(Received August 31, 1970; revision accepted for publication April 12, 1971.)
ADDRESS FOR REPRINTS: (R.A.Z. ) P.O. Box 551, Fort Collins, Colorado 80521.
PEDIATBICS, Vol. 48, No. 4, October 1971
566
AN
EFFECTIVE
PROGRAM
FOR
REDUCING
GROUP
A
STREPTOCOCCAL
PREVALENCE
Robert A. Zimmerman, Ph.D., Betty A. Biggs, R.N., Richard A. Bolin, Elizabeth Wilson, Ph.D., James H. Mathews, BA, C. Bruce Cropp, BS,
and Arthur H. Auernheimer, BA
From tlze Streptococcal Disease Section, Ecological Investigations Program, Center for Disease Control, Health Services and Mental Health Administration, Public Health Service, U.S. Department of Health,
Education, and WTelfare, Fort Collins, Colorado, and Sangre Dc Cristo School District, Mosca, Colorado
ABSTRACT. A relatively simple and inexpensive
streptococcal control program was applied to two
school populations located in an area of high
ende-micity in Colorado. Throat cultures were obtained
from children admitting sore throat and from a
small, continuously rotating random sample of the
student body. This method of surveillance
pro-vided a reliable index of total streptococcal
inci-dence in the two schools. Children with Group A
positive cultures sought consultation with private
physicians on a voluntary basis. The application of
these sampling procedures resulted in a reduction
of prevalence rates to less than 5%. Comparable endemic prevalence rates observed in school
chil-dren in three other Colorado communities averaged
21.9.
The program described is practical and
effec-tive in substantially lowering the incidence of
Group A infections and reducing risk to
develop-ment of nonsuppurative sequelae. Pediatrics, 48:
566, 1971, STREPTOCOCCUS, SCHOOL CHILI)REN
STUDY, EPIDEMIOLOGY, ANTIBODIES.
I
T has been shown that bacteriologicsur-veillance and enforced treatment can
provide control of streptococcal infections
and their nunsuppurative complications in
military populations, although occasional
food-borne streptococcal epidemics do
oc-cur. Relatively few attempts have been
made to reduce substantially Group A prey-alence in civilian high risk groups, notably
the school child populationJ The only
sustained c’ffoit has been the successful
pro-gram undertaken iii Casper, Wyoming,
which has been described in detail
else-where. 10
This report describes a successful
at-tempt to lower substantially Group A prey-alence rates in two school popitlatioiis in an
area of high endemicity in Colorado. Our
primary objective was to reduce prevalence
below 5% by means of the most simple
sampling procedure that would provide a
reliable index of incidence in the total
pop-ulation. Although patterned after the
meth-ods employed in the Wyoming project, our
study is substantially different in several
re-spects. Our protocol demonstrates that
streptococcal infections can be controlled
relatively simply through a combination of
(
1)
use of lay personnel in dailysurveil-lance; (2) education of children and
par-cuts; (3) voluntary treatment of positive
individuals; and (4) provision of laboratory
support.
METHODS
Demographic Data
The two schools selected are in tile small
towns of Mosca and Hooper, located 8
miles apart, in the San Luis Valley of
Cob-rado. They were chosen because the
Cob-rado State Department of Public Health
has long regarded the San Luis Valley as a
“hot spot” for streptococcal disease and
nonsuppurative ,‘ Both schools
experienced an epidemic of Group A,
M-type 2, T-type 2 in October 1969. The
Sangre Dc Cristo School District includes
the elementary school
(
K through 6) inHooper and the junior-senior high school
(
7 through 12)
in Mosca. The children areand a substantial number are of
Spanish-American descent. Total enrollment is
ap-proximately 250 students divided almost
equally between lower and upper grades. Data collected from several other Cob-rado communities were used for compara-tive purposes. Weekly or biweekly throat
cultures had been collected from a random-ized sample of school children in Colorado
Springs, Frisco, and Loveland from 1964 to
1966 for the purpose of establishing base-line Group A prevalence rates. In addition, a
consolidated school, Sierra Grande
(
Kthrough 12
)
,
Blanca, Colorado, was used asa direct control. This school, with 275 stu-dents, is also located in the San Luis Valley; the ethnic composition of the student body is similar to the Mosca-Hooper populations. Throat cultures were obtained from a
ran-domized selection of one-half the student body on each of two occasions in the spring of 1970.
Education
Explanations of the project were first
given to the local Medical Society. Upon
re-ceipt of their cooperation, a letter describ-ing our objectives was sent to all parents in the school district. Then several meetings of
parents, teachers, and pupils were held to
further explain the program and to outline
and stress tile potential dangers of
un-treated streptococcal disease.
Approxi-mately 94 family units were associated with
the two schools. A minimum of 70% of the
parents attended one of two evening
ses-sions held. This rate of attendance was
known, since clinical specimens were
ob-tamed from the adults at these meetings. These persons had agreed to participate in other aspects of our investigations not de-scribed in this report. The high level of pa-rental cooperation can probably be attrib-uted to the fact that most of the parents in
the San Luis Valley have a heightened
awareness of the “strep throat” problem
due to past experience. One of us (B.B.)
also made several personal contacts with
parents liable to back understanding due to
communication problems. Finally, at the
TABLE I
GROUP A PREVALENCE 1tATES IN TIlE MOSCA AND IIOOPER Seiioois
Number Nu nber Number Percent Date Cultured Beta’s GrOUJ) A Group .4
1O/3O69* 50 - 58 23.Z
11/10* 36 - ‘27 11.4
11/Is 252 8 23 9.1
1/6/70 ‘218 ‘2’2 18 8.3
1/1’2 69 4 3 4.3
1/19 39 4 2 5.1
1’6 58 ‘2 3.4
/‘2 46 1
sI’9 63 4 3.2
2it; 53 10 6 11.3
/‘23 49 2 4.1
3/”2 .51 6 Z 3.9
3/9 45 (; 4.4
3/16 47 2 ‘2 4.3
3/23 38 3
C2
.5.33/30 43 6 4 9.3
46 46 3 3 6.5
4/13 51 i 0 0.0
4/0 41 3 2 4.9
4/7 48 1 0 0.0
5/11 26 8 3 1.3
‘fotil from
1/6/70 l,23l 90 56 4.5
*Data provided by Dr. C. David McGuire, 1)ireetor
of Laboratories, Colorado State Department of Public
Health.
end of the school year, all parents received material describing the results obtained and
expressing appreciation for their help.
Surveillance and Specimen Collection
At the beginning of each school day,
teachers asked the students if anyone had a sore throat. Throat cultures were obtained by the school nurse at Mosca and a trained lay person at looper from all children re-plying affirmatively. Swabs were collected
even in the absence of signs of pharyngitis. At the end of each week, a preselected
ran-dom sample of approximately 10% of both
school populations was cultured whether symptomatic or not. These random samples divided into 10 lists of students (100% of
schedule insured that every student would
be cultured at least twice during the
re-mainder of the school year. New admissions to the student body were cultured during
the first week in attendance and then
placed on one of the 10 random lists. No
child was cultured more than once in any
particular week. Swabs, upon collection, were placed in tubes containing 5 gm of
sib-ica gel and forwarded to the laboratories of the Streptococcal Disease Section, Center
for Disease Control, Fort Collins, Colorado,
by special delivery mail each Friday
after-noon. All children in attendance at the
schools were cultured by personnel from
the Streptococcal Disease Section at the be-ginning of surveillance and at the close of the school year.
Fifteen cubic centimeters of blood
speci-mens were collected from over 92% of the
students at least twice during the surveil-lance period for the purpose of antibody ti-tration.
Voluntary Treatment
When a child was found to be positive
for Group A, a notice was sent home to the parent advising consultation with a private
physician. A form was provided at the bot-torn of the notice with which the parent
could advise the school nurse of the date of
physician consultation and whether or not
treatment was administered. Children
posi-tive for groups other than Group A were
not notified.
Laboratory
Specimens were received and processed by the Fort Collins Laboratories by proce-dares described e1sewhere.1 Group A posi-tive results were telephoned to the schools within 9 days of the date of swab collection.
Group A precipitating and type-specific hemagglutinating antibodies were titrated in all sera. The latter procedure has been previously described.14
TABLE 11*
CoIPAItisoN OF C0IIIICNITY EXPERIENCE WITH VARIOUS Gaou A SEROTYPES BASED ON SERUM ANTIBODY TITERS
,
A Type 1 Type 2 ,
lype 5 Type b Type 9
, ‘
lype 1 GroupPercent A Abwith t
Colorado Springs,
Colorado
%w/l60titer 11 30.0 ND 34.0 5.0 43.7 30.0 4.9
CMT 57 30 <10 36 87
Frisco, Colorado
%w/l6otiter 96 57.0 ND c25.0 15.0 46.2 40.0 51.2
GMT 101 24 <10 36 47
Loveland, Colorado
%w/l6otiter 127 55.0 ND 23.0 3.0 46.9 60.0 48.4
(;MT 156 18 <10 30 102
Losca and Ilooper,
Colorado
%w/l60titer 211 18.3 46.3 l.4 ND 79.7 64.7 67.1
GMT 18 77 15 414 134
*‘ftkeri in part from Phibbs, et al)#{176}
tDetermined by immunodiffusion. This antibody is directed against the Group A does hot play a role in active immunity, but is merely an index of previous experience.
Geometric mean titer.
ND=Not done.
OCT NOV z
>
a,
Fic. 1. Comparison of Group A prevalence in Mosca-Hooper (M-ll),
1969-70, with rates in Colorado Springs, Frisco, and Loveland (CS, F, L). The vertical lines represent minimum and maximum prevalence rates observed.
RESULTS
Table I provides Group A prevalence
rates in the Mosca-Hooper schools begin-fling with the mass culturing in October 1969 slightly after the estimated peak of the
suspected epidemic and terminating with
the mass culturing toward the end of the
school year. The sharp reduction in
preva-bence from 23.2% to 8.3% at the start of
daily surveillance can be attributed to the fact that most of the children were cultured four times during the 9-week period. More than 90% of the positive children, most of whom carried the epidemic strain, received
adequate therapy. Therefore, this 8.3%
probably represents an artificially bower
baseline than one should expect in
Cob-rado school children. The baseline can be
seen in Figure 1 where the Mosca-Hooper
experience is compared to average Group A
prevalence rates in untreated school chil-dren residing in three other Colorado com-munities. Nevertheless, this lowered
base-line was only exceeded during 2 of the 18
weeks of daily surveillance. The 56 Group A’s isolated were distributed among 25 pu-pus. If one does not consider the 21 Group
A isolates identified during the two mass
culturings on January 6 and May 11, 1970,
35 isolations remain. Of these, 17 were re-covered from children admitting sore throat
and 18 cultured from the random lists of
children who were mostly asymptomatic.
Of the 56 Group A isolates, 95% were
T-typeabbe and only 4% M-typeabbe.
The 1,231 throat cultures collected pro-vide an average of five per child. In reality,
more than 30% of the students had more
than five, with every child having at least three cultures and many pupils having 10.
As previously noted, Figure 1 compares
the several Colorado communities with
maximum and minimum rates observed
during the 3-year period. These rates
ranged from 32.7% to 15.3%, with an
over-all average of 21.9%. The Colorado rates
are comparable to those described by other investigators who studied school popula-lions in three widely separated geographic
areas of the U.S.1517 These values may be
compared with the Mosca-Hooper average
of4.5% (Table I).
Half of the student body of Sierra
Grande, the “control” school, was cultured
March 23, 1970, and the remainder May 11,
1970. Group A prevalence was 8.2% and
12.3% respectively. These rates were
Hooper during the same weeks. All positive
children were treated at a nearby clinic.
Community experience with various
Group A serotypes can be compared
retro-spectiveby by determining percentages of
students with significant amounts of serum
type-specific antibodies. Table II provides
these values and shows that the
Mosca-Hooper children, while having less
experi-ence with Group A, M-type 1, have had
considerably more exposure to Types 9 and
12. These latter types may have occurred
in epidemic proportions as suggested by the
high titers shown by a majority of the pop-ubation. \Ve k-now that a Type 12 epidemic
occurred in Loveland in 1964 to 1965 and a
potential Type 9 epidemic was aborted in
Frisco with extensive therapy in 1965 to
1966.
All 25 positive children identified at
Mosca and Hooper received therapy,
ab-though five isolates were obtained from one
boy before treatment was instituted. One
instance of treatment failure was noted
de-spite tile student receiving apparently
ade-quate therapy on two occasions. This girl
was positive four times before the organism
was finally eradicated.
No cases of nonsuppurative sequelae
oc-ciirred after surveillance commenced.
DISCUSSION
Although the operation in the
Mosca-Hooper schools was patterned after the suc-cessful Casper, Wyoming surveillance pro-gram, there were some essential differences.
Education of both the bay and
profes-sional residents of Natrona County,
Wyo-ming has been intensively undertaken
through mass communications media for
more than 12 years. This has resulted in an
unusually knowledgeable population as
re-gards streptococcal disease and has
encour-aged widespread support. Our education
efforts consisted of a few meetings and a
letter describing the program.
Streptococcal diseases are excludable by
law in Wyoming. Therefore, every Natrona
County child found to be Group A positive
is removed from school and not readmitted without a phsyician’s statement verifying treatment or a negative throat culture. In
our study, positive children were taken to a physician voluntarily.
Every child in the Natrona County
school system is examined physically once each week for signs and symptoms of
phar-yngitis. Thus, all symptomatic children are
cultured. In our protocol, aside from chil-dren admitting sore throat, only a small
pre-selected random sample
(
10%) arecul-tured each week on a continuous rotation
basis. The importance of culturing these
random samples is demonstrated by the fact that one-half of all of the Group A isolates
were recovered from this group.
The rationale for the two mass culturing programs by personnel of the Streptococcal
Disease Section was to determine if the
protocol described would accurately esti-mate the true prevalence in the schools. We believe that the culturing of children with sore throat plus the small random sample provides a sufficiently accurate estimate of Group A incidence
(
Table I).The presence of significant levels of
type-specific antibodies against several Group A
serotypes indicates that the Mosca-Hooper
children have had at least as much if not
more exposure to Group A streptococci as
children living in other Colorado
com-munities. A comparison of overall average prevalence rates suggests the surveillance
program succeeded in reducing Group A
experience by fivefold
(
Fig. 1)
. Therefore,we believe that the objective of reducing
Group A prevalence below 5% and
sub-stantially reducing risk of rheumatic fever and gbomerubonephritis is both practical and attainable. In addition, this type of pro-gram virtually eliminates risk of
streptococ-cal respiratory epidemics occurring in the population under surveillance.
It should be emphasized that the M and
T typing of Group A streptococci and
de-termination of antibody profiles are not
strepto-ARTICLES
coccal infections. These tools were
em-pboyed in this study for their
epidemiologi-cal value and to provide information
enabling the reader to compare the study
schools with streptococcal experience in
other communities.
The cost of operating a program such as
the one described in this report will, of
course, vary with the locale. However, if
one considers that the persons collecting the clinical material in the schools are ei-ther volunteers or on a payroll for other ser-vices and that the cost of treatment is han-died on a personal family basis, the major expenditure is for laboratory processing. These costs will vary depending upon babo-ratory volume, techniques, and efficiency. In four public health laboratories in the
States of Colorado and Wyoming, estimated costs per culture for streptococcal identifi-cation through a grouping procedure range from $0.20 to $0 95 18
SUMMARY
Relatively few attempts have been made,
aside from the Natrona County, Wyoming
project, to control streptococcal infections in high risk population groups. These projects
have been of complex design and have
re-quired considerable expenditures of effort.
A simple surveillance procedure, employing
use of lay personnel, was applied to two
school populations in an area of Colorado noted to be highly endemic for streptococ-cal infections and nonsuppurative sequelae, particularly rheumatic fever. Type-specific
antibody profiles of the students indicated extensive previous streptococcal experience.
As a result of the project, Group A preva-lence was reduced below 5%, representing more than a fourfold decrease in average rates observed in other Colorado
communi-ties in which such a program was not
at-tempted.
Although less sophisticated than the
Wy-oming program, the protocol described in
this report demonstrates that interested and
cooperative children, parents, school
offi-cials, and physicians can achieve the
desir-able goal of substantial reduction of
strep-tococcal infections in the community.
REFERENCES
1. Rammelkamp, C. H., Denny, F. W., and
Wan-namaker, L. W. : Studies on Epidemiology of
Rheumatic Fever in Armed Services.
Mm-neapolis : University of Minnesota Press,
1952.
2. Frank, P. F., Stollerman, G. H., and Miller,
L. F. : Protection of a military population from rheumatic fever. J.A.M.A., 193:775,
1965.
3. Kilton, R. M., and Zimmerman, R. A. :
Strepto-coccal prevalence in cadets. Rocky
Moun-tam Med. J., 65:36, 1968.
4. Farber, R. E., and Korif, F. A. : Foodborne epi-dernic of group A beta-hemolytic
streptococ-cus. Public Health Rep., 73:203, 1958.
5. Commission on Acute Respiratory Diseases:
Study of food-borne epidemic of tonsillitis and pharyngitis due to B-hemolytic
strepto-coccus, Type 5. Bull. Hopkins Hosp., 77:
143, 1945.
6. Hill, H. R., Zimmerman, R. A., Reid, C. V. K.,
Wilson, E., and Kilton, R. NI. : Food-borne
epidemic of streptococcal pharyngitis at the
United States Air Force Academy. New
Eng. J. Med., 280:917, 1969.
7. Bunn, W. H., and Bennett, H. : Community
control of rheumatic fever. J.A.M.A., 157:
986, 1955.
8. Phibbs, B. P., Becker, D., Lowe, C. R., Holmes,
R., Fowler, R., Scott, 0. K., Roberts, K., Watson, \V., and Malott, R.: The Casper
project: An enforced mass culture
strepto-coccal control program. J.A.M.A., 166:1113,
1958.
9. Cornfield, D., \Verner, C., Weaver, R.,
Bel-lows, M. T., and Hubbard, J. P.:
Strepto-coccal infection in a school population: pre-liminary report. Ann. Intern. Med., 49:1305, 1958.
10. Phibbs, B. P., Taylor, J., and Zimmerman, R. A. : An evaluation of a community-wide streptococcal control project. The Natrona
County Primar’ Prevention Program,
Casper, Woming. J.A.M.A., 214:2018,
1970.
11. Morton, W. E., and Lichty, J. A.: Rheumatic
heart disease epidemiology: II. Colorado’s high-risk low-socioeconomic region in 1960. Amer. J. Epidemiol., 92:113, 1970.
12. Morton, W. E., Warner, A. L., Weil, J. V.,
Shmock, C. L., Snyder, J., and Lichtz, J. A.:
THE ART OF TORMENTING CHILDREN ACCORDING TO
MISS JANE COLLIER WRITING IN 1804
13. Wilson, E., Zimmerman, R. A., and Moody,
M. D. : Value of T-agglutination typing of
group A streptococci in epidemiologic inves-tigations. Health Lab. Sci., 5:199, 1968. 14. Zimmerman, R. A., Mathews, J., and Wilson,
E.: Microtiter indirect hemagglutination
procedure for identification of streptococcal M-protein antibodies. Appl. Microbiol., 16: 1640, 1968.
15. Nicholas, W. E.,and Steele, C. P.:Occurrence
of groupable beta hemolytic streptococci.
J.A.M.A., 181:197, 1962.
16. Cornfeld, D., and Hubbard, J. P.: A four-year
study of the occurrence of beta hemolytic
streptococci in 64 school children. New Eng.
J. Med., 264:211, 1961.
17. Quinn, R. W.: Carrier rates for hemolytic
streptococci in school children. Amer. J.
Ep-idemiol., 82:1, 1965. 18. Personal communications.
Few women in English literature have dis-tinguished themselves as satirists. But Miss
J ane Collier, who is little known even to
au-thorities on the history of English satire, could at times rise to Swiftian irony. An example of how to torment children from her little-known
book entitled “An Essay on the Art of
Ingeni-ously Tormenting” follows:
. . . That you pursue the method called
IN-DULGENCE, which I have already marked out.
This will infallibly make them miserable while
infants; as common experience must shew ( sic)
you, that no children are so fretful, peevish, and
uneasy, as those who are so indulged. And although
you may, by this means, breed up a parcel of
head-strong, hard-hearted cubs, who, when old
enough, will defy your power; yet you may, in the
mean time, amuse yourself with your servants,
your acquaintance, and your friends, who may
chance to be more fitted by nature, or education,
for your purpose. You may go out of the world,
also, with the pleasing reflection, that you have left
behind you a set of wolves, cats, and foxes, of
your own educating; who will help to plague and
torment all the rest of mankind.
NOTED BY T. E. C., Jn., M.D.
REFERENCE
1. Collier, P.: An Essay on the Art of Ingeniously Tormenting; with Proper Rules for the
Exer-cise of that Amusing Study. London: Andrew
