Assessing spatial variability in observed infectious disease spread in a prospective time–space series

Most of the growing prospective analytic methods in space-time disease surveillance and intended functions of disease surveillance systems focus on earlier detection of disease outbreaks, disease clusters, or increased incidence. The spread of the virus such as SARS-CoV-2 has not been spatially and temporally uniform in an outbreak. With the identification of an infectious disease outbreak, recognizing and evaluating anomalies (excess and decline) of disease incidence spread at the time of occurrence during the course of an outbreak is a logical next step.We propose and formulate a hypergeometric probability model that investigates anomalies of infectious disease incidence spread at the time of occurrence in the timeline for many geographically described populations (e.g., hospitals, towns, counties) in an ongoing daily monitoring process. It is structured to determine whether the incidence grows or declines more rapidly in a region on the single current day or the most recent few days compared to the occurrence of the incidence during the previous few days relative to elsewhere in the surveillance period. The new method uses a time-varying baseline risk model, accounting for regularly (e.g., daily) updated information on disease incidence at the time of occurrence, and evaluates the probability of the deviation of particular frequencies to be attributed to sampling fluctuations, accounting for the unequal variances of the rates due to different population bases in geographical units.We attempt to present and illustrate a new model to advance the investigation of anomalies of infectious disease incidence spread by analyzing subsamples of spatiotemporal disease surveillance data from Taiwan on dengue and COVID-19 incidence which are mosquito-borne and contagious infectious diseases, respectively. Efficient R programs for computation are available to implement the two approximate formulae of the hypergeometric probability model for large numbers of events.

COVID-19, which first emerged at the end of 2019 and spread worldwide in 2020, has caused many deaths and remains prevalent. To reduce the infection and spread of COVID-19, various methods of personal hygiene are currently being emphasized. In this study, we evaluated changes in the incidence of contagious infectious skin diseases treated in dermatology clinics to determine if they were associated with improvements in personal hygiene after the COVID-19 outbreak.

First Line of Defense

Systematic Review:National Notifiable Infectious Disease Surveillance System in China

Approaches used to early and accurately characterize epidemiologic patterns of disease incidence in a temporal and spatial series are becoming increasingly important. Cluster tests are generally designed for retrospective detection of epidemiologic anomalies in a temporal or space-time series. Timely identification of anomalies of disease or poisoning incidence during ongoing surveillance or an outbreak requires the use of sensitive statistical methods that recognize an incidence pattern at the time of occurrence. This report describes 2 novel analytical methods that focus on detecting anomalies of incidence at the time of occurrence in a temporal and space-time series. The first method describes the paucity of incidence at the time of occurrence in an ongoing surveillance and is designed to evaluate whether a decline in incidence occurs on the single current day or during the most recent few days. The second method provides an overall assessment of current clustering or paucity of incidence in a space-time series, allowing for several space regions. We illustrate the application of these methods using a subsample of a temporal series of data on the largest dengue outbreak in Taiwan in 2015 since World War II and demonstrate that they are useful to efficiently monitor incoming data for current clustering and paucity of incidence in a temporal and space-time series. In light of the recent global emergence and resurgence of Zika, dengue, and chikungunya infection, these approaching for detecting current anomalies of incidence in the ongoing surveillance of disease are particularly desired and needed.

Strengthening the BTWC: The role of the Biological and Toxin Weapons Convention in combating natural and deliberate disease outbreaks

ObjectiveAssess the legal framework establishing disease surveillance in Nigeria and identify major factors affecting the performance of the surveillance system.IntroductionThe outbreak of infectious diseases with a propensity to spread across international boundaries is on an upward rise. Such outbreaks can be devastating with significant associated morbidity and mortality. The recent Ebola Virus Disease outbreak in West Africa which spread to Nigeria is an example.(1) Nigeria like several other African countries implements the Integrated Disease Surveillance and Response (IDSR) system as its method for achieving the International Health Regulations (IHR). Yet, compliance to the IDSR is questioned. This study seeks to investigate the legal instruments in place and the factors affecting performance of the disease surveillance in the country.MethodsThe study reports the first objective of a larger study to investigate compliance to disease surveillance by private health providers.(2) An investigative search of the literature for legal instruments on disease surveillance in Nigeria was carried out. In addition, key informants were identified and interviewed at the national level and in selected states. The six states in the South-West were identified for an in-depth study. The IHR focal person and the National Health Management Information System officer were interviewed at the national level. The state epidemiologists and the state health management information system (HMIS) officers across the six states were interviewed. Each state has only one state epidemiologist and one HMIS officer as such it was a total sample. In all, 14 key informants were interviewed.ResultsSix legal instruments were identified as seen in table 1. The most recent comprehensive legal instrument on infectious disease control in Nigeria is a 2005 policy on IDSR. This is further supported by the National Health Act of 2014. However, the National Health Act is not detailed for infectious disease control. The substantive law which governs infectious diseases in Nigeria, the Quarantine Act was enacted almost a century ago during the colonial era in 1926. None of the states studied has an active law on infectious disease surveillance as noted by key informants. While all states refer to the IDSR policy, none has formally ratified the document. There are two independent overlapping data collection systems on infectious diseases: the IDSR and the National Health Management Information System (NHMIS). Data on malaria, HIV and tuberculosis are among data collected across the two systems. This was identified by key informants as a problem since the data collection forms differed across systems and almost always result in differing statistics. In addition, this duplication causes overburdening of frontline workers expected to fill the parallel data collection tools and results in inefficiency of the system. Funding of the surveillance system was identified to be inadequate with significant reliance on international partners.ConclusionsA review of the national law on disease surveillance to address emerging global health security challenges is necessary. State legislators need to enact or ratify national laws on infectious disease monitoring and control in their states. The duplication across the NHMIS and the IDSR surveillance system requires harmonization to improve efficiency. Government needs to invest more resources in disease surveillance.References. Makinde OA. As Ebola winds down, Lassa Fever reemerges yet again in West Africa. J Infect Dev Ctries [Internet]. 2016 Feb 28;10(02):199–200. Available from: http://www.jidc.org/index.php/journal/article/view/81482. Makinde OA, Odimegwu CO. Disease Surveillance by Private Health Providers in Nigeria: A Research Proposal. Online J Public Health Inform [Internet]. 2016 Mar 24;8(1). Available from: http://ojphi.org/ojs/index.php/ojphi/article/view/6554

Continuing challenge of infectious diseases in India

This review examines Nigeria's need for enhanced infectious disease response and surveillance systems, comparing current models and effective deployments from other nations. The review adopted the critical literature analysis method to synthesise findings from peer-reviewed journal articles, official reports, and case studies. The analysis compared Nigeria's infectious disease surveillance, response, and intervention practices with global best practices to identify gaps and propose actionable recommendations. Findings revealed serious weaknesses in Nigeria's infectious diseases surveillance system. For instance, COVID-19 exposed serious flaws in the nation’s contact tracing and testing capacity, with about 1.78 million samples tested by mid-2021, compared with 3.2 million in South Africa. Whereas, malaria causes 60% of outpatient visits and more than 194,000 mortalities annually. About 41 mortalities were linked to cholera epidemics within the second quarter of 2024, resulting from inadequate water and sanitation facilities. Findings revealed underreporting of infectious diseases in Nigeria, including Tuberculosis (TB) where 15.5% of bacteriologically confirmed cases in Lagos in 2022 went unreported. During the early outbreak of COVID-19, only 10–50% of symptomatic cases were reported. Findings also showed the financial burden posed by infectious diseases, including malaria which costs Nigeria about $1.1 billion annually. To improve disease surveillance and response in Nigeria, the review recommended the implementation of digital health technologies including mHealth and GIS mapping. While also enhancing healthcare worker training, instituting integrated disease surveillance systems, and fortifying health policy frameworks.

Hard-to-reach populations (i.e. those stigmatised, marginalised, underrepresented, or otherwise disadvantaged) such as men who have sex with men and immigrants are at higher risk for infectious diseases. Reaching these populations, studying their behaviour and/or testing individuals for infectious diseases is essential for developing effective prevention programmes and disease surveillance. These populations, however, lack sampling frames making it difficult to collect representative quantitative data using common probability-based sampling methods. Respondent-driven sampling (RDS), a variant of snowball sampling, is an effective method to recruit these populations and to make unbiased population estimates using a statistical model. RDS starts with recruiting a convenience sample of the target population (so-called “seeds”). These seeds are then asked to recruit a number of other eligible individuals of their social network. This process continues which leads to chains of recruitment, with several waves of recruits. The process of respondent-driven recruitment is very similar to the way infectious diseases such as influenza and mumps transmit through populations. This provides opportunities to use the method with a different aim: the detection of cases within networks. Finding infectious cases is an essential element for prevention of further spread in the population and individual health consequences. Essential as it is to public health, conventional contact tracing is a rather timely, costly and, up to a certain degree, really frustrating activity. Studying and making use of social networks may help to understand and control the spread of infectious diseases transmitted via direct contact. These diseases do not spread at random through a population, but follow the underlying patterns of contact networks. This entails that cases tend to cluster by time and space, and their contact persons are at a higher risk for infection. Same as with RDS, respondent-driven detection (RDD) starts with individuals being asked to recruit relevant contact persons from their network. These contact persons are then asked to do the same, resulting in successive waves of contact persons. A case is reached through contact with a known case, similar to pathogens spreading through these contact relationships. RDD may therefore enhance conventional contact tracing, providing further insight in the extent of outbreaks, in a quick and less laborious manner for public health professionals. Using three examples from public health practice, this workshop provides participants insights in the methodology of online respondent-driven methods (RDS and RDD), how these provide behavioural and epidemiological knowledge on networks and the spread of infectious diseases, and highlights pre-requisites for successful implementation in practice. Lastly, an interactive discussion will be held with the audience on how attendees can apply these methods for their own public health challenges. Key messages RDS is used to sample hard-to-reach populations to collect their social, sexual and behavioural information, and to make unbiased population estimates. RDD is used to detect infectious cases or clusters of disease.

Journal of School HealthVolume 70, Issue 6 p. 262-264 Talking Sexual Health: A National Application of the Health Promoting School Framework for HIV/AIDS Education in Secondary Schools Anne Mitchell, Anne Mitchell Anne Mitchell MA, Dip Ed: , Manager, Community Liaison Unit; Debbie Ollis, Med, Project Officer, National Schools Project; and Jan Watson BA, Dip Ed, Grad Dip Lib, Project Officer, National Schools Project, Australian Research Center for Sex, Health, and Society, La Trobe University, 215 Franklin St., Melbourne 3000, Australia. The authors gratefully acknowledge the generous financial contribution to support the printing of this article from the Department of Health Promotion, Noncommunicable Disease Prevention and Surveillance, Noncommunicable Disease and Mental Health Cluster, World Health Organization, Headquarters, Geneva, Switzerland.Search for more papers by this authorDebbie Ollis, Debbie Ollis Anne Mitchell MA, Dip Ed: , Manager, Community Liaison Unit; Debbie Ollis, Med, Project Officer, National Schools Project; and Jan Watson BA, Dip Ed, Grad Dip Lib, Project Officer, National Schools Project, Australian Research Center for Sex, Health, and Society, La Trobe University, 215 Franklin St., Melbourne 3000, Australia. The authors gratefully acknowledge the generous financial contribution to support the printing of this article from the Department of Health Promotion, Noncommunicable Disease Prevention and Surveillance, Noncommunicable Disease and Mental Health Cluster, World Health Organization, Headquarters, Geneva, Switzerland.Search for more papers by this authorJan Watson, Jan Watson Anne Mitchell MA, Dip Ed: , Manager, Community Liaison Unit; Debbie Ollis, Med, Project Officer, National Schools Project; and Jan Watson BA, Dip Ed, Grad Dip Lib, Project Officer, National Schools Project, Australian Research Center for Sex, Health, and Society, La Trobe University, 215 Franklin St., Melbourne 3000, Australia. The authors gratefully acknowledge the generous financial contribution to support the printing of this article from the Department of Health Promotion, Noncommunicable Disease Prevention and Surveillance, Noncommunicable Disease and Mental Health Cluster, World Health Organization, Headquarters, Geneva, Switzerland.Search for more papers by this author Anne Mitchell, Anne Mitchell Anne Mitchell MA, Dip Ed: , Manager, Community Liaison Unit; Debbie Ollis, Med, Project Officer, National Schools Project; and Jan Watson BA, Dip Ed, Grad Dip Lib, Project Officer, National Schools Project, Australian Research Center for Sex, Health, and Society, La Trobe University, 215 Franklin St., Melbourne 3000, Australia. The authors gratefully acknowledge the generous financial contribution to support the printing of this article from the Department of Health Promotion, Noncommunicable Disease Prevention and Surveillance, Noncommunicable Disease and Mental Health Cluster, World Health Organization, Headquarters, Geneva, Switzerland.Search for more papers by this authorDebbie Ollis, Debbie Ollis Anne Mitchell MA, Dip Ed: , Manager, Community Liaison Unit; Debbie Ollis, Med, Project Officer, National Schools Project; and Jan Watson BA, Dip Ed, Grad Dip Lib, Project Officer, National Schools Project, Australian Research Center for Sex, Health, and Society, La Trobe University, 215 Franklin St., Melbourne 3000, Australia. The authors gratefully acknowledge the generous financial contribution to support the printing of this article from the Department of Health Promotion, Noncommunicable Disease Prevention and Surveillance, Noncommunicable Disease and Mental Health Cluster, World Health Organization, Headquarters, Geneva, Switzerland.Search for more papers by this authorJan Watson, Jan Watson Anne Mitchell MA, Dip Ed: , Manager, Community Liaison Unit; Debbie Ollis, Med, Project Officer, National Schools Project; and Jan Watson BA, Dip Ed, Grad Dip Lib, Project Officer, National Schools Project, Australian Research Center for Sex, Health, and Society, La Trobe University, 215 Franklin St., Melbourne 3000, Australia. The authors gratefully acknowledge the generous financial contribution to support the printing of this article from the Department of Health Promotion, Noncommunicable Disease Prevention and Surveillance, Noncommunicable Disease and Mental Health Cluster, World Health Organization, Headquarters, Geneva, Switzerland.Search for more papers by this author First published: 09 October 2009 https://doi.org/10.1111/j.1746-1561.2000.tb07435.xCitations: 9 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. 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Africa has the highest burden of infectious diseases in the world and yet the least capacity for its risk management. It has therefore become increasingly important to search for 'fit-for- purpose' approaches to infectious disease surveillance and thereby targeted disease control. The fact that the majority of human infectious diseases are originally of animal origin means we have to consider One Health (OH) approaches which require inter-sectoral collaboration for custom-made infectious disease surveillance in the endemic settings of Africa. A baseline survey was conducted to assess the current status and performance of human and animal health surveillance systems and subsequently a strategy towards OH surveillance system was developed. The strategy focused on assessing the combination of participatory epidemiological approaches and the deployment of mobile technologies to enhance the effectiveness of disease alerts and surveillance at the point of occurrence, which often lies in remote areas. We selected three study sites, namely the Ngorongoro, Kagera River basin and Zambezi River basin ecosystems. We have piloted and introduced the next-generation Android mobile phones running the EpiCollect application developed by Imperial College to aid geo-spatial and clinical data capture and transmission of this data from the field to the remote Information Technology (IT) servers at the research hubs for storage, analysis, feedback and reporting. We expect that the combination of participatory epidemiology and technology will significantly improve OH disease surveillance in southern Africa.

Objective To determine the incidence, clinical manifestation and part of lymphokines which represent the balance of Th1 and Th2 in the role of the immunologic mechanisms for IRIS(immune restoration inflammatory syndromes)in patients initiating HAART(Highly Active Antiretroviral Therapy).Methods A prospective study of all patients initiating HAART was performed. A period of six months tracking initiating HAART was performed. The incidence of IRIS, time of occurrence and clinical disease spectrum were recorded. The main T lymphokines including IL-2, INF-γ, IL-4, IL-10 which on behalf of the balance of Th1 and Th2 were detected. To explore the immunopathologic mechanisms for IRIS, the levels of T lymphokines at pre-HAART, initiating HAART for 1 month, 3months and 6 months were compared in IRIS group and non-IRIS group, healthy group. Results A total of 212 patients were enrolled in this study. 59 patients were diagnosed as IRIS at a median of 21 days after HAART initiation (QR 19 days).The main disease spectrum included tuberculosis, herpes virus infections, pneumocystis jirovecii pneumonia. No matter in the IRIS group or non-IRIS group, the main lymphokines baseline of IL-2, INF-γ reduced and IL-4, IL-10 increased before HAART compared to healthy group (P ＜ 0. 05), which had the tendency to restore balance relations initiating HAART. The lymphokines levels had significant difference between baseline and 6 months initiating HAART (P ＜ 0. 05). The changed levels of lymphokines between IRIS group and non-IRIS group before HAART had significant difference compared to healthy group. IL-2, INF-γ increased level[(11.68 ± 2. 89) pg/ml vs (8.52 ±2.26) pg/ml; (22. 19 ± 6. 22) pg/ml vs (18.34 ±5. 35) pg/ml] and IL-10 decreased level [(19. 21 ± 4. 03) pg/ml vs (23. 19 ± 5.92) pg/ml] had significant difference between IRIS group and non-IRIS group initiating HAART I month(P ＜0. 05). Conclusions The incidence of IRIS during 6 months initiating HAART in HIV/AIDS was 27. 8%, IRIS usually occurred in 1 month initiating HAART. The most common disease spectrum was infectious disease, including tuberculosis and herpes virus infection. Lymphokine of Th1 and Th2 existed unbalance in IRIS group and non-IRIS group before HAART. The unbalance tendency in IRIS group was more obvious. All lymphokines had the trend to recover balance. IL-2, INF-γ significantly increased and IL-10 significantly decreased, which might involve the occurrence of the IRIS. Key words: Lymphokines/ME; Immune reconstitution inflammatory syndrome/ME; Antiretroviral therapy,highly active/AE; Acquired immunodeficiency syndrome/DT

The federal government has collected information on communicable diseases since 1924, under the legislative authority of the Statistics Canada Act and the Health Canada Act (1,2). Aggregate data on communicable diseases was initially collected and collated by The Dominion Bureau of Statistics (later changed to Statistics Canada), but this responsibility, with the exception of tuberculosis, was transferred to the Laboratory Centre for Disease Control (LCDC) in 1988. Responsibility for tuberculosis was subsequently transferred to the LCDC in 1995. Currently, information on communicable diseases under national surveillance is managed by the Division of Disease Surveillance within the Bureau of Infectious Diseases, LCDC. The delivery of health care and public health services is identified in the Canadian Constitution as a provincial power. The federal government has powers over the provision of safe food and the importation of communicable diseases, and has the power to assist in a crisis such as an infectious disease outbreak. Although communicable disease surveillance is carried out under provincial authority, coordination and monitoring occur at the federal level. Provincial and federal health authorities reach agreement on communicable disease surveillance by means of a joint committee called the Advisory Committee on Epidemiology (ACE) and its subcommittee on communicable diseases. The Division of Disease Surveillance is frequently asked why all infectious diseases of general interest are not nationally notifiable. First, disease surveillance requires money, time and energy for health care providers, local health units, provinces, territories or Health Canada to report and collect data on every communicable disease. Second, it requires considerable time and effort to make a disease nationally notifiable because every province and territory needs to go through the legislative or regulatory process of making the disease reportable within their jurisdictions. The process is managed by setting priorities to decide where to put the greatest effort. Criteria for priority setting should be explicit and measurable, and should minimize the influence of such factors as personal interest and political agendas. To the utmost degree possible, the criteria should be based on scientific evidence. Above all, “the challenge is to make the priority-setting process transparent and open to criticism and revision” (3). Before 1987, there was no mechanism in place to evaluate newly emerging diseases and compare them with the diseases that were being reported. Accordingly, in 1987, ACE established a subcommittee on communicable diseases to develop a systematic process to determine which communicable diseases should be monitored at the national level. The subcommittee asked which diseases should be routinely monitored, how should they be monitored and whether they should be monitored at all. These are important questions that have led to a priority setting exercise with the following objectives: to ensure national surveillance of major infectious diseases that threaten the health of Canadians; to support the development and evaluation of programs that are currently in place and those which have been proposed; to ensure the participation of Canada in the global surveillance of specific health threats; and to determine the best use of human and financial resources in the prevention and control of communicable diseases. The priority setting process involves several steps: establishing the criteria; subdividing each criterion into levels; assigning points to each level within each criterion; summing the points and assigning a total score to each disease; ranking the diseases from highest to lowest score; and determining a cut-off point that would allow the inclusion and exclusion of

European Collaboration in Infectious Diseases Surveillance: Where to Go?