Pediatric Dermatology Vol. 32 No. 1 91–96, 2015
Management of a Trichophyton tonsurans Outbreak in a Day-Care Center Robert M. Gray, B.M., B.Ch., M.A.,* Caroline Champagne, M.B.Ch.B., M.R.C.P., M.Sc.,‡ David Waghorn, M.B., B.S., M.Sc., D.R.C.O.G., F.R.C.Path.,† Eugene Ong, B.M., B.Ch.,* Sophie A. Grabczynska, F.R.C.P.,– and Jill Morris, M.B., Ch.B., M.P.H., F.F.P.H.* *Thames Valley Public Health England Centre, Oxfordshire, UK, †Buckinghamshire Healthcare National Health Service Trust, Wycombe Hospital, Buckinghamshire, UK, ‡Department of Dermatology, Churchill Hospital, Oxford, UK, ¶Buckinghamshire Healthcare National Health Service Trust, Amersham Hospital, Buckinghamshire, UK
Abstract: Trichophyton tonsurans is the leading cause of tinea capitis in the United Kingdom (UK) as well as causing tinea corporis. This organism has been linked to several outbreaks in the UK and abroad, and such outbreaks may be prolonged since T. tonsurans can be difficult to control. There remains an incomplete consensus in the literature on the optimal management of such outbreaks of this infection. Following notification that a child with T. tonsurans was identified at a day-care center in the UK, initial investigations identified nine cases of fungal infection involving children and staff over the previous 7 months. We report on the management of an outbreak of T. tonsurans tinea capitis and tinea corporis among children and staff in a day-care center. An outbreak control team with representatives from dermatology, microbiology, daycare center management, and the Health Protection Agency initiated case ascertainment by scalp inspection and brushing of all children and staff at the nursery. Two complete rounds of screening were required before the outbreak was declared over. Infection control measures included antifungal shampoo use, exclusion of identified cases for a short period, removal of shared items from the center, and enhanced decontamination of fomites. The outbreak, which lasted longer than 12 months, involved 12 children and 7 staff members. Of these, 12 cases were confirmed by positive fungal culture. T. tonsurans is difficult to manage, especially in childcare settings, but case ascertainment, appropriate treatment with oral agents, and sustained infection control measures can be effective in controlling such outbreaks.
Address correspondence to Jill Morris, M.B., Ch.B., M.P.H., F.F.P.H., Thames Valley Public Health England Centre, Public Health England Chilton, Didcot, Oxon OX11 0RQ, UK, or e-mail: [email protected]. DOI: 10.1111/pde.12421
© 2014 Wiley Periodicals, Inc.
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92 Pediatric Dermatology Vol. 32 No. 1 January/February 2015
Trichophyton tonsurans is the number one cause of tinea capitis in the United Kingdom (1–3) and has been associated with several outbreaks in the childcare setting (4–7). The incidence of T. tonsurans infection has risen sharply in Europe in recent years, to the extent that some commentators advocate screening in primary schools (1,2); a similar increase in incidence has not been seen in the United States. This organism is most commonly seen in children, African and Caribbean races, and urban populations and may be transmitted during certain contact sports (e.g., wrestling) (1,8). The fungus primarily causes tinea capitis, although tinea corporis may also occur, the latter being more common in adults. With tinea capitis, the organism resides within the hair follicle (endothrix infection). It can be difficult to diagnose, does not fluoresce under a Wood’s light, and can be resistant to treatment. On several occasions this has led to prolonged outbreaks (7,9). Elimination of scalp infection requires systemic antifungal therapy with agents such as terbinafine. In the spring of 2011 a hospital microbiologist was informed that a child had been diagnosed with tinea capitis after a private dermatology consultation. The child’s parents reported similar signs in several other children attending their child’s day-care center. On initial investigation, five children and four staff members at the day-care center had current or recent fungal infection of the skin or scalp. Their general practitioners had individually treated several for “ringworm.” Two of the children tested positive for T. tonsurans on mycological culture. The day-care center had not been aware of these diagnoses previously and the potential cross-infection that was occurring. The five affected children all had tinea capitis, whereas the adult infections involved exposed skin sites of the head and neck. METHODS An outbreak control team (OCT) was established to investigate and manage this outbreak. This OCT included representatives from dermatology, microbiology, day-care center management, and the local Health Protection Unit (now part of Public Health England). The day-care center had 40 children and 12 staff, with most children attending part time. The children were divided into three groups based on age (Table 1) and came from a broad range of ethnic groups, including Caucasian, Asian, and Afro-Caribbean individuals, with a high immigrant representation. Although staff were generally allocated to one group for their work, there was a degree of crossover,
TABLE 1. Population of the nursery in March 2011 Group
Age (yrs)
Population, n
1 2 3 Total
40 kg = 250 mg Adults: 250 mg daily
RESULTS Results of the screening rounds and cases identified between screening rounds are shown in Table 2. The initial screening round in March 2011 identified two cases of T. tonsurans in children (patients B and C), both in group 3. One of a twin from group 2 then presented to a dermatologist with tinea faciei (patient D). Skin scrapings confirmed T. tonsurans in this twin. Extension of the round 1 screening to all children identified one further child (patient E, group 2) with T. tonsurans. After the first round of screening (all children and adults), two staff members presented with tinea corporis (both positive for T. tonsurans). Of these, one was a new member of the staff (patient G), and one had presented previously in 2010 with a fungal infection positive for T. tonsurans (patient F). One child from group 3 then presented to their general practitioner with a facial skin lesion and was treated for presumed fungal infection without sampling. Of the children and staff rescreened in June 2011, five tested positive for T. tonsurans: three children from group 3 (patients B, H [the presumptive index case], and I), one child from group 1 (patient J), and one staff member (patient K). Further details on previous screening results and symptoms of these patients are given in Table 2. Five of the previously confirmed cases tested negative on this rescreen, suggesting effective treatment. After the second full screen and with routine staff screening in place, only one staff member who had previously negative screens subsequently grew T. tonsurans on culture. This staff member (patient
This outbreak report highlights the difficulty in controlling T. tonsurans infections. Factors contributing to the difficulty include a long incubation period (6 wks to clinical symptom development), so those infected may be infectious to others before they become symptomatic (11), and that patients may not seek treatment for the often mild clinical symptoms, tinea capitis can be difficult to diagnose clinically (particularly by nonspecialists), and screening has limited sensitivity. Also, T. tonsurans may persist in the environment after the successful treatment of patients, potentially leading to reinfection of cases. The day-care center setting exacerbates these difficulties. It can be difficult to maintain strict hygiene precautions with young children, especially when there is significant sharing of toys and other items. In addition to the day-care center being a potential source of infection, household contacts and the household environment may be a source of infection or reinfection. The presumptive index case identified during this outbreak was a 4-year-old Afro-Caribbean boy. His initial presentation in August 2010 was with tinea capitis, but a number of the other cases in the outbreak comprised fungal lesions on the hands, neck, and face, particularly among the staff. This pattern of lesions suggests that the dominant mode of transmission for the staff was direct skin-on-skin or hair-on-skin contact during the handling and cuddling of infants by the staff caring for them. They would then become potential sources for the spread of further infection. In this outbreak, several children and staff who were clinically suspected of being cases tested negative during the initial screening, only to test positive later. Thus it is likely that screening was only partially sensitive. Previous experiences with T. tonsurans screening have shown only moderate agreement between the clinical detection of scalp infection by
Gray et al: An Outbreak of Trichophyton tonsurans
trained individuals and culture positivity on brushings taken from the same patient (2,12). The likely explanation is that clinical examination and scalp brushing are only partially sensitive diagnostic methods, so we advocate combining the two methods when undertaking screening and basing the decision of when to treat on the combined results rather than on either modality in isolation. The clearance of T. tonsurans scalp infection requires oral antifungal therapy, and follow-up brushings should be performed to confirm true mycological clearance. For children, a long duration of oral therapy can lead to compliance and tolerability problems (13), as well as being costly. An 8- to 10-week course of griseofulvin has historically been the treatment of choice for tinea capitis, but expert opinion has shifted in favor of a 2- to 4-week course of oral terbinafine therapy for tinea capitis when Trichophyton is the suspected cause. A recent meta-analysis found that courses of terbinafine achieve 54% to 94% mycological cure rates and showed no significant difference in effectiveness or tolerability between terbinafine and griseofulvin (14). A subsequent Cochrane review similarly found terbinafine to be noninferior to griseofulvin for the treatment of tinea capitis when T. tonsurans is the causative agent (15). Published guidelines from the European Society for Paediatric Dermatology concur that terbinafine is not inferior in efficacy to griseofulvin for T. tonsurans tinea capitis (16). Although terbinafine is commonly used in the United Kingdom for treatment of T. tonsurans, griseofulvin is still considered the criterion standard of therapy in the United States. Similarly, in Europe, griseofulvin remains the first-choice treatment for tinea cases caused by Microsporum species, and thus decisions regarding which agent to use should reflect known local epidemiology. Also, availability of the agent can play a part, with griseofulvin availability varying greatly from country to country. In this day-care center outbreak, oral terbinafine was the agent we recommended for T. tonsurans culture-positive cases, and there were no reports of poor tolerability, although, given the outbreak context, it was agreed to augment this oral therapy with ketoconazole-based antifungal shampoos to prevent transmission of infection. We also recommended that all screen-negative children and household contacts use the shampoos to avoid asymptomatic, low fungal load carriers from being infectious to others. The sporicidal effect of such shampoos is established and support exists for their use as effective therapy in the treatment of cases (17) and for prophylaxis in households of clinical cases (18,19).
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There is no clear consensus on exclusion policy for children with tinea infections. Initially, symptomatic children were allowed to attend day care, which is in line with several commentators’ recommendations (20,21). Children may shed spores for several weeks before they develop clinical symptoms and for several weeks after treatment is initiated, but the exclusion of children for weeks at a time is impractical. Given the ongoing difficulty with halting transmission, after the second round of screening it was agreed that all symptomatic children and staff would be excluded until 72 hours after the commencement of oral treatment. Although short in comparison with the period of infectivity, it was hoped that such 72-hour exclusions would reduce the likelihood of transmission. Advocacy of school exclusion for infected children may also be found in the literature (2,18,19,22). From this outbreak it is possible to postulate a correlation between the length of exposure to infected individuals and the likelihood of developing T. tonsurans infection. Of the 40 children attending the center, 10 attended full time (5 days/wk) and 30 attended part time (
Management of a Trichophyton tonsurans Outbreak in a Day-Care Center Robert M. Gray, B.M., B.Ch., M.A.,* Caroline Champagne, M.B.Ch.B., M.R.C.P., M.Sc.,‡ David Waghorn, M.B., B.S., M.Sc., D.R.C.O.G., F.R.C.Path.,† Eugene Ong, B.M., B.Ch.,* Sophie A. Grabczynska, F.R.C.P.,– and Jill Morris, M.B., Ch.B., M.P.H., F.F.P.H.* *Thames Valley Public Health England Centre, Oxfordshire, UK, †Buckinghamshire Healthcare National Health Service Trust, Wycombe Hospital, Buckinghamshire, UK, ‡Department of Dermatology, Churchill Hospital, Oxford, UK, ¶Buckinghamshire Healthcare National Health Service Trust, Amersham Hospital, Buckinghamshire, UK
Abstract: Trichophyton tonsurans is the leading cause of tinea capitis in the United Kingdom (UK) as well as causing tinea corporis. This organism has been linked to several outbreaks in the UK and abroad, and such outbreaks may be prolonged since T. tonsurans can be difficult to control. There remains an incomplete consensus in the literature on the optimal management of such outbreaks of this infection. Following notification that a child with T. tonsurans was identified at a day-care center in the UK, initial investigations identified nine cases of fungal infection involving children and staff over the previous 7 months. We report on the management of an outbreak of T. tonsurans tinea capitis and tinea corporis among children and staff in a day-care center. An outbreak control team with representatives from dermatology, microbiology, daycare center management, and the Health Protection Agency initiated case ascertainment by scalp inspection and brushing of all children and staff at the nursery. Two complete rounds of screening were required before the outbreak was declared over. Infection control measures included antifungal shampoo use, exclusion of identified cases for a short period, removal of shared items from the center, and enhanced decontamination of fomites. The outbreak, which lasted longer than 12 months, involved 12 children and 7 staff members. Of these, 12 cases were confirmed by positive fungal culture. T. tonsurans is difficult to manage, especially in childcare settings, but case ascertainment, appropriate treatment with oral agents, and sustained infection control measures can be effective in controlling such outbreaks.
Address correspondence to Jill Morris, M.B., Ch.B., M.P.H., F.F.P.H., Thames Valley Public Health England Centre, Public Health England Chilton, Didcot, Oxon OX11 0RQ, UK, or e-mail: [email protected]. DOI: 10.1111/pde.12421
© 2014 Wiley Periodicals, Inc.
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92 Pediatric Dermatology Vol. 32 No. 1 January/February 2015
Trichophyton tonsurans is the number one cause of tinea capitis in the United Kingdom (1–3) and has been associated with several outbreaks in the childcare setting (4–7). The incidence of T. tonsurans infection has risen sharply in Europe in recent years, to the extent that some commentators advocate screening in primary schools (1,2); a similar increase in incidence has not been seen in the United States. This organism is most commonly seen in children, African and Caribbean races, and urban populations and may be transmitted during certain contact sports (e.g., wrestling) (1,8). The fungus primarily causes tinea capitis, although tinea corporis may also occur, the latter being more common in adults. With tinea capitis, the organism resides within the hair follicle (endothrix infection). It can be difficult to diagnose, does not fluoresce under a Wood’s light, and can be resistant to treatment. On several occasions this has led to prolonged outbreaks (7,9). Elimination of scalp infection requires systemic antifungal therapy with agents such as terbinafine. In the spring of 2011 a hospital microbiologist was informed that a child had been diagnosed with tinea capitis after a private dermatology consultation. The child’s parents reported similar signs in several other children attending their child’s day-care center. On initial investigation, five children and four staff members at the day-care center had current or recent fungal infection of the skin or scalp. Their general practitioners had individually treated several for “ringworm.” Two of the children tested positive for T. tonsurans on mycological culture. The day-care center had not been aware of these diagnoses previously and the potential cross-infection that was occurring. The five affected children all had tinea capitis, whereas the adult infections involved exposed skin sites of the head and neck. METHODS An outbreak control team (OCT) was established to investigate and manage this outbreak. This OCT included representatives from dermatology, microbiology, day-care center management, and the local Health Protection Unit (now part of Public Health England). The day-care center had 40 children and 12 staff, with most children attending part time. The children were divided into three groups based on age (Table 1) and came from a broad range of ethnic groups, including Caucasian, Asian, and Afro-Caribbean individuals, with a high immigrant representation. Although staff were generally allocated to one group for their work, there was a degree of crossover,
TABLE 1. Population of the nursery in March 2011 Group
Age (yrs)
Population, n
1 2 3 Total
40 kg = 250 mg Adults: 250 mg daily
RESULTS Results of the screening rounds and cases identified between screening rounds are shown in Table 2. The initial screening round in March 2011 identified two cases of T. tonsurans in children (patients B and C), both in group 3. One of a twin from group 2 then presented to a dermatologist with tinea faciei (patient D). Skin scrapings confirmed T. tonsurans in this twin. Extension of the round 1 screening to all children identified one further child (patient E, group 2) with T. tonsurans. After the first round of screening (all children and adults), two staff members presented with tinea corporis (both positive for T. tonsurans). Of these, one was a new member of the staff (patient G), and one had presented previously in 2010 with a fungal infection positive for T. tonsurans (patient F). One child from group 3 then presented to their general practitioner with a facial skin lesion and was treated for presumed fungal infection without sampling. Of the children and staff rescreened in June 2011, five tested positive for T. tonsurans: three children from group 3 (patients B, H [the presumptive index case], and I), one child from group 1 (patient J), and one staff member (patient K). Further details on previous screening results and symptoms of these patients are given in Table 2. Five of the previously confirmed cases tested negative on this rescreen, suggesting effective treatment. After the second full screen and with routine staff screening in place, only one staff member who had previously negative screens subsequently grew T. tonsurans on culture. This staff member (patient
This outbreak report highlights the difficulty in controlling T. tonsurans infections. Factors contributing to the difficulty include a long incubation period (6 wks to clinical symptom development), so those infected may be infectious to others before they become symptomatic (11), and that patients may not seek treatment for the often mild clinical symptoms, tinea capitis can be difficult to diagnose clinically (particularly by nonspecialists), and screening has limited sensitivity. Also, T. tonsurans may persist in the environment after the successful treatment of patients, potentially leading to reinfection of cases. The day-care center setting exacerbates these difficulties. It can be difficult to maintain strict hygiene precautions with young children, especially when there is significant sharing of toys and other items. In addition to the day-care center being a potential source of infection, household contacts and the household environment may be a source of infection or reinfection. The presumptive index case identified during this outbreak was a 4-year-old Afro-Caribbean boy. His initial presentation in August 2010 was with tinea capitis, but a number of the other cases in the outbreak comprised fungal lesions on the hands, neck, and face, particularly among the staff. This pattern of lesions suggests that the dominant mode of transmission for the staff was direct skin-on-skin or hair-on-skin contact during the handling and cuddling of infants by the staff caring for them. They would then become potential sources for the spread of further infection. In this outbreak, several children and staff who were clinically suspected of being cases tested negative during the initial screening, only to test positive later. Thus it is likely that screening was only partially sensitive. Previous experiences with T. tonsurans screening have shown only moderate agreement between the clinical detection of scalp infection by
Gray et al: An Outbreak of Trichophyton tonsurans
trained individuals and culture positivity on brushings taken from the same patient (2,12). The likely explanation is that clinical examination and scalp brushing are only partially sensitive diagnostic methods, so we advocate combining the two methods when undertaking screening and basing the decision of when to treat on the combined results rather than on either modality in isolation. The clearance of T. tonsurans scalp infection requires oral antifungal therapy, and follow-up brushings should be performed to confirm true mycological clearance. For children, a long duration of oral therapy can lead to compliance and tolerability problems (13), as well as being costly. An 8- to 10-week course of griseofulvin has historically been the treatment of choice for tinea capitis, but expert opinion has shifted in favor of a 2- to 4-week course of oral terbinafine therapy for tinea capitis when Trichophyton is the suspected cause. A recent meta-analysis found that courses of terbinafine achieve 54% to 94% mycological cure rates and showed no significant difference in effectiveness or tolerability between terbinafine and griseofulvin (14). A subsequent Cochrane review similarly found terbinafine to be noninferior to griseofulvin for the treatment of tinea capitis when T. tonsurans is the causative agent (15). Published guidelines from the European Society for Paediatric Dermatology concur that terbinafine is not inferior in efficacy to griseofulvin for T. tonsurans tinea capitis (16). Although terbinafine is commonly used in the United Kingdom for treatment of T. tonsurans, griseofulvin is still considered the criterion standard of therapy in the United States. Similarly, in Europe, griseofulvin remains the first-choice treatment for tinea cases caused by Microsporum species, and thus decisions regarding which agent to use should reflect known local epidemiology. Also, availability of the agent can play a part, with griseofulvin availability varying greatly from country to country. In this day-care center outbreak, oral terbinafine was the agent we recommended for T. tonsurans culture-positive cases, and there were no reports of poor tolerability, although, given the outbreak context, it was agreed to augment this oral therapy with ketoconazole-based antifungal shampoos to prevent transmission of infection. We also recommended that all screen-negative children and household contacts use the shampoos to avoid asymptomatic, low fungal load carriers from being infectious to others. The sporicidal effect of such shampoos is established and support exists for their use as effective therapy in the treatment of cases (17) and for prophylaxis in households of clinical cases (18,19).
95
There is no clear consensus on exclusion policy for children with tinea infections. Initially, symptomatic children were allowed to attend day care, which is in line with several commentators’ recommendations (20,21). Children may shed spores for several weeks before they develop clinical symptoms and for several weeks after treatment is initiated, but the exclusion of children for weeks at a time is impractical. Given the ongoing difficulty with halting transmission, after the second round of screening it was agreed that all symptomatic children and staff would be excluded until 72 hours after the commencement of oral treatment. Although short in comparison with the period of infectivity, it was hoped that such 72-hour exclusions would reduce the likelihood of transmission. Advocacy of school exclusion for infected children may also be found in the literature (2,18,19,22). From this outbreak it is possible to postulate a correlation between the length of exposure to infected individuals and the likelihood of developing T. tonsurans infection. Of the 40 children attending the center, 10 attended full time (5 days/wk) and 30 attended part time (
