How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 - PDF Document

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  1. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Karen A. Moriello DVM DipACVD Clinical Professor of Veterinary Dermatology Dane County Humane Society, Dane County Wisconsin Dermatophyte Treatment Program Annex Facility …and Dr. Sandra Newbury* of UC, Davis who was the DCHS shelter veterinarian whose vision and dedication to shelter medicine field research proved “ringworm is a treatable and curable disease in shelters” *Current address: Sandra Newbury, DVM , National Shelter Medicine Extension Veterinarian, Koret Shelter Medicine Program, Center for Companion Animal Health, U C Davis School of Veterinary Medicine Trichophyton infections in people, this is not from the cat! 1

  2. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Skin diseases are common in shelters…. No evidence that the primary pathogen of importance (Microsporum canis) alters its pathogenicity unlike other infectious agents (e.g. viral infections) Contagious and easily transmitted BUT is non-life threatening Skin lesions almost never cause any long term damage Treatable and curable Good prognosis Has features similar to many other skin diseases such as Cheyletiella, Sarcoptes, Otodectes, fleas, and ticks The primary reason dermatophytosis is of importance in shelters is that it is a disease of public health concern Routine intake procedures (e.g. vaccination, application of flea control) do not protect the population from disease, unless a screening protocol is in place Affects the most adoptable population in a shelter (i.e. kittens and puppies) This is a highly charged topic with respect to management (And a possible PR nightmare) Microsporum canis is the primary pathogen of concern in shelters Highly variable: geographic region, population density, husbandry practices, intake procedures, etc. Reports of 4 to 100% but numbers can be misleading depending upon whether the study reports prevalence based solely upon positive culture status or makes correlates cats that are truly infected (lesions, Wood’s lamp positive, culture positive) “Culture positive” simply means infective spores were found on the hair coat, it does not necessarily mean the cat is infected 2

  3. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Cat to cat transmission is the most common mode Spores must make contact with the skin Spores must adhere to the skin and defeat skin/cat defense mechanisms Successful infection also requires micro trauma that compromises the epidermal skin barrier Incubation from contact and germination to obvious clinical lesions is approximately 14 to 21 days Can only in skin 8256 fungal culture from various shelter cats 628 were culture positive Looked at age, sex, hair length, presence of lesions, source (surrender vs. stray) What was SIGNIFICANT for culture positive status? Age (1.3 x more likely in kitten/juvenile vs. adult) Hair length (1.3 x more likely in medium and long haired cats compared to short hair) Lesions(2.4 x more likely to be culture positive than non lesional cats) 3

  4. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Cats that cannot groom for any reason Skin trauma from bites, scratches, ectoparasites Matted hair coats Maceration of skin from high humidity from dampness post cleaning Cats in poor body condition from debilitating and/or concurrent diseases Age extremes-the very young, the very old STRESS All of these can transmit infective spores or be a trigger for skin trauma 4

  5. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Major problem with environmental contamination is confounding culture results Toothbrush cultures cannot distinguish between fomite carriers and truly infected cats Fomite transmission that leads to infection is hard to document FACTS AND MYTHS ABOUT SPORES IN THE ENVIRONMENT Fungal spores can only grow and multiply when they successfully contact the skin surface, germinate and invade skin and hairs…….. They are like M&M’s, what ever falls out of the bag (or off the cat!) is all you have….Again, they do not multiply, ….. FUNGAL SPORES ARE NOT LIKE MOLD, THEY DO NOT GROW , INVADE AND SPREAD IN THE ENVIRONMENT 5

  6. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 FACTS AND MYTHS ABOUT SPORES IN THE ENVIRONMENT Do forced air heating systems spread spores? Field study: Culture plates were placed over forced air heating vents in a facility housing cats under treatment. Plates were always culture negative. HOWEVER the furnace filter was always culture positive! Furnace filters trap infective spores, get the best filters you can afford and change them monthly or sooner if full of cat hair and dirt. Money well spent! *These studies were funded by an unrestricted gift from Maddie’s Fund In Progress: Decontamination of Textiles-Winn Foundation In Progress: Decontamination of Pet and Foster Homes After Exposure to an Infected Cat* *These studies were funded by an unrestricted gift from Maddie’s Fund Environmental control for ringworm needs to be constant and continual If it is all you can do, it is a lot! Two most important steps Aggressive mechanical removal of hair and debris Aggressive scrubbing with a detergent and rinse clean water 6

  7. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 There is no “magic” disinfectant (including bleach!) Any cat safe disinfectant fails if the area is not properly prepared Spores are protected from contact with disinfectants by dirt, debris and the hair shaft AGGRESSIVE good old fashioned cleaning and washing with a detergent is the most valuable step in decontamination Must rinse the area with clean water and allow it to dry BEFORE applying a disinfectant GET STAFF FRIENDLY CLEANING TOOLS 3M Easy Trap Duster Like a “Post a Note” Swiffer! 3M Easy Scrub Flat Mop Tool Re-usable and easily cleaned! 7

  8. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Carefully read the label and look for products tested against Trichophyton mentagrophytes In vitro studies found many over the counter products for controlling this pathogen killed M. canis when used properly In vivo field studies still need to be performed Snuck in the label of “one step "products are comments to “grossly remove debris before use”… Thoroughly soak area and keep it wet for the time on the label (5-10 min) Skin lesions tend to start on thinly haired areas where spores can contact skin Skin lesions are often found in areas where there has been micro trauma Clinical signs directly reflect how the disease is transmitted and the normal pathogenesis 8

  9. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Ears, Ears, Ears….. Rex Cat Mix 9

  10. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Reservoirs near eyes MECHANICAL CARRIERS or TRULY INFECTED??? “It’s ringworm until proven other wise.” OH, NO IT’S NOT!! 10

  11. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Open admission shelter with screening program on intake: Culture data from 5644 cats over 24 months 584 culture positive cats (10.3%) 381 of 5644 cats had skin lesions (6.75%) Only 94 of 5644 cats were both lesional and culture positive and found to be infected (1.6%) 490 cultures positive cats were found to be fomite carriers, Note: Only 1 in 4 cats with skin lesions had dermatophytosis And only 1.6% of cats had ringworm, not 10.3% Public safety • Outbreak prevention Foster homes Life and death decisions Because there is no other way to know Physical Examination** Skin lesions may be felt before seen Examine in good lighting Consider using a flashlight as a strong beam may identify lesions otherwise missed Wood’s lamp** Direct Examination of Hairs** Fungal Culture **On site, cost effective, time effective screening tools 11

  12. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Comment that 50% of clinical specimens glow has been repeated over and over in the literature Comment appears to stem from human medicine where human hygiene practices greatly influence Wood’s lamp examinations Experience from shelter cats (Another Field Study!) Fomite carrier cats do not glow Infected untreated cats with true ringworm lesions- very very commonly GLOW •Areas with skin lesions are most likely to glow, it can take several minutes for glowing to be obvious, be patient •POSITIVE hairs glow bright green •Dust and dander glow white or blue-white are NEGATIVE •Medications and oils on the hair coat can glow yellow, orange, etc, these are Negative •Carpet fibers can also glow, some even apple green-you can easily tell a carpet fiber from a cat hair Pictures courtesy of A. Canupp Subtle lesion missed on physical exam but found with a Wood’s Lamp Pluck hairs in direction of growth so they do not break, place in mineral oil and coverslip prior to examination is produced when cat ringworm glows on hairs The glowing can be affected by lots of things, including bathing Cannot always find glowing hairs on infected cats Glowing is caused by a metabolite that 12

  13. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 This test is only helpful if Wood’s positive hairs are examined. Infected hairs (arrow) are pale, wider and easily visible when compared to normal hairs. The image at the left shows a close up. The hair is cuffed with infective spores. Wood’s Lamp Use In Laboratory If you pluck hairs and then cannot find them, hold the Wood’s lamp near the microscope stage and the hairs will glowing allowing you to find them for viewing. 13

  14. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Wood’s Lamp Use In Laboratory A positive direct examination is confirmation of infection. Treatment can be started while fungal culture is pending. This information can be available on Day 1 of admission. This is an important and powerful aid in management of ringworm in shelters. Adding new methylene blue to mineral oil can be helpful. Here the infected hair absorbs the stain. Normal hairs will not. Use a new toothbrush and comb the entire cat’s body for 20 strokes and/or until there are hairs in the bristles If the cat has lesions, culture all other areas first Pay special attention to face, bell of the ear, eyes, digits Note: Individually wrapped toothbrushes are sterile Toothbrushes can be bought in bulk on line from hospitality supply stores 14

  15. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 If the samples are not going to be set up immediately, wrap the head of the toothbrush in an inexpensive plastic sandwich bag. (DO NOT KNOT. It is important to be able to easily remove the bag from the head of the toothbrush.) This protects the person taking the sample out of the bag from ringworm spores. Place wrapped toothbrush into a plastic bag. Double wrapping protects against accidental human infection. The person setting up the samples can remove it without exposure. Place ID information ON THE BAG or on slip inside. THIS IS WRONG! 1. The toothbrush head is not wrapped exposing the person opening the bag to spores 2. The person taking the specimen out of the bag is using bare hands. 3. The combination of bare hands and an unwrapped toothbrush can lead to human infections and spread of spores! 4. This can result in cross contamination. •Always set up cultures in a clean area •Hold culture plates with medium side up •Gently stab the tips of the toothbrush into the media. •If the tips are yellow, you have done it right. •Cover the whole plate in a consistent pattern. •Use Chlorox wipes as a drop cloth to prevent contamination of area 15

  16. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Inoculating plates with fungal culture surface UP can cause the following problems: •False positive cultures due to spores falling on plate •Spreading of spores into the air while stabbing the plate •Contamination of area Need to inoculate with glowing hair Look for pale or white colony with a red ring of color developing around it as it grows Ignore any colony with NO red ring of color developing it as it grows Ignore ANY COLONY that is heavily pigmented YES IT IS THAT SIMPLE TO IDENTIFY THE COLONIES THAT MUST BE SAMPLED Where is the suspect pathogen? 16

  17. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 It’s not the type of medium that matters most, it’s the temperature of incubation that matters most (not room temperature! >70° or higher) You want the most medium volume per dollar you can get Can also purchase petridish plates from sources 17

  18. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Simply getting a “positive” or “negative” for Microsporum canis is not satisfactory for making informed decisions in shelters “P” score or “Pathogen score” refers to the number of colony forming units growing on a plate and is used in decision making for treatment and for monitoring response to treatment.* This is a useful tool to communicate accurately fungal culture results to staff involved care of ringworm cats. It can also be used to help monitor environmental decontamination *This is explained in detail in chapter on Dermatophytosis in Infectious Diseases of the Dog and Cat (Greene CE, 2012) and in the Dermatophytosis chapter in Infectious Disease Management in Animal Shelters (Miller L, Hurley K 2009 P1(1-4 CFU) P2 (5-9 CFU) Colony counts: Colony forming units (CFUs) - done on all plates P3 (>10 CFU) P1 or P2 cat No lesions on repeat examination and Wood’s lamp examination-fomite carrier, prophylactic topical treatment and “go” Lesions on repeat examination and Wood’s lamp examination-truly infected, culture was obtained early in the infection: TREAT CAT P3 Cat >10 colonies often too many to count Could be truly infected or fomite carrier exposed to contaminated environment, TREAT CAT 18

  19. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Simple infected group Otherwise healthy cats or kittens with confirmed lesions, lesions limited in extent, if otherwise healthy these cats will respond well to therapy Complicated infection group Widespread lesions, inflammatory lesions, long hair/matted hair other illnesses (ie. URI), history of prior treatment, surrendered for resistant “ringworm”, semi-feral/feral cats. These cats are complicated to treat because antifungal therapy must be coordinated with treatment for other pre- existing diseases Lesion free but culture positive Consists of cats that may be mechanically carrying spores on the hair coat (dust mops) or cats with early lesions that are not seen but mature enough to be spreading spores. Colony forming units on culture, examination and Wood’s lamp examination will help differentiate fomite carriers from early infection Effective topical applied twice weekly Lime sulfur Enilconazole Systemic Antifungal Itraconazole 21 day course Daily course Week on/Week off Terbinafine (recommendation based upon field study) 21 day course …go for the wet and smelly. Slide Courtesy of Dr. Newbury, UC Davis Shelter Medicine Program 19

  20. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Dilution and Mixing 1:16 dilution 8 oz of water and 120 oz of water Mix by putting 8 oz. of lime sulfur in EMPTY GALLON , then fill to 1 gallon Warm water Mix fresh solution each time, discard excess Materials Safety Data Sheet Lime Sulfur Solution: Commercial Use Calcium polysulfide Materials Safety Data Sheet Lime Sulfur Solution: Veterinary 97.8% Lime sulfur Identical products Look different due to labeling Both diluted the same 29% Garden Sprayers Half gallon sprayer is preferred. Easily lifted when full. Solution stays warm. Short stubby spray nozzle helps with control. Clean thoroughly after each use. Fill with hot water and allow to discharge completely to prevent clogging of nozzle and valve. 20

  21. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Improper mixing of topical antifungal rinse, shake bottle before using! Wetting cats prior to applying rinse, makes it harder for liquid to “cling” to hair coat Matted hair coat that must be clipped Poor application technique-often face is missed Using compounded itraconazole Cat has underlying medical problem Environmental contamination causing false positives In group housing, unrecognized infected cat Cats will clinically cure before they are fungal culture negative Two negative cultures at weekly intervals Weekly fungal cultures ARE less expensive Cost per fungal culture is less than or equal to one animal care day Weekly cultures will identify cats faster, often 2-4 weeks sooner than by starting cultures at 4 weeks Weekly fungal cultures will decrease the time cats are in confinement, decrease the number of dips they need to receive, and decrease personnel costs. Will identify cats that are fomite carriers as they will rapidly become culture negative Will identify cats that are not curing due to some treatment complication 21

  22. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 #1: Do not start moving cats around #2: Start AGGRESSIVE CLEANING Mechanical removal of debris Scrub, scrub, scrub, scrub…… and then Rinse… Apply disinfectant at USUAL dilution Do daily until a decision has been made #3: Collect information for the veterinary visit and assessment What clinical signs were noted and when? Is it limited to a group of animals?, litter of kittens? Do staff have lesions? What diagnostics have been done? Wood’s lamp? Direct examination? How was it confirmed? Fungal culture? What medium? Was it confirmed via color change or mycological exam? Collect plates if possible. What have you done so far? Assess what your shelter can do Cleaning and decontamination (and clutter busting) recommendations for ringworm are a benefit for all infectious diseases Become competent with a Wood’s lamp and direct examinations-litter of infected kittens is a good place to start Confirms infection and treatment decisions can be made Will help contain an possible outbreak 22

  23. How Shelters Are Beating Ringworm (And Yours Can, Too!) 7/12/2012 Dr. Moriello has received research funding* and unrestricted gifts** for research from: Winn Foundation for Feline Research* Companion Animal Grant, University of Wisconsin* Maddie’s Fund** DVM Pharmaceuticals** Novaritis Animal Health, Alpharma, Pfizer Limited** AND too many to count unrestricted gifts from private individuals whose generosity has allowed my laboratory to do research on questions of importance to our community and to help people and cats in need during outbreaks 23