National Infectious Diseases Surveillance data of South Korea

Article information

Epidemiol Health. 2014;36.e2014030
Publication date (electronic) : 2014 November 11
doi : https://doi.org/10.4178/epih/e2014030
Division of Infectious Disease Surveillance, Korea Centers for Disease Control and Prevention, Osong, Korea
Correspondence: Eunhee Cho Division of Infectious Disease Surveillance, Korea Centers for Disease Control & Prevention, 187 Osongseangmyeong 2-ro, Cheongwon 363-951, Korea Tel: +82-43-719-7160, Fax: +82-43-719-7188, E-mail: cho6404@korea.kr
Received 2014 April 25; Accepted 2014 October 1.

Abstract

The Korea Centers for Disease Control and Prevention (KCDC) operate infectious disease surveillance systems to monitor national disease incidence. Since 1954, Korea has collected data on various infectious diseases in accordance with the Infectious Disease Control and Prevention Act. All physicians (including those working in Oriental medicine) who diagnose a patient with an infectious disease or conduct a postmortem examination of an infectious disease case are obliged to report the disease to the system. These reported data are incorporated into the database of the National Infectious Disease Surveillance System, which has been providing web-based real-time surveillance data on infectious diseases since 2001. In addition, the KCDC analyzes reported data and publishes the Infectious Disease Surveillance Yearbook annually.

INTRODUCTION

In general, national notifiable infectious diseases are those that cause severe infections with poor prognoses; are highly contagious and can be prevented with appropriate quarantine, vaccination, or chemical therapy; or require management and control by conducting research. The designation of a notifiable disease is multi factorial. As a result, there are numerous discrepancies in the definition of these diseases across various countries. The incidence of infectious diseases and issues related to these diseases change with time; therefore, frequent updates to relevant information are required. The purpose of designating national notifiable infectious diseases is to protect the public from the threat of infectious diseases by effectively controlling the disease using an accurate and sensitive surveillance system and by appropriately allocating the available resources.

The incidence of national notifiable infectious diseases is calculated using data reported by medical providers (Western and Oriental medical doctors) to health institutions in accordance with the Infectious Disease Control and Prevention Act [1]. Physicians working at clinics or hospitals report cases of infectious disease to their regional health center. These data are reviewed by local health authorities and transferred to the Korea Centers for Disease Control and Prevention (KCDC). After final confirmation from the KCDC, a report of these national statistics is published. According to the diagnosis and reporting standards in the “case definitions for national notifiable infectious diseases [2],” cases with an infectious disease are classified as three groups; an infectious disease patient (pathogen identifier), a patient with a suspected infection (unidentified pathogen carrier), or a pathogen carrier. The scope of each infectious disease report varies depending on the disease characteristics.

The Mandatory Surveillance System requires obligatory reporting on infectious diseases ‘without delay’ to a district health center. In comparison, the Sentinel Surveillance System receives the report on weekly from the designated sites. In addition, the Complementary Sentinel Surveillance System consists of a school-based infectious disease surveillance program and ocular infectious disease surveillance program.

Since the start of the surveillance system, many changes to the computer system structure have made. In the early stages of the construction of the surveillance system, a client-server based method between health institutions was the main way of data collection. However, from January 18, 2007, the reporting method using paper-based assessment was converted to a computer-based assessment. This computerized disease surveillance system was more efficient, flexible, and convenient than the paper-based assessment. In 2009, an internet-based reporting system was developed for use in clinics and hospitals. This system allowed for near real-time assessments the incidence of infectious diseases nationwide as well as quick data collection and a rapid response. From May 18, 2007, a web statistics system on infectious disease (http://stat.cdc.go.kr) was established. These efforts improved public accessibility to system data. In 2011, this website was updated as the infectious disease web-statistics system (http://is.cdc.go.kr/nstat/index.jsp) and it provides data on 54 infectious diseases that are mandatorily reported. In addition, the Infectious Disease Surveillance Yearbook, which organizes and analyzes the overall incidence of national notifiable infectious diseases, is published and distributed annually [3]. Reported infectious disease surveillance data since 1954 which is based on the Infectious Disease Control and Prevention Act is presented in Table 1.

Reported cases of national infectious diseases in South Korea, 1954-2013

DATA ACCESSIBILITY

The Disease Web Statistics System (http://is.cdc.go.kr/nstat/index.jsp) provides real-time data on 54 national notifiable infectious diseases specified by area, sex, age, infected region, and period. Moreover, it is possible to compare the current weekly incidence to that of the previous year. These data can be presented as tables or figures, and downloaded as a spreadsheet.

KEY FINDINGS AND PUBLICATIONS

The Sentinel Surveillance System monitors 24 of the 78 national notifiable infectious diseases. The KCDC uses these data to estimate the trends and patterns of some infectious diseases. The data only consists of the number of reported cases at each sentinel site and does not contain detailed information of each individual case; therefore, the national incidence of sentinel infectious diseases is difficult to estimate using the sentinel surveillance data. The main purpose of this data is to determine trends and patterns of infectious diseases.

For example, one study used these sentinel surveillance data to analyze influenza cases and hospitalizations of severe pneumonia nationwide [4]. This analysis used the sentinel surveillance data on sentinel influenza sites from 2005 to 2010 as well as national health insurance claims data from the Health Insurance Review and Assessment Service (influenza diagnostic codes J09-J11). In addition, the number of influenza patients per month, the total numbers of out-patients, and the total numbers of hospital visits were extracted for analysis. With these data, an estimation model was created (Figure 1) [4].

Figure 1.

Procedure of model development to calculate influenza incidence. KCDC, Korea Centers for Disease Control and Prevention; a is constant, B1, B2, B3, C1, C2, and C3 are coefficients from this regression model.

From Roh YK. Modeling the national pandemic influenza cases and inpatients of pneumonia in Korea. Osong: Korea Centers for Disease Control and Prevention; 2011 [4].

In this paper, the number of influenza patients in Seoul on November 2009 was estimated using this formula; final number of patients=constant + C1×(estimated number of patients ×W3)+C2×(year-2004). Minor differences between the estimated value based on the model and the health insurance claims data were found.

STRENGTHS AND WEAKNESSES

The reporting of national notifiable diseases is standardized and provides up-to-date information including diagnostics and the epidemiological characteristics of each infectious disease. Moreover, these data are distributed to healthcare sites regularly. However, the reporting of national notifiable infectious diseases in South Korea relies on the passive reporting of healthcare workers. Thus, the reporting rate is relatively low. Nevertheless, the number of patients with an infectious disease can be estimated using existing data. The KCDC not only seeks to encourage the reporting of infectious diseases that present at healthcare sites but also continues to develop ways to improve the current systems using multidimensional approaches, not limited to passive reporting.

Notes

The authors have no conflicts of interest to declare for this study.

SUPPLEMENTARY MATERIAL

Supplementary material is available at http://www.e-epih.org/.

References

1. Korea Ministry of Government Legislation. Infectious Disease Control and Prevention Act. [cited 2014 Nov 10]. Available from: http://law.go.kr/ (Korean).
2. Korea Ministry of Government Legislation. Case definitions for national notifiable infectious diseases. [cited 2014 Nov 10]. Available from: http://law.go.kr/ (Korean).
3. Korea Centers for Disease Control and Prevention(KCDC). 2013 Infectious diseases surveillance yearbook Osong: KCDC; 2014. p. 50–63. (Korean).
4. Roh YK. Modeling the national pandemic influenza cases and inpatients of pneumonia in Korea Osong: Korea Centers for Disease Control and Prevention; 2011. (Korean).

Article information Continued

Figure 1.

Procedure of model development to calculate influenza incidence. KCDC, Korea Centers for Disease Control and Prevention; a is constant, B1, B2, B3, C1, C2, and C3 are coefficients from this regression model.

From Roh YK. Modeling the national pandemic influenza cases and inpatients of pneumonia in Korea. Osong: Korea Centers for Disease Control and Prevention; 2011 [4].

Table 1.

Reported cases of national infectious diseases in South Korea, 1954-2013

Disease 1954-1959 1960-1969 1970-1979 1980-1989 1990-1999 2000-2009 2010-2013 Total
Cholera 0 1,972 206 145 196 210 14 2,743
Typhoid fever 5,398 40,790 13,018 2,481 3,012 2,198 566 67,463
Paratyphoid fever 193 440 64 172 164 795 223 2,051
Shigellosis 1,004 2,705 1,703 534 3,368 6,986 783 17,083
Enterohemorrhagic Escherichia coli - - - - - 431 246 677
Viral hepatitis A - - - - - - 7,585 7,585
Pertussis 75,941 75,002 18,187 8,381 444 186 390 178,531
Tetanus 0 0 6 53 12 109 72 252
Measles 67,901 116,435 48,877 26,075 13,327 56,061 266 328,942
Mumps 25,314 32,945 15,186 10,483 13,084 28,099 36,747 161,858
Rubella - - - - - 413 142 555
Japanese encephalitis 11,763 14,587 862 1,641 18 33 63 28,967
Varicella - - - - - 81,291 125,773 207,064
Malaria - 8,497 35,689 0 9,765 18,576 3,585 76,112
Hansen’s disease - 1,891 10,952 2,881 1,166 423 25 17,338
Scarlet fever 19 37 170 1,808 1,210 977 5,158 9,360
Meningococcal meningitis 116 157 36 81 40 114 29 457
Legionellosis - - - - - 106 104 210
Vibrio vulnificus sepsis - - - - - 536 244 780
Murine typhus - 0 4 4 136 378 137 659
Scrub typhus - - - - 3,534 42,761 29,791 76,086
Leptospirosis - - - 596 432 1,193 193 2,414
Brucellosis - - - - - 620 83 703
Rabies - 268 28 2 1 5 0 304
Hemorrhagic fever with renal syndrome - - 349 450 1,230 3,683 1,734 7,446
Primary/secondary/congenital syphilis - - - - - - 2,551 2,551
Creutzfeldt-Jakob disease - - - - - - 108 108
Dengue fever - - - - - 321 598 919
Q fever - - - - - 51 42 93
West Nile fever - - - - - - 1 1
Lyme borreliosis - - - - - - 16 16
Melioidosis - - - - - - 3 3
Chikungunya fever - - - - - - 2 2
Sever fever with thrombocytopenia syndrome - - - - - - 36 36

From Korea Centers for Disease Control and Prevention (KCDC). 2013 Infectious diseases surveillance yearbook. Osong: KCDC; 2014 [3].