Involving Health Care Providers - NCBI

5 downloads 2226 Views 460KB Size Report
Health care providers need to be immune to .... These data support recommendations that all health care providers likely to come in contact with measles should ...
A Measles Outbreak at University Medical Settings Involving Health Care Providers DEAN G. SIENKO, MD, CANDACE FRIEDMAN, MPH, HARRY B. MCGEE, MPH, MICHAEL J. ALLEN, MPH, WILLIAM F. SIMONSEN, MAPA, BERTTINA B. WENTWORTH, PHD, THOMAS C. SHOPE, MD, AND WALTER A. ORENSTEIN, MD, MPH Results Abstract: In 1985, a measles outbreak involved 14 students and non-student contacts in Michigan. Eight transmissions occurred at university medical facilities; five of these were likely airborne transmissions. Medical students and a medical resident were involved in the outbreak's propagation. Health care providers need to be immune to measles. Measles should be suspected in young adults with compatible illnesses; persons suspected to have measles should be placed in stringent respiratory isolation to preclude airborne transmission. (Am J Public Health 1987; 77:1222-1224.)

Introduction In recent years the proportion of measles cases exposed in medical and university settings has increased. 12 From January through March 1985, a measles outbreak involved nine students and five non-student contacts in southeast Michigan. Eight case patients were exposed to measles in medical settings. This report highlights measles transmission within a university's medical facilities while focusing on the airborne route as a mode of transmission of the measles virus. Methods All suspected measles cases reported to the Michigan Department of Public (MDPH) from January through March 1985 were investigated using standard measles case-reporting forms. A case was defined as a person with a rash of at least three days duration; having a fever of at least 38 degrees Celsius; and having either cough, coryza, or conjunctivitis.3 Transmission was defined as face-to-face if a casepatient had been within three feet of an infectious person during the latter's infectious period (i.e., four days before or after rash onset). Transmission was defined as airborne if a case-patient had no known direct person-to-person contact with an infectious person, but had been in the same location where an infectious person had been at the same proximate time. Available acute- and convalescent-phase serum specimens from case-patients were tested at the MDPH laboratory with immune adherence hemagglutination4 or at the University of Michigan hospital laboratory with indirect immunofluorescence.5 These methods also tested acute-phase sera for measles-specific IgM antibody following column separation. The preventability and degrees of diagnostic certainty of cases were determined using standard Centers for Disease Control (CDC) classifications.3 From the Division of Field Services, Epidemiology Program Office, Centers for Disease Control (Dr. Sienko); the University of Michigan Hospitals (Ms. Friedman and Dr. Shope); the Michigan Department of Public Health (Dr. Sienko, and Mssrs. McGee, Allen, Simonsen and Dr. Wentworth), and the Division of Immunization, Center for Preventive Services, Centers for Disease Control (Dr. Orenstein). Address reprint requests to Dr. Dean G. Sienko, Division of Surveillance and Epidemiologic Studies, Centers for Disease Control, 1600 Clifton Road, Atlanta, GA 30333. This paper, submitted to the Journal October 27, 1986, was revised and accepted for publication March 20, 1987.

1 222

Case symptoms, serologies, and places where exposed are presented in Table 1. Eight of the 14 cases were serologically confirmed, the remaining cases were "confirmed" by epidemiologic association. Eight of the 11 adult cases reported gastrointestinal symptoms. Five exposures occurred in the hospital, two in a mental health facility, and one at the student health center. The outbreak is depicted in Figure 1. Five cases probably contracted measles from airborne spread. Nine of the 14 cases were preventable by CDC standards. The outbreak was unearthed after an hitherto unknown index case was retro-

spectively discovered. The index case (Case No. 1) was a 21-year-old foreign student who, on January 10, returned from winter recess in Venezuela. On January 19, he became ill with fever and chills; thereafter, he developed nausea and about 30 bouts of vomiting. He was admitted to the University A hospital with dehydration and fever. On January 24, he developed a diffuse maculopapular rash. His clinical presentation coupled with historical information that typhoid fever had occurred near his home in Venezuela lead to a working diagnosis of typhoid fever. The measles diagnosis was subsequently confirmed by retrieved sera. The index case transmitted measles via airborne spread to an 8-month-old child (Case No. 5) in the emergency room on January 23. The index case entered the emergency room at 12:37 am and was taken promptly to treatment room A, where he remained for the duration of his emergency room stay. The child arrived at 1:06 am and was taken to treatment room C, traversing nearly the same route as the index case. Rooms A and C are separated by room B, and contain full floor-to-ceiling walls and doors. The child was discharged at 2:00 am. The index case left the emergency room for the general medicine ward at 3:05 am. On the general medicine ward the index patient infected two University A medical students (Cases No. 2 and No. 3) via airborne spread. Both students stated that they were never within three feet of his bed and the nursing staff reported that the index case was nonambulatory until the day preceding his discharge because of dehydration. One of the medical students (Case No. 2) transmitted measles to a University A freshman (Case No. 9) at the student health center on February 8. The medical student arrived at 11:30 am with a fever, cough and rash; she was placed in a single patient examining room. At 2:00 pm the freshman seated himself in the adjacent waiting room. However, the door of the room where the medical student was being examined was left ajar, and attending medical personnel walked in and out of the room several times. Case No. 10 contracted measles while purchasing medications at the University A hospital pharmacy. Two hours previously, Case No. 4 (an internal medicine resident) passed by the pharmacy enroute to being evaluated for her illness. Neither the resident nor the infectious medical students were on duty in the hospital that day. AJPH September 1987, Vol. 77, No. 9

PUBLIC HEALTH BRIEFS TABLE 1-Case Ages, Serologies, Symptoms and Places of Exposure in Measles Outbreak, Michigan, 1985

Symptoms

Serology Result Case No. 1 2 3 *4

~56

7 8 9 10 *11 12 13 14

Age

Acute

Convalescent

Cough

21 24 25 29

Neg. 1:20

1:64 1:160

X X X X X X X X X X X X X

8 mo. 20 20 23 19 24 02 11 20 18

Not Taken 1:128 1:16 1:64 (IgM) Not Taken Not Taken 1:4096 1:32 1:16 1:512 1:2048 1:64 (IgM) 1:64 1:2048 1:256 1:4096 1:256

Coryza

Conjunctivitis

Koplik's spots

Diarrhea

Vomiting

X X X X

X

X X X

X X

X X X

X X X X

X X X

X

X X

X

X X X X

X

X X

X X

X X

Place of Exposure Venezuela

Hospital Hospital Hospital Hospital Residence Residence Mental Health Health Clinic

Hospital

X X

X

Residence Mental Health

Dormitory Dormitory

X

*Serology results from the University of Michigan laboratory, all others from the Michigan Department of Public Health laboratory.

The remaining cases (Nos. 4, 6, 7, 8, 11, 13 anid 14) had face-to-face contact with a known case. The mode of spread to case No. 12 (a mental health patient) is uncertain, although transmission is linked to one of the two medical students.

Centers for Disease Control recommendations state that

patients with suspected or confirmed measles should be placed in respiratory isolation until four days after rash onset. Such action requires the prerequisite consideration of measles in the differential diagnosis of compatible illnesses. As more children reach adulthood without developing immunity,

Discussion In this outbreak, the majority of measles transmissions occurred in medical facilities. Infectivity from three medical students and a resident eventually led to measles in an additional six persons. These data support recommendations that all health care providers likely to come in contact with measles should be immune.6 Airborne measles transmission has been previously described,7-'0 and almost 40 per cent of the cases in this outbreak probably acquired measles via airborne transmission. One person (Case No. 10) was apparently infected by aerosolized particles emitted as long as two hours before his exposure; we believe this constitutes the longest interval of documented airborne transmission of the measles virus, yet is within the known period of virus viability."

measles must be considered in young adults with otherwise unexplained, febrile, rash illnesses. Awareness that gastrointestinal symptoms might be present during the measles prodrome in young adUilts may increase the index of suspicion for measles and lead to appropri'ate respiratory isolation measures.

A recent study concluded that the major reason for the failure to eliminate measles in the United States was that persons for whom vaccine is indicated have not been vaccinated.'13 Medical institutions and universities can contribute to measles elimination by vaccinating susceptible employees and students. The unmet goal of eliminating indigenous measles in the United States is unlikely to be achieved until this is accomplished.

~~~Face -to -face

-------0

Airborne

__O

~

~~~~Indefinite Preventable

0

Nonpreventable

El

2324 25 26 27 2e29 3031 / 2 3 4 5 6 7 e 9 lOll1 12 13 14 15 /6 /7 le 1920 2122 23 24 25 26 27 26

JAN

FEB

2 3 4 5 6

758

9 10

MAR

DATE OF RASH ONSET

FIGURE I-Schematic of Measles Outbreak by Dates of Rash Onset Indicating Mode of Transmission and Case Preventability, Michigan 1985

AJPH September 1987, Vol. 77, No. 9

1223

PUBLIC HEALTH BRIEFS

ACKNOWLEDGMENTS The authors wish to acknowledge the infectious disease sections and emergency room staff at the University of Michigan hospital, the staffs of the student health clinics at the University of Michigan, Wayne State University, and Eastern Michigan University, and the staff of the Washtenaw County Health Department for their cooperation in conducting this investigation. We also wish to acknowledge the valuable assistance of Drs. Robert Gunn, William Hall and Kenneth Wilcox. Gabriel Contreras, Pat Hurst provided graphic assistance, and Loraine Good provided editorial assistance.

REFERENCES 1. Davis RD, Orenstein WA, Frank JA, et al: Transmission of measles in medical settings: 1980 through 1984. JAMA 1986: 255:1295-1298. 2. Centers for Disease Control (CDC): Measles on college campuses-United States, 1985. MMWR 1985; 34:445-449. 3. CDC: Classification of measles cases and categorization of measles elimination programs. MMWR 1983; 31:707-711. 4. Lennette ET, Lennette DA: Immune adherence hemagglutination: alternative to complement-fixation serology. J Clin Microbiol 1978; 7:282-285. 5. Brown GC, Maasaab HF. Veronelli JA, et al: Rubella antibodies in human sera: Detection by the indirect fluorescent antibody technique. Science 1964: 145:943-944.

6. Williams WW: Guidelines for infection control in hospital personnel. Infect Control 1983: 4:326-349. 7. Riley EC, Murphy G, Riley RL: Airborne spread of measles in a suburban elementary school. Am J Epidemiol 1978; 107:421-432. 8. Bloch AB, Orenstein WA, Ewing WM, et al: Measles outbreak in a pediatric practice: Airborne transmission in an office setting. Pediatrics 1985; 75:676-683. 9. Remington PL, Hall WN, Davis IH, et al: Airborne transmission of measles in a physician's office. JAMA 1985; 253:1574-1577. 10. CDC: Interstate importation of measles following transmission in an airport-California, Washington, 1982. MMWR 1983; 32:210, 215-216. 11. DeJong JG, Winkler K: Survival of measles virus in air. Nature 1964; 201:1054-1055. 12. Garner JS, Simmons BP: Guidelines for isolation precautions in hospitals. Infect Control 1983; 4:245-325. 13. Frank JA, Orenstein WA, Bart KJ, et al: Major impediments to measles elimination: The modern epidemiology of an ancient disease. Am J Dis Child 1985: 139:881-888.

NOTE: CDC defines measles as preventable in US citizens: 1) at least 16 months of age; 2) born after 1956; 3) lacking adequate immunity; 4) without medical contraindication to vaccine: and 5) without religious or philosophical exemption.

National Academy of Sciences Symposium: Frontiers in the Nutrition Sciences The Food and Nutrition Board of the National Research Council/National Academy of Sciences will hold its annual symposium intitled Frontiers in the Nultrition Sciences, on December 9, 1987, in the auditorium of the National Academy of Sciences in Washington, DC. The program is designed to examine the current status and to identify future directions for research and training in the nutrition sciences. In the first two sessions, speakers will review advances in certain basic and applied sciences that offer opportunities for developing programs and undertaking collaborative research in the United States and internationally. The third session will offer insights into trends and directions in research and training in university nutrition departments, medical schools, and schools of public health. A panel discussion will focus on factors that have slowed progress and those that might enhance opportunities for research and training in the nutrition sciences. The registration desk opens at 8:30 am on December 9. Admission is free; preregistration not required. The program begins at 9:00 am. Application has been made to the American Dietetic Association for continuing education credits. For further information contact: Beth Hamill National Academy of Sciences 2101 Constitution Avenue, NW Washington, DC 20418 (202) 334-2251

1224

AJPH September 1987, Vol. 77, No. 9