Surveillance System For Communicable Diseases Research Articles

Surveillance of travel-associated gastrointestinal infections in Norway, 2009–2010: are they all actually imported?

The Norwegian Surveillance System for Communicable Diseases (MSIS) includes variables related to travel for clinicians to fill when notifying travel-associated infections. We measured the completeness and validated the travel-history information for salmonellosis, campylobacteriosis, giardiasis and shigellosis reported in 2009-2010. Of all 8,978 selected infections in MSIS, 8,122 (91%) were reported with place of infection of which 5,236 (65%) were notified as acquired abroad, including 5,017 with symptoms. Of these, 2,972 (59%) notifications had information on both date of arrival in Norway and date of symptom onset, so time between travel and illness onset could be assessed. Taking in account the incubation period, of the 1,435 infections reported as travel-associated and for which symptom onset occurred after return to Norway, 1,404 (98%) would have indeed been acquired abroad. We found a high level of completeness for the variable 'place of infection'. Our evaluation suggests that the validity of this information is high. However, incomplete data in the variables 'return date to Norway' and 'date of symptoms onset', only allowed assessment of the biological plausibility of being infected abroad for 59% of the cases. We encourage clinicians to report more complete travel information. High quality information on travel-associated gastrointestinal infections is crucial for understanding trends in domestic and imported cases and evaluating implemented control measures.

Assessment of communicable disease surveillance system in Gazera State, Sudan, 2009

Assessment of communicable disease surveillance system in Gazera State, Sudan, 2009

The Norwegian immunisation register – SYSVAK

The Norwegian immunisation register, SYSVAK, is a national electronic immunisation register. It became nationwide in 1995. The major aim was to register all vaccinations in the Childhood Immunisation Programme to ensure that all children are offered adequate vaccination according to schedule in the programme, and to secure high vaccination coverage. Notification to SYSVAK is mandatory, based on personal identification numbers. This allows follow up of individual vaccination schedules and linkage of SYSVAK data to other national health registers for information on outcome diagnoses, such as the surveillance system for communicable diseases. Information from SYSVAK is used to determine vaccine coverage in a timely manner. Coverage can be broken down to regional/local levels and used for active surveillance of vaccination coverage and decisions about interventions. During the 2009 influenza A(H1N1)pdm09 pandemic, an adaptation of SYSVAK enabled daily surveillance of vaccination coverage on national and regional levels. Currently, data from SYSVAK are used, among others, in studies on adverse events related to pandemic vaccination. Future challenges include maximising usage of collected data in surveillance and research, and continued improvement of data quality. Immunisation registers are rich sources for high quality surveillance of vaccination coverage, effectiveness, vaccine failure and adverse events, and gold mines for research.

Usefulness of health registries when estimating vaccine effectiveness during the influenza A(H1N1)pdm09 pandemic in Norway

BackgroundDuring the 2009-2010 pandemic in Norway, 12 513 laboratory-confirmed cases of pandemic influenza A(H1N1)pdm09, were reported to the Norwegian Surveillance System for Communicable Diseases (MSIS). 2.2 million persons (45% of the population) were vaccinated with an AS03-adjuvanted monovalent vaccine during the pandemic. Most of them were registered in the Norwegian Immunisation Registry (SYSVAK). Based on these registries, we aimed at estimating the vaccine effectiveness (VE) and describing vaccine failures during the pandemic in Norway, in order to evaluate the role of the vaccine as a preventive measure during the pandemic.MethodsWe conducted a population-based retrospective cohort study, linking MSIS and SYSVAK with pandemic influenza vaccination as exposure and laboratory-confirmed pandemic influenza as outcome. We measured VE by week and defined two thresholds for immunity; eight and 15 days after vaccination.ResultsThe weekly VE ranged from 77% to 96% when considering 15 days or more after vaccination as the threshold of immunity and from 73% to 94% when considering eight days or more. Overall, 157 individuals contracted pandemic influenza eight or more days after vaccination (8.4/100,000 vaccinated), of these 58 had onset 15 days or more after vaccination (3.0/100,000 vaccinated). Most of the vaccine failures occurred during the first weeks of the vaccination campaign. More than 30% of the vaccine failures were found in people below 10 years of age.ConclusionsHaving available health registries with data regarding cases of specific disease and vaccination makes it feasible to estimate VE in a simple and rapid way. VE was high regardless the immunity threshold chosen. We encourage public health authorities in other countries to set up such registries. It is also important to consider including information on underlying diseases in registries already existing, in order to make it feasible to conduct more complete VE estimations.

A Surveillance Model for Human Avian Influenza with a Comprehensive Surveillance System for Local-Priority Communicable Diseases in South Sulawesi, Indonesia

The government of Indonesia and the Japan International Cooperation Agency launched a three-year project (2008–2011) to strengthen the surveillance of human avian influenza cases through a comprehensive surveillance system of local-priority communicable diseases in South Sulawesi Province. Based on findings from preliminary and baseline surveys, the project developed a technical protocol for surveillance and response activities in local settings, consistent with national guidelines. District surveillance officers (DSOs) and rapid-response-team members underwent training to improve surveillance and response skills. A network-based early warning and response system for weekly reports and a short message service (SMS) gateway for outbreak reports, both encompassing more than 20 probable outbreak diseases, were introduced to support existing paper-based systems. Two further strategies were implemented to optimize project outputs: a simulation exercise and a DSO-centered model. As a result, the timeliness of weekly reports improved from 33% in 2009 to 82% in 2011. In 2011, 65 outbreaks were reported using the SMS, with 64 subsequent paper-based reports. All suspected human avian influenza outbreaks up to September 2011 were reported in the stipulated format. A crosscutting approach using human avian influenza as the core disease for coordinating surveillance activities improved the overall surveillance system for communicable diseases.

Phenotypic and genotypic properties of Neisseria gonorrhoeae isolates in Norway in 2009: antimicrobial resistance warrants an immediate change in national management guidelines

Despite rapidly diminishing treatment options for Neisseria gonorrhoeae and high levels of ciprofloxacin resistance worldwide, Norwegian guidelines still recommend ciprofloxacin as empirical treatment for gonorrhea. The present study aimed to characterize phenotypical and genotypical properties of N. gonorrhoeae isolates in Norway in 2009. All viable N. gonorrhoeae isolates (n = 114) from six university hospitals in Norway (2009) were collected, representing 42% of all notified gonorrhea cases. Epidemiological data were collected from the Norwegian Surveillance System for Communicable Diseases and linked to phenotypical and genotypical characteristics for each N. gonorrhoeae isolate. Resistance levels to the antimicrobials examined were: ciprofloxacin 78%, azithromycin 11%, cefixime 3.5%, ceftriaxone 1.8%, and spectinomycin 0%. The minimum inhibitory concentrations of gentamicin varied from 1.5 to 8 mg/L. Forty-one (36%) of the isolates were β-lactamase-producing, 17 displayed penA mosaic alleles, and 72 different N. gonorrhoeae multiantigen sequence types (ST; 37 novel) were identified. The most common ST was ST1407 (n = 11), containing penA mosaic allele. Four of these isolates displayed intermediate susceptibility/resistance to cefixime. The N. gonorrhoeae strains circulating in Norway were highly diverse. The level of ciprofloxacin resistance was high and the Norwegian management guidelines should promptly exclude ciprofloxacin as an empirical treatment option for gonorrhea.

Staff views about the quality of the communicable diseases surveillance system in Khartoum state, Sudan, 2005-2007: a qualitative study

Surveillance staff are vital to the success of surveillance of infectious diseases. In this study, we interviewed staff of the Communicable Diseases Surveillance System (CDSS) in Khartoum state individually and in focus groups to assess their views about the quality of the system for the years 2005-07. The quality of CDSS was considered poor because the system was not representative as it included neither the private nor military sectors nor the important teaching hospitals. It also lacked timeliness due to poor documentation, was inflexible since it did not rapidly respond to emerging and re-emerging diseases such as SARS and avian flu in its notification lists, and it did not use the data collected to apply interventions for control and prevention of communicable diseases on a routine basis. While staff were committed to the surveillance system and felt they worked hard, they were also demotivated and in the long run this might affect their performance.

Assessing the Spreading Patterns of Dengue Infection and Chikungunya Fever Outbreaks in Lower Southern Thailand Using a Geographic Information System

The aims of this study were to assess the incidence of dengue infection (DEN) and chikungunya fever (CHIK) and determine the direction and speed of CHIK between August 2008 and June 2009 in lower southern Thailand. The National Communicable Disease Surveillance System database and a geographic information system containing data on case locations were combined. R and ArcView were used for identifying incidence, direction, and speed of disease outbreaks. A total of 27,166 patients were identified, of which 3319 and 23,847 had DEN and CHIK, with incidences of 73 and 521 per 100,000, respectively. The direction of the CHIK outbreak moved from south to north with a median speed of 7.5 km per week. CHIK cases increased after 6 weeks of increasing cumulative rainfall with variation of average daily temperatures (23.7-30.7 degrees C) per week. There was no clear association of DEN with climate variables. The combination of surveillance and geographic information system data of DEN and CHIK can be used to determine the speed and direction of disease spread. DEN is endemic, but CHIK is an emerging disease. Because of the rapid spread of CHIK, strict and timely integrated vector control programs after case notification must be implemented.

Assessment of core activities and supportive functions for the communicable diseases surveillance system in Khartoum state, Sudan, 2005-2007.

We conducted a descriptive, retrospective, cross-sectional study to assess the core activities and supportive functions of the communicable diseases surveillance system (CDSS) in Khartoum state, Sudan, for the period 2005-2007. This is the first assessment conducted for CDSS in Khartoum state. The CDSS was studied in terms of core activities and supportive functions. We found that knowledge of the system was 100% at all levels. Data reporting was over the recommended standard of 80% at all levels. Data analysis, epidemic preparedness and feedback were below the recommended standard. All assigned CDSS staff members were trained. Lower levels lacked modern technologies for data reporting and analysis. The CDSS system in Khartoum state is centralized; moreover, the system has not been updated, it is poorly documented and has a shortage of staff at lower levels.

A survey of core and support activities of communicable disease surveillance systems at operating-level CDCs in China.

BackgroundIn recent years, problems like insufficient coordination, low efficiency, and heavy working load in national communicable disease surveillance systems in China have been pointed out by many researchers. To strengthen the national communicable disease surveillance systems becomes an immediate concern. Since the World Health Organization has recommended that a structured approach to strengthen national communicable disease surveillance must include an evaluation to existing systems which usually begins with a systematic description, we conducted the first survey for communicable disease surveillance systems in China, in order to understand the situation of core and support surveillance activities at province-level and county-level centers for disease control and prevention (CDCs).MethodsA nationwide survey was conducted by mail between May and October 2006 to investigate the implementation of core and support activities of the Notifiable Disease Reporting System (NDRS) and disease-specific surveillance systems in all of the 31 province-level and selected 14 county-level CDCs in Mainland China The comments on the performance of communicable disease surveillance systems were also collected from the directors of CDCs in this survey.ResultsThe core activities of NDRS such as confirmation, reporting and analysis and some support activities such as supervision and staff training were found sufficient in both province-level and county-level surveyed CDCs, but other support activities including information feedback, equipment and financial support need to be strengthened in most of the investigated CDCs. A total of 47 communicable diseases or syndromes were under surveillance at province level, and 20 diseases or syndromes at county level. The activities among different disease-specific surveillance systems varied widely. Acute flaccid paralysis (AFP), measles and tuberculosis (TB) surveillance systems got relatively high recognition both at province level and county level.ConclusionsChina has already established a national communicable disease surveillance framework that combines NDRS and disease-specific surveillance systems. The core and support activities of NDRS were found sufficient, while the implementation of those activities varied among different disease-specific surveillance systems.

Design of Nivārana: The power of information in prevention of epidemics

Communicable disease surveillance is an important function that is needed to control the spread of communicable diseases. The Epidemiology Unit (EU) is the principal governmental organization responsible for disease surveillance in Sri Lanka and possesses a wealth of disease related data collected over a period of several decades. Since the early detection and rapid response is the mainstay of controlling a communicable disease outbreak in a community, acquiring the ability for; collection of complete data island-wide in a timely manner, analysis of such data, and timely dissemination of analyzed data as well as guidelines on appropriate interventions will no doubt strengthen the EU’s capacity to implement disease prevention and control activities more efficiently and effectively. The software solution “Nivārana” aims to pool the information that is available through data collection and to minimize the response time by the EU and the other preventive health care institutions thereby minimizing the spread of disease. Several existing communicable disease surveillance systems were analysed to identify their capabilities and limitations. Information dissemination was identified as a completely ignored feature in existing systems as a limitation. Use of multiple data sources for better and accurate decision making was seen as an important aspect. Set of design considerations are identified to focus the design to be suitable for Sri Lanka and as well as for other developing countries. Rooted on these design considerations, the system design was carried out using object oriented concepts. The system is designed to fulfil the requirements that are set by the EU and to be configurable in division hierarchy and diseases. With the analysis capabilities and set of comprehensive reporting capabilities combined with swift information dissemination will no doubt make the public health care officers equipped with relevant, up-to-date information that could be used to control the communicable diseases. Keywords : Communicable Disease Surveillance, ICT Sri Lanka Journal of Bio-Medical Informatics 2010; 1 (3):169-178 DOI: 10.4038/sljbmi.v1i3.1767

A discussion on the strategy of evaluating the communicable disease surveillance systems in US Center for Disease Control and Prevention and World Health Organization

To compare the different surveillance system evaluation guidelines proposed by US Center for Disease Control and Prevention (CDC) and WHO, so as to develop an evaluation strategy suitable for communicable disease surveillance systems in China. Systematic collection and review on the guidelines that were proposed by US CDC and WHO. Situation analysis together with feasibility analysis were linked to the analysis of evaluation strategy used in China. US CDC guidelines were more appropriate for evaluating those single or simple systems that focusing on those 'system characteristics' while the. WHO protocols were more appropriate for evaluating the multi-system or complicated system which focusing on data related to 'system functions'. The US CDC guidelines had been widely used in China and it was the right moment to start to evaluate the functions. More flexible and comprehensive strategy based on national conditions is needed when constitute the national communicable disease surveillance evaluation guidelines. The multi-step strategy described in this article could be used as reference.

Syphilis epidemiology in Norway, 1992-2008: resurgence among men who have sex with men.

BackgroundIn recent years, the number of syphilis cases has stabilised in many countries of Western Europe, however several countries have reported increases among men who have sex with men (MSM). The aim of this article was to describe the epidemiology of early syphilis in Norway in 1992-2008.MethodsCases of early syphilis and congenital syphilis reported to the Norwegian Surveillance System for Communicable Diseases (MSIS) 1992-2008 were described by route of transmission, gender, age, birthplace, stage of disease, HIV co-infection, source partner and place of infection.ResultsThe incidence of reported syphilis ranged from 0.05 (1992) to 1.50 (2002) per 100 000 person-years. Of 562 cases reported to MSIS during the study period, 62% were men infected by another man. The proportion of those, infected homosexually increased from 0 (1992-1994) to 77% (2008). Most of them were Norwegians (83%). The proportion of HIV co-infection among homosexually infected increased over time and reached 39% in 2008. The majority reported being infected by a casual partner (73%) and in the municipality of Oslo (72%). Of 152 heterosexually infected men 64% were Norwegians; 51% were infected by casual contacts and 20% by commercial sex workers; 73% were infected abroad. Among 56 women, 57% were Norwegians, 57% were infected by a steady partner and 40% were infected abroad. Almost half (46%) were diagnosed in the early latent stage. Four cases had congenital syphilis, two of whom were adopted from abroad.ConclusionsSyphilis is rare in Norway, but MSM represent almost two thirds of cases. The increase of HIV co-infected cases among MSM may enhance transmission of both infections. We recommend sexually active MSM to be tested for syphilis 2-4 times a year. Due to its variable clinical course, syphilis might be difficult to recognise at an early stage among women in a low-prevalence population. We estimate current practice of prenatal screening in Norway as sufficient.

The epidemiology of gonorrhoea in Norway, 1993–2007: past victories, future challenges

BackgroundGonorrhoea, a bacterial infection caused by Neisseria gonorrhoeae, has been increasing in several European countries, particularly among men who have sex with men (MSM) and teenagers. We describe the epidemiology of gonorrhoea in Norway in the recent 15 years in order to guide recommendations on the diagnosis, treatment and prevention of gonorrhoea. An evaluation of the Norwegian Surveillance System for Communicable Diseases (MSIS) in 1994, involving GPs and microbiological laboratories, suggested that the system has a high coverage, capturing over 90% of patients diagnosed with gonorrhoea.MethodsUsing MSIS data on gonorrhoea cases we analysed specific trends by route of transmission, age, gender, anatomical sampling site, antimicrobial resistance and travel history from 1993–2007 and, to focus on more recent trends, from 2003–2007. MSM and heterosexual cases were defined by route of transmission.ResultsFrom 1993 to 2007, 3601 gonorrhoea cases were reported. MSM cases increased from 10 in 1994 to 109 cases in 2004. From 2003–2007, the incidence of gonorrhoea was 5.4/100,000 person-years (95%CI: 4.9–6.0). Over these five years, MSM accounted for an average of 80 cases per year, of which 69% were infected by casual partners. In the same period, 98% of heterosexually infected had a positive swab from urethra only and only two (0.3%) from the pharynx. Only one woman (0.5%) was positive from the rectum. From 1993 – 2007, antimicrobial resistance results were reported for 3325 N. gonorrhoeae isolates (98% of cultured samples). The proportion resistant to quinolone has risen from 3% in 1995 to 47% in 2007, with 81% of the latter isolated from patients infected in Asia.ConclusionThe overall incidence of gonorrhoea in Norway remains low, but the increasing number of MSM cases calls for new, more effective approaches to prevention. Infections originating from abroad represent a constant risk of importing antimicrobial resistant N. gonorrhoeae. Due to the prevalence of quinolone resistant N. gonorrhoeae in Norway, third-generation cephalosporins should replace quinolones as the first choice in treatment guidelines. We advocate antimicrobial susceptibility testing for all cases and recommend taking samples for culture from all exposed anatomical sites.

Overvåking og forekomst av antibiotikaresistens i Norge

Antimicrobial resistance has become increasingly prevalent in clinically important microbes since the 1970s. The global situation affects also Norway. This article reviews the surveillance of antimicrobial resistance in Norway and its results in recent years. The article is based on the author's own experience and a non-systematic literature review. There are three systems for surveillance of antimicrobial resistance in Norway: The Norwegian Surveillance System for Communicable Diseases (MSIS), the Norwegian Surveillance System for Antimicrobial Drug Resistance (NORM), and the European Antimicrobial Resistance Surveillance System (EARSS). Surveillance results and individual studies show that the prevalence of resistance is lower in Norway than in other countries. However, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), penicillin non-susceptible pneumococci and gram-negative enteric bacteria with extended spectrum betalactamases are present within the bacterial population in Norway. The surveillance systems support each other and are important tools to combat antimicrobial resistance. Continued surveillance, good laboratory diagnostics, prudent antibiotic use and effective infectious disease control are necessary measures to prevent and contain antimicrobial resistance in Norway.

A community-level Communicable Disease Surveillance System in a Metropolitan city.

A community-level Communicable Disease Surveillance System in a Metropolitan city.

AIDS-related primary central nervous system lymphoma: a Norwegian national survey 1989–2003

BackgroundPrimary central nervous system lymphoma (PCNSL) is a frequent complication in acquired immunodeficiency syndrome (AIDS). The objective of this survey was to investigate incidence, clinical features, radiological findings, histologic diagnosis, treatment and outcome for all patients with histologically verified AIDS-related PCNSL diagnosed in Norway in 1989–2003.MethodsWe identified the patients by chart review of all cases recorded as PCNSL in The Norwegian Cancer Registry (by law recording all cases of cancer in Norway) and all cases recorded as AIDS-related PCNSL in the autopsy registry at a hospital having 67% autopsy rate and treating 59% of AIDS patients in Norway, from 1989 to 2003. Histologic material and radiological images were reviewed. We used person-time techniques to calculate incidence rates of PCNSL among AIDS patients based on recordings on AIDS at the Norwegian Surveillance System for Communicable Diseases (by law recording all cases of AIDS in Norway).ResultsTwenty-nine patients had histologically confirmed, newly diagnosed AIDS-related PCNSL in Norway from 1989–2003. Only 2 patients had this diagnosis established while alive. AIDS patients had 5.5% lifetime risk of PCNSL. Their absolute incidence rate of PCNSL per 100 person-years was 1.7 (95%CI: 1.1–2.4) and decreased during the consecutive 5-year periods from 3.6, to 2.5, and to 0.4 (p < 0.001). Median survival from initial symptom of PCNSL was 2.3 months, but one patient was still alive 4 years after completed radiotherapy.ConclusionThis is the first national survey to confirm decreasing incidence of AIDS-related PCNSL. Despite dismal survival in most patients, the possibility of long term survival should prompt more aggressive diagnostics in suspected PCNSL.

Effectiveness of a 2+1 dose schedule pneumococcal conjugate vaccination programme on invasive pneumococcal disease among children in Norway

The 7-valent pneumococcal conjugate vaccine (PCV-7) was licensed in Norway in 2001. In July 2006, PCV-7 was introduced in the Norwegian Childhood Vaccination Programme in a 2+1 dose schedule, with immunizations administered at 3, 5 and 12 months of age. PCV-7 was offered through the vaccination programme to all children born from January 2006, i.e. a catch-up for children aged 3–6 months. Prior to 2006 the use of PCV-7 was negligible. The effectiveness of the PCV-7 vaccination programme was assessed using data on invasive pneumococcal disease (IPD) incidence obtained from the Norwegian Surveillance System for Communicable Diseases, serotype distribution from the National Reference Laboratory for Pneumococci, and vaccine coverage and vaccination status from the Norwegian National Vaccination Register. Vaccine coverage quickly reached high levels; 95% of children >3 months born from January 2006 had received at least one immunization with PCV-7. The incidence rate of IPD among children <2 years rapidly declined; the rate of vaccine serotype IPD in this age group fell from an average of 47.1 cases/100,000 population in the 2 years prior to PCV-7 introduction to 13.7 cases/100,000 population in 2007. The incidence rate of nonvaccine serotype IPD remained stable. The vaccine programme effectiveness was estimated to be 74% (95% CI 57–85%). No vaccine failure was seen after complete primary immunization with two vaccine doses. Our findings indicate that PCV-7 provides highly effective protection against vaccine serotype IPD when administered in a 2+1 dose schedule.

Implications of the International Health Regulations (2005) for communicable disease surveillance systems: Tunisia's experience

Background In May 2005, the revised International Health Regulations, known as IHR (2005), were adopted in response to the evolving nature of communicable diseases (CD) and the rapid increase in global trade and travel. CD surveillance is an integral part of a country's core requirements under the regulations. Methods The implications of these requirements were assessed as part of a review of the national CD surveillance system of Tunisia using a qualitative methodology of strengths, weaknesses, opportunities and threats (SWOT). Results Tunisia is some way towards meeting the requirements of IHR (2005) while some specific areas that need to be addressed are highlighted for improvement: standardization of surveillance documents, strengthening the role of the laboratory in surveillance, increased human resources and training. Conclusions Tunisia's experience can offer some lessons to other countries in this process. While meeting the capacity obligations of IHR (2005) requires investment and commitment, this investment will enable countries to better protect themselves against public health emergencies arising within their borders and threatening from elsewhere in the world.

Introduction and Evaluation of Communicable Disease Surveillance in the Republic of Korea

Effective communicable disease surveillance systems are the basis of the national disease prevention and control. Following the increase in emerging and re-emerging infectious diseases since late 1990 s, the Korean government has strive to enhance surveillance and response system. Since 2000, sentinel surveillance, such as influenza sentinel surveillance, pediatric sentinel surveillance, school-based sentinel surveillance and ophthalmological sentinel surveillance, was introduced to improve the surveillance activities. Electronic reporting system was developed in 2000, enabling the establishment of national database of reported cases. Disweb, a portal for sharing communicable disease information with the public and health care workers, was developed. In general, the survey results on usefulness and attributes of the system, such as simplicity, flexibility, acceptability, sensitivity, timeliness, and representativeness, received relatively high recognition. Compared to the number of paid cases of national health insurance, reported cases by national notifiable disease surveillance system, and various sentinel surveillance system, the result of the correlation analysis was high. According to the research project conducted by KCDC, the reporting rate of physicians in 2004 has also greatly improved, compared with that in 1990 s. However, continuous efforts are needed to further improve the communicable disease surveillance system. Awareness of physicians on communicable disease surveillance system must be improved by conducting education and information campaigns on a continuous basis. We should also devise means for efficient use of various administrative data including cause of death statistics and health insurance. In addition, efficiency of the system must be improved by linking data from various surveillance system.