Report

DEMOGRAPHIC STUDY OF HEAD LICE INFESTATIONS IN

SACRAMENTO COUNTY SCHOOL CHILDREN

STEPHAN BILLSTEIN, M.D., M,P.H. AND PENNY LAONE, C,H,N,

ABSTRACT: Head lice infestations have becomea problem in school children in SacramentoCounty. An open study was conducted to deter-mine how widespread head lice infestations wereamong preschool and elementary school childrenin Sacramento County and to see how effective anewly marketed over-the-counter pediculicidecontaining 0.3% pyrethrins synergized by 3.0%piperonyl butoxide was. The public health nursefor this study visited the homes of all reported pa-tients infested with head lice. She verified andprovided the pyrethrins-based treatment for 248children, aged 6 months to 12 years. The childrenwere Caucasian, Mexican-American, black andother ethnic backgrounds and from low, middleand upper income levels. All the patients weresuccessfully treated, and the school children wereable to return to their classes in a short time.

During the past several years, the Sac-ramento County Health Agency has receivednumerous reports from both parents andschool personnel of head lice infestation inschool children. Children were referred toclinics, physicians, or pharmacists for treat-ment of head lice and yet upon return toschool, were still noticed to have indications

Address for reprints: Stephan Billstein, M,D,, M,P.H,,Suite 902, 1390 Market Street, San Francisco, CA 94102,

From the Department of Community Health,Sacramento County, California

of remaining infestations and, therefore, hadto be sent home. Consequently, some ofthese children v̂ /ere actually out of school forweeks at a time.

Since lice infestation is not a required re-portable disease, the true incidence of headlice infestation is unknown. Gamma benzenehexachloride has been the method of treat-ment recommended in county clinics and bycounty disease control persons until thisstudy. This treatment modality required aprescription and, therefore, impeded rapidcontrol methods in the case of reported out-breaks.

Therefore, the Sacramento County DiseaseControl Section conducted this study to try todetermine how endemic lice were in thecommunity and whether a newly marketedover-the-counter pediculicide, a productcontaining 0,3% pyrethrins synergized by3.0% piperonyl butoxide, was effective. Allinfested children were offered free treatmentwith the pyrethrin-based pediculicidal liquid.

0011-9059/79/0500/0301/$00,70 © International Society of Tropical Dermatology, inc.

301

302 INTERNATIONAL JOURNAL OF DERMATOLOGY May 1979 Vol. 18

Materials and Methods

Preschool and elementary school childrenwith head lice infestations were included inthe study. Awareness of this program hadbeen achieved by lectures and mailings toschool nurses and by media interviews withthe study investigator and public healthnurse. When a child with head lice was iden-tified by school personnel, the school nursediscussed this study with the family. If thefamily elected to receive treatmentelsewhere, the child was not referred to thestudy.*

If the family agreed to participate, theschool nurse called the public health nurse. Iffamily members discovered the infestation,they called the public health nurse directly.Once the public health nurse was aware of acase, she made an appointment to visit thechild's home within 24 hours (except forweekends and holidays).

During the initial home visit, the publichealth nurse examined every member of thehousehold for evidence of head lice infesta-tion. Those parents who elected to receivefree treatment signed a consent form andwere given sufficient pyrethrins-basedpediculicide to treat all those infected. Theproper use of the medication was discussed,as were procedures to disinfect fomites to re-duce transmission of the infestation and pos-sible reinfestation. A second home visit wasmade as soon as possible to determinewhether or not the head lice had been eradi-cated. Once eradication was verified, thechildren were allowed to return to school.

The school health nurse, during the homevisits, obtained demographic information forevery infested member of the household whowas 12 years of age or younger. The parent orguardian completed a form concerning the

* However, children were not allowed back in schooluntil their primary source of care certified that they werefree of lice. These records were not available to the pub-lic health department because of school confidentialitylaws. Lice infestation is not a required reportable diseasein California.

presence of itching, redness, or edema on thescalp both before and after treatment with thepyrethrins-based pediculicide.

Results

A total of 248 children (119 boys and 129girls) ranging in age from six months to 12years participated in the study. The mean ageof the 119 boys was 6.86 years, that of thegirls, 7.60 years. Overall, the mean age of thechildren was 7.25 years. Of the 53 childrenaged 4 years or under, 30 (56.6%) were boys,while among the 195 who were 5 years orolder, 106 (54.4%) were girls.

The majority of the children studied wereeither Caucasian (45.6%) or Mexican-American (33.5%). The percentage ofchildren in this study who were Mexican-American was much greater than their repre-sentation in the total population ofSacramento County (9.2%), while the percen-tage of Caucasian children treated was muchlower than their representation in the popula-tion (80.5%). The percentage of black chil-dren in the study (3.6%) was also less thantheir representation in the population (5.8%).

Some intormation on the socioeconomicstatus of the 105 families studied was avail-able. In many instances, the mother was thehead of the household and the father's occu-pation was unknown. Most of the mothers(71%) were homemakers, though 16% werewhite collar workers, 9% were blue collarworkers and 4% were students. The majorityof the fathers for whom data were available(64 families) were blue collar workers {77%),while 20% were white collar workers and3% were students.

Excluding two Air Force bases and aprison, Sacramento County contains 86 cen-sus tracts. From the 1970 Census it was de-termined that the income level was low«$9,000) in 24, middle ($9,000-12,500) in37 and high (>$12,500) in 25. There werereported cases of lice infestation included inthe study from 71% of the low income cen-

No, 4 HEAD LICE INFESTATIONS Billstein and Laone 303

sus tracts, from 54% of the middle incometracts and from 32% of the high incometracts. Most of the cases in the study camefrom the middle income tracts (52%); the lowincome tracts provided 36% of the studycases, and the high income tracts provided12%.

A special Sacramento County Census,taken in 1975, determined that there were87,000 children between 0 and 12 years ofage in the total population. The study in-cluded 76 cases per 10,000 population inthis age range among the low income tracts;the case rate per 10,000 population of 0 to12 years was 23 among the middle incometracts and 16 among the high income tracts.

The number of children per family rangedfrom one to 12 and averaged 3,7, The aver-age number of infested children per familywas 2.35 (range one to six). The smallerfamilies had a greater percentage of infestedchildren per family than did the largerfamilies. For example, in 21 of the 26families with two children, both childrenwere infested. Similarly, in 16 of the 27families with three children, all three chil-dren were infested. In contrast, there were 12families with seven or more children and innone of them were all the children infested,A maximum of five children were infested inthree of four families with seven children,while a maximum of four children were in-fested in any of the larger families.

The head lice infestation was discoveredby a school nurse, teacher or other schoolpersonnel in 113 cases, by the family in 131cases, and by someone else in four cases. Ofthe 248 children, 164 had had no previousinfestation. Of the 84 cases with previous in-festation, 20 prior infestations had beeneradicated within the four weeks prior to thecurrent infestation; 61 had occurred morethan four weeks previous; and three had oc-curred at an unknown time in the past.

The treatment given for the previous infes-tation was known in 77 of the 84 cases, Amajority of these children had used a gamma

benzene hexachloride preparation while therest had been treated with a variety of othercommonly used pediculicides. Several arti-cles in the literature'"'' as well as a recenttext^ have made reference to resistance togamma benzene hexachloride of some bodylice and some head lice strains in countriesother than the United States, but this has notbeen observed in America, Resistance toboth DDT preparations and malathion ofbody louse strains outside the U,S,A, hasbeen noted as well.

Before it is concluded that repeated treat-ment of head lice infestation is due to a resis-tant louse strain, the following possibilitiesshould be considered: (1) failure to followinstructions completely, (2) no treatment ofthe household or intimate contacts, (3) rein-festation, and (4) the presence of persistentpruritus without lice infestation due to (a) irri-tation by the pediculicide, (b) irritation orsensitization to previous medications, or (c)patient anxiety.

For 50 of the 84 children in this study whowere previously infested, data were availableon how long it took them to return to schoolafter their prior therapy as well as after theircurrent therapy with the 0,3% pyrethrins,3,0% piperonyl butoxide pediculicide. Somechildren undoubtedly remained out of schoolafter the lice had been eradicated because ofcolds or other problems. With thepyrethrins-based pediculicide, the mean timebetween diagnosis and return to school was2,9 days. With prior therapy, the mean timewas 5,9 days. This difference is statisticallysignificant at the 5% level (using the pairedt-test). The detailed instructions on personalhygiene and the control of lice within thehome, which were given to the parents bythe public health nurse, no doubt played apart in the more rapid eradication of in-festation.

The symptoms associated with lice infesta-tion, i,e,, itching, redness and swelling of thescalp, disappeared following the pyrethrins-based pediculicide therapy in the vast major-

304 INTERNATIONAL JOURNAL OF DERMATOLOGY May 1979 Vol, 18

ity of cases. In 121 of the 138 cases whereitching was present prior to treatment, thesymptom disappeared; and there were fivenew cases of itching that were reported dur-ing treatment. Of the seven cases of pre-treatment swelling, five disappeared aftertreatment and no new incidences were re-ported. There were 32 cases of redness priorto treatment; 21 of them had disappeared andone new case was reported after treatment.

Comments and Conclusions

The study population is a limited samplerepresenting only those cases reported to andtreated by the public health nurse of the Sac-ramento County Health Agency assigned tothis project and does not include those casestreated privately or in other clinics. Althoughit had been hoped that an estimate of the trueincidence of infestation in SacramentoCounty would have been obtained from thisstudy, this objective was not fulfilled due tothe unavailability of records of those infestedchildren treated outside the SacramentoCounty Health Agency,

Our sample reflected the general im-pression**'̂ that more girls than boys becomeinfested with head lice after starting school,while the sex distribution is roughly equalduring preschool years (in fact, our samplecontained more male than female pre-schoolers).

The percentage of black children in thestudy population compared to the repre-sentation in the county roughly supports theimpression that lice infestation is infrequentin the U.S. among blacks, but by no meansnonexistent.

Head lice infestation occurred in allsocioeconomic groups in our sample. How-

ever, the incidence of lice infestation in oursample was much greater for the lowest in-come level. This may reflect extensive under-reporting in the other groups or the use ofprivate versus public health care resourcesrather than an actual greater incidence in thepoorer tracts.

Rapid, complete eradication of infestationwas achieved in these cases by a programcombining therapy with a new 0.3%pyrethrins/3.0% piperonyl butoxidepediculicide and general hygiene instruction.This included instruction on disinfection ofbed linens, clothes, combs, and other fo-mites. The families were also cautioned toinstruct the children not to share combs,brushes, hair ribbons, and other headgear.

Drug Names

0,3% pyrethrins + 3,0% piperonyl butoxide: RIDgamma benzene hexachloride: Kwell

References

1, Busvine, J. R,: Inheritance of DDT-resistance inbody lice. Bull, World Health Org, 36:431, 1967,

2, Cratz, N, C : The Current Status of Louse InfestationThroughout the World, The Control of Lice andLouse-Borne Diseases, Proceedings InternationalSymposium Control of Lice and Louse-Borne Dis-eases, Washington, D, C, Pan American HealthOrganization, 1973, p, 23,

3, Maunder, J. W,: Resistance to organochlorine insec-ticides in head lice and trials using alternative com-pounds, Med, Off, 125:27, 1971,

4, Wright, J, W,, and Pal, R,: Second survey ofinsecticide-resistance in body lice, 1958-1963,Bull, World Health Org, 33:485, 1965,

5, Cratz, N, C : Treatment resistance in louse control.In: Scabies and Pediculosis, Edited by Orkin, M,,Maibach, H, I,, Parish, L, C, and Schwartzman, R.M. Philadelphia, J, B, Lippincott Company, 1977, p,185,

6, Slonka, C, F,, et al,: Epidemiology of an outbreak ofhead lice in Georgia, Am, J, Trop, Med, Hyg,25:739, 1976,

7, Slonka, F, G,, et al,: An epidemic of Pediculosiscapititis. J, Parasitol, 63:377, 1977,