National Public Health Surveillance System Research Articles

Impact of rurality on maternal and infant health indicators and outcomes in Maine

Rural residents may face health challenges related to geographic barriers to care, physician shortages, poverty, lower educational attainment, and other demographic factors. In maternal and child health, these disparities may be evidenced by the health risks and behaviors of new mothers, the health of infants born to these mothers, and the care received by both mothers and infants. To determine the impact of rurality on maternal and child health in Maine, USA, 11 years of data (2000-2010) for the state of Maine from the Pregnancy Risk Assessment Monitoring System (PRAMS) project were analyzed. PRAMS is a national public health surveillance system that uses questionnaires to survey women who had delivered live infants in the previous 2-4 months. Using a geographic information system, each questionnaire response was assigned a rurality tier (urban, suburban, large rural town, or isolated rural community) based on the rural-urban commuting area code of the town of residence of the mother. Results from the four rurality tiers were compared using the survey procedures in Statistical Analysis Software to adjust for the complex sampling strategy of the PRAMS dataset. Means (for continuous variables) and percentages (for categorical variables) were calculated for each rurality tier, along with 95% confidence intervals. Significant differences between rurality tiers were tested for using F-tests or χ2 tests. If significant differences between rurality tiers existed (p<0.05), specific tiers were judged to be different from each other if their 95% confidence intervals did not overlap. A total of 12 600 mothers responded to the PRAMS questionnaire during the study period. Compared to mothers from more urban areas, rural mothers were younger (10.5% of mothers from isolated rural areas were teenagers compared to 6.2% of mothers from urban areas), less well educated, less likely to be married, and more likely to live in lower income households (39.6% of isolated rural mothers had household incomes ≤US$20 000/year vs 28.8% of urban mothers). Rural mothers had higher pre-pregnancy body mass indexes (BMIs; average BMI 26.1 for isolated rural women vs 25.3 for urban women) and were more likely to smoke but less likely to drink alcohol (both before and during pregnancy). Compared to mothers from more urban areas, rural mothers were not sure they were pregnant until a later gestational age but received prenatal care just as early and were just as likely to receive prenatal care as early as they wished. There were no differences among rurality tiers in Caesarean section rates, rates of premature births (<37 weeks gestation), or rates of underweight births (<2500 g). However infants born to rural mothers were less likely to be breastfed (52.9% of isolated rural vs 60.9% of urban infants breast fed for ≥8 weeks). These results show that, while rural women face significant demographic and behavior challenges, their access to prenatal care, the care they receive while pregnant, and the outcomes of their pregnancies are similar to those of urban women. These results highlight areas where focused pre-pregnancy and prenatal education may improve maternal and child health in rural Maine.

Evaluation of dengue fever reports during an epidemic, Colombia.

OBJECTIVETo assess the validity of dengue fever reports and how they relate to the definition of case and severity.METHODSDiagnostic test assessment was conducted using cross-sectional sampling from a universe of 13,873 patients treated during the fifth epidemiological period in health institutions from 11 Colombian departments in 2013. The test under analyses was the reporting to the National Public Health Surveillance System, and the reference standard was the review of histories identified by active institutional search. We reviewed all histories of patients diagnosed with dengue fever, as well as a random sample of patients with febrile syndromes. The specificity and sensitivity of reports were estimated for this purpose, considering the inverse of the probability of being selected for weighting. The concordance between reporting and the findings of the active institutional search was calculated using Kappa statistics.RESULTSWe included 4,359 febrile patients, and 31.7% were classified as compatible with dengue fever (17 with severe dengue fever; 461 with dengue fever and warning signs; 904 with dengue fever and no warning signs). The global sensitivity of reports was 13.2% (95%CI 10.9;15.4) and specificity was 98.4% (95%CI 97.9;98.9). Sensitivity varied according to severity: 12.1% (95%CI 9.3;14.8) for patients presenting dengue fever with no warning signs; 14.5% (95%CI 10.6;18.4) for those presenting dengue fever with warning signs, and 40.0% (95%CI 9.6;70.4) for those with severe dengue fever. Concordance between reporting and the findings of the active institutional search resulted in a Kappa of 10.1%.CONCLUSIONSLow concordance was observed between reporting and the review of clinical histories, which was associated with the low reporting of dengue fever compatible cases, especially milder cases.

A pilot behavioural and biological surveillance survey for HIV and other bloodborne infections among Aboriginal people in Regina, Saskatchewan.

Aboriginal people in Canada are disproportionately affected by HIV and other blood-borne infections. A-Track is a national public health surveillance system designed to monitor HIV and related infections, behaviours and socio-demographic factors among Aboriginal populations in Canada. The pilot survey for the A-Track surveillance system, the first of its kind in Canada, was conducted in Regina, Saskatchewan and implemented via a community and public health partnership. To assess the prevalence of HIV, hepatitis C, syphilis and associated risk behaviours and socio-demographic factors among Aboriginal people in Regina, Saskatchewan. This focus of the pilot survey was to provide this surveillance information for public health action and to determine whether this type of public health surveillance activity could be conducted in an urban setting across Canada. Survey participants were self-identified Aboriginal people (First Nations, Inuit or Métis) or those who claimed Aboriginal ancestry and between the ages of 16 and 60 years. These individuals were also asked to provide a blood sample for HIV, hepatitis C and syphilis antibody testing. Descriptive analyses were performed with sex-based comparisons. There were 1064 people who participated in the survey. Their average age was 33 years and 51% were male. The majority of participants (93%) lived in urban Regina at the time of the survey. Just over half (53.2%) of all participants had been removed from their families during childhood; 29.9% had lived in a residential or boarding school during childhood; and 57.7% had lived at some point in a correctional facility. Among the 1,045 participants who provided a blood sample of sufficient quantity for testing, 5.2% were HIV seropositive and 55.8% of these were aware of their HIV status. The lifetime exposure to hepatitis C was 41.6%, with significantly higher proportions of males than females testing positive for hepatitis C exposure. Syphilis seroprevalence was very low (<1%). Almost three-quarters (71.5%) of participants reported being tested for HIV at least once in their lifetime and among those ever tested, 67.6% had been tested during the 12 months prior to the interview. Aboriginal people are disproportionately affected by the HIV/AIDS epidemic in Canada. The findings from the A-Track pilot survey can be used to inform and evaluate prevention and treatment services for HIV and other related infections among Aboriginal people. Lessons learned from the pilot survey could also be used to guide the possible implementation of A-Track in other urban and/or reserve locations in Canada.

Key findings from a national enhanced HIV surveillance system: 2010 - 2012.

People who inject drugs represent an important risk group in Canada's HIV epidemic. I-Track is a national public health surveillance system designed to monitor HIV and hepatitis C prevalence and associated risk behaviour factors among people who inject drugs in Canada. Information is collected through cross-sectional surveys conducted periodically at sentinel sites across Canada. I-Track Phase 3 was conducted between April 26, 2010 and August 7, 2012 across 11 participating sentinel sites. To assess the prevalence of HIV, lifetime exposure to hepatitis C and associated risk behaviours among people who inject drugs in Canada to guide and help evaluate HIV and hepatitis C prevention, treatment and control activities. People who had injected drugs in the six months prior to the interview and who met the minimum age of consent participated in an interviewer administered survey and provided a blood sample for HIV and hepatitis C antibody testing. Descriptive analyses were performed with sex-based comparisons. There were 2,687 people who participated in the survey. 68.2% were male, 60.9% were between the ages of 30 and 49 years and 36.2% self-identified as Aboriginal. Among the participants who provided a blood sample of sufficient quantity for testing, 11.2% were HIV seropositive and their lifetime exposure to hepatitis C infection was 68.0%. Drugs commonly injected included cocaine (64.3%), hydromorphone (47.2%), non-prescribed morphine (47.0%), oxycodone (37.7%) and heroin (26.7%). Injecting with previously used needles and/or other injection equipment was reported by 15.5% and 34.5% of participants, respectively. Just over one-third reported having two or more sex partners in the six months prior to the interview (34.4%) and using a condom at last sex (36.6%). The majority of participants had tested at least once in their lifetime for HIV or hepatitis C (92.9% and 91.4%, respectively). A large proportion of the participants who reported being HIV positive were under the care of a doctor (95.0%) and nearly two-thirds were taking medications prescribed for their HIV infection at the time of the interview (66.0%). HIV seroprevalence and lifetime exposure to hepatitis C infection were high among I-Track Phase 3 participants. Although many participants reported safe injection and safe sexual practices, a high proportion of participants reported risk behaviours associated with acquisition and transmission of HIV and hepatitis C. People who inject drugs continue to represent an important risk group in Canada's HIV epidemic and the I-Track Phase 3 survey findings highlight the need for continued treatment and prevention services, as well as routine and integrated testing among people who inject drugs.

Environmental Public Health Tracking: Success Stories from a Collaborative Surveillance System

The National Environmental Public Health Tracking Program facilitates the linkage of environmental information to health outcomes through development of a national standards-based public health surveillance system that provides useful information to improve where we live and work. State tracking programs have successfully used their tracking networks to identify and educate at-risk communities. Other success stories include endeavours to improve surveillance, support epidemiologic studies, target prevention efforts, and inform policymakers. Future directions include identifying knowledge gaps, developing plans for adding new data sources and collaborators to fill those gaps, and improving application and utility of the Tracking Networks.

Applications and Comparisons of Four Time Series Models in Epidemiological Surveillance Data

Public health surveillance systems provide valuable data for reliable predication of future epidemic events. This paper describes a study that used nine types of infectious disease data collected through a national public health surveillance system in mainland China to evaluate and compare the performances of four time series methods, namely, two decomposition methods (regression and exponential smoothing), autoregressive integrated moving average (ARIMA) and support vector machine (SVM). The data obtained from 2005 to 2011 and in 2012 were used as modeling and forecasting samples, respectively. The performances were evaluated based on three metrics: mean absolute error (MAE), mean absolute percentage error (MAPE), and mean square error (MSE). The accuracy of the statistical models in forecasting future epidemic disease proved their effectiveness in epidemiological surveillance. Although the comparisons found that no single method is completely superior to the others, the present study indeed highlighted that the SVMs outperforms the ARIMA model and decomposition methods in most cases.

Automated early warning system for the surveillance of Salmonella isolated in the agro-food chain in France

Non-typhic Salmonella is one of the major bacterial pathogens that cause foodborne infections as well as economic losses for the food production industry. There is therefore a need to improve early detection to prevent the emergence and spread of Salmonella within the agro-food chain. The passive laboratory-based surveillance system of the Salmonella network has been integrated into the French Food Safety Agency's working plan. The objective of this study was to evaluate the ability of this network to detect unusual Salmonella contamination as early as possible in the agro-food chain. Three statistical methods were used to detect unusual events from the time-series of counts. After an experimental period of more than 1 year, this approach detected several unusual events linked to contamination in the agro-food chain that were confirmed in a timely manner at national or regional levels. This evaluation also reinforced the position of the Salmonella network as an integral part of the national public health surveillance system.

Internet surveillance systems for early alerting of health threats

In order to gather a comprehensive picture of potential epidemic threats, public health authorities increasingly rely on systems that perform epidemic intelligence (EI). EI makes use of information that originates from official sources such as national public health surveillance systems as well as from informal sources such as electronic media and web-based information tools.

Environmental Public Health Tracking/Surveillance in Canada: A Commentary

Although public debate in Canada about climate change and air pollution is louder than ever, the state of the environment remains a relatively neglected determinant of health, and environmental public health infrastructure and programs are poorly developed. Health Canada has only recently begun to develop a national environmental public health tracking or surveillance system. The authors review progress on environmental public health tracking in other jurisdictions and suggest a strategic approach to the development of a coherent national system of sensitive, targeted surveillance indicators for environmental health by addressing the following questions: Which environmental hazards and exposures, and which health effects along the continuum from "release" to "health effect," should be tracked? Which indicators are scientifically robust and practical for tracking environmental health problems in Canada?

Improvement of a national public health surveillance system through use of a quality circle

Surveillance systems for infectious diseases build the basis for effective public health measures in the prevention and control of infectious diseases. Assessing and improving the quality of such national surveillance systems is a challenge, as many different administrations and professions contribute to a complex system in which sensitive information must be exchanged in a reliable and timely fashion. We conducted a multidisciplinary quality circle on the national public health surveillance system in Germany which included clinicians, laboratory physicians, and staff from local and state health departments as well as from the Robert Koch-Institut. The recommendations resulting from the quality circle included proposals to change the federal law for the control of infectious diseases as well as practical activities such as the change of notification forms and the mailing of faxed information letters to clinicians. A number of recommendations have since been implemented, and some have resulted in measurable improvements. This demonstrates that the applied method of quality circle is a useful tool to improve the quality of national public health surveillance systems.

Blueprint for a National Public Health Surveillance System for the 21st Century

This article lays out a blueprint for public health surveillance and assessment for the year 2000 and beyond. The blueprint defines the roles of local, state, and national public health agencies and partners in the medical care system in conducting surveillance and assessment activities. It proposes a new over-arching National Public Health Surveillance System to be the conceptual framework for all public health surveillance and assessment activities into the 21st century.

The future of national public health surveillance in the United States.

Public health surveillance systems should have the capacity to collect and analyze data, disseminate data to public health programs, and regularly evaluate the effectiveness of the use of disseminated data. Unfortunately, in the United States, systems of public health surveillance are fragmented and do not adequately address either current or new potential challenges to public health. This commentary addresses components of any effort toward a national public health surveillance system and highlights examples of these components in state and national surveillance developments.

Pertussis—United States, January 1992-June 1995

Pertussis was a major cause of morbidity and mortality among infants and children in the United States during the prevaccine era (i.e., before the mid-1940s). Since pertussis became a nationally reportable disease in 1922, the highest number of pertussis cases (approximately 260,000) was reported in 1934; the highest number of pertussis-related deaths (approximately 9000) occurred in 1923. Following the licensure of whole-cell pertussis vaccine combined with diphtheria and tetanus toxoids (DTP) in 1949 and the widespread use of DTP among infants and children, the incidence of reported pertussis declined to a historical low of 1010 cases in 1976 (Figure 1). However, since the early 1980s, reported pertussis incidence has increased cyclically with peaks occurring in 1983, 1986, 1990, and 1993 (1-3). This report summarizes national surveillance data for pertussis from January 1992 through June 1995 from CDC's National Public Health Surveillance System (NPHSS) and Supplementary Pertussis Surveillance System (SPSS) and assesses the effectiveness of pertussis vaccination in the United States during this period using vaccination coverage data from CDC's National Health Interview Survey (NHIS).

Variations in national infectious diseases surveillance in Europe

Because the Maastricht treaty includes a chapter on public health in the European Community (EC) public health surveillance needs to be developed at EC level. To assess the feasibility of EC surveillance we did a survey of national systems in Europe in 1991-92. In seventeen countries (twelve EC plus Austria, Finland, Norway, Sweden, and Switzerland) the public health institution(s) responsible for surveillance were visited to collect standardised data on surveillance systems for sexually transmitted diseases (STD), hepatitis, and tuberculosis (TB). Surveillance systems varied widely by type, design, and quality. Although mandatory notification has a place in nearly all countries there is a trend towards voluntary systems based on samples of physicians, clinics, or laboratories. The time unit for reporting ranged from daily to once a year. For mandatory notification systems of STD completeness of reporting varied from over 90% to less than 10% and most countries did not use case definitions. Surveillance data were disseminated through national epidemiological bulletins in twelve countries, and the bulletin was a weekly one in six. The heterogeneity of national public health surveillance systems that this survey has revealed points to the need for a coordinated approach if surveillance at an EC level is to be developed.