CONFÉRENCE DES RÉGIES RÉGIONALES DE LA SANTÉ ET DES SERVICES SOCIAUX DU QUÉBEC SANTÉ PUBLIQUE INSPQ - Montréal 567 1:111
M m - ) Institut national de santé publique du Québec 4835, avenue Christophe-Colomb, bureau 200 Montréal (Québec) H2J3G8 Tél.: (514) 597-0606 Prevention and control of pediculosis (head lice) in schools and child care centers Intervention guide Board of Regional Public Health Directors (Conseil des directeurs et directrices régionaux de santé publique) Conference of the Regional Health and Social Services Boards of Quebec (Conférence des régies régionales de la santé et des services sociaux du Québec) May 1997
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Pediculosis (head lice) in schools and child care centers iv FOREWORD Pediculosis (head lice) is a typical example of a public health problem which necessitates the collaboration of all sectors concerned to reach a solution. The present document is addressed mainly to professionals from CLSCs, INFO-SANTE and regional public health branches. However, other professionals concerned with this problem could also find the document useful for understanding the proposed procedure. Here, we provide guidelines for the prevention and control of pediculosis in schools and child care centers, in a public health perspective; This document is an intervention guide and. not a list of strict rules to follow in a uniform fashion in all regions of Quebec. Our goal is to establish an intervention policy for pediculosis, which conforms to the existing public health recommendations, while allowing the public health workers to apply the proposed measures according to available resources and the degree of collaboration offered by the various partners involved (families, schools, daycare centers and health establishments and organizations). The document should be completed at the regional level with tools adapted to various intervention environments. This document conforms with the recommendations mapped out by the Provincial committee on infectious diseases in child care centers, a consulting body of the Public Health Protection Branch of the Ministry of Health and Social Services (Direction de la protection de la santé publique du ministère de la Santé et des Services sociaux) and the Quebec Board of Child Care Services (Office des services de garde à l'enfance du Québec). We have also integrated, into the text, expert opinions and suggestions sent to us by professionals from several Quebec regions.
Pediculosis (head lice) in schools and child care centers iv This document was prepared by Julio Soto, M.D. Ph.D., for the Consultation Committee on Infectious Diseases of the Board of Regional Public Health Directors. RESEARCH AND DOCUMENT DRAFTING Docteur Julio Soto Laval Regional Health and Social Services Board Collaborators: Dr. Marie-Claude Bernard Dr. Suzanne Charbonneau Dr. Hélène Dupont Dr. Fernand Guillemette Dr. Theresa Gyorkos Mrs. Paulette Harvey Mrs. Aline Lachance Dr. Claire Lemieux Dr. François Levac Dr. Alain Millette Dr. Pierre Pilon Mrs. Angèle Rousseau Mrs. Carole Toupin Mrs. Danielle Vachon Mauricie-Bois-Francs(04) Laval (13) Outaouais (07) Mauricie-BoiSTFrancs (04) Epidemiology Service for the Montreal General Hospital Saguenay-Lac-St-Jean (02) Laval (13) Chaudière-Appalaches (12) Montérégie (16) Outaouais (07) Montreal-Center (06) Abitibi-Temiscamingue. (08) Norman-Bethune (13) CLSC Laval (13)
Pediculosis (head lice) in schools and child care centers iv ACKNOWLEDGMENTS We wish to thank everyone who read this document and made comments or suggestions for its improvement. We are particularly indebted to Mrs. Micheline Rousseau for the typing, and to Mrs. Danielle Léonard for the final formatting.
Pediculosis (head lice) in schools and child care centers iv TABLE OF CONTENTS FOREWORD.! I ACKNOWLEDGMENTS TABLE OF CONTENTS Ill IV 1. PEDICULOSIS ; 1 2. BIOLOGY OF HEAD LICE 1 3. EPIDEMIOLOGICAL AND CLINICAL ASPECTS...2 4. DEFINITIONS...3 4.1 SUBJECT (infested case) 3 4.2 CONTACTS. 3 5. CONTROL METHODS 3 5.1 Intervention.....»...»»...».»»»...»...»»»..»»»».. 3 5.2 Control measures... 5.2.1 Treatment of subject and infested contacts 4 5.2.2 Exclusion 5 53 Preventive measures...».. IM MMMM..a..».»..*...»...» (MM M.MMMMIMMMMM. MM..M... M... ^F DECISION FLOW-CHART FOR THE CONTROL OF PEDICULOSIS IN SCHOOL AND CHILD CARE CENTERS 7 6. LIST OF PEDCULOSIS PRODUCTS REGISTERED IN CANADA... 8 7. MYTHS AND REALITIES ON THE SUBJECT OF HEAD LICE 9 REFERENCES 10
Pediculosis (head lice) in schools and child care centers iv 1. PEDICULOSIS There exist three species of lice which infest human beings: Pedicuius humanus capitis (head louse), Pedicuius humanus corporis (body louse) and Phthirus pubis (pubic louse or crab louse). All three are Anoplura insects (wingless) which need human beings to feed and develop. We will only discuss the head louse. An important increase in P. humanus capitis infestations has been observed throughout the world since the 1970's. In the United States, infantile pediculosis is considered the most frequent disease after the cold. In Quebec, the annual infestation rate in elementary schools is estimated at 2.9%, affecting more than 10,000 elementary school children per year. In spite of the fact that the infestation is relatively benign and that head lice do not transmit other diseases, pediculosis of the scalp and hair constitutes an important public health problem. This is due to its easy transmission in densely populated environments, the social stigma associated with its presence, the resources used to control its spread, the costs generated to treat the infection and the inherent risks associated with the use of pediculicides. 2. BIOLOGY OF HEAD LICE The adult parasite is barely visible to the naked eye (the size of a pinhead 2 to 4 mm in diameter). Its life cycle lasts 20 to 30 days in total. After a maturation period of approximately two weeks, the mated louse lays her eggs (nits) at a frequency of approximately 6 to 8 per day. The nits, clustered and glued with a cement sheath to the hair of the host, are found close to the roots (1 mm from the scalp). It takes between 4 and 10 days for them to hatch. After hatching, the young lice must feed off human blood within 24 hours. The survival of the parasite depends on environmental conditions. The human scalp offers ideal conditions (temperature between 28 C and 33 C and relative humidity 70% to 90%). Away from the human body, the survival of the parasites is very limited (between 1 and 3 days maximum depending on age and environmental conditions).
Pediculosis (head lice) in schools and child care centers iv 3. EPIDEMIOLOGICAL AND CLINICAL ASPECTS Humans constitute the only reservoir for this condition. Head lice is easily transmitted by direct contact with an infested host (head to head). Contact with personal belongings (hair brushes, combs, hats, pillow cases, etc.) seem to play a secondary role in the transmission (minimal risk according to certain authors). Contagiosity will remain until parasites are destroyed as well as the nits in the hair or on contaminated personal belongings (fomites). The average incubation period is 10 days. Once settled on the new host, the lice become attached to the epidermis using their teeth, introducing their stingingsucking mouthparts and injecting saliva containing anticoagulants to facilitate the removal of blood. The saliva of the insect is responsible for an allergic reaction in the host which is accompanied with itching and scratch marks (excoriation). Lice and nits are found stuck to the hair root (figure 1), particularly behind the ears and the back of the head, but sometimes also in the eyebrows or beard. Figure 1 Living head lice and viable nits (louse eggs) (magnified 10X) Burroughs Wellcome Inc. Qu6., Canada The viability of a nit is determined by the presence of an intact operculum (protective cover) situated on its free extremity, by its location (between 1 and 6 mm from the scalp), and by the yellowish and opaque white color of the shell (an empty nit is paler and translucent).
Pediculosis (head lice) in schools and child care centers iv 4. DEFINITIONS 4.1 SUBJECT (infested case) Any person with living head lice and viable nits (louse eggs) in his/her hair. 4.2 CONTACTS Any person having had direct contact with an infested person or with objects (combs, hairbrushes, hats, caps, pillow cases, others) used regularly by infested persons. For the purposes of intervention, the following groups are considered contacts: > all household members; > all students in the class of an elementary or secondary school (in the case of teaching staff, it depends on the nature of the contact); > all children and staff of child care centers and preschools. 5. CONTROL METHODS Following the detection of one or several cases in a school or child care center, an intervention must be carried out and, if necessary, the following control and prevention measures applied. 5.1 Intervention i. Identify the contacts (see definition above); send a letter to teaching staff and parents of contacts (the letter should contain information on the disease, how it spreads, how to examine the head and treatment, control and prevention methods);
Pediculosis (head lice) in schools and child care centers iv look for other infested cases among contacts. If the examination of the children's heads is done at school or in the daycare, it is recommended that the persons concerned (parents of children under 14 years of age) be notified before carrying out this intervention. 5.2 Control measures 5.2.1 Treatment of subject and infested contacts > Treat only infested persons. Prophylactic treatment is not advised especially in schools and child care centers and preschools. > Use a product registered in Canada (see list on page 9) following the health professional's or the manufacturer's instructions. > Given the possibility of nit survival after the first application, the treatment consists of two applications. The second application must be administered from 7 to 10 days after the first, even in the absence of signs of active infestation (living lice and viable nits). In order to facilitate follow-up, simultaneous treatment of infested persons is recommended. > Permethrin is the drug of first choice. In comparison to other pediculicides, this product is less toxic and very effective (strong insecticidal and ovicidal activity). > If live lice are observed in the two days following the first application of a pediculicide product, it is recommended to repeat the treatment at once using another product. The new product will be applied for a second time 7 to 10 days later. > If eyebrows are affected, apply petroleum jelly, Lacri-lube, for example, in a thick layer at least twice a day (TID to QID in young children who could remove this product by rubbing their eyes) for one week. The dead nits can be removed using eyebrow tweezers. > Never use lindane on pregnant women, women who are breastfeeding, or on children under 6 years of age. > Cutting hair is not necessary, either before or after treatment.
Pediculosis (head lice) in schools and child care centers iv > Permethrin-based products help to unglue the nits following washing and rinsing of the hair. > If the nits remain after the first application of a product, for aesthetic purposes, they can be removed with a fine comb. > Using vinegar to unglue nits is not recommended, because vinegar can remove the remaining pediculicide (especially permethrin) and thus reduce its residual action. > Washing the hair with ordinary shampoo (without conditioner or cream rinse) does not affect the residual effect of a product such as permethrin. > Pediculicide products must be kept out of reach of children. > Most insurance plans reimburse costs of pediculicides if prescribed by a physician. 5.2.2 Exclusion > The infested person must be temporarily excluded from the group until the first application of the recommended treatment. If the product has been used properly, it greatly reduces contagiousness by eliminating live lice. > A person who still has nits following the application of a recommended treatment against lice should not be excluded from the group. After treatment, nits are usually either dead (empty) or too young to be contagious. The residual effect and the second application of the product will destroy the young parasites in the following days. > If a person shows signs of active infestation (living lice and viable nits) after the date of the second application, this person should be excluded form the group and referred to a health professional. Such treatment failures may be due to, failure to use the product properly or reinfestation from other subjects or resistance to the product (less frequent).
Pediculosis (head lice) in schools and child care centers 10 iv 5.3 Preventive measures Awareness and education campaign directed towards parents and teaching staff to promote early detection of lice and nits and the rigorous application of control measures. This could be done at the beginning of the school year. Awareness campaign in the school/child care environment to ensure that children do not share their combs, hairbrushes, hats, caps. Regular examination of hair for lice and nits. It is not necessary to do a systematic examination; the aim is developing good monitoring practices in the target environments. This could be done with the collaboration of concerned partners if the awareness activities have been previously carried out. If the proposed control measures have been followed, the treatment or cleaning of objects in the environment of the infested person (control of the environment) is not necessary. If in a particular context, it is deemed necessary to apply control measures to the environment, the personal effects (combs, hairbrushes, hats, caps, others) used regularly by the infested persons may be cleaned by dipping them in one of the three following solutions: > a disinfectant (Lysol at 2%, for example); > an anti-lice shampoo for one hour; > hot water (approximately 65 C or 150 F) for 5 to 10 minutes; Dry cleaning or storage (for ten days) in a plastic bag of certain personal effects is also an effective technique. Spraying the house, furniture or other objects in the environment with an insecticide is not indicated. This measure is ineffective for the control of pediculosis and could represent an important health risk for persons or animals. Finally, the best preventive measure in matters of crisis management is regional consultation. It is a question of developing an intervention policy against pediculosis which involves a sharing of responsibilities among all concerned sectors.
Pediculosis (head lice) in schools and child care centers 10 iv DECISION FLOW-CHART FOR THE CONTROL OF PEDICULOSIS IN SCHOOL AND CHILD CARE CENTERS EXCLUSION + IDENTIFY CONTACTS + NOTIFY PARENTS * SEARCH FOR INFESTED CASES + TREAT INFESTED CASES 4> 1ST APPLICATION * 7-10 DAYS AFTER (ACTIVE INFESTATION OR NOT) EXCLUSION v 1* CHOICE PERMETHRIN CHILD MAY RETURN TO CLASS 2 nd APPLICATION + IF SIGNS OF ACTIVE INFESTATION PERSIST * EXCLUSION RE-ADMISSION AFTER AN ASSESSMENT CARRIED OUT BY A HEALTH PROFESSIONAL
Pediculosis (head lice) in schools and child care centers 10 6. LIST OF PEDCULOSIS PRODUCTS REGISTERED IN CANADA PRODUCT (COMMERCIAL NAME) FORMULATIONS CHARACTERISTICS permethrin (Nix ) conditioner or cream rinse (after shampooing) recommended treatment, strong insecticidal and ovicidal activity, residual effect of approximately 14 days, low toxicity, benign skin reactions (1%), possible devélopment of resistance. pyrethrin (R&C, Lice-Enz ) shampoo, foam known insecticidal and ovicidal activity, persons allergic to ragweed and chrysanthemums must use it with caution, foam can trigger anaphylactic reaction, contact dermatitis and may reach cornea. pyrethrin-bioallethrin and pipemoyl butoxide (Para ) shampoo and aerosol known insecticidal and ovicidal activity, persons allergic to ragweed and chrysanthemums must use it with caution, foam can trigger anaphylactic reaction, contact dermatitis. lindane (Kwellada ) shampoo not always ovicidal, possible neurotoxicity, benign skin reactions (2-3%), not to be used on children under 6 years of age, on pregnant or breastfeeding women. acetic acid, camphre, citronella, sodium lauryl ether sulfate (SH- 206 ) shampoo effectiveness not documented, benign skin reactions (3-4%), possible development of resistance Note: In 1991, the malathlon-based product (Prioderm ) was recalled from the Canadian market due to its variable effectiveness as a function of the excipient or vehicle used.
Pediculosis (head lice) in schools and child care centers 10 7. MYTHS AND REALITIES ON THE SUBJECT OF HEAD LICE MYTHS 1. An infestation of head lice means that the child and the family are not clean. 2. Head lice can survive weeks in clothing, hats, hair brushes and bed sheets. 3. Head lice carry numerous serious diseases and the infestation has serious medical risks. 4. Head lice, body lice and pubic lice (crab lice) are all the same, except that they are found in distinct parts of the body. 5. All infestations of head lice display symptoms. 6. No risk is linked to the frequent use of head lice treatments. REALITIES 1. Anyone can get head lice, regardless of his or her social class or personal hygiene. 2. Head lice rarely survive more than 36 hours after having left a human head. 3. Head lice are not carriers of any human disease and do not cause any serious illness. 4. Head lice, body lice and pubic lice are distinct species and present different disease risks. 5. Many people are asymptomatic. 6. An incoitect use or accidental ingestion (drinking it) of the treatment can prove dangerous. Always follow the instructions for use. These products are toxic if swallowed or overused. 7. Head lice treatment kills both nits and lice. 7. Lice are very sensitive to treatment but nits are more likely to survive. 8. A single treatment along with a good shampoo, conditioner or cream rinse against head lice is sufficient. 9. Family members and classmates must be treated without verifying if lice are present. 10. Spraying the house and furniture using an anti-head lice spray reduces the risk of reappearance. 11. The "no nits" policies of schools reduce outbreaks of head lice. 8. A second treatment 7 to 10 days after the first is now recommended. 9. Household members, students in the class, children and daycare workers must be examined with care and treated only if they are infested. 10. There are no data to demonstrate that spraying the environment contributes to the control of head lice. Instead, spraying can be harmful to the family and animals. 11. There are no data proving that the "no nits" policies in schools contribute to the control of head lice. The above information has been adapted from the Canadian Pediatric Society (Paediatric Child Health 1996; Vol. 1. No. 3: page 249)
Pediculosis (head lice) in schools and child care centers 10 References American Public Health Association & American Academy of Pediatrics. Caring for our children. National Health and Safety Performance Standards: Guidelines for Out-of-Home Child Care Programs. Washington, DC 20005,1993. Benenson AS. Control of Communicable Diseases in Man. 16th Edition. American Public Health Association, Washington DC, 1995. Champagne M. La pédicuiose. Master's thesis. Faculty of Pharmacy. Université de Montréal. 1988. Chunge RN, Scott FE, Underwood JE, Zavarella KJ. A review of the epidemiology, public health importance, treatment and control of head lice. Can J Public Health 1991;82:192-200. Chunge RN, Scott FE, Underwood JE, Zavarella KJ. A pilot study to investigate transmission of head lice. Can J Public Health 1991; 82:207-208. Comité de maladies infectieuses et d'immunisation. Les infestations par les poux de tête: Une démangeaison persistante. Statement from the Canadian Paediatric Society. Paediatr Child Health 1996; 1(3): 244-9. Comité provincial des maladies infectieuses en services de garde à l'enfance. Guide de prévention et de contrôle des infections. Second edition, (to be published bythemhssin 1997). Clove, Longyear. Head lice. Yearbook of Dermatology, p. 60.1994. Ewasechko CA. Prevalence of head lice (pedicuius capitis) among children in a rural central Alberta school. Can J Public Health 1981; 72:249-57. Mathias RG, Wallace JF. The hatching of nits as a predictor of treatment failure with lindane andpyrethrin shampoos. Can J Public Health 1990;81:237-239. N'Guyen VX, Robert P. Drug use evaluation in community pharmacies: a survey of policies for head lice treatment with non prescription drugs. J Pharm Clin 1993; 12: 222-7. Reed & Carnrick. Lice & Scabies. From Infestation to Disinfestation. New jersey (Pamphlet). 1976. Kenilworth,
Pediculosis (head lice) in schools and child care centers 10 Robert P. La pédiculose et son traitement, (conference notes). Faculty of Pharmacy of the Université de Montréal. 1995 Whiting DA. Pediculosis (Lice). Chapter 44 IN Donowitz LG (Editor). Infection Control in the Child Care Center and Preschool. Williams & Wilkins, Baltimore, 1991.
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