Studies in the epidemiology of tinea pedis. II. Dermatophytes on the floors of swimming-baths

A Practical Guide to Curing Onychomycosis: How to Maximize Cure at the Patient, Organism, Treatment, and Environmental Level

Onychomycosis is a fungal nail infection caused by dermatophytes, non-dermatophyte molds, and yeasts. Treatment of this infection can be difficult, with relapse likely to occur within 2.5 years of cure. The objective of this article is to review factors that can impact cure and to suggest practical techniques that physicians can use to maximize cure rates. Co-morbidities, as well as disease severity and duration, are among the many patient factors that could influence the efficacy of antifungal therapies. Furthermore, organism, treatment, and environmental factors that may hinder cure include point mutations, biofilms, affinity for non-target enzymes, and exposure to fungal reservoirs. To address patient-related factors, physicians are encouraged to conduct confirmatory testing and treat co-morbidities such as tinea pedis early and completely. To combat organism-focused factors, it is recommended that disruption of biofilms is considered, and drugs with multiple routes of delivery and unique mechanisms of action are prescribed when traditional agents are not effective. Extending follow-up periods, using combination treatments, and considering pulse regimens may also be of benefit. Through these practical techniques, physicians can maximize cure and limit the risk of relapse and re-infection.

Potential transmission pathways of clinically relevant fungi in indoor swimming pool facilities

Possible transmission pathways of fungi in indoor swimming pool facilities were assessed through fungal counting in different areas of the facilities and typing of the collected fungal isolates. Air, water and surface samples were collected from seven different indoor swimming pool facilities. Fungal species were identified based on their internal transcribed spacer (ITS) sequences. Maximum fungal concentrations of 6.2 CFU/cm², 1.39 CFU/100 mL, and 202 CFU/m³ were found on surfaces, in water and air, respectively. In total, 458 isolates were obtained, belonging to 111 fungal species, of which 50 species were clinically relevant. Phialophora oxyspora (13.3%) and Trichosporon dohaense (5.0%) were the most frequently isolated species and were merely detected on floors, as were the dermatophytes, Trichophyton interdigitale and T. rubrum. Penicillium spp. and Aspergillus spp. were the dominant fungi in water and air. No typical patterns of fungal concentrations along the preferential pathways of pool visitors were observed, however, sites where pool visitors converge while moving from one room (e.g. dressing room) to another (e.g. shower room) and walking barefoot displayed the highest fungal concentrations thus posing the highest risk of contamination. The dispersal of fungi on floors is most likely facilitated by the pool visitors and cleaning tools. Clinically relevant fungi, including the ones rarely identified in nature, were widely detected on floors, in water and in air, as well as on cleaning tools and flexibeams. Preventive measures such as cleaning should minimize the prevalence of clinically relevant fungi in swimming pool facilities since these potentially pose health risks to those vulnerable for infections.

Swimming pools and fungi: An epidemiology survey in Polish indoor swimming facilities

Environmental conditions for swimming facilities may support fungal growth and also may represent a biological risk for users. However, since previously published studies both cleaning procedures and sanitary regulations are likely to have been improved. The aim of the study was to examine whether attendance to public swimming pools was still a risk factor for fungal infection of the skin in Poland. We investigated the occurrence of mycotic species, in a sample from Polish swimming pools. Detection and identification of isolated species were achieved by cultural and morphological methods. Study revealed high incidence of yeast and yeast-like fungi. Candida spp. and Rhodotorula rubra were commonly detected, followed by Aspergillus spp. and Trichophyton mentagrophytes. Surprisingly, the prevalence of clinically important species isolated from swimming pool environments did not reflect prevalence of those species in Polish population. The present results are in agreement with previous research and support that swimming pools remain an important reservoir of clinically important fungi, yet the exposure associated with swimming pools may not be a major source of dermatophytic infection in Poland.

Dermatophyte infections in environmental contexts

Fungal dermal diseases caused by the molds of the Dermatophyte family are among the most frequent infectious diseases affecting quality of life. There are 3 attributed sources of infection by Dermatophytes:1) humans; 2) animals and 3) soil. Dermatophytes posses the ability to utilize keratin from human and animal tissues, or debris from dead animal sources found in soil, such as feathers, skin or nails. Hence, Dermatophytes are abundant in different ecological niches. All 3 groups can infect humans, causing dermatophytoses manifested in different clinical entities involving skin, hair or nails. The mode of infection of the Dermatophytes is via direct or indirect contact. Dermatophytes are found universally, however the relative prevalence of dermatophytoses caused by different Dermatophytes may vary in different geographic areas according to climatic conditions or lifestyle. Thus, studies in different geographic areas assessing the specific fungal etiology involved are of epidemiological relevance serving as baseline information for management of dermatophytoses at the local level. The present article will focus, mostly, on epidemiological data from published surveys conducted in different geographic/climatic areas analyzing the prevalence of specific Dermatophyte species in regard to gender, age, type of infection in context of environmental factors.

Preventive effects of various types of footwear and cleaning methods on dermatophyte adhesion

Tinea pedis is contagious and typically spreads from infected to non-infected persons. The purpose of this study was to evaluate the efficacy of footwear in preventing tinea pedis adhesion. Using the stamp culture method, we investigated the effectiveness of preventing dermatophyte passage by the wearing of stockings made of nylon, socks made of cotton and tabi (Japanese socks), as well as the effect of removing dermatophytes from these items by washing with soap, cold water and cold water after turning inside-out. For sandals, sneakers and boots, we also investigated the effect of dermatophyte removal by pouring cold water into the footwear, wiping with a wet towel, and pouring boiling water into the footwear. The wearing of socks or tabi was effective in preventing passage of dermatophytes. The stocking material proved to be too thin to prevent passage. On the inner side of socks (the side of the sole), all treatments were effective at removing dermatophytes, but on the outer side of socks (the side touching the surface of the sandals), the treatment of washing in cold water after turning inside-out resulted in significantly more dermatophytes as compared with the other treatments. Pouring cold water, wiping with a wet towel and pouring boiling water were all effective for removing dermatophytes from sandals and sneakers. However, for boots, the treatment of pouring cold water was less effective. To prevent the adhesion of dermatophytes to sandals, wearing socks or tabi was effective, and the treatments of washing socks in cold water after turning inside-out and of pouring cold water into the boots were less effective than the others.

Ecology of dermatophytes and other keratinophilic fungi in swimming pools and polluted and unpolluted streams

The biodiversity and richness of keratinophilic fungal communities including dermatophytes were assessed in three stream sites and three swimming pools in the Nablus district in Palestine, using hair baiting (HBT) and surface dilution plate (SDP) techniques, over 8- and 6-month periods, respectively. The effect of wastewater effluent and selected ecological factors on these fungi in relation to species diversity and population densities were also considered. Fifty keratinophilic fungal species were recovered from the aquatic habitats studied, of which 42 were recovered from stream sites and 22 from swimming pools. Of these fungi 6 were either dermatophytes (Microsporum gypseum, and Trichophyton mentagrophytes) or dermatophyte related species (Chrysosporium merdarium, Ch. tropicum, Ch. keratinophilum and T. terrestre). The most frequently isolated species in the three pools were Acremonium strictum and Cladosporium cladosporioides, using Sabouraud dextrose agar medium (SDA). The most abundant species were Acr. strictum, and Aspergillus flavus. However, only 4 species were isolated using the SDA medium amended with 5-flurocytosine (5-FC). The most frequent and abundant species in the three stream sites using SDA medium were Geotricum candidum, and Penicillium chrysogenum. The most frequent species in the three sites using the 5-FC medium, was Paecilomyces lilacinus. Using HBT, the most abundant and frequent species in the three stream sites were G. candidum, and Pa. lilacinus, on SDA medium, and Pa. lilacinus, and Gliocladium nigrovirens on the 5-FC medium. The 5-FC medium was more suitable for the isolation of dermatophytes and closely related species than the SDA medium; 6 were recovered on 5-FC, whereas only one on the SDA medium. Variation in the levels of keratinophilic fungal populations from the three stream sites sampled 5 times over an 8-month period, followed comparable fluctuation patterns. Wastewater affected fungal population densities with the highest levels in the un-polluted stream sites, and lowest in the heavily polluted sites. Swimming pools, polluted and un-polluted stream sites were found to be rich in pathogenic and potentially pathogenic fungi.

[Risk factors linked to the transmission of papilloma virus in the school environment. Alicante, 1999]

OBJECTIVE

The aim of this study is to describe an outbreak of plantar warts and to analyse the risk factors wich determining the transmission.

DESIGN

Cross-sectional survey.

SETTING

A school of Alicante.

PARTICIPANTS

1,620 students.

MEASUREMENTS AND MAIN RESULTS

Description and analysis of the outbreak. We studied the magnitude and the association between risk factors (sports activities and hygiene habits) and disease by logistic regression model. We estimated the crudes and adjusted odds ratio (OR) and the confidence intervals (CI) of 95%. We carry out environmental study and active search of cases. The global rate of answer to the cross-secctional survey was 70.86%. Reported cases were 221, the global attack rate was 19.25%. The outbreak occurred over 16 months. We did not find statistical significal difference either by sex (P=.138) or age (P=.233). The hygiene conditions of the swimming pool and the changing room were adapted. The risk of disease increased with the number of activities taking place (P=.001). The OR adjusted for hygiene habits was: use of changing room 0.95 (95% CI, 0.38%-2.41%), use of shower rooms 1.06 (95% CI, 0.70%-1.62%), walking barefoot in the changing room 1.97 (95% CI, 1.39%-2.79%) and showering barefoot 0.97 (95% CI, 0.58%-1.64%).

CONCLUSIONS

Outbreak of person to person transmission, the floor of the changing rooms was the prime cause of transmission. We did not find any association between the use of public swimming pool and the disease

Demonstration of dermatophyte dissemination from the infected soles using the foot-press method

We have designed a new direct isolation method, the foot-press method, to survey dissemination of dermatophytes from the infected soles. A total of 56 untreated patients with tinea pedis were examined. The infected soles of 42 patients were pressed onto actidione-chloramphenicol-5-fluorocytosine (5FC)-gentamicin sulphate Sabouraud glucose medium prepared in a large culture dish; the culture media were then incubated at 25 degrees C. Dermatophytes were isolated in 30 out of the 42 patients, while no dermatophytes could be grown from 10 healthy controls. The number of isolated colonies from each patient ranged from 1 to 97 (mean +/- SD, 11 +/- 20). The isolation frequencies were higher in the patients of hyperkeratotic type and in those with tinea unguium, while causative organisms and the extent of the lesions did not affect the results of the footpress method significantly. In order to reveal the morphology of disseminated dermatophytes, 1 x 1 cm pieces of culture media were cut out from culture dishes after pressing infected soles and were examined microscopically. Dermatophyte-like spores or hyphae, most of which were detached from cornified cells, could be seen in 10 out of 14 patients. Subsequently performed slide cultures isolated dermatophytes from approximately 70% of the pieces on which dermatophyte-like fungi were observed.

The descriptive epidemiology of tinea pedis in the community

Tinea pedis is a common inflammatory skin condition due to infection by dermatophyte fungi. A number of epidemiological studies have been completed on the frequency of tinea pedis in the community, particularly sporting and occupational groups and schools. Most studies have focused on small, high-risk populations. These include occupational groups involving manual labour, sporting groups such as swimmers, and those working or living in confined conditions with shared washing facilities, which favour the opportunity for cross-infection. Most studies show that the frequency of tinea pedis is higher in males than females. Tinea pedis infections appear to be least common among children, but do occur, and are commonly misdiagnosed. The difference between clinical disease and confirmed diagnosis by culture is not always clear when statistics of disease frequency have been presented. Clear diagnosis criteria indicating the level of mycologically confirmed diagnosis should be reported in future studies that include statistics on disease frequency. Future epidemiological studies should also aim to be population-based in order to obtain a more complete picture of disease frequency.

Fungal contamination of the floors of swimming pools, particularly subtropical swimming paradises

We compared the level of dermatophyte contamination of the floors of traditional swimming pools and of subtropical swimming paradises, a new type of indoor swimming pool introduced in Belgium in 1981. From the results of routine hygiene inspections over several years and of a comparative study, we can conclude that the floors of subtropical swimming pools are much more highly contaminated by dermatophytes than the floors of traditional swimming pools. This higher degree of contamination is due to the huge number of visitors, the complexity of construction, the choice of materials and the long opening hours. In both types of swimming pools, the predominant species was Trichophyton mentagrophytes var. interdigitale, followed by T. rubrum. Other dermatophytes, such as Microsporum canis and M. gypseum, were isolated sporadically.

Isolation of dermatophytes from house dust on a medium containing gentamicin and flucytosine

Dermatophytes are usually isolated from house dust by using actidione-chloramphenicol Sabouraud glucose medium (ACS medium). We have prepared a new medium, 5FC medium, by adding gentamicin sulphate (GS) and 5-fluorocytosine (5FC) to ACS medium to achieve more efficient isolation of dermatophytes from house dust. 5FC medium was more effective in isolating dermatophytes than ACS medium or ACS medium supplemented with GS alone. Trichophyton rubrum could be grown from 13 out of 19 house dust samples from the homes of patients with tinea pedis (68.4%), and T. mentagrophytes could be grown from 17 out of 21 (81.0%). Two of 20 house dust samples from the home of a control family without dermatophytosis grew only one colony of dermatophytes in 5FC medium; the rest of the samples showed no growth. The number of colonies isolated on 5FC medium was much higher than on ACS medium (5.3 vs. 2.0 for T. rubrum and 17.2 vs. 2.1 for T. mentagrophytes). In addition, the size of the isolated colonies was much larger than that on ACS medium. Thus, 5FC medium can be regarded as a useful tool for isolating dermatophytes from various contaminated samples.

Incidence of occult athlete's foot in swimmers

Athlete's foot is a dermatophytic infection frequently found in adults. This disease is, in some cases, asymptomatic. In order to evaluate the incidence of subclinical infection, we obtained 300 toe-web samples from the fourth interdigital space of 150 regular swimmers. More over, 66 specimens from the pool area were analysed. The method used was the carpet technique described by Mariat et al. (10). The fungal isolates were identified according to standard methods. A list of epidemiological data was completed for every swimmer. In our results, 22 swimmers had positive cultures (15%), 8 of these cases had no lesions (36%). They included 7 infections with Trichophyton mentagrophytes (87.5%) and one with T. rubrum (12.5%). We observed one case with a dual infection. Only one sample from the inanimate environment was positive. This study showed a significant incidence of occult athlete's foot in swimmers. To control this endemic problem, adequate preventive measures must be taken.

Athlete's Foot: Clinical Update

In brief: Athletes are particularly prone to athlete's foot because they are generally more exposed than others to conditions that encourage fungal growth, eg, communal showers and locker rooms. Diagnosis of athlete's foot rests on clinical suspicion and laboratory testing. Treatment may consist of topical antifungal agents and, for more resistant cases, oral griseofulvin. Preventive measures include keeping the feet dry, wearing nonocclusive leather shoes or sandals and absorbent cotton socks, and applying talcum or antifungal powder at least twice daily.

Staphylococci in swimming pool water

During a period of five years 1192 water samples from swimming pools were examined for staphylococci and 338 for coliform organisms only. Eighty-nine different pools were sampled.Numbers of staphylococci, estimated by the membrane filtration technique did not bear any significant relation to either bathing load or concentration of free chlorine.Wide variation in the staphylococcal count was observed when different parts of a pool were sampled on the same occasion.The only practicable standard for pool samples in relation to staphylococci would appear to be that these organisms should be absent from 100 ml. water when the pool has been out of use during at least ten hours before sampling if filtration and chlorination are adequate.