Evaluation of the National Notifiable Disease Surveillance System in Taiwan: an example of varicella reporting

Despite the mandatory reporting by laws, the incompleteness of notifiable infectious disease reporting is well-documented in many countries for various diseases. The purpose of this study is to investigate the completeness of varicella reporting in Taiwan. Annual reports of National Notifiable Disease Surveillance System in Taiwan were compared to the annual outpatient claims of National Health Insurance (NHI) in the years of 2000, 2001, and 2002. Age and area-specific reporting rates of varicella were calculated by dividing the respective reported cases by the number of incidence cases. The reporting rate was the highest in aged 0 year in all years, followed by the 20-29- and 30-39-year groups. The reporting rate in each age group increased gradually during the study period. Other than Taipei City, the reporting rates in all regions were below 9% during this period. This study suggested that varicella reporting rate is very low in Taiwan. In addition, the reporting rates were inconsistent in 2000-2002, making the estimation of prevalence and vaccine efficacy using data from the National Notifiable Disease Surveillance System almost impossible. This study indicated that the physicians in Taiwan should improve their knowledge and attitude toward notifiable infectious diseases.     

A study of the average run length characteristics of the National Notifiable Diseases Surveillance System

This study examines the statistical properties (that is, false positive and negative signals) in detecting unusual patterns of reported cases of diseases from the Centers for Disease Control and Prevention's National Notifiable Diseases Surveillance System. Control charts are applied to the residuals of one-step ahead forecasts based on Box-Jenkins models of reported cases of disease. Simulation and analytical techniques are used to study the average run length characteristics of these control charts for various types of changes in the levels of the series, including spike, trend and step changes. The average run lengths for the highly correlated disease series are much longer than for the usual independent data case. This increase in the average run lengths is strongly influenced by the type of change in the level of the series and by the type of control chart. Understanding the average run length characteristics of the control charts can lead to timely detection of changes in the levels of disease series, and subsequent timely public health actions to decrease unnecessary morbidity and mortality.     

Australia's notifiable disease status, 2009: annual report of the National Notifiable Diseases Surveillance System

In 2009, 65 diseases and conditions were nationally notifiable in Australia. States and territories reported a total of 236,291 notifications of communicable diseases to the National Notifiable Diseases Surveillance System, an increase of 48% on the number of notifications in 2008. This increase was largely due to cases of influenza A(H1N1) pandemic 2009. In 2009, the most frequently notified diseases were vaccine preventable diseases (101,627 notifications, 43% of total notifications), sexually transmissible infections (73,399 notifications, 31% of total notifications), and gastrointestinal diseases (31,697 notifications, 13% of total notifications). There were 18,861 notifications of bloodborne diseases; 8,232 notifications of vectorborne diseases; 1,919 notifications of other bacterial infections; 552 notifications of zoonoses and 4 notifications of quarantinable diseases.     

Australia's notifiable diseases status, 2005: annual report of the National Notifiable Diseases Surveillance System

In 2005, 60 diseases and conditions were nationally notifiable in Australia. States and territories reported a total of 125,461 cases of communicable diseases to the National Notifiable Diseases Surveillance System: an increase of 10% on the number of notifications in 2004. In 2005, the most frequently notified diseases were sexually transmissible infections (51,557 notifications, 41% of total notifications), gastrointestinal diseases (29,422 notifications, 23%) and bloodborne diseases (19,278 notifications, 15%). There were 17,753 notifications of vaccine preventable diseases; 4,935 notifications of vectorborne diseases; 1,826 notification of other bacterial infections (legionellosis, leprosy, meningococcal infections and tuberculosis) and 687 notifications of zoonotic diseases.     

Australia's notifiable disease status, 2008: annual report of the National Notifiable Diseases Surveillance System

In 2008, 65 communicable diseases and conditions were nationally notifiable in Australia. States and territories reported a total of 160,508 notifications of communicable diseases to the National Notifiable Diseases Surveillance System, an increase of 9% on the number of notifications in 2007. In 2008, the most frequently notified diseases were sexually transmissible infections (69,459 notifications, 43% of total notifications), vaccine preventable diseases (34,225 notifications, 21% of total notifications) and gastrointestinal diseases (27,308 notifications, 17% of total notifications). There were 18,207 notifications of bloodborne diseases; 8,876 notifications of vectorborne diseases; 1,796 notifications of other bacterial infections; 633 notifications of zoonoses and 4 notifications of quarantinable diseases.     

Australia's notifiable diseases status, 1998. Annual report of the National Notifiable Diseases Surveillance System

In 1998 there were 85,096 notifications to the National Notifiable Diseases Surveillance System; slightly lower than in 1997 (89,579). The number of measles cases remained low, and well below the number reported in the outbreak years of 1993 and 1994. Rubella notifications further decreased and remained low in 1998. The Measles Control Campaign from August to November 1998, did not impact significantly on the number of measles or rubella cases reported for 1998. Notifications of Haemophilus influenzae type b reached a record low since surveillance began in 1991, and appeared to have stabilised at a low rate since the introduction of the conjugated vaccine in 1992. The previously reported outbreak of pertussis in 1997 tapered off in early 1998. Food-borne disease, or detection of disease, appeared to be on the rise with an increase in notification rates of campylobacteriosis and salmonellosis. Notifications of hepatitis A decreased, correcting the previous high number of notifications in 1997. Sexually transmissible diseases (STDs) increased. Notifications for chlamydial infection were the highest for all sexually transmitted diseases and third highest for all notifiable diseases. Notifications of gonococcal infection also continued to rise and have doubled since 1991, whilst notifications for syphilis increased slightly after falling steadily over recent years. Arbovirus infections of concern in 1998 were dengue outbreaks in Far North Queensland and the first case of Japanese Encephalitis for mainland Australia, highlighting the importance of surveillance of arboviruses and vectors for their detection and management.     

Australia's notifiable diseases status, 1997. Annual report of the National Notifiable Diseases Surveillance System

In 1997 there were 89,579 notifications to the National Notifiable Diseases Surveillance System. A notable feature of 1997 was the pertussis outbreak which peaked towards the end of the year and resulted in 10,668 cases being notified. The highest number of notifications received was for hepatitis C (unspecified) with 19,692 notifications; this is the first year for which data have been reported for New South Wales and South Australia for this disease category. The number of measles cases rose after the low number reported in 1996 but is still well below the number reported in the outbreak years of 1993 and 1994. Rubella notifications continued to decline in 1997. Notifications of Haemophilus influenzae type b appeared to have stabilised at a low rate, having declined markedly after introduction of the conjugated vaccine in 1992. The number of cases of campylobacteriosis remained steady after having risen for several years. Notifications of hepatitis A cases rose considerably, much of this being due to one outbreak in New South Wales. The number of cases of salmonellosis rose while shigellosis numbers dropped slightly. Notifications for chlamydial infection and gonococcal infection continued to rise, whilst those for syphilis continued to fall.     

Australia's notifiable diseases status, 2006: annual report of the National Notifiable Diseases Surveillance System

In 2006, 66 diseases and conditions were nationally notifiable in Australia. States and territories reported a total of 138,511 cases of communicable diseases to the National Notifiable Diseases Surveillance System: an increase of 10.4% on the number of notifications in 2005. In 2006, the most frequently notified diseases were sexually transmissible infections (57,941 notifications, 42% of total notifications), gastrointestinal diseases (27,931 notifications, 20% of total notifications) and vaccine preventable diseases (22,240 notifications, 16% of total notifications). There were 19,111 notifications of bloodborne diseases; 8,606 notifications of vectorborne diseases; 1,900 notifications of other bacterial infections; 767 notifications of zoonoses and 3 notifications of quarantinable diseases.     

Australia's notifiable diseases status, 2003 annual report of the National Notifiable Diseases Surveillance System.

In 2003, 58 diseases and conditions were notifiable at a national level in Australia. States and territories reported a total of 104,956 cases to the National Notifiable Diseases Surveillance System an increase of 3.2 per cent on the total number of notifications in 2002. In 2003, the most frequently notified diseases were sexually acquired infections (38,854, 37% of total notifications), gastrointestinal diseases (24,655 notifications, 24%) and bloodborne viruses (20,825 notifications, 20%). There were 11,113 notifications of vaccine preventable diseases, 6,780 notifications of vectorborne diseases, 1,826 notification of other bacterial infections and 903 notifications of zoonotic diseases.     

Evaluation of Australia's National Notifiable Disease Surveillance System.

The Australian National Notifiable Diseases Surveillance System (NNDSS) is a passive surveillance system that collects information on communicable diseases. The Australian Government manages NNDSS under the auspices of the Communicable Diseases Network Australia (CDNA). Data collected by each state and territory are collated, analysed and disseminated by the Australian Government Department of Health and Ageing. We report the first evaluation of NNDSS since it was established in 1991. Three primary stakeholder groups were surveyed: (a) CDNA members, (b) the National Surveillance Committee and (c) the readership of Communicable Diseases Intelligence, the primary means of data dissemination from NNDSS. The evaluation revealed that the system was acceptable, structurally simple, and that the data collected were actively used by stakeholders. However, the lack of clearly documented aims and objectives for NNDSS, inflexibility to changing needs, lack of timeliness and complexity in processes were seen as problematic. The results of this evaluation, supported by recent federal funding to enhance national biosecurity, will provide the framework for enhancing NNDSS to meet national communicable disease surveillance requirements in Australia.     

Australia's notifiable diseases status, 2001: annual report of the National Notifiable Diseases Surveillance System.

In 2001 there were 104,187 notifications of communicable diseases in Australia reported to the National Notifiable Diseases Surveillance System (NNDSS). The number of notifications in 2001 was an increase of 16 per cent of those reported in 2000 (89,740) and the largest annual total since the NNDSS commenced in 1991. In 2001, nine new diseases were added to the list of diseases reported to NNDSS and four diseases were removed. The new diseases were cryptosporidiosis, laboratory-confirmed influenza, invasive pneumococcal disease, Japanese encephalitis, Kunjin virus infection, Murray Valley encephalitis virus infection, anthrax, Australian bat lyssavirus, and other lyssaviruses (not elsewhere classified). Bloodborne virus infections remained the most frequently notified disease (29,057 reports, 27.9% of total), followed by sexually transmitted infections (27,647, 26.5%), gastrointestinal diseases (26,086, 25%), vaccine preventable diseases (13,030 (12.5%), vectorborne diseases (5,294, 5.1%), other bacterial infections (1,978, 1.9%), zoonotic infections (1,091, 1%) and four cases of quarantinable diseases. In 2001 there were increases in the number of notifications of incident hepatitis C, chlamydial infections, pertussis, Barmah Forest virus infection and ornithosis. There were decreases in the number of notifications of hepatitis A, Haemophilus influenzae type b infections, measles, rubella, Ross River virus infections and brucellosis. This report also summarises data on communicable diseases from other surveillance systems including the Laboratory Virology and Serology Reporting Scheme and sentinel general practitioner schemes. In addition, this report comments on other important developments in communicable disease control in Australia in 2001.     

Australia's notifiable diseases status, 2000. Annual report of the National Notifiable Diseases Surveillance System.

In 2000, there were 89,740 notifications of communicable diseases in Australia collected by the National Notifiable Diseases Surveillance System (NNDSS). The number of notifications in 2000 was an increase of 5.9 per cent over those reported in 1999 (84,743) and the largest reporting year since the NNDSS commenced in 1991. Notifications in 2000 consisted of 28,341 bloodborne infections (32% of total), 24,319 sexually transmitted infections (27%), 21,303 gastrointestinal infections (24%), 6,617 vaccine preventable infections (7%), 6,069 vectorborne infections (7%), 2,121 other bacterial infections (legionellosis, meningococcal infection, leprosy and tuberculosis) (2%), 969 zoonotic infections (1%) and only one case of a quarantinable infection. Steep declines in some childhood vaccine preventable diseases such as Haemophilus influenzae type b, measles, mumps and rubella, continued in 2000. In contrast, notifications of pertussis and legionellosis increased sharply in the year. Notifications of bloodborne viral diseases (particularly hepatitis B and hepatitis C) and some sexually transmitted infections such as chlamydia, continue to increase in Australia. This report also summarises data on communicable diseases from other surveillance systems including the Laboratory Virology and Serology Surveillance Scheme (LabVISE) and sentinel general practitioner schemes. In addition this report comments on other important developments in communicable disease control in Australia in 2000.     

Australia's notifiable diseases status, 1999: annual report of the National Notifiable Diseases Surveillance System.

In 1999 there were 88,229 [corrected] notifications of communicable diseases in Australia reported to the National Notifiable Diseases Surveillance System (NNDSS). The number of notifications in 1999 was an increase of 3 per cent on notifications in 1998 (85,227) and the second largest reporting year since the NNDSS commenced in 1991. Notifications in 1999 consisted of 29,977 bloodborne infections (34% of total), 22,255 gastrointestinal infections (25%), 21,704 sexually transmitted infections (25%), 5,986 vector borne infections (7%),5,228 vaccine preventable infections (6%), 1,967 (2%) other bacterial infections (legionella, meningococcal, leprosy and tuberculosis), 1,012 zoonotic infections (1%) and 3 quarantinable infections (0.003%). Notifications of bloodborne viral diseases particularly hepatitis B and hepatitis C and some sexually transmitted infections such as gonorrhoea and chlamydia continue to increase in Australia. Steep declines in vaccine preventable diseases such as Haemophilus influenzae type b, measles, mumps and rubella continued in 1999. This report also summarises data on communicable diseases from other surveillance systems including the Laboratory Virology and Serology Surveillance Scheme (LabVISE) and sentinel general practitioner schemes. In addition this report comments on other important developments in communicable disease control in Australia in 1999.     

Australia's notifiable diseases status, 2002: Annual report of the National Notifiable Diseases Surveillance System.

There were 57 infectious diseases notifiable at the national level in Australia in 2002. States and territories reported 100,278 cases of infectious diseases to the National Notifiable Diseases Surveillance System (NNDSS), a fall of 4 per cent compared to the number of notifications in 2001. In 2002, the most frequently notified diseases were, sexually transmitted infections (31,929 reports, 32% of total notifications), gastrointestinal infections (26,708 reports, 27% of total notifications) and bloodborne infections (23,741, 24%). There were 11,711 (12% of total) cases of vaccine preventable diseases, 3,052 (3% of total) cases of vectorborne diseases, 1,155 (1% of total) cases of zoonotic infections, two cases of quarantinable diseases (Vibrio cholerae O1) and 1,980 cases of other bacterial diseases, notified to NNDSS. Compared to 2001, notifications of sexually transmitted infections increased by 16 per cent and gastrointestinal infections by 2 per cent while bloodborne infections fell by 18 per cent. The number of notifications of chlamydial infection and Q fever were the highest since 1991 and 1995 respectively. By contrast, the number of notification for hepatitis A and measles were the lowest since 1991. For other notifiable diseases, the number of notifications was within the range of the five years between 1997 and 2002 (range = five-year mean plus or minus two standard deviations). This report also includes 2002 summary data on communicable diseases from other surveillance systems including the Laboratory Virology and Serology Reporting Scheme and sentinel general practitioner schemes.     

Reporting race and ethnicity data--National Electronic Telecommunications System for Surveillance, 1994-1997

Reporting accurate and complete race and ethnicity data in public health surveillance systems provides critical information to target and evaluate public health interventions, particularly for minority populations. A national health objective for 2000 is to improve data collection on race and ethnicity in public health surveillance and data systems. To determine progress toward meeting this goal in CDC's National Electronic Telecommunications System for Surveillance (NETSS), the percentage of case reports of selected nationally notifiable diseases reported through NETSS with information regarding a patient's race and ethnicity was calculated for 1994-1997. The findings of this study indicate these data were received for approximately half of the cases, and the completeness of reporting of race and ethnicity data to NETSS had not improved.     

The National Surveillance System for Sexually Transmitted Diseases in Italy. STD Surveillance Working Group.

Sexually transmitted diseases (STDs) have increased in importance in recent decades as a result of their wider dissemination, the emergence of new etiologic agents, and changes in sexual behaviors. In Italy, gonorrhea and syphilis are among the 71 diseases for which reporting is legally mandated. Despite these legal requirements, however, considerable underreporting has been documented. The need for more reliable data has led to the establishment of a formal sentinel surveillance system for STDs. The Italian National STD Surveillance Network, which involves 47 reporting centers, was established in 1990. A total of 5,049 patients were reported during the pilot study and the first 6 months of surveillance. For men, the most frequently reported diseases were genital warts and nongonococcal urethritis; for women, the most frequent diagnoses were nonspecific vaginitis and genital warts. The objectives of this system are threefold: a) to obtain a rapid and accurate assessment of the occurrence and spread of STDs; b) to identify trends in disease occurrence; and c) to monitor changes over time by geographic area.     

Adequacy of reporting race/ethnicity in clinical trials in areas of health disparities

Although federal initiatives have mandated broader inclusion of minorities in clinical research on diseases that have disparities in health by race and ethnicity, it is not clear whether these initiatives have affected reporting of trial results. The objective of this study was to examine the reporting of race/ethnicity in clinical trials reports in areas of known disparities in health (i.e., diabetes, cardiovascular disease, HIV/AIDS, and cancer) and to determine what factors were associated with reporting of race/ethnicity in results. We performed a Medline search covering the period January 1989 to Oct 2000 to identify clinical trials of diabetes, cardiovascular disease, HIV/AIDS, and cancer published in the Annals of Internal Medicine, JAMA, and New England Journal of Medicine. The main outcome measure was the reporting of participation and of results by race/ethnicity of trial participants. Of 253 eligible trials, 40% (n=102) were non race-focused yet did not report race, while 2% (n=4) were non gender-focused and did not report gender. Forty-six percent of trials that reported the race/ethnicity of the sample reported only one or two racial/ethnic categories, and in 43% of these trials the total number of individuals reported in each race/ethnicity category did not equal the total reported sample size. Analysis of results by race/ethnicity was reported in only two trials, and by gender in only three trials. In diseases with known racial and ethnic disparities, many clinical trials do not report the race/ethnicity of the study participants, and almost none report analyses by race/ethnicity. Although federal initiatives mandate inclusion of minority groups in research, that inclusion has not translated to reporting of results that might guide therapeutic decisions.