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Prevention of meningitis in a day-care center: Management of an outbreak of Haemophilus influenzae type b
PREVENTIVE
MEDICINE
16, 261-268 (1987)
Prevention of Meningitis in a Day-Care Center: an Outbreak of Haemophilus influenzae CHRISTINE
L. WILLIAMS, M.D., M.P.H.*,’ ALDA CHEN ANITA S. CURRAN, M.D., M.P.H.?
Management Type b LEE,
*Department of Pediatrics, New York Medical College, Valhalla, New fwestchester County Department of Health, Bureau of Disease White Plains, New York 10601
B.S.N.,? York 10595, Control,
of
AND and
The care of infants and toddlers in nursery school and day-care centers in increasingly large numbers over the past decade poses special problems with respect to communicable disease control. This age group is particularly susceptible to those infectious agents (bacterial, viral, and parasitic) spread by close personal contact. This study describes an outbreak of Huemophilus influenzae type b meningitis in a large nursery school in Westchester County, New York. Organized efforts to control the outbreak through recommendation of rifampin prophylaxis were undertaken and evaluated. Compliance following the first case of meningitis was unacceptably low (45% of children and 33% of staff). Following the second case, however, compliance rose to 90% among child attendees and 79% among staff. Recommended procedures for implementation of control measures are described. o 19x7 ACdemic Press, Inc.
INTRODUCTION Haemophilus influenzae type b is the leading cause of bacterial meningitis in the United States, resulting in an estimated 8,000 cases per year (5). In addition, this organism is responsible for a number of other serious diseases, such as epiglottitis, septic arthritis, facial cellulitis, osteomyelitis, and pneumonia. Invasive H. influenzae type b disease occurs predominantly in children under 6 years of age, with the highest incidence occurring among children between ages 6 months and 2 years (9, 11, 28). Only recently has H. injluenzae type b been widely publicized as a contagious disease (14). Reports of outbreaks among children in day-care centers (13, 22, 27, 32), in hospitals and institutions (15), and by household contacts (4, 10, 16, 33) emerged in the 1970s and emphasized the significance of secondary attack rates, particularly in children under 2 years of age. In a national study of household contacts of H. influenzae type b invasive disease, the secondary attack rate was shown to be 0.5% for children under 6 years, 3.4% for children under 2 years, and 6% for infants under 1 year of age (33). Since more than half of secondary cases occurred within 1 week of exposure in young children (33), studies were undertaken to determine the efficiency of antibiotic prophylaxis in preventing the spread of this disease (6,7, 12, 17- 19, 20, 23, 29, 30). A multicenter, prospective trial of rifampin prophylaxis of household and day-care contacts of patients with systemic H. inJluenzae type b disease was un’ To whom reprint requests should be addressed. 261 0091-7435187 $3.00 Copyright Q 1987 by Academic Press, Inc. All rights of reproduction in any form rererved.
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dertaken during 1979 to 1981 by the U.S. Centers for Disease Control (3). Results indicated that among children less than 48 months of age, rifampin prophylaxis showed a trend toward efficacy in household contacts. Among day-care center contacts, however, the number of cases was too small for meaningful statistical analysis. Based on these findings, the American Academy of Pediatrics Committee on Infectious Disease issued preliminary recommendations in the fall of 1982 for rifampin prophylaxis for all household and nursery school/day-care center contacts of a case of invasive H. ir@uenzae type b disease where exposed children under 4 years of age might be involved (1). These recommendations were subsequently revised by the committee 2 years later to advise rifampin prophylaxis in day-care or nursery school contacts following two cases of invasive H. influenzae type b disease within 60 days rather than following a single case as recommended previously (2). At the same time it was also expected that a vaccine against H. influenzae type b would be available within the coming year, at least for children over 18 to 24 months of age. In New York State, all cases of H. influenzae type b meningitis must, under the New York State Public Health Law and the New York State Sanitary Code, be reported to local health departments. The following account describes control measures undertaken by the Westchester County Department of Health following report of an outbreak of H. influenzae type b meningitis in a large nursery school within the county. At the time of the outbreak, the vaccine was not yet marketed. CASE REPORT
On October 9, 1984, the Westchester County Health Department was notified of the occurrence of a case of H. injhenzae type b meningitis in a child attending a large, private day-care center. In investigating this report, it was discovered that a previous case had occurred in the center 2 weeks before but had not been reported to the Health Department. The first case had been a 33-month-old girl hospitalized on Sunday, September 23. She had attended full-day sessions at the center through the preceding Friday. Twenty-three other children attended this class. Although this case was not reported to the Health Department, the child’s physician had notified the center of the case and recommended that children and staff receive rifampin prophylaxis. This was done; however, no records or followup data were obtained to determine the extent of compliance. Fifteen days following hospitalization of the index case, a second child from a different class in the day-care center was hospitalized with H. iPlfluenzae type b meningitis. Organisms from both cases were p-lactamase positive. Biotyping to establish further similarity between the organisms was not possible, however. The second case was a 20-month-old boy in a class of 14 children. His mother reported that he had received rifampin prophylaxis (20 mg/kg dose) for 4 days following report of the index case. He then had returned to school for a full week following completion of the medication, prior to becoming ill. This child’s physician telephoned the Health Department to report this case and to request assistance with follow-up at the nursery school. The second case had attended full-day school until the Friday before his early-Monday admission.
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MEASURES
Following report of the second case to the Health Department, the Bureau of Disease Control held an emergency meeting with the school staff to explain the steps required to control further spread of the disease. A letter from the Health Department explaining the situation and recommending rifampin prophylaxis for all nursery school children and staff was distributed at school to parents the same day and also mailed to their homes. A follow-up form was enclosed for parents to report compliance following both the first and the second meningitis cases. The nursery school enrolled approximately 160 children between 6 months and 6 years of age. The mean age of all children attending the nursery school was 40 months with 34 (21%) under 2 years of age, representing those at highest risk of acquiring the disease. RESULTS
Parents of 145 children (90%) returned the follow-up form to the Health Department. Reports indicated that following the first case of meningitis 45% (65/145) received rifampin prophylaxis from their private physicians (20 mg/kg/day x 4 days). By contrast, 90% received rifampin following the second case of meningitis (131/145). Of the 32 staff members, 24 returned the follow-up questionnaires (67%). Only 8 (33%) indicated that they had taken rifampin following the first meningitis case. This increased to 19 (79%) after the second case. Rifampin compliance rates for each of the eight classes and the after-school group were analyzed separately (Table 1). Rates following the index case varied from 36 to 59%, while rates following the second case ranged from 75 to 100%.
RIFAMPIN
COMPLIANCE,
TABLE I BY NURSERY SCHOOL CLASS, FOLLOWING H. injluenzae TYPE b MENINGITIS
Median Class
No. attendees
age (months)
1 2” 3 46 5 6 7 8 9’
1.5 14 16 23 19 17 20 19 17
9 18.5 25 31 40 40 50 54 64
No. of follow-up forms 15 13 15 22 16 14 20 15 15
FIRST AND SECOND
Percentage of respondents on rifampin prophylaxis: case No. 1 40 46 47 59 38 36 35 47 53
CASES OF
Percentage of respondents on rifampin prophylaxis: case No. 2 93 100 93 91 94 93 80 75 100
a Compliance rate based on 14 attendees following first case, and 13 attendees (eliminating second case) following second case. b Compliance rate based on 23 attendees following first case (eliminating first case), and 24 attendees following second case. c After-school class; predominately kindergarten students.
WILLIAMS,
264
LEE, AND CURRAN Following Following
Case Case
No I No.2
80
c 5 2
60
kf
40
20
0 C loss in)
1115)
Median Age(mos)
9
II(l4) 185
lIW6l
IE(23)
P(l9)
25
31
40
FIG. 1. Rifampin compliance by class, following meningitis.
YI(17)
L!Ul20)
S!llI(l9)
40
50
54
After school(l7) 64
Totolll60) 40
first and second cases of H. in~7uenzae
type b
Almost all physicians contacted by parents following the second case of meningitis prescribed rifampin prophylaxis (except for four instances where they prescribed another antibiotic because of intercurrent illness). Two physicians (neither of whom were pediatricians) declined to prescribe rifampin, even after report of the second case. On follow-up 4 months after report of this outbreak, the two children who contracted meningitis had recovered and returned to school. No additional cases of meningitis or other invasive H. influenzae type b disease had occurred in this nursery school. DISCUSSION
In New York State, responsibility for implementing recommendations for prophylaxis of H. influenzae type b disease in nursery-school and day-care center contacts is generally assigned to the local health departments for several reasons: (a) cases of H. in.uenzae type b meningitis are reportable by state law to health departments, (b) health departments are staffed with public health nurses and disease control personnel needed to implement and evaluate control measures, and (c) local health departments are able to request additional assistance to control disease outbreaks from state and federal public health departments if the need arises. In day-care centers, the need for rapid mobilization of forces in implementing control measures is obvious. This reflects the fact that most secondary cases among close contacts occur within the first week after exposure and because the mechanics of informing parents, educating them, and motivating them to seek medical advice with respect to rifampin prophylaxis can be time consuming and in some cases delayed too long to be effective. When large day-care centers are involved in an outbreak of H. inJZuenzae type b disease, such a report must al-
PREVENTION
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MENINGITIS
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24.5
most be considered a public health emergency to achieve an acceptably high rifampin prophylaxis rate among center children and staff. Direct distribution of rifampin from the health departments is a time-saving alternative, if feasible. The case reported above illustrates several important points. First is the observation that it takes more than a telephone call to a day-care center informing it of the situation and the need for prophylaxis for compliance to occur at an acceptable level. The second point illustrated is that even after a strong recommendation by county health officials with concerted follow-up efforts, the results are not 100%. Better compliance may be achieved by on-site distribution of rifampin by the local health departments. In the situation reported, 90% of children and 79% of staff responding were rifampin-compliant following the second case of H. inJluenzae type b meningitis. It has been suggested that compliance rates of 75% or greater are needed to prevent additional secondary cases in group settings such as day care (3), so that the actual figures achieved could be considered successful. On the other hand, the low rates of compliance after the first case (45% children and 33% staff) were apparently too low to reduce spread of the disease in the center. Ironically, the child who developed the second case of meningitis reported had actually received rifampin prophylaxis, although he returned to school a full week following completion of the medication before onset of illness. It is possible that (a) the child did not receive the rifampin, (b) the child was among the small percentage whose carriage of the organism is not eradicated by rifampin at the 20-mg/kg dose (daily for 4 days), or (c) the rifampin was successful in eliminating nasopharyngeal carriage (or preventing acquisition), but the child was then recolonized upon return to school. Nasopharyngeal cultures from children and staff at the center involved were not done. There was some concern voiced by health officials, parents, and school staff over whether to exclude children from school for a 2-month period if their physician or parents declined rifampin prophylaxis. While, legally, the Health Department would not have been able to enforce such an exclusion, a recommendation to parents to this effect could have been made by either the department or the nursery school itself. This was not done, however, as it was believed that many working parents would simply enroll their child in a different day-care center. Within the past months since this outbreak occurred, a vaccine for H. inJluenzae type b has been approved and marketed. With availability of the new vaccine, a revised update on recommendations for prevention and prophylaxis of invasive H. injkenzae type b disease was published in March 1986 (31). In this revision, the Advisory Committee on Immunization Practices (ACIP) emphasizes that written parental notification should be the first step following report of a case of H. inj7uenzae type b disease in day-care centers in which another child under 2 years old has been exposed. They also recommend that “strong consideration should be given to administering rifampin prophylaxis to all children and staff in the classroom, regardless of age.” Vaccination with the H. influenzae type b vaccine probably does not affect nasopharyngeal carriage and subsequent transmission to a susceptible classmate. The revised 1986 ACIP recommendations do not specifically address situations
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involving multiple cases in more than one classroom in a day-care center, such as occurred in the present report. The previous recommendations advocated “administering rifampin to all infants and supervisory personnel when two or more cases of invasive disease have occurred among attendees within 60 days” (2). Thus, it is likely that the latter would still apply in a situation of multiple cases. This opinion is echoed by a recent publication of the California State Health Department (26). In the present case, the decision to recommend rifampin for all the children in the day-care center following the second case of H. influenzae type b disease in a 2-week period of time was based on the ACIP recommendations at the time of the outbreak and the advice of both the state Health Department and pediatric infectious disease specialists. Presence of young infants at the center, mingling of children at recess and lunch periods, and rotation of staff among classrooms were all taken into consideration in the decision. In conclusion, the case in point illustrates the need for rapid public health action in implementing control measures for invasive H. inflclenzae type b disease in day-care or nursery school settings. Pediatricians and hospital infection control personnel should be cognizant of the need to report all such cases to the local health department for investigation and follow-up as soon as diagnosis is suspected or confirmed. A decision about whether and to whom, to recommend rifampin prophylaxis, in any particular case would be made based on the ages of the day-care attendees, the timing and intensity of last exposure to the index case(s), and the intermingling of children and staff at the center. Prophylaxis in centers caring for infants under 1 to 2 years of age would be recommended more readily after a single case of H. influenzae type b disease than in a center with all 3- to 4-year-old attendees. More than one case (within 60 days) in a preschool center would ordinarily require prophylaxis of all children and staff. Finally, education of involved staff and community physicians with respect to new control measures recommended is essential to successful implementation. Meeting in person with day-care center staff at the onset of an outbreak is important to optimize compliance and follow-through. Dealing with noncompliant physicians is more difficult, since there are some who either are not aware of the recommendations or do not accept them (8, 21, 29). Sending each parent a copy of the current recommendations (31) which they could show their physician, if necessary, might minimize the rate of physician noncompliance. REFERENCES 1. American Academy of Pediatrics. “Report of the Committee on Infectious Diseases,” 19th ed. American Academy of Pediatrics, Evanston, IL, 1982. 2. American Academy of Pediatrics. Report of the Committee on Infectious Diseases. Pediatrics 74, 301-302 (1984). 3. Band, J. D., Fraser, D. W., and Ajello, G. Prevention of Haemophilus influenzae type b disease. JAMA 251, 2381-2386 (1984). 4. Campbell, R. L., Zedd, A. J., and Michaels, R. H. Household spread of infection due to Haemophilus influenzae type b. Pediatrics 66, 115- 117 (1980). 5. Centers for Disease Control. Bacterial meningitis and meningococcemia-United States 1978. Morbidity and Mortality Weekly Report 28(24), 277-279 (1979).
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IN DAY CARE
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6. Cox, F., Trincher, R., Rissing, J. P., Patton, M., McCracken, C. H. and Granoff, D. M. Rifampin prophylaxis for contacts of Haemophilus inj7uenzae type b disease. JAMA 245, 1043- 1045 (1981). 7. Daum, R. S., Glode, M. P., and Goldmann, D. A. Rifampin chemoprophylaxis for household contacts of patients with invasive infections due to Haemophilus influenzae type b. J. Pediatr. 98,485-491 (1981). 8. Daum, R. S., and Halsey, N. A. Counterpoint: The Red Book opts for red urine. Pediatr. Infect. Dis. 1, 378-381 (1982). 9. Feldman, W. E., Ginsburg, C. M., and Allen, D. Relation of concentrations of Haemophilus inj7uenzae type b in cerebrospina] fluid to late sequelae of patients with meningitis. J. Pediatrics 100, 209-219 (1982). 10. Filice, G. A., Andrews, J. S., Jr., Hudgins, M. P., rf a[. Spread of Haemophilus influenzae: Secondary illness in household contacts of patients with H. irzfluenzae meningitis. Amer. J. Dis. Child. 132, 757-759 (1978). 1I. Fraser, D. W., Gei], C. C., and Felman, R. A. Bacterial meningitis in Bernadillo County, New Mexico: A Comparison with three American populations. Amer. J. Epidemiol. 100, 29-34 (1974). 12. Gessert, C., Granoff, D. M., and Gilsdorf, J. Comparison of rifampin and ampicillin in day-care center contacts of Haemophilus injluenzae type b disease. Pediatrics 66, l-4 (1980). 13. Ginsburg, C. M., McCracken, G. H., Jr., Rae, S., et al. Haemophilus inj7uenzae type b disease: Incidence in a day care center. JAMA 238, 604-607 (1977). 14. Glode, M. P., Daum, R. S., Goldmann, D. A., et al. Haemophilus influenzae type b meningitis: A contagious disease of children. Brit. Med. J. 280, 899-901 (1980). 15. Glade, M. P., Schiffer, M. S., Robbins, J. B., et al. An outbreak of Haemophilus influenzae type b meningitis in an enclosed hospital population. J. Pediatr. 88, 36-40 (1976). 16. Glade, M. P., Daum, R. S., Leclair, J., et al. Haemophilus inj7uenzae meningitis: Secondary illness in household contacts. Brit. Med. J. 2, 899-901 (1980). 17. Glode, M. P., Daum, R. S., Halsey, N. A., er ul. Rifampin alone and in combination with trimethoprim in chemoprophylaxis for infections due to Haemophilus injluenzae type b. Rev. Infect. Dis. 5, S549-S555 (1983). 18. Granoff, D., Gilsdorf, J., Gessert, C., et al. Haemophilus injluenzae type b disease in a day-care center: Eradication of carrier state by rifampin. Pediatrics 63, 397-401 (1979). 19. Granoff, D. M., and Daum, R. S. Spread of Haemophilus influenzae type b: Recent epidemiologic and therapeutic considerations. J. Pediatr. 97, 854-860 (1980). 20. Horner, D. B., McCracken, G. H., Jr., Ginsburg, C. M., et al. A comparison of three antibiotic regimens for eradication of Haemophilus influenzae type b from the pharynx of infants and children. Pediatrics 66, 136-138 (1980). 21. Mann, J. M., and Hull, H. F. New Haemophilus inj7uenzae type b control strategy: Premature commitment to prophylaxis? Pediatrics 72, I l8- 121 (1983). 22. Melish, M. E., Nelson, A. J., Martin, T. E.. et al. Epidemic spread of Haemophilus in$uenzae type b in a day care center. Pediatr. Res. 10, 348 (1976). 23. Murphy, T. V., Chrane, D. F., McCracken, G. H., Jr., et al. Rifampin prophylaxis v placebo for household contacts of children with Haemophilus injluenzae type b disease. Amer. J. Dis. Child. 137, 627-632 (1983). 24. Osterholm, M. T., and Murphy, T. V. Does rifampin prophylaxis prevent disease caused by Huemophilus influenzae type b? JAMA 251, 2408-2409 (1984). 25. Polysaccharide vaccine for prevention of Haemophilus influenzae type b disease. Recommendations of the Immunization Practices Advisory Committee (ACIP). Morbidity und Morralify Weekly Reporr 34(15), 201-205 (1985). 26. Questions of public health concern. Cal$omiu Morbidity 27 (I) July l I, (1986). 27. Redmond, S. R., and Pinchichero, M. E. Haemophilus influenzae type b disease: An epidemiologic study with special reference to day care centers. JAMA 252, 2581-2584 (1984). 28. Se]], S. H. W., Merrill, R. E., Doyne, E. D., and Zinskey, E. P., Jr. Long-term sequelae of Haemophilus influenzae meningitis. Pediutrics 49, 206-211 (1972). 29. Shapiro, E. D., and Wald, E. R. Efficacy of rifampin in eliminating pharyngeal carriage of Haemophilus influenzue type b. Pediatrics 66, 5-8 (1980).
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30. Sumaya, C. V., Jorgensen, J. H., Townsend, S., et al. Comparison of trimethoprim-sulfa and rifampin in eradication of Haemophilus influenzae type b (Hib) infections in a day-care center. Pediatr. Res. 14, 565 (1980) (abstract). 3 1. Update: Prevention of Haemophilus influenzae Type b Disease. Recommendations of the Immunization Practices Advisory Committee (ACIP). Morbidity and Mortality Week/y 35(1 I), 170- 180 (1986). 32. Ward, J. I., Gorman, G., Phillips, C., et al. Haemophilus inj7uenzae type b disease in a day-care center: Report of an outbreak. J. Pediatr. 92, 713-717 (1978). 33. Ward, J. I., Fraser, D. W., Baraff, L. J., et al. Haemophilus influenzae meningitis: A national study of secondary spread in household contacts. New Engl. J. Med. 301, 122-126 (1979).
MEDICINE
16, 261-268 (1987)
Prevention of Meningitis in a Day-Care Center: an Outbreak of Haemophilus influenzae CHRISTINE
L. WILLIAMS, M.D., M.P.H.*,’ ALDA CHEN ANITA S. CURRAN, M.D., M.P.H.?
Management Type b LEE,
*Department of Pediatrics, New York Medical College, Valhalla, New fwestchester County Department of Health, Bureau of Disease White Plains, New York 10601
B.S.N.,? York 10595, Control,
of
AND and
The care of infants and toddlers in nursery school and day-care centers in increasingly large numbers over the past decade poses special problems with respect to communicable disease control. This age group is particularly susceptible to those infectious agents (bacterial, viral, and parasitic) spread by close personal contact. This study describes an outbreak of Huemophilus influenzae type b meningitis in a large nursery school in Westchester County, New York. Organized efforts to control the outbreak through recommendation of rifampin prophylaxis were undertaken and evaluated. Compliance following the first case of meningitis was unacceptably low (45% of children and 33% of staff). Following the second case, however, compliance rose to 90% among child attendees and 79% among staff. Recommended procedures for implementation of control measures are described. o 19x7 ACdemic Press, Inc.
INTRODUCTION Haemophilus influenzae type b is the leading cause of bacterial meningitis in the United States, resulting in an estimated 8,000 cases per year (5). In addition, this organism is responsible for a number of other serious diseases, such as epiglottitis, septic arthritis, facial cellulitis, osteomyelitis, and pneumonia. Invasive H. influenzae type b disease occurs predominantly in children under 6 years of age, with the highest incidence occurring among children between ages 6 months and 2 years (9, 11, 28). Only recently has H. injluenzae type b been widely publicized as a contagious disease (14). Reports of outbreaks among children in day-care centers (13, 22, 27, 32), in hospitals and institutions (15), and by household contacts (4, 10, 16, 33) emerged in the 1970s and emphasized the significance of secondary attack rates, particularly in children under 2 years of age. In a national study of household contacts of H. influenzae type b invasive disease, the secondary attack rate was shown to be 0.5% for children under 6 years, 3.4% for children under 2 years, and 6% for infants under 1 year of age (33). Since more than half of secondary cases occurred within 1 week of exposure in young children (33), studies were undertaken to determine the efficiency of antibiotic prophylaxis in preventing the spread of this disease (6,7, 12, 17- 19, 20, 23, 29, 30). A multicenter, prospective trial of rifampin prophylaxis of household and day-care contacts of patients with systemic H. inJluenzae type b disease was un’ To whom reprint requests should be addressed. 261 0091-7435187 $3.00 Copyright Q 1987 by Academic Press, Inc. All rights of reproduction in any form rererved.
262
WILLIAMS,
LEE,
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dertaken during 1979 to 1981 by the U.S. Centers for Disease Control (3). Results indicated that among children less than 48 months of age, rifampin prophylaxis showed a trend toward efficacy in household contacts. Among day-care center contacts, however, the number of cases was too small for meaningful statistical analysis. Based on these findings, the American Academy of Pediatrics Committee on Infectious Disease issued preliminary recommendations in the fall of 1982 for rifampin prophylaxis for all household and nursery school/day-care center contacts of a case of invasive H. ir@uenzae type b disease where exposed children under 4 years of age might be involved (1). These recommendations were subsequently revised by the committee 2 years later to advise rifampin prophylaxis in day-care or nursery school contacts following two cases of invasive H. influenzae type b disease within 60 days rather than following a single case as recommended previously (2). At the same time it was also expected that a vaccine against H. influenzae type b would be available within the coming year, at least for children over 18 to 24 months of age. In New York State, all cases of H. influenzae type b meningitis must, under the New York State Public Health Law and the New York State Sanitary Code, be reported to local health departments. The following account describes control measures undertaken by the Westchester County Department of Health following report of an outbreak of H. influenzae type b meningitis in a large nursery school within the county. At the time of the outbreak, the vaccine was not yet marketed. CASE REPORT
On October 9, 1984, the Westchester County Health Department was notified of the occurrence of a case of H. injhenzae type b meningitis in a child attending a large, private day-care center. In investigating this report, it was discovered that a previous case had occurred in the center 2 weeks before but had not been reported to the Health Department. The first case had been a 33-month-old girl hospitalized on Sunday, September 23. She had attended full-day sessions at the center through the preceding Friday. Twenty-three other children attended this class. Although this case was not reported to the Health Department, the child’s physician had notified the center of the case and recommended that children and staff receive rifampin prophylaxis. This was done; however, no records or followup data were obtained to determine the extent of compliance. Fifteen days following hospitalization of the index case, a second child from a different class in the day-care center was hospitalized with H. iPlfluenzae type b meningitis. Organisms from both cases were p-lactamase positive. Biotyping to establish further similarity between the organisms was not possible, however. The second case was a 20-month-old boy in a class of 14 children. His mother reported that he had received rifampin prophylaxis (20 mg/kg dose) for 4 days following report of the index case. He then had returned to school for a full week following completion of the medication, prior to becoming ill. This child’s physician telephoned the Health Department to report this case and to request assistance with follow-up at the nursery school. The second case had attended full-day school until the Friday before his early-Monday admission.
PREVENTION
OF MENINGITIS
CONTROL
IN DAY
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CARE
MEASURES
Following report of the second case to the Health Department, the Bureau of Disease Control held an emergency meeting with the school staff to explain the steps required to control further spread of the disease. A letter from the Health Department explaining the situation and recommending rifampin prophylaxis for all nursery school children and staff was distributed at school to parents the same day and also mailed to their homes. A follow-up form was enclosed for parents to report compliance following both the first and the second meningitis cases. The nursery school enrolled approximately 160 children between 6 months and 6 years of age. The mean age of all children attending the nursery school was 40 months with 34 (21%) under 2 years of age, representing those at highest risk of acquiring the disease. RESULTS
Parents of 145 children (90%) returned the follow-up form to the Health Department. Reports indicated that following the first case of meningitis 45% (65/145) received rifampin prophylaxis from their private physicians (20 mg/kg/day x 4 days). By contrast, 90% received rifampin following the second case of meningitis (131/145). Of the 32 staff members, 24 returned the follow-up questionnaires (67%). Only 8 (33%) indicated that they had taken rifampin following the first meningitis case. This increased to 19 (79%) after the second case. Rifampin compliance rates for each of the eight classes and the after-school group were analyzed separately (Table 1). Rates following the index case varied from 36 to 59%, while rates following the second case ranged from 75 to 100%.
RIFAMPIN
COMPLIANCE,
TABLE I BY NURSERY SCHOOL CLASS, FOLLOWING H. injluenzae TYPE b MENINGITIS
Median Class
No. attendees
age (months)
1 2” 3 46 5 6 7 8 9’
1.5 14 16 23 19 17 20 19 17
9 18.5 25 31 40 40 50 54 64
No. of follow-up forms 15 13 15 22 16 14 20 15 15
FIRST AND SECOND
Percentage of respondents on rifampin prophylaxis: case No. 1 40 46 47 59 38 36 35 47 53
CASES OF
Percentage of respondents on rifampin prophylaxis: case No. 2 93 100 93 91 94 93 80 75 100
a Compliance rate based on 14 attendees following first case, and 13 attendees (eliminating second case) following second case. b Compliance rate based on 23 attendees following first case (eliminating first case), and 24 attendees following second case. c After-school class; predominately kindergarten students.
WILLIAMS,
264
LEE, AND CURRAN Following Following
Case Case
No I No.2
80
c 5 2
60
kf
40
20
0 C loss in)
1115)
Median Age(mos)
9
II(l4) 185
lIW6l
IE(23)
P(l9)
25
31
40
FIG. 1. Rifampin compliance by class, following meningitis.
YI(17)
L!Ul20)
S!llI(l9)
40
50
54
After school(l7) 64
Totolll60) 40
first and second cases of H. in~7uenzae
type b
Almost all physicians contacted by parents following the second case of meningitis prescribed rifampin prophylaxis (except for four instances where they prescribed another antibiotic because of intercurrent illness). Two physicians (neither of whom were pediatricians) declined to prescribe rifampin, even after report of the second case. On follow-up 4 months after report of this outbreak, the two children who contracted meningitis had recovered and returned to school. No additional cases of meningitis or other invasive H. influenzae type b disease had occurred in this nursery school. DISCUSSION
In New York State, responsibility for implementing recommendations for prophylaxis of H. influenzae type b disease in nursery-school and day-care center contacts is generally assigned to the local health departments for several reasons: (a) cases of H. in.uenzae type b meningitis are reportable by state law to health departments, (b) health departments are staffed with public health nurses and disease control personnel needed to implement and evaluate control measures, and (c) local health departments are able to request additional assistance to control disease outbreaks from state and federal public health departments if the need arises. In day-care centers, the need for rapid mobilization of forces in implementing control measures is obvious. This reflects the fact that most secondary cases among close contacts occur within the first week after exposure and because the mechanics of informing parents, educating them, and motivating them to seek medical advice with respect to rifampin prophylaxis can be time consuming and in some cases delayed too long to be effective. When large day-care centers are involved in an outbreak of H. inJZuenzae type b disease, such a report must al-
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most be considered a public health emergency to achieve an acceptably high rifampin prophylaxis rate among center children and staff. Direct distribution of rifampin from the health departments is a time-saving alternative, if feasible. The case reported above illustrates several important points. First is the observation that it takes more than a telephone call to a day-care center informing it of the situation and the need for prophylaxis for compliance to occur at an acceptable level. The second point illustrated is that even after a strong recommendation by county health officials with concerted follow-up efforts, the results are not 100%. Better compliance may be achieved by on-site distribution of rifampin by the local health departments. In the situation reported, 90% of children and 79% of staff responding were rifampin-compliant following the second case of H. inJluenzae type b meningitis. It has been suggested that compliance rates of 75% or greater are needed to prevent additional secondary cases in group settings such as day care (3), so that the actual figures achieved could be considered successful. On the other hand, the low rates of compliance after the first case (45% children and 33% staff) were apparently too low to reduce spread of the disease in the center. Ironically, the child who developed the second case of meningitis reported had actually received rifampin prophylaxis, although he returned to school a full week following completion of the medication before onset of illness. It is possible that (a) the child did not receive the rifampin, (b) the child was among the small percentage whose carriage of the organism is not eradicated by rifampin at the 20-mg/kg dose (daily for 4 days), or (c) the rifampin was successful in eliminating nasopharyngeal carriage (or preventing acquisition), but the child was then recolonized upon return to school. Nasopharyngeal cultures from children and staff at the center involved were not done. There was some concern voiced by health officials, parents, and school staff over whether to exclude children from school for a 2-month period if their physician or parents declined rifampin prophylaxis. While, legally, the Health Department would not have been able to enforce such an exclusion, a recommendation to parents to this effect could have been made by either the department or the nursery school itself. This was not done, however, as it was believed that many working parents would simply enroll their child in a different day-care center. Within the past months since this outbreak occurred, a vaccine for H. inJluenzae type b has been approved and marketed. With availability of the new vaccine, a revised update on recommendations for prevention and prophylaxis of invasive H. injkenzae type b disease was published in March 1986 (31). In this revision, the Advisory Committee on Immunization Practices (ACIP) emphasizes that written parental notification should be the first step following report of a case of H. inj7uenzae type b disease in day-care centers in which another child under 2 years old has been exposed. They also recommend that “strong consideration should be given to administering rifampin prophylaxis to all children and staff in the classroom, regardless of age.” Vaccination with the H. influenzae type b vaccine probably does not affect nasopharyngeal carriage and subsequent transmission to a susceptible classmate. The revised 1986 ACIP recommendations do not specifically address situations
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involving multiple cases in more than one classroom in a day-care center, such as occurred in the present report. The previous recommendations advocated “administering rifampin to all infants and supervisory personnel when two or more cases of invasive disease have occurred among attendees within 60 days” (2). Thus, it is likely that the latter would still apply in a situation of multiple cases. This opinion is echoed by a recent publication of the California State Health Department (26). In the present case, the decision to recommend rifampin for all the children in the day-care center following the second case of H. influenzae type b disease in a 2-week period of time was based on the ACIP recommendations at the time of the outbreak and the advice of both the state Health Department and pediatric infectious disease specialists. Presence of young infants at the center, mingling of children at recess and lunch periods, and rotation of staff among classrooms were all taken into consideration in the decision. In conclusion, the case in point illustrates the need for rapid public health action in implementing control measures for invasive H. inflclenzae type b disease in day-care or nursery school settings. Pediatricians and hospital infection control personnel should be cognizant of the need to report all such cases to the local health department for investigation and follow-up as soon as diagnosis is suspected or confirmed. A decision about whether and to whom, to recommend rifampin prophylaxis, in any particular case would be made based on the ages of the day-care attendees, the timing and intensity of last exposure to the index case(s), and the intermingling of children and staff at the center. Prophylaxis in centers caring for infants under 1 to 2 years of age would be recommended more readily after a single case of H. influenzae type b disease than in a center with all 3- to 4-year-old attendees. More than one case (within 60 days) in a preschool center would ordinarily require prophylaxis of all children and staff. Finally, education of involved staff and community physicians with respect to new control measures recommended is essential to successful implementation. Meeting in person with day-care center staff at the onset of an outbreak is important to optimize compliance and follow-through. Dealing with noncompliant physicians is more difficult, since there are some who either are not aware of the recommendations or do not accept them (8, 21, 29). Sending each parent a copy of the current recommendations (31) which they could show their physician, if necessary, might minimize the rate of physician noncompliance. REFERENCES 1. American Academy of Pediatrics. “Report of the Committee on Infectious Diseases,” 19th ed. American Academy of Pediatrics, Evanston, IL, 1982. 2. American Academy of Pediatrics. Report of the Committee on Infectious Diseases. Pediatrics 74, 301-302 (1984). 3. Band, J. D., Fraser, D. W., and Ajello, G. Prevention of Haemophilus influenzae type b disease. JAMA 251, 2381-2386 (1984). 4. Campbell, R. L., Zedd, A. J., and Michaels, R. H. Household spread of infection due to Haemophilus influenzae type b. Pediatrics 66, 115- 117 (1980). 5. Centers for Disease Control. Bacterial meningitis and meningococcemia-United States 1978. Morbidity and Mortality Weekly Report 28(24), 277-279 (1979).
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6. Cox, F., Trincher, R., Rissing, J. P., Patton, M., McCracken, C. H. and Granoff, D. M. Rifampin prophylaxis for contacts of Haemophilus inj7uenzae type b disease. JAMA 245, 1043- 1045 (1981). 7. Daum, R. S., Glode, M. P., and Goldmann, D. A. Rifampin chemoprophylaxis for household contacts of patients with invasive infections due to Haemophilus influenzae type b. J. Pediatr. 98,485-491 (1981). 8. Daum, R. S., and Halsey, N. A. Counterpoint: The Red Book opts for red urine. Pediatr. Infect. Dis. 1, 378-381 (1982). 9. Feldman, W. E., Ginsburg, C. M., and Allen, D. Relation of concentrations of Haemophilus inj7uenzae type b in cerebrospina] fluid to late sequelae of patients with meningitis. J. Pediatrics 100, 209-219 (1982). 10. Filice, G. A., Andrews, J. S., Jr., Hudgins, M. P., rf a[. Spread of Haemophilus influenzae: Secondary illness in household contacts of patients with H. irzfluenzae meningitis. Amer. J. Dis. Child. 132, 757-759 (1978). 1I. Fraser, D. W., Gei], C. C., and Felman, R. A. Bacterial meningitis in Bernadillo County, New Mexico: A Comparison with three American populations. Amer. J. Epidemiol. 100, 29-34 (1974). 12. Gessert, C., Granoff, D. M., and Gilsdorf, J. Comparison of rifampin and ampicillin in day-care center contacts of Haemophilus injluenzae type b disease. Pediatrics 66, l-4 (1980). 13. Ginsburg, C. M., McCracken, G. H., Jr., Rae, S., et al. Haemophilus inj7uenzae type b disease: Incidence in a day care center. JAMA 238, 604-607 (1977). 14. Glode, M. P., Daum, R. S., Goldmann, D. A., et al. Haemophilus influenzae type b meningitis: A contagious disease of children. Brit. Med. J. 280, 899-901 (1980). 15. Glade, M. P., Schiffer, M. S., Robbins, J. B., et al. An outbreak of Haemophilus influenzae type b meningitis in an enclosed hospital population. J. Pediatr. 88, 36-40 (1976). 16. Glade, M. P., Daum, R. S., Leclair, J., et al. Haemophilus inj7uenzae meningitis: Secondary illness in household contacts. Brit. Med. J. 2, 899-901 (1980). 17. Glode, M. P., Daum, R. S., Halsey, N. A., er ul. Rifampin alone and in combination with trimethoprim in chemoprophylaxis for infections due to Haemophilus injluenzae type b. Rev. Infect. Dis. 5, S549-S555 (1983). 18. Granoff, D., Gilsdorf, J., Gessert, C., et al. Haemophilus injluenzae type b disease in a day-care center: Eradication of carrier state by rifampin. Pediatrics 63, 397-401 (1979). 19. Granoff, D. M., and Daum, R. S. Spread of Haemophilus influenzae type b: Recent epidemiologic and therapeutic considerations. J. Pediatr. 97, 854-860 (1980). 20. Horner, D. B., McCracken, G. H., Jr., Ginsburg, C. M., et al. A comparison of three antibiotic regimens for eradication of Haemophilus influenzae type b from the pharynx of infants and children. Pediatrics 66, 136-138 (1980). 21. Mann, J. M., and Hull, H. F. New Haemophilus inj7uenzae type b control strategy: Premature commitment to prophylaxis? Pediatrics 72, I l8- 121 (1983). 22. Melish, M. E., Nelson, A. J., Martin, T. E.. et al. Epidemic spread of Haemophilus in$uenzae type b in a day care center. Pediatr. Res. 10, 348 (1976). 23. Murphy, T. V., Chrane, D. F., McCracken, G. H., Jr., et al. Rifampin prophylaxis v placebo for household contacts of children with Haemophilus injluenzae type b disease. Amer. J. Dis. Child. 137, 627-632 (1983). 24. Osterholm, M. T., and Murphy, T. V. Does rifampin prophylaxis prevent disease caused by Huemophilus influenzae type b? JAMA 251, 2408-2409 (1984). 25. Polysaccharide vaccine for prevention of Haemophilus influenzae type b disease. Recommendations of the Immunization Practices Advisory Committee (ACIP). Morbidity und Morralify Weekly Reporr 34(15), 201-205 (1985). 26. Questions of public health concern. Cal$omiu Morbidity 27 (I) July l I, (1986). 27. Redmond, S. R., and Pinchichero, M. E. Haemophilus influenzae type b disease: An epidemiologic study with special reference to day care centers. JAMA 252, 2581-2584 (1984). 28. Se]], S. H. W., Merrill, R. E., Doyne, E. D., and Zinskey, E. P., Jr. Long-term sequelae of Haemophilus influenzae meningitis. Pediutrics 49, 206-211 (1972). 29. Shapiro, E. D., and Wald, E. R. Efficacy of rifampin in eliminating pharyngeal carriage of Haemophilus influenzue type b. Pediatrics 66, 5-8 (1980).
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30. Sumaya, C. V., Jorgensen, J. H., Townsend, S., et al. Comparison of trimethoprim-sulfa and rifampin in eradication of Haemophilus influenzae type b (Hib) infections in a day-care center. Pediatr. Res. 14, 565 (1980) (abstract). 3 1. Update: Prevention of Haemophilus influenzae Type b Disease. Recommendations of the Immunization Practices Advisory Committee (ACIP). Morbidity and Mortality Week/y 35(1 I), 170- 180 (1986). 32. Ward, J. I., Gorman, G., Phillips, C., et al. Haemophilus inj7uenzae type b disease in a day-care center: Report of an outbreak. J. Pediatr. 92, 713-717 (1978). 33. Ward, J. I., Fraser, D. W., Baraff, L. J., et al. Haemophilus influenzae meningitis: A national study of secondary spread in household contacts. New Engl. J. Med. 301, 122-126 (1979).