• No results found

PUBLIC HEALTH

N/A
N/A
Protected

Academic year: 2020

Share "PUBLIC HEALTH"

Copied!
8
0
0

Loading.... (view fulltext now)

Full text

(1)

PUBLIC HEALTH

THE

EPIDEMIOLOGY

AND

INVESTIGATION

OF

HOSPITAL-ACQUIRED

STAPHYLOCOCCAL

DISEASE

IN

NEWBORN

INFANTS

Andrew C. Fleck, Jr., M.D., M.P.H., and Jerome 0. Klein, M.D.

Department of Health, State of New York

I)r. Fleck is Epidemiologist, New York State Department of Health.

I)r. Klein is Epidemic Intelligence Officer, Communicable Disease Center, Public health Service, United States l)epartment of Health, Education and \Velfare (assigned to the New york State

Depart-inent of Health).

ADDRESS: (A.C.F.) 84 Holland Avenue, Albany 8, New York.

CONTRIBUTOR’S

SECTION

1102

PEnIAr1IIcs, I)ecembcr 1959

T

HE PROBLEM of hospital-acquired

staph-ylococeal disease presents singular

fea-tures to the epidemiologist. The parasite can be demonstrated to be widely dispersed in the hospital environment, but produces clinical disease in only certain classes of patients, such as infants, nursing mothers and debilitated. Rogers’ explained this

phe-nomenon when he stated that “major

altera-tions in local and systemic resistance are necessary before staphylococci can invade and actively multiply within human tis-sues.” Since the true determinate of the

disease event is the host susceptibility and

IlOt the presence of the pathogen, the actual presence of one of the various possible

staphylococcal sources and routes of

trans-mission may or may not cause an epidemic,

depending on the class of susceptibles cx-posed. Newborn infants constitute only one

d)f these classes. The newborn infant has a

susceptibility to staphylocoecal disease epi-demiologically manifested by lesions of the

skin and breast. Post partum, mothers have a local susceptibility of the breast tissue. Patients with influenza have a susceptible respiratory tract. As a consequence, the

epi-demiology of staphyloeoeeal disease of the newborn infant probably differs from the epidemiology of staphylococeal disease in otiler classes of suseeptibles.

The present discussion is limited to the

epidemiology of disease in newborn infants.

Tile material is drawn from investigation of

nursery outbreaks in New York State and

a review of the literature.

CLINICAL MANIFESTATIONS

The development of any stapilylococeal lesion in a newborn infant is potentially

dangerous. Trivial disease is sometimes

fol-lowed by chronic furunculosis, staphylococ-cal pneumonia, septicemia or death.

The early lesions in infants affect the su-perficial layers of the skin. They consist of small vesicles or pustules surrounded with

a small zone of erythema, and appear most

commonly on the face, buttocks and

inter-triginous areas. Vesicular, crusting,

puru-lent or bullous manifestations of impetigo are also common. Purulent conjunctivitis

has been prominently reported in the

Eng-lish literature. These minor superficial

le-sions most commonly appear on tile third

or fourth day of life (Table I).

The major manifestations are: subeuta-neous abscesses, breast abscesses, pneu-monia and the metastatie lesions of

septi-cemia. Major disease will usually be present in 15% of the total cases in an outbreak of

staphylococcal infection. The onset of sub-cutaneous abscesses has been observed as

early as the third day of life and as late as

(2)

TABLE I

INCUBATION PEluoDs OF PUSTULES, IMPETiGO AND

CoNJuNc-rIvITIs IN NEWBORN INFANTS IN Six

OUTBREAKS IN NURSERIES IN NEW YORK STATE

Interval from Birth

to Onset

(days)

Cases

Number Per Cent of Total

0-I si-s 4-5 6-7 8-9 10-11 H-IS OvenS 1 40 37 Fl 4 2 I 8 1.0 38.0 35.0 11.5 3.9 2.0 1.0 7.6

Total 105 100.0

of 5 days to as long as 2 months. In general, infants with major forms of staphylococcal

disease have previously had minor

manifes-tations, such as pustules or impetigo of the skin.

The frequency of occurrence of major

and minor disease manifestations under epidemic conditions is shown in Table II.2h1

SOURCES OF INFECTION

The primary goal of epidemiologic

inves-tigation is identification of the causative

source of staphylococci and the most

prob-able route of transmission to the suscepti-ble host. In order to reach this goal, the

epi-demiologist must study the distribution of disease in the population and not the distri-bution of the bacteria. This concept is often ignored in the literature. Staphylococcal

disease in the infant is a reaction between a specific microorganism and the human host. Studies which consider only the reactions of the host without disease, such as coloni-zation, do not add much to our knowledge

of the epidemiology of staphylococcal

dis-ease. Such studies are essentially baeterio-logic; they are not epidemiologic. In addi-tion to the discovery of a possible source of

staphylococci, it must also be siiovn, at least indirectly, that the source is actually involved in production of disease.

The most commonly demonstrated source of staphylococci is the clinically infected individual, which in the parlance of epi-demiologists is a clinical case as opposed to a healthy carrier. This is most often found

in personnel who have frequent intimate contact with a sizable group of infants. Minor lesions are overlooked many times and may remain unsuspected as a source of an outbreak. In one instance9 a nursery nurse with chronic suppurative sinusitis, pyroderma and furunculosis was

over-looked as a common source for an outbreak

TABLE II

FREQUENCY OF OCCURRENCE OF MINOR AND SEVERE TYPES OF STAPRYLOCOCCAL SEPSIS IN OUTBREAKS

IN Fouit UPSTATE NEW YORK NURSERIES COMPARED TO TEN NURSERY

Our-BREAKS REPORTED IN THE LITERATURE

Type uf ep.ci.

Minor:

Pyoderna

Conjunctivitiu Omphalitis

New York Stale Reported in the Literature

Nurseries

.4 B C D

Total % of Total Reference Number Total % of Total (I) (5) -(4) (5) -(6)

-(7) (5) (9) (10) -(ii) 18 I 53 4 35 -31 -104 5 6 73.0 4.0 5.0 18 -36 -Q 17 64 93 51 21 & -51 I 101 -31 .51 1 I 389 133 I 63.0 1.0 0.3 Severe: Abscess Breast abscess O,teitis

Pneumonia and/or septicemia

-I 4 7 -5 -S -6 I 3 3.0 8.0 ‘t.0 5 -8 3 -6 -7 3 S -S I I 3 -1 35 Q0 1 13 6.0 3.0 0.3 .0

Unclassified I 1 - - 1.0 - - - - 10 - - 16 - - Q6 4.0

(3)

for a period of 3 months. Other

investiga-tors ilave similarly ideiltified a clinically’ ttI)parent lesion, often minor in nature, as tile emmon SOIlC( of an outbreak in a

nursery.”

A thorough dild painstaking effort should be made to eliminate tile possibility that a lesion in tile IlurSery personnel may be tile common cause of tile outbreak. A clinical history and a physical examination should l)e obtained for all persons who have

inti-mate contact with all or most of tile infants

IITI One or more nurseries. The most suspect are tilose persons who are in contact, by

virtue of their work, with all infants within

a nursery tllrotigil tile dressing and feeding

of tile infants. Other persons who are in contact VitIl till infants in the nursery but do not feed or clothe infants are less sus-pect.

‘With consideration given to the degree

of intimacy of various groups one can set

up priorities in tile search for a common

source of lesions or carriers. Persons with

limited contact with only a few infants are less probable suspects as sources. However,

tiley may’ serve as sources for introducing

staphylococci.

Staphylococci \Vilich originate from a

Ic-5iOfl as a source, may be spread by direct contact as in kissing or touching the lesion. Indirect contact is also possible where the infective lesions contaminate hands, toys,

surgical instruments or other material ob-jects which ill turn convey tile organisms to

the patient. Direct contact by droplet

trans-mission may also occur by projection through coughing or sneezing.

In addition to tile source lesion, the nursery infants may be maintaining an in-troduced epidemic strain in the nares or throat. The older infants apparently serve

as a source of stapilylococci for new

admis-5iOIl5. The mecilanisnl ‘hereby the new

ar-rivals are infected is not clearly described.

Such a reservoir is usually demonstrated to be I)resent where tilere is a maximum op-portunity for contact transmission as a re-stilt of overcrowding of the nursery and absence of proper handwashing by

person-nd.7’ 8, 11, 17 In this type of situation fllost of tile infants present in tile nursery will be

nasal carriers of the epidemic strain.

Con-comitantly, nursery personnel nay sllO\’

absence, or a minimal level, of nasal car-riage of the epidemic strain.

In one outbreak in New York State’TM the removal of an infant reservoir of

staphy-lococci was accomplished by treatment of

tile infants with nasally applied topical an-tibiotics for a week. The outbreak termi-nated abruptly. The inference was strong

tilat the outbreak was being perpetuated by

a nasal reservoir of staphylococci in an

in-fant. In another outbreak, 55% of the infants were found to be nasal carriers. Tile re-moval of tile reservoir of infection by this same method reduced but did not

termi-nate tile outbreak. This suggests that even though a reservoir in the infants is demon-strated, it may not be a sole operating

cause of an outbreak. Nasal carriage in the infants may only be a reflection of the

dis-ease that is occurring in the environment. In addition to the healthy infant carrier, personnel carriers are potential sources of

staphylococci. During the investigation of outbreaks in Upstate New York, a total of

217 nursery personnel who were in contact with all infants in the affected nurseries had nasal cultures taken. Seventeen (8%) were found to be carriers of the type 80/81 epidemic strain. In almost all instances

tilese carriers vere recent employees who were not present in the nursery at the time

tile outbreak started. This observation sug-gests that personnel carriers of the epi-demic strain may be victims rather than causes of epidemics. Similar findings have been reported Wilicil seem to support this

tileory.” The incrimination of personnel carriers as sole effective sources for nursery

outbreaks or for nasal colonization of

in-fants is not supported by all the available evidence.

Fekety et al.i believed that the removal of personnel carriers controlled an

out-break. However, they also instituted

(4)

Rountree et al.bo reported an outbreak

wherein the phage types isolated from le-sions in the infants and from the nares of healthy personnel were tile same. Nasal

treatnlent of the personnel carriers with

antibiotics was followed by a reduction in

the attack rate. Other factors, such as

over-crowding and identification and treatment of lesions among personnel, may Ilave played dominant roles.

A fourth hypothetical source of

epidemic-strain staphylococci is the umbilicus.20

Some authorities have recommended tilat precautionary measures, such as tile

paint-ing of the umbilical stump with antiseptic

dyes, i)e adopted. This procedure does

re-duce the rate at which newborn infants

are colonized with staphylococci, but there

has been no demonstration that this has an

influence on tile attack rate of disease in tile infants. Evidence against tile umbilicus

as a source of infection has been described by Fairchild et al.,21 who found a 30% rate

of umbilical colonization with type 80/81 staphylococci. In a 1-month follow-up of a group of 144 infants, they failed to find any clinical evidence of stapilylococeal disease.

On tile basis of bacteriologic surveys, a

wide variety of fomites Ilave been

sug-gested as sources. Technically such items

are depots and not true sources. Their

staphylocoecal content must be eontinu-ously replenished from iluman sources.

However the literature leaves the reader with the impression that any place or object

sllOWfl to ilarbor staphylococci must nec-essarily be a route by which they spread to

patients.2224 Such bacteriologic evidence does not establisil l fomite as an effective

source. A fomite can only be incriminated 1)y tile epidemiologic demonstration that a

higher incidence of disease occurs among infants in contact \Vltll the fomite than in

infants \VllO have no contact with the

fo-mite. On tile basis of nursery experience,

the evidence available does not support

fomites as an effective source of staphy-lococci capable of producing outbreaks.

The only instance in which we have been able to epidemiologically incriminate a

fo-mite, was in an outbreak caused by

con-taminated circumcision sets. This outbreak

was essentially surgical.

There is a parallel hypothesis that

pro-ioses a multiplicity of contaminated

fo-mites coming into contact with susceptible

infants to produce epidemics. In the

out-i)reaks in New York State in the larger 1105-pitals with more than one nursery unit, we

found tilat tile disease differs significantly

in the way it affects one nursery unit as

compared to another. This is more consist-ent with a lesion or carrier as the source than multiple fomites as sources, \vilich are usually common to all nurseries.

Finally, another Ilypothetical source of

staphylococci is tile air. The increasing in-terest in air as a source has resulted in a large body of scientific literature dealing

with problems of air-sampling, air-condi-tioning, laundry chutes and contamination

of air. As in tile ease with fomites, the dem-onstration of the presence of pathogens in

tile air does not incriminate tile air as an effective source. It must be shown that the distribution of disease in the population at risk follows tile distribution of the air

sup-plies.

MeLeod has noted:25 “Unless it is shown

otherwise, it would appear reasonable to

consider tilat when bacteria in the dried

state are present as general contaminants of

the environment this may have no more significance than as a reflection of the fact that disease caused by them is taking place

in tile environment. It should not be as-sumed that these dried environmental

de-posits have a significant part to play in the spread.”

In two nursery outbreaks in Upstate New York it was possible to demonstrate whether

or not an air source was operative. In one

outbreak in which two nurseries were equally affected, the air-borne route of transmission was eliminated Ofl the basis

that the two nurseries received separate air suI)1)lies. In tile Otiler instance, tile air

sup-ply was common to two Ilurseries but only

one nursery had a significant rate of disease.

(5)

transmission in the form of dust and droplet nuclei, but it is limited to cases from burn

dressing-rooms and surgical arenas,

per-haps because a more susceptible portal of entry is present in such cases.

INVESTIGATION OF OUTBREAKS

The epidemiologic method requires that

each infant in the population at risk be

fol-lowed for at least 15 days after birth and be classified either as a case or as a non-ease

of staphylococcal disease. Such a elassifica-tion of the infants at risk should be based on definite clinical criteria of infection

es-tablished a priori. Bacteriologic evidence

should only be used to confirm the clinical

diagnosis. In the investigation one must be

as certain of the absence of disease for a non-ease diagnosis as he is of the presence of disease in a case. The proportion of the group which is ill defines the problem.2#{176}

The development and proper use of van-ous specific attack rates enables one to

de-velop inferential evidence for or against the

various hypothetical sources and routes of

transmission. Rational control efforts are based on such evidence.

Any observed association between higher attack rates and personal factors on envi-ronmental or chronologic factors will pro-vide guidance to the most fruitful areas for

investigation. Conversely, the absence of such associations will eliminate certain lines of inquiry as being unimportant. A few of the factors which should be explored are: the proportion of infants diseased in each

nursery, time relations of onset of

individ-ual cases, common contacts of infants with procedures such as circumcision on persons with lesions or known carriers of the

epi-demic strain.

A search should be made for lesions in personnel as a source. A clinical history and physical examination, with particular atten-tion to the skin and respiratory system,

should be obtained for personnel in contact with the infants.

A bacteriologic and phage-typing identi-fication of all isolates from lesions in infants

and personnel will identify a common

epi-demic strain, if it is present. With proper

application of the epidemiologic method,

the source and route of transmission can be

identified. The most probable diagnosis

serves as the guide for definitive control.

Control by application of measures

sug-gested by epidemiologic findings does not reduce the desirability of general measures,

such as the improvement of hygiene, review and correction of aseptic procedures, and housekeeping practices. These measures

minimize the opportunities for direct and indirect transmission of many diseases. However, the termination of an outbreak

can be promptly achieved if the source and

means of transmission of the causative strain are known.

SUMMARY AND CONCLUSIONS

On the basis of present knowledge, the various sources and accompanying

path-ways by which effective contacts between susceptible infants and the staphylococcus take place in the nursery outbreaks are as

follows: 1) Direct contact with infective Ic-sions; 2) direct and indirect contact spread from the asymptomatic infant carrier to the susceptible infant within the nursery, par-ticularly under conditions of overcrowding

and poor nursery technique.

Personnel carriers, fomites and air-borne

droplet nuclei and dust, as sources of out-breaks, do not command a body of eon-vincing epidemiologic evidence at this time.

The epidemiologic investigation of

cry-acquired disease requires that each

in-fant at risk be followed for a minimum of

15 days. The most probable source and

route of transmission of the causative or-ganism can be identified. Control efforts should be based on the epidemiologic diag-nosis.

REFERENCES

1. Rogers, D. E. : The current problem of

staphylococcal infection. Ann. Int. Med.,

45:748, 1956.

2. Clarke, A.

J.

R., et al.: Neonatal infection of the skin by Staphylococcus pyogenes.

M.

J.

Australia, 43:655, 1956.

(6)

out-break of staphylococcal infections among mothers and infants in a sub-urban hospital. Am.

J.

Pub. Health, 48:

298, 1958.

4. Gillespie, W. A., Pope, R. C., and

Simp-son, K. : Pemphigus neonatorum caused

by Staphylococcus aureus type 71. Brit.

M.J., 1:1044, 1957.

5. Hutchison,

J.

G., and Bowman, W. D.: Staphylococcal epidemiology in a

ma-ternity hospital. Acta paediat., 46:125,

1957.

6. Monro, J. A., and Markham, N. P. :

Staphy-lococcal infection in mothers and

in-fants. Lancet, 2: 186, 1958.

7. Ravenholt, R. T., et al.: Epidemiology and

prevention of nursery-derived staphy-lococeal disease. New England

J.

Med.,

257:789, 1957.

8. Murray, W. A., et a!.: Evaluation of a phone survey in an outbreak of

staphy-lococcal infection in a hospital nursery

for the newborn. Am.

J.

Pub. Health, 48:310, 1958.

9. Smith, R. T. : The role of a chronic carrier in an epidemic of staphylococcal disease in a newborn nursery. A.M.A.

J.

Dis. Child., 95:461, 1957.

10. Timburv, M. C., et al.: A staphylococcus type 80 epidemic in a materity hospital. Lancet, 2:1081, 1958.

1 1. Wysham, D. N., et al.: Staphylococcal in-fections in an obstetric unit. New Eng-land

J.

Med., 257:292, 1957.

12. Poole, W. H., and Whittle, C. H. :

Epi-demic pemphigus on the newly born.

Lancet, 1:1323, 1935.

13. Elliott, S. D., Gillespie, E. H., and Hol-land, E. : An outbreak of pemphigus neonatorum in a maternity home. Lan-cet, 1:169, 1941.

14. Hobbs, B. : Epidemic staphvlococeal in-fections ill nursing homes. Great Britain

Pub. Health Lab. Service Month. Bull., 3:11, 1944.

15. Williams, G. C., Sims-Roberts, C., and

Cook, C. T. : Notes on an outbreak of

pemphigus neonatorum in a private

nursing home. Great Britain Pub. Health

Lab. Service Month. Bull., 6: 13, 1947. 16. Knott, F. A., and Blaildey,

J.

B. : The control of Staphylococcus aureus

infec-tions in a maternity department.

J.

Obst.

& Gynaec. Brit. Emp., 51:386, 1944.

17. Shaeffer,

J.

E., et al.: Staphylococcal

infec-tions in newborn infants. I. Study of an

epidemic among infants and nursing

mothers. PEDIATRICS, 18:750, 1956.

18. Klein,

J.,

and Rogers, E. : Use of a nasal

antibiotic cream during a nursery

out-break of staphylococcal disease. New

England

J.

Med., 260:1012, 1959.

19. Rountree, P., et a!.: Control of

staphylo-coceal infection of the newborn by

treatment of nasal carriers in the staff. M. J. Australia, 43:528, 1956.

20. Jellard,

J.

: Umbilical cord as reservoir of infection in a maternity hospital. Brit.

M.J., 1:925, 1957.

21. Fairchild, J. P., et al.: Flora of the

umbili-cal stump.

J.

Pediat., 53:538, 1958. 22. Hurst, V., et al.: Hospital laundry and

refuse chutes as sources of

staphylococ-cic cross-infection. J.A.M.A., 167:1223,

1958.

23. Walter, C. W., et al.: Bacteriology of the

bedside carafe. New England

J.

Med., 259:1198, 1958.

4. Ravenholt, 0. H., et a!.: Eliminating blankets as an infection source. Hos-pitals, 32:75, 1958.

25. Dubos, R., ed. : Bacterial and Mvcotic In-fections of Man, 3rd Ed. Philadelphia,

Lippincott, 1958, p. 100.

26. New York State Joint Committee on

Staphv-lococeal Infections : Control of Staphy-lococcal Infections in Hospitals. Albany,

(7)

1959;24;1102

Pediatrics

Andrew C. Fleck, Jr. and Jerome O. Klein

INFANTS

HOSPITALACQUIRED STAPHYLOCOCCAL DISEASE IN NEWBORN

PUBLIC HEALTH: THE EPIDEMIOLOGY AND INVESTIGATION OF

Services

Updated Information &

http://pediatrics.aappublications.org/content/24/6/1102

including high resolution figures, can be found at:

Permissions & Licensing

http://www.aappublications.org/site/misc/Permissions.xhtml

entirety can be found online at:

Information about reproducing this article in parts (figures, tables) or in its

Reprints

http://www.aappublications.org/site/misc/reprints.xhtml

(8)

1959;24;1102

Pediatrics

Andrew C. Fleck, Jr. and Jerome O. Klein

INFANTS

HOSPITALACQUIRED STAPHYLOCOCCAL DISEASE IN NEWBORN

PUBLIC HEALTH: THE EPIDEMIOLOGY AND INVESTIGATION OF

http://pediatrics.aappublications.org/content/24/6/1102

the World Wide Web at:

The online version of this article, along with updated information and services, is located on

American Academy of Pediatrics. All rights reserved. Print ISSN: 1073-0397.

References

Related documents

The approach proposed in the present study applies Restricted Boltzmann Machines (RBM), Echo State Networks (ESN) and fuzzy classification for predicting potential

The Spatial Data Transfer Standard (SDTS) was developed to allow the transfer of digital spatial data sets between spatial data software. The Content Standard for Digital

The translocation of elk (Cervus elaphus) to Fort Riley Military Installation restored a component of the tallgrass prairie fauna that had been absent for over a century.

This paper documents the existence and main patterns of inter-industry wage differentials across a large number of industries for 8 EU countries (Belgium, Germany, Greece,

However, the level of specialization for particular plant species differed among fungal groups, root-associated endophytic fungal communities being highly specialized on

After all, participation rights increase with employment size not only with respect to number of (unpaid and full-time) works councilors, noted earlier, but also regarding the right

Five ethnic groups (Hausa, Fulani, Sabe, Ibariba and Tiv) have extensive knowledge on the multipurpose uses of Moringa oleifera while the remaining three ethnic groups (Yoruba, Igbo

In a subgroup analysis of patients with structural heart disease, the risk factors significantly associated with outcome of death included history of MI, use of diuretics, presence