Scientific Data Documentation
National Notifiable Disease Surveillance System, 1989
DESCRIPTION
The NNDSS file in WONDER contains nationally notifiable diseases
reported weekly by State and Territorial epidemiologists to the
Division of Surveillance and Epidemiology (DSE), Epidemiology
Program Office (EPO), Centers for Disease Control (CDC), using
the National Electronic Telecommunications System for
Surveillance (NETSS). The operation of NETSS is facilitated by
agreements between CDC and the Council of State and Territorial
Epidemiologists (CSTE) on reportable conditions, protocols for
formatting and transmitting data, and standard case definitions.
Designated staff members in each participating agency provide and
prepare the data for weekly publication in the "Morbidity and
Mortality Weekly Report" (MMWR).
Over 40 diseases are reported through this system. In WONDER,
the following variables are available for events reported as
individual case records: age, gender, race/ethnicity, county of
residence, State, and MMWR week of report; from aggregate
records, State and MMWR week of report. Line-listed data are not
available from this file.
LIMITATIONS
Data reported for 1989 by Arizona, California, Nebraska, and
Wyoming are represented as aggregate counts, since these states
were not reporting individual case data for all of 1989.
For some events (amebiasis, aseptic meningitis, chickenpox,
Hansen disease (leprosy), measles, mumps, pertussis, rheumatic fever,
rubella, and tetanus), cases may be reported to the State health department
by number only. For these events, United States distributions by
county, age, gender, and race/ethnicity will include only those
cases reported as individual records and the distribution will
not equal the total cases reported.
Case counts by age, gender, and race/ethnicity are available from
this file at State level only due to confidentiality guidelines.
Data for AIDS, animal rabies, gonorrhea, primary and secondary
syphilis, congenital syphilis, and tuberculosis are more likely
to be reported as aggregate counts in this file. These data are
based on provisional weekly reports to NETSS, and the totals may
not agree with the case counts provided by the National Center
for Infectious Diseases (NCID) or the National Center for
Prevention Services (NCPS) for publication in the MMWR "Summary
of Notifiable Diseases." Reports for all other events can be
verified by reference to the MMWR "Summary of Notifiable
Diseases".
VARIABLES
Event Codes
Disease or Injury Code
AIDS 10560
Amebiasis 11040
Anthrax 10350
Aseptic meningitis 10010
Botulism, foodborne 10530
Botulism, infant 10540
Botulism, other 10550
Brucellosis 10020
Chickenpox (varicella) 10030
Cholera 10470
Congenital rubella syndrome 10370
Congential syphilis 10316
Diphtheria 10040
Encephalitis, primary 10050
Encephalitis, post chickenpox 10070
Encephalitis, post mumps 10080
Encephalitis, post other 10090
Gonorrhea 10280
Hepatitis A 10110
Hepatitis B 10100
Hepatitis non-A, non-B 10480
Hepatitis, unspecified 10120
Legionellosis 10490
Leprosy (Hansen disease) 10380
Leptospirosis 10390
Malaria 10130
Measles, imported 10510
Measles, indigenous 10500
Meningococcal infection 10150
Mumps 10180
Pertussis 10190
Plague 10440
Poliomyelitis, paralytic 10410
Psittacosis 10450
Rabies, animal 10340
Rabies, human 10460
Rheumatic fever 11050
Rocky Mountain spotted fever 10250
Rubella 10200
Salmonellosis 11000
Shigellosis 11010
Syphilis, primary and secondary 10310
Tetanus 10210
Toxic-shock syndrome 10520
Trichinosis 10270
Tuberculosis 10220
Tularemia 10230
Typhoid fever 10240
Typhus murine 10260
These five-digit codes are similar to the three-digit codes
presently used for reporting notifiable diseases to the
MMWR. These codes, although not universally used, are
easier and simpler to use than universal coding schemes,
such as ICD-9.
Note that some events are represented by more than one code
(botulism, encephalitis, hepatitis, measles, sexually-
transmitted diseases). Selection of more than one event
will be possible in a future enhancement of this file in
WONDER, such as ALL measles, ALL hepatitis, ALL sexually-
transmitted diseases.
Selection of an event which produces the message "There were
no cases found with these criteria" should be interpreted as
no cases reported.
Selection of an event will sometimes produce a message that
the event is not notifiable in some states. This
information can be verified by reference to the MMWR
"Summary of Notifiable Diseases," in the table of reported
cases by geographic division and area.
State and County Codes
Coding for States and counties is based on Federal
Information Processing Standards (FIPS). This scheme
designates a two-digit code for each State based on
alphabetical order and a three-digit code for each county
generally using odd numbers to allow for the addition of new
counties. The code for unknown county is 999.
Distributions for the United States include Washington, D.C.
and New York City as separate reporting areas. Selection of
the State of New York will EXCLUDE New York City.
Territories (American Samoa, Guam, Commonwealth of the
Northern Mariana Islands, Puerto Rico, and the Virgin
Islands) can be selected separately.
Selection of a group of states or territories will be
possible in a future enhancement of this file in WONDER.
Counties reporting zero (0) or less than four (4) cases are
not shown.
Age Groups
Selection by age group will provide distributions from all
individual case records. Distributions may not equal total
cases reported for the event if some states reported
aggregate counts.
Gender
Selection by gender will provide distributions from all
individual case records. Distributions may not equal total
cases reported for the event if some states reported
aggregate counts.
Race/Ethnicity
Selection by race/ethnicity will provide distributions from
all individual case records. Distributions may not equal
total cases reported for the event if some states reported
aggregate counts.
MMWR Week
The weekly report of notifiable diseases covers the week
preceding the report's publication. The week begins Sunday
and ends on Saturday. The case count for MMWR week
represents cases reported and entered into the State's
surveillance system during the current reporting week. A
week-ending calendar is published by the Division of
Surveillance and Epidemiology, EPO, CDC, which is available
through the help facility for MMWR week in WONDER.
BACKGROUND INFORMATION
In 1878 an Act of Congress authorized the collection of morbidity
reports by the Public Health Service to establish quarantine
measures for diseases such as cholera, smallpox, plague, and
yellow fever. In 1893 another Act authorized the collection of
information on a weekly basis from state and municipal
authorities throughout the United States, and gradually an
increasing number of states submitted monthly and annual
summaries to the Public Health Service. It was not until 1925,
however, that all states began to report regularly.
Responsibilities for data collection and analysis were
subsequently transferred several times within the Public Health
Service. Responsibility for collecting the weekly data on the
notifiable diseases and publishing them in the "Morbidity and
Mortality Weekly Report" (MMWR) and the annual "Summary of
Notifiable Diseases" resides in the Epidemiology Program Office
at CDC.
Up until the early 1980's, weekly reports of aggregate counts of
the notifiable diseases were made by State health departments to
CDC by telephone. However, in 1984 the Epidemiologic
Surveillance Project (ESP) was initiated by CDC and the State
Epidemiologists in Colorado, Michigan, Minnesota, New York,
Washington, and Wisconsin to demonstrate the feasibility of
transmitting disease surveillance data electronically from State
health department computer systems to the CDC. From those
beginnings ESP has steadily grown so that now all of the States,
New York City, the District of Columbia, and Puerto Rico are
participating, and the name was changed to NETSS to reflect its
nationwide scope.
Three concepts were integral to the initial design of this
system. First, each State health department could continue to
use its existing computerized disease surveillance system to
transmit data to CDC. Second, specific data concerning each case
of a reportable disease would be transmitted to CDC. Finally,
these computerized case records would supplant the States' weekly
telephone reporting to the NNDSS. This is the system that
provides the information that is published in Tables 1 and 2 of
the MMWR.
Disease surveillance systems vary widely from State to State. The
diseases under surveillance, the reporting sources and the size
of the systems may differ. NETSS was designed to allow States
to use their existing disease databases as much as possible.
These State systems have implemented their systems on a variety
of computers using different programs and data formats. In
October 1991, thirty-eight reporting areas are using a software
package called Epi Info for their surveillance system. This is
an epidemiologic data base and analysis system that has been
developed and supported by the Division of Surveillance and
Epidemiology of the Epidemiology Program Office at CDC. In some
States CDC has provided technical support. Such support has been
limited to consultation regarding system implementation and in
some cases 3 to 5 days of onsite technical assistance to
computerize their surveillance system.
In general, similar steps are followed by all States currently
participating in NETSS.
1. Data are reported to the State health department from
county health departments, hospitals, physicians, and
laboratories. These data are entered into the State/county
computer and analyzed for local needs.
2. Weekly, a program is run against the State surveillance
data base that selects the records to be transmitted to CDC
and converts the record format and codes from the State
conventions to the NETSS report format. A subfile of the
selected records, in the NETSS format, is created.
3. Most of the State reports are transmitted through the
Public Health Network on BT North America (known by users as
Dialcom).
4. An electronic mail message containing the weekly NETSS
file is sent to the CDC mailbox in Dialcom.
5. CDC staff reads these messages, uploads the data to the
CDC mainframe computer, edits it, and then updates the NETSS
master database.
6. Each week a summary report is sent to each State
describing the number of records transmitted, the number of
new records, updates, and records deleted. In addition,
coding errors are indicated and a year-to-date summary of
the State's reports is included.
7. Should corrections be necessary the State retransmits the
correct data and the incorrect record is revised.
NETSS data are summarized and published weekly in the MMWR and
more extensive analyses are included in the MMWR annual summary.