In this thesis, I investigated the relationship between host and pathogen in multi-host and multi-pathogen systems at the interface between wildlife and domestic species. The term “epidemiological interaction” was central to my thesis, and was defined as “any ecological interaction between two host populations resulting in the transmission of one or more pathogen”. Epidemiological interactions are related to the processes of transmission between hosts and I investigated how these epidemiological interactions between different host populations could be investigated in a given ecosystem. I developed two research frameworks to estimate these epidemiological interactions: 1) an a priori approach based on the host data and assuming that the mobility of hosts and the resulting contacts between host populations would be crucial factors influencing the epidemiological interactions; 2) an a posteriori approach based on the pathogen data, assuming that epidemiological pathways previously used by some pathogen species can be used in the future by other pathogens. The animalpathogen model used to test the first approach was the bird-avian influenza viruses’ model. Longitudinal counting and sampling protocols of domestic and wild birds over two years were used to analyse community composition and abundance of hosts to compare with the prevalence of avian influenza viruses. I could, for the first time, show a persistence of low pathogenic avian influenza strains in an African ecosystem, and investigate the relationships with both the potential maintenance hosts (Afro-tropical ducks and resident species) and hosts that introduced the virus into the system from Europe or Asia (paleartic migrants). With the estimation of epidemiological interaction using host community data, I estimated the contact rate between wild and domestic avian compartments (intensive poultry, backyard and farmed ostrich compartments) and assigned a risk to this interaction based on dynamic and non dynamic factors for each bird species. This approach highlights the species or seasons at risk for the domestic compartments (or for the wild bird compartments depending on the perspective) in order to orientate surveillance or control options. This type of data and framework can also be used in mechanistic modelling to predict the spread of a pathogen after its introduction in one compartment. I tested the host approach in a broader dataset at the Southern African region level with similar counting and sampling database in multiple study sites, showing that the variability of host communities across the region could explain the variability of pathogen detection (however, finding a causal relationship was impossible). Finally, I theoretically developed the pathogen approach by combining tools used in parasite community ecology, molecular epidemiology and social network analysis and gave a theoretical example using a rodent and human macro and microparasite dataset. This thesis has explored the field of transmission ecology and offered ways to quantify the processes of transmission between host populations. Theoretically, I have developed a fundamental reflexion around epidemiological interactions and formulated hypotheses on their potential for being independent of the parasite species. Practically, I have developed tools to provide information for decision-making in order to improve efficiency of surveillance and control programmes at the wildlife/domestic interface particularly adapted to detect emerging infectious disease spill-over process. / Thesis (PhD)--University of Pretoria, 2011. / Zoology and Entomology / unrestricted

Magister Chirurgiae Dentium (MChD) / There is an absence of both dental services and systematic planning to meet the oral health needs of the Black* population ~f greater Cape Town. Little epidemiological data exists upon which such planning can be based. This study describes the prevalence and treatment need related to tooth decay and periodontal disease ofaXhosa-speaking* squatter community on the outskirts of Cape Town. An age and sex stratified sample of 290 adults attending the SACLA clinic in Crossroads were examined. Examiner variability was measured by a percentage intra-examiner agreement for the DMFT of 95% and for the CPITN 84%. Cohen's kappa statistic, for tooth-specific caries detection errors was k = 0.877. The mean DMFT was 11.8 and varied little with sex or age below 55 years. After this age, the DMFT climbs steeply due largely to the rapid increase in the M value (missing teeth). The results show that for every tooth needing to be extracted, two teeth per subject required a restoration. Only three subjects already had some restorations. Periodontal health was reflected by a high prevalence of calculus (TN2 = 99%; MNS = 5.2) for the whole sample. Deep pockets were detected in 13% of those aged between 15 and 29 years, but only at a relatively low intensity (MNS = 0.1). This prevalence reached a high 60% for those aged between 45 and 64 years (MNS = 1.7). All subjects require oral hygiene instruction and gross scaling in at least four sextants, according to CPITN criteria. In conclus~on it is noted that there is a shortage of relevant epidemiological information necessary to the planning of oral health services to improve the oral health of the Xhosa-speaking community in the Western Cape. Caries prevalence rates are already high in young adults and a high tooth mortality rate and an absence of fillings, suggests that extraction is the only form of treatment made available to this community. The absence of appropriate prevention strategies such as water fluoridation is reflected in these results. The existence of small amounts of severe periodontal disease in young adults is of concern. The high prevalence of mild (and preventable) periodontal disease, seems to reflect a low awareness of the condition and/or a lack of resources to control it. It is no coincidence that such poor oral health was observed in this, a poor, peri-urban squatter community. This study, serves as a sad reminder of the maldistribution of oral health and socia-economic resources in South Africa. The socia-economic and political character of this community is reflected by the epidemiological picture of oral health observed in the study. It is clear that further data must be collected, especially a clear assessment of community-expressed needs. Active planning must take place urgently to integrate oral health with Primary Health Care to rectify the serious misuse and maldistribution of oral health resources required to improve the oral health of this population.

Over the past century, the prevalence of immune-mediated inflammatory diseases (IMIDs) has increased worldwide. It has been identified that exposures to environmental factors early in life are associated with increased risk of these diseases. However, hypothesis-driven analyses do not always identify all risk or protective factors, nor do they adequately explain interactions between variables on the risk of disease. Data mining has the capability of exploring the data without considering specific a priori hypotheses, instead providing possible hypotheses for further analysis. Though, data mining techniques are still not popular among epidemiologists as a trustworthy analytical tool to analyze population-based diseases due to inexplicability of some of the methods (e.g., neural networks), unfamiliarity with, or uncommon use of machine learning and data mining methods in real-world health care applications. At the same time, large amounts of routinely collected health data are amassed as a matter of operating electronic health systems. Routinely collected health data are not collected for research purposes; however, they are great sources of information for research as a secondary use of the data. In this study, following the design science research methodology, we developed a methodology to reliably analyze health administrative data using data mining techniques to provide reproducible, reliable, and trustworthy findings. The reliable data mining methodology on health administrative data was designed in this study to address impartiality, validity, and sustainability concerns in five stages: Data Selection, Preprocessing, Modelling, Evaluation, and Feedback. As part of the main contributions, we developed two unique preprocessing guidelines as the key components of the designed methodology in order to standardize technical steps and address contextual sources of bias. While the proposed methodology is general in its design, to evaluate the designed methodology, we implemented it in several case studies on the real health administrative data housed at ICES, Ontario, first to analyze children suffering with an IMID in Ontario, predict new cases, and, most importantly, generate new hypotheses. The first case study was extended to a second one to narrow focus from all IMIDs to asthma which formed the majority of the IMID cases. Eventually, a third case study was implemented focusing on inflammatory bowel disease (IBD) and systemic autoimmune rheumatic diseases (SARDs) to better compare the findings. We applied both predictive and descriptive modelling techniques such as decision tree, neural network, logistic regression, and k-means clustering on the prepared datasets with more than 700K records and over 80 input variables. We built classification models with notable quality of performance (AUC of 68%), identified the significant factors associated to IMIDs, and extracted multifactorial rules causing protectiveness against or high risk of developing asthma, IBD, and SARDs. The factors that highly contributed to the extracted multifactorial rules were “general childhood infection”, “use of antibiotics”, “streptococcus pyogenes”, “respiratory infection”, “gastroenteritis”, “mother's prevalence of any IMID”, and “baby's sex”. The findings were evaluated and verified by health experts. Most data mining studies which are applied to health data do not handle bias and confounding in their work. However, the systematic errors were identified, and their risks were assessed in these case studies due to following the designed reliable methodology. The results with high risk of bias were reported to disregard. Therefore, this process allowed us to apply data mining techniques to discover new multifactorial rules and identify the factors with the highest impact among the 128 factors observed in the past epidemiological studies, while preserving the trust of domain experts in the results.

Many immunization programs in developing countries arr now undergoing a period of rapid utilization. Innovative strategies, such as immunization holidays, are being tried. Political commitment and enthusiasm are high. There is a strong desire by health professionals to protect the lives of many children from the untimely death and/or disability resulting from infectious diseases preventable by vaccination. Evaluation of an immunization program can benefit other elements of the health system, particularly those that are not amenable to objective evaluation as immunization. In this case, immunization can serve as an indicator of the overall performance of the health system. The problems revealed by evaluation of the immunization program could therefore be taken as problems generic to the health services as a whole. In remedying the problems for immunization, approaches that would improve the health services as a whole should be sought. The primary purpose of this study was to determine the intrinsic and extrinsic factors contributing to coverage and participation rates of the vaccination program in Arssi, Ethiopia. vaccination program participation is relatively easy to estimate, although its importance should not be overemphasized as the primary goal of immunization programs is the reduction in mortality, morbidity, and disability resulting from infectious diseases preventable by vaccination. The survey questionnaire, adopted by the World Health Organization (WHO), was one of the instruments used for this project. Results of the evaluation in 1988 showed that only 66.5% of the children surveyed were fully vaccinated, while 26.9% were partially vaccinated, and 16.6% were not vaccinated at all. Comparisons of the survey results between the years 1983, 1985, and 1988 was made to determine whether or not there was improvement in vaccination coverage between the years. Decisions about the differences of the survey results in population proportions between the years were based on whether or not the differences were scientifically significant, leading us to the rejection of the null hypothesis of no difference (zero), and whether or not the results were scientifically important (whether or not the results showed an increase in vaccination coverage). An increase in usage rate was noticed more in 1988 than the previous survey results of 1985 and 1983. Mothers or guardians were asked about the possible reasons of immunization failures when their children or themselves were found partially or not-vaccinated. The reasons included such facts as lack of information, lack of motivation, obstacles/barriers, and wrong/improper vaccination techniques. Based on the literature review and the survey results, recommendations were made to help correct the observed problems and achieve a higher level of vaccination coverage.

Traditional disease surveillance can be augmented with a wide variety of open sources, such as online news media, twitter, blogs, and web search records. Rapidly increasing volumes of these open sources are proving to be extremely valuable resources in helping analyze, detect, and forecast outbreaks of infectious diseases, especially new diseases or diseases spreading to new regions. However, these sources are in general unstructured (noisy) and construction of surveillance tools ranging from real-time disease outbreak monitoring to construction of epidemiological line lists involves considerable human supervision. Intelligent modeling of such sources using text mining methods such as, topic models, deep learning and dependency parsing can lead to automated generation of the mentioned surveillance tools. Moreover, real-time global availability of these open sources from web-based bio-surveillance systems, such as HealthMap and WHO Disease Outbreak News (DONs) can aid in development of generic tools which will be applicable to a wide range of diseases (rare, endemic and emerging) across different regions of the world. In this dissertation, we explore various methods of using internet news reports to develop generic surveillance tools which can supplement traditional surveillance systems and aid in early detection of outbreaks. We primarily investigate three major problems related to infectious disease surveillance as follows. (i) Can trends in online news reporting monitor and possibly estimate infectious disease outbreaks? We introduce approaches that use temporal topic models over HealthMap corpus for detecting rare and endemic disease topics as well as capturing temporal trends (seasonality, abrupt peaks) for each disease topic. The discovery of temporal topic trends is followed by time-series regression techniques to estimate future disease incidence. (ii) In the second problem, we seek to automate the creation of epidemiological line lists for emerging diseases from WHO DONs in a near real-time setting. For this purpose, we formulate Guided Epidemiological Line List (GELL), an approach that combines neural word embeddings with information extracted from dependency parse-trees at the sentence level to extract line list features. (iii) Finally, for the third problem, we aim to characterize diseases automatically from HealthMap corpus using a disease-specific word embedding model which were subsequently evaluated against human curated ones for accuracies. / Ph. D.

<p dir="ltr">Antigenically variable pathogens (AVPs) pose a significant infectious disease burden, but vaccine development is extremely difficult due to their ability to quickly evolve beyond host immunity. Existing models of AVP spread have not been able to sufficiently account for host immune history, population mobility patterns, and pathogen evolutionary dynamics. This thesis aims at creating a computational framework built from the concept of antibody landscapes to overcome these issues, thereby increasing the understanding of how these pathogens spread and evolve in order to improve vaccine design.</p><p><br></p><p dir="ltr">Briefly, the proposed stochastic framework is built from "the ground up'' using principles of antibody landscapes, in which we begin by devising a mechanism to describe how the landscape changes due to repeated pathogen exposure. Extending this to a (sub)population-level permits integration into a meta-population model that is further parameterized by geographic influences. Virus evolution is driven by a statistically meaningful model of antigenic drift in the underlying antigenic space. While the framework is robust and, in principle, capable of modeling a variety of AVPs, we focus on influenza H3N2 as a case study due to its data availability and persistently low and unpredictable vaccine efficacy.</p><p><br></p><p dir="ltr">Experimental results demonstrate that we can statistically significantly predict various properties of H3N2 evolution and population level immunity, including prevalence level, the timing of emergence of new antigenic clusters, the positions of unseen strains in antigenic space, as well as the geographic locations where new strains and antigenic clusters emerge. Through analysis of the simulated outcomes, we identified a population level of immune protection against circulating strains (titre value of approximately 5 units), which when approached, seems to signal an upcoming antigenic drift. Using this insight, we propose a new vaccine strain selection strategy that shows notable improvements in vaccine effectiveness and stability. Additionally, we estimate that it could reduce annual morbidity by 73.4 ± 40.8 million (17% ± 9%) in the Northern Hemisphere and 56.7 ± 38.0 million (10% ± 6%) in the Southern Hemisphere. In summary, this novel framework can accurately replicate the interplay between pathogen evolution and population-level immune responses decades into the future from a mechanistic perspective, and be used to design improved vaccines.</p>

FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A subnotificaÃÃo de casos de Aids representa um dos principais problemas enfrentados pela vigilÃncia epidemiolÃgica da Aids. Dessa forma este trabalho teve como objetivo, conhecer a subnotificaÃÃo dos casos de Aids em adultos no municÃpio de Fortaleza, nos anos de 2002 e 2003, aplicando o mÃtodo de captura e recaptura. Estimou-se ainda, a subnotificaÃÃo em dois hospitais de referÃncia para Aids, Hospital SÃo Josà â HSJ e Hospital Geral de Fortaleza â HGF. Nesse estudo foram utilizados dados secundÃrios do Sistema de InformaÃÃo de Agravo de NotificaÃÃo â Sinan, Sistema de Controle de Exames Laboratoriais - Siscel e Sistema de InformaÃÃes sobre Mortalidade - SIM, comparando os trÃs sistemas e considerando como notificados os casos confirmados no Sinan. Os casos foram emparelhados no Programa RecLink II. ApÃs o emparelhamento dos casos foram selecionados os elegÃveis para aplicaÃÃo do mÃtodo de captura e recaptura, utilizando os estimadores de Lincoln-Petersen e o de Chapman. A subnotificaÃÃo estimada para Fortaleza foi de 33,1%, e 14,1%, tendo como referÃncia o Sinan e comparando com as fontes Siscel e SIM, respectivamente. Para os hospitais S. Josà e HGF a subnotificaÃÃo foi de 5,4% e 90,5%, na mesma ordem, comparando o Sinan com o Siscel. Este trabalho demonstrou uma elevada subnotificaÃÃo de casos de Aids no municÃpio de Fortaleza nos anos de 2002 e 2003 e que a subnotificaÃÃo quando avaliada por fonte, comparando o Siscel com o Sinan, ela à mais de duas vezes superior à estimada quando comparada à das fontes SIM/Sinan, demonstrando ser o Siscel uma importante fonte de notificaÃÃo de casos de Aids. Quanto à subnotificaÃÃo nas duas unidades de SaÃde, observa-se um percentual bem mais elevado para o HGF. O Programa RecLink II mostrou ser uma opÃÃo simples para o reconhecimento dos casos nÃo notificados no Sinan e em relaÃÃo a tÃcnica de captura e recaptura, pode ser utilizada de forma simples e rÃpida e com baixo custo, comparando os sistemas dois a dois em pesquisas pontuais. Diante dos achados nesse estudo, recomenda-se que o Sinan-Aids seja comparado em periodicidade mensal, com todas as fontes de informaÃÃes disponÃveis que possam contribuir para reduÃÃo da subnotificaÃÃo de Aids / Underreporting is one of the major problems challenging epidemiologic AIDS surveillance. The objective of this study was to estimate the level of underreporting of AIDS in adults in Fortaleza in the period 2002-2003 using the capture-recapture method. In addition, the level of underreporting at two hospitals for AIDS referral (Hospital SÃo Josà â HSJ, and Hospital Geral de Fortaleza â HGF was estimated. The study relied on three secondary databases: SINAN (national disease surveillance), SISCEL (laboratory test control) and SIM (mortality information). The systems were compared and cases confirmed by SINAN were considered as reported. Cases from the two databases were paired using the software RecLink II. Subsequently cases eligible for the capture-recapture method were selected using the Lincoln-Petersen and Chapmam estimators. The levels of underreporting were estimated at 33.1% and 14.1% for SISCEL and SIM, respectively. Underreporting for SISCEL was 5.4% at HSJ and 90.5% at HGF. The study shows a considerable level of underreporting of AIDS cases in Fortaleza for the period 2002-2003 and suggests that SISCEL is an important source of AIDS reporting considering that it allowed to detect levels of underreporting more than twice the estimates derived from the sources SIM and SINAN. The level of underreporting was considerably higher at HF than at HSJ. The software RecLink II was shown to be a practical tool for identifying cases not reported to SINAN. The capture-recapture method is a simple, time-saving and inexpensive way to compare two systems when necessary. Considering the findings of the present study, SINAN-AIDS should be compared monthly with all relevant information systems in order to reduce levels of AIDS underreporting

Inequalities in levels of health between regions within a country are frequently regarded as a problem. Zimbabwe is characterised by poor and unequal conditions of health (both the state of people‘s health and health services). The health system of the country shows severe spatial inequalities that are manifested at provincial, district and even local levels. The current research therefore examines and analyses the spatial inequalities and temporal variation of health conditions in Zimbabwe. Composite indices were used to determine the people‘s state of health in Zimbabwe. Administrative districts were ranked according to the level of people‘s state of health. Cluster analysis was also performed to demarcate administrative districts according the level of health service provision. Districts with minimum difference were demarcated in a single cluster. Clusters were delineated using data on patterns of diseases and health and such clusters were used to demarcate the country‘s spatial health system according to the Adapted Epidemiological Transition Model. This was meant to evaluate the applicability of the model to Zimbabwe. It emerged from the research that generally the country‘s health conditions are poor and the health system is characterised by severe spatial inequalities. Some districts are experiencing poor health service provision and serious health challenges and are still in the age of pestilence and famine but others have good health service provision as well as highly developed health conditions and are in the age of degenerative and man-made diseases of the epidemiological transition model. It further emerged that the country‘s health has been evolving with signs of improvement since the 1990s. Some proposals are made in research for spatial development of health in the country. Recommendations were made regarding possible adjustment to previous strategies and policies used in Zimbabwe, for the development of the health system of the country. New strategies were also recommended for the improvement of the health system of the country. / Geography / Ph.D. (Geography)

INTRODUCTION: Epidemiological transition theory, first postulated by Omran in 1971, provides a useful framework for understanding cause-specific mortality changes and may contribute usefully to predictions about cause-specific mortality. However, understandings of mortality transitions and associated epidemiological changes remain poorly defined for public health practitioners due to lack of evidence from low- and middle-income countries. Therefore, understanding of the concept and development of epidemiological transition theory as well as population burden of premature mortality attributable to risk factors is needed. OBJECTIVES: This thesis aims to understand how epidemiological transition theory has been applied in different contexts, using available evidence on mortality transitions from high, middle- and low- income countries, as well as the contribution of risk factors to mortality transitions, particularly for premature mortality. METHODS: A Medline literature search from 1971 to 2013 was conducted to synthesise published evidence on mortality transition (paper I). A descriptive analysis of trends in cause of death using INDEPTH data was conducted, focusing on specific causes of death in 12 INDEPTH sites in Africa and Asia, using the INDEPTH 2013 standard population structure for appropriate comparisons across sites (paper II). A retrospective dynamic cohort database was constructed from Swedish population registers for the age range 30-69 years during 1991-2006, to measure reductions in premature non-communicable disease mortality using a life table method (paper III). Prospective cohort data from Västerbotten Intervention Programme from 1990 to 2006 were used to measure the magnitude of premature non-communicable disease mortality reductions associated with risk factor changes for each period of time (paper IV). FINDINGS: There were changes in emphasis in research on epidemiological transition over the four decades from 1971 to 2013, from cause of death to wide-ranging aspects of the determinants of mortality with increasing research interests in low-and middle-income countries, with some unconsidered aspects of social determinants contributing to deviations from classic theoretical pathways. Mortality rates declined in most sites, with the annual reductions in premature adult mortality varied across INDEPTH sites, Sweden, which now is at late stage of epidemiological transition stage, achieved a 25% reduction in premature mortality during 1991-2006. Overall downward trends in risk factors have helped to reduce premature mortality in the population of Västerbotten County, but some benefits were offset by other increasing risks. The largest mortality changes accrued from reductions in smoking, hypertension and hypercholesterolaemia. CONCLUSIONS: This thesis established patterns of current epidemiological transition in high, middle-and low-income countries (Asia and Africa), where the theory fits the transition patterns in some countries, but with some needs for further adjustments in other settings, as well as deviations from the classical ET theory in the last four decades. It highlights the need to identify the burden of mortality and morbidity, particularly for reducing mortality occurring before the age of 70 years and its attribution to risk factors, which are a major public health challenge. This informs shifting of public health priorities and resources towards prevention and control of chronic non-communicable disease risk factors.

<p>Uprkos rezultatima postignutih imunizacijom, veliki ka&scaron;alj je i danas vodeći uzrok smrti među zaraznim bolestima protiv kojih se sprovodi imunizacija. Postojanje različitih vrsta nadzora, prisutnih nedostataka laboratorijske dijagnostike oboljenja, slabosti u dostupnim definicijama slučaja velikog ka&scaron;lja i neprepoznavanje oboljenja, otežavaju realno sagledavanje opterećenja velikim ka&scaron;ljem i poređenje postignutih rezultata u različitim zemljama. Postojeće definicije slučaja velikog ka&scaron;lja nisu prihvatljive u svim uzrastima. Cilj istraživanja je bio da se na reprezentativnom uzorku Grada Novog Sada utvrdi: stopa incidencije velikog ka&scaron;lja tokom jedne godine savremenog nadzora; senzitivnost i specifičnost definicija slučaja velikog ka&scaron;lja, datih od strane Globalne pertusis inicijative za tri uzrasne grupe. U istraživanje je uključeno 213 ispitanika pacijenata iz sentinelnog nadzora nad velikim ka&scaron;ljem Doma zdravlja Novi Sad i 107 ispitanika pacijenata iz hospitalnog nadzora sa iste teritorije koji su ispunjavali predložene definicije slučaja za tri uzrasne grupe (0-3 meseca; 4 meseca-9 godina života; 10 godina i stariji). Podaci za istraživanje dobijeni su popunjavanjem anketnog upitnika. Laboratorijsko testiranje sumnji na veliki ka&scaron;alj sprovedeno je u Centru za mikrobiologiju Instituta za javno zdravlje Vojvodine. Kod pacijenata sa ka&scaron;ljem u trajanju do 21 dan testiranje je vr&scaron;eno upotrebom PCR metoda, a kod pacijenata sa ka&scaron;ljem u trajanju vi&scaron;e od 21 dan, dokazivanje oboljenja vr&scaron;eno je upotrebom ELISA IgA i IgG serolo&scaron;kih testova. Potvrđenim slučajem velikog ka&scaron;lja smatran je pacijent sa ispunjenom definicijom slučaja oboljenja i laboratorijskom potvrdom oboljenja, PCR ili ELISA testom. Procenjena stopa incidencije velikog ka&scaron;lja u Novom Sadu je 237,7/100.000, a stopa incidencije hospitalizovanih u Novom Sadu je 16,4/100.000. Najvi&scaron;e stope incidencije velikog ka&scaron;lja u sentinelnom nadzoru registruju se u uzrastu 10-14, a u hospitalnom u uzrastu od 7 do 9 godina. Senzitivnost, specifičnost i stepen verovatnoće pozitivnog rezultata testiranog simptoma/znaka iz predloženih definicija slučaja se razlikuju po uzrastima i po pojedinim simptomima/znacima. Predložene definicije slučaja u uzrastima od 4 meseca do 9 godina i u uzrastu od 10 godina i starijih imaju veću verovatnoću otkrivanja obolelih u hospitalnom u odnosu na sentinelni nadzor za pojedine simptome/znakove. Budući da je tokom istraživanja u sentinelnom nadzoru oboljenje potvrđeno kod svakog petog, a u hospitalnom kod svakog drugog testiranog pacijenta, predložene definicije slučaja se mogu koristiti u nadzoru nad velikim ka&scaron;ljem.</p> / <p>Despite all results achieved by immunization, pertussis is still the leading cause of death among vaccine preventable diseases. Different types of surveillance and laboratory confirmation of pertussis, weakness of existing case definitions for pertussis and broad spectrum clinical manifestation of disease, complicate overview of disease and result comparison of surveillance in different countries. The current pertussis case definition is not acceptable for all age groups of patients. The aim of this research was to determine: the pertussis incidence rate in population of Novi Sad during one year of modern surveillance; the sensitivity and specificity of clinical case definition for pertussis, given by the Global Pertussis Initiative for three age groups, with a representative sample of population in the City of Novi Sad. 213 patients from sentinel surveillance of pertussis Novi Sad Health Centre and 107 hospitalized patients from Novi Sad, who fulfilled criteria of case definition proposed for the three age groups (0-3 months, 4 months-9 years; 10 years of age and older), were included in the research. Research data obtained from a questionnaire. Laboratory testing of suspected cases were conducted at the Centre for Microbiology, Institute of Public Health of Vojvodina. For patients with coughing less than 21 days PCR method was used, and for patients with cough lasting more than 21 days, laboratory confirmation of disease was performed using ELISA IgA and IgG serological tests. Confirmed case of pertussis consider to be a patient with symptoms/signs according to proposed case definition and with laboratory confirmation of the pertussis, PCR or ELISA. Estimated incidence rate of pertussis for population in the city of Novi Sad was 237.7/100,000, and the pertussis incidence rate in hospitalized patient in Novi Sad was 16.4/100,000. The highest incidence rate of pertussis in the sentinel surveillance was registered in the age group 10-14 and in the hospital surveillance in the group 7 to 9 years of age. The values of sensitivity, specificity and positive likelihood ratio of symptoms/signs from the proposed case definition were calculated and they different by age and by certain symptoms/signs from proposed case definition. Certain symptoms/signs of the proposed case definition have a higher probability of detection among patients aged 4 months to nine, and at the age of ten year and older, in the hospital versus those in sentinel surveillance for pertussis. During research from the patients who were tested in sentinel surveillance every fifth was laboratory confirmed case and in the hospital surveillance every second patient was confirmed case, so the proposed case definitions can be used in the surveillance of pertussis.</p>