adults 32.7% 23.8% Children 43.1 % 30.0%

Table 2: Yeast colonization of the oral cavity of patients (adapted from (8)) (Excluding patients with oral candidosis)

Yeasts C. albicans

Ad u Its 44.3 % 43.1 % Children 40.9 % 30.8%

W. Meinhof and R. Spring: Oral Candidosis

doses at best starts at the epidemiology of predisposing factors, a topic which clearly is too large for the present occasion.

When, at the beginning, it has been stated that till today we have no information on the frequency of oral candidosis in the popula- tion at large, this is not absolutely correct as we nowadays have some insight into pres- cribing habits.

In some countries including the Federal Republic of Germany the analysis of pres- cribing habits provides an opportunity to obtain comparatively exact data on the incidence of individual diseases.

During one week 2.200 practising physi- cians, selected by demoscopic representa- tive sampling, submit copies of their pres- criptions with additional diagnostic and patient data to the Institute for Medical Stat- istics. The diagnostic data were coded in accordance with the 9th Revision of the ICD Classification proposed by WHO. All data are projected on national level and published quarterly.

The coding of diagnoses according to the ICD classification may occasionally be inaccurate, if the data provided by the reporting physicians are not perfectly clear.

Another element of uncertainty to be taken into account arises from the fact, that no detailed information on the diagnostic method is available.

A correlation with sales figures of the pharmaceutical industry shows, that the accuracy of the data arrived at in t h s man- ner varies by f 15 %.

Despite these ambiguities a fairly clear picture of the development of oral candi- dosis in the past ten years is obtained. While in 1979 the number of oral candidosis cases diagnosed by practising physicians was about 243.000 corresponding to an incidence of 0.4 %, this figure has gone up to about 486.000 already by 1988, corre- sponding to 0.8 O h , i.e. continuously as can be derived from Figure 1.

The age distribution is typical insofar as oral candidosis occurs mainly in infancy (Figure 2).

A n evaluation of the morbidity figures in the individual age groups shows, that the doubling of the incidence of oral candidosis within the past ten years is attributable to two factors: a highly disproportionate increase in infancy and a doubling of the incidence in the segment of the older popu- lation. The morbidity figures of the age groups between 5 and 40 years remain unchanged (Figure 3).

As regards therapeutic habits, practising physicians almost exclusively treat oral can- didosis locally, using oral ketoconazole only in about 0.3 '/o of the cases.

Within the last ten years miconazole gel, introduced in Germany in 1980, has played a significant part in the treatment of oral candidosis, especially in infants. The com- parative development of prescriptions of polyenes and azoles for oral candidosis is shown in Fig. 4.

References

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Bauer, J. (1974): Vergleichende Untersuchungen iiber die Hefebesiedlung in Mund und Nase. Inau- gural-Dissertation Munchen. Conen, J. (1986): Mykosen im Langzeitbereich eines psychiatrischen Krankenhauses. Inaugural- Dissertation Aachen. Deteiing, H.-P. (1962): Experimentelle Untersu- chungen iiber den Befall der Mundhohle mit Hefe- pilzen unter besonderer Beriicksichtigung einer antimycetischen Testung handelsublicher Mund- pflegemittel und zahnarztlicher Desinfizienzien. Inaugural-Dissertation Hamburg. Hauck, H. (1981): Cundidu-Mykosen im Alter. Grosse-Scripta 6. Grosse Verlag Berlin. Hundertmark, U. (1977): Untersuchungen iiber Haufigkeit und Vorkommen des SproBpilzbefalles bei stationar behandelten Patienten in einer Dermatologischen Klinik. Inaugural-Dissertation Wurzburg. Korting, H.C. (1 989): Dermatomykosen bei AIDS. Mykologische Fortbildungstagung ,,!SO Jahre Mykologie seit Johann Lucas Schonlein". Bamberg, 29. April 1989. Malicke, H. (1963): Experimentelle Untersuchun- gen iiber das Vorkommenvon Hefepilzen bei Neu- geborenen und Sauglingen. Inaugural-Disserta- tion Hamburg. Odds, EC. (1988): Cundidu and candidosis. Bail- likre Tindall: London, Philadelphia, Toronto, Sid- ney, Tokyo.

Correspondence: Prof. Dr. Wolf Meinhof, Hautklinik der Medizinischen Fakultat, Klinikum PauwelsstraRe, D-5 100 Aachen, FRG

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