Emergence of medicine for mass gatherings: lessons from the Hajj

Although definitions of mass gatherings (MG) vary greatly, they consist of large numbers of people attending an event at a specific site for a finite time. Examples of MGs include World Youth Day, the summer and winter Olympics, rock concerts, and political rallies. Some of the largest MGs are spiritual in nature. Among all MGs, the public health issues, associated with the Hajj (an annual pilgrimage to Mecca, Saudi Arabia) is clearly the best reported-probably because of its international or even intercontinental implications in terms of the spread of infectious disease. Hajj routinely attracts 2·5 million Muslims for worship. WHO's global health initiatives have converged with Saudi Arabia's efforts to ensure the wellbeing of pilgrims, contain infectious diseases, and reinforce global health security through the management of the Hajj. Both initiatives emphasise the importance of MG health policies guided by sound evidence and based on experience and the timeliness of calls for a new academic science-based specialty of MG medicine.     

Epidemiology and Transmission Dynamics of Infectious Diseases and Control Measures

The epidemiology and transmission dynamics of infectious diseases must be understood at the individual and community levels to improve public health decision-making for real-time and integrated community-based control strategies. Herein, we explore the epidemiological characteristics for assessing the impact of public health interventions in the community setting and their applications. Computational statistical methods could advance research on infectious disease epidemiology and accumulate scientific evidence of the potential impacts of pharmaceutical/nonpharmaceutical measures to mitigate or control infectious diseases in the community. Novel public health threats from emerging zoonotic infectious diseases are urgent issues. Given these direct and indirect mitigating impacts at various levels to different infectious diseases and their burdens, we must consider an integrated assessment approach, ‘One Health’, to understand the dynamics and control of infectious diseases.     

From the Cover: Optimizing infectious disease interventions during an emerging epidemic

The emergence and global impact of the novel influenza A(H1N1)v highlights the continuous threat to public health posed by a steady stream of new and unexpected infectious disease outbreaks in animals and humans. Once an emerging epidemic is detected, public health authorities will attempt to mitigate the epidemic by, among other measures, reducing further spread as much as possible. Scarce and/or costly control measures such as vaccines, anti-infective drugs, and social distancing must be allocated while epidemiological characteristics of the disease remain uncertain. Here we present first principles for allocating scarce resources with limited data. We show that under a broad class of assumptions, the simple rule of targeting intervention measures at the group with the highest risk of infection per individual will achieve the largest reduction in the transmission potential of a novel infection. For vaccination of susceptible persons, the appropriate risk measure is force of infection; for social distancing, the appropriate risk measure is incidence of infection. Unlike existing methods that rely on detailed knowledge of group-specific transmission rates, the method described here can be implemented using only data that are readily available during an epidemic, and allows ready adaptation as the epidemic progresses. The need to observe risk of infection helps to focus the ongoing planning and design of new infectious disease surveillance programs; from the presented first principles for allocating scarce resources, we can adjust the prioritization of groups for intervention when new observations on an emerging epidemic become available.     

South-to-North, cross-disciplinary training in global health practice: ten years of lessons learned from an infectious disease field course in Jamaica

Global commerce, travel, and emerging and resurging infectious diseases have increased awareness of global health threats and opportunities for collaborative and service learning. We review course materials, knowledge archives, data management archives, and student evaluations for the first 10 years of an intensive summer field course in infectious disease epidemiology and surveillance offered in Jamaica. We have trained 300 students from 28 countries through collaboration between the University of the West Indies and U.S. partner universities. Participants were primarily graduate students in public health, but also included health professionals with terminal degrees, and public health nurses and inspectors. Strong institutional synergies, committed faculty, an emphasis on scientific and cultural competencies, and use of team-based field research projects culminate in a unique training environment that provides participants with career-developing experiences. We share lessons learned over the past decade, and conclude that South-to-North leadership is critical in shaping transdisciplinary, cross-cultural, global health practice.     

Global perspectives for prevention of infectious diseases associated with mass gatherings

We assess risks of communicable diseases that are associated with mass gatherings (MGs), outline approaches to risk assessment and mitigation, and draw attention to some key challenges encountered by organisers and participants. Crowding and lack of sanitation at MGs can lead to the emergence of infectious diseases, and rapid population movement can spread them across the world. Many infections pose huge challenges to planners of MGs; however, these events also provide an opportunity to engage in public health action that will benefit host communities and the countries from which participants originate.     

人工智能助力热带传染病防控研究

自新型冠状病毒肺炎疫情发生以来,人工智能技术在热带传染病领域应用的先进性逐渐凸显。人工智能技术的应用对缓解疾病诊疗负担、降低疾病漏诊和误诊率、提升疾病监测预警能力、提高医药和疫苗研发效率等均具有显著成效。本文分析了人工智能在热带传染病防控研究中的应用现状,论述了人工智能在该领域疾病诊疗、监测预警、疫苗与药物挖掘、医疗与公共卫生服务和全球卫生治理中的重要价值。鉴于人工智能助力热带传染病防控面临着诊断单一和不准确、开放环境监测预警能力不佳、智能系统服务能力有限、大数据管理困难、模型可解释性较差等方面的难题,本文提出了加强多种热带传染病多模态智能诊断、重视开放环境下媒介生物和风险人群智能监测预警、加快智能防控系统研发、强化伦理安全、大数据管理与模型可解释性等发展建议。     

Could a virus contribute to weight gain?

OBJECTIVE: Obesity is a serious public health problem associated with increased morbidity and mortality. Although the causes for obesity are unclear, it seems that environmental, genetic, neural and endocrine factors contribute to its development. However, the rapid global spread of obesity resembles epidemiologically the spread of an infectious disease. Thus far, little consideration has been given to the possibility that the epidemic of obesity could be due to an infectious agent. Seven viruses and a scrapie agent have been implicated in obesity. DESIGN: This review evaluates the infectious pathogens and the evidence that these viruses are associated with obesity and concludes that a strong evidence base is emerging that associates certain viruses with obesity. CONCLUSION: More work is however required to elucidate the mechanisms of weight gain after viral infection. In the mean time, discounting viruses as a contributing factor to obesity would deprive us of a potential new avenue of investigating and treating the ever increasing epidemic of obesity.     

Endemic infectious diseases and biological warfare during the Gulf War: a decade of analysis and final concerns.

Infectious diseases were one of the first health threats confronted by Coalition troops deployed to the Arabian desert in August 1990. On the basis of experiences in World War II, the major endemic infectious disease risks were thought to be sandfly fever, cutaneous leishmaniasis, diarrheal disease, and malaria. Although there was active surveillance, no case of sandfly fever and few other endemic infectious diseases were identified among over 500,000 U.S., British, and Canadian ground troops. In addition, there was no diagnosis of biological warfare (BW) exposure, and BW agents were not detected in clinical, environmental, or veterinary samples. The most common infectious disease problems were those associated with crowding (acute upper respiratory infections) and reduced levels of sanitation (travelers-type diarrhea). Only one endemic infectious disease has been confirmed as causing chronic health problems: visceral Leishmania tropica infection (viscerotropic leishmaniasis). However, this protozoan infection was diagnosed in only 12 U.S. veterans, and no new cases have been identified during the last 8 years. Infectious diseases were not a serious problem for Gulf War troops because of extensive preventive medicine efforts and favorable weather and geographic factors. Moreover, it is unlikely that an endemic infectious disease or a BW agent could cause chronic health problems and remain undetected over a 10-year period.     

Hepatitis C virus prevention, care, and treatment: from policy to practice

The prevention of hepatitis C virus (HCV) infection and associated health conditions (eg, cirrhosis and hepatocellular carcinoma) is a public health priority in the United States. Hepatitis C virus-related morbidity and mortality is increasing at a time when the advent of highly effective therapies greatly increases opportunities to prevent HCV transmission and disease. In 2010, the Institute of Medicine recommended that national action be taken to address this "underappreciated health concern for the nation." In response, in 2011, the US Department of Health and Human Services (HHS) published a viral hepatitis action plan that guides response to the viral hepatitis epidemic by providing explicit steps to be undertaken by specific HHS agencies to improve provider training and community education; expand access to testing, care, and treatment; strengthen public health surveillance; improve HCV preventive services for injection drug users; develop a hepatitis C vaccine; and prevent HCV transmission in healthcare settings. For all aspects of the action plan, infectious disease specialists and other clinicians assume a key role in efforts to reduce HCV-related morbidity and mortality. With successful collaboration of the public and private sectors, the hepatitis C epidemic can be forever silenced.     

A veterinarian's experience of the spring 2004 avian influenza outbreak in Laos

Since it was first reported in December 2003, the outbreak of avian influenza A/H5N1 has spread to at least nine countries in Asia, affected multiple species of animals, and caused at least 42 human deaths. The magnitude and extent of this zoonotic outbreak are unprecedented, continue to grow, and threaten the start of a global human influenza pandemic. Control of the H5N1 outbreak has required the implementation of integrated human and veterinary health surveillance and response efforts. These efforts have also necessitated an unprecedented level of bilateral and multilateral international communication and cooperation. This report describes the contribution of one public-health veterinarian to the H5N1 outbreak response effort in Laos, and emphasises the value of multidisciplinary approaches to addressing this and future emerging infectious disease outbreaks.     

Mitigating Future Respiratory Virus Pandemics: New Threats and Approaches to Consider

Despite many recent efforts to predict and control emerging infectious disease threats to humans, we failed to anticipate the zoonotic viruses which led to pandemics in 2009 and 2020. The morbidity, mortality, and economic costs of these pandemics have been staggering. We desperately need a more targeted, cost-efficient, and sustainable strategy to detect and mitigate future zoonotic respiratory virus threats. Evidence suggests that the transition from an animal virus to a human pathogen is incremental and requires a considerable number of spillover events and considerable time before a pandemic variant emerges. This evolutionary view argues for the refocusing of public health resources on novel respiratory virus surveillance at human–animal interfaces in geographical hotspots for emerging infectious diseases. Where human–animal interface surveillance is not possible, a secondary high-yield, cost-efficient strategy is to conduct novel respiratory virus surveillance among pneumonia patients in these same hotspots. When novel pathogens are discovered, they must be quickly assessed for their human risk and, if indicated, mitigation strategies initiated. In this review, we discuss the most common respiratory virus threats, current efforts at early emerging pathogen detection, and propose and defend new molecular pathogen discovery strategies with the goal of preempting future pandemics.     

The 60-year battle against tuberculosis in Hong Kong—a review of the past and a projection into the 21st century

Abstract:   Over the past 60 years, tuberculosis (TB) control in Hong Kong has gone through three phases of development. The first phase (from 1948 to the 1960s) was a phase of a wide spread of infectious diseases due to poor environmental hygiene and sanitation, overcrowding, malnutrition and the influx of residents returning to Hong Kong after the end of Pacific War. The second phase (from the 1970s to the 1980s) was a phase of rising chronic noncommunicable diseases due to the aging of the population. The third phase (1990s to the present) was a phase of double burden of diseases including both chronic noncommunicable diseases and the emergence of new infectious diseases.
The factors responsible for the successful control of TB in Hong Kong over the past 60 years are largely due to policy and commitment in resources by the government, contributions from non-governmental organizations, academic institutions, public-spirited individuals, the community and the devotion and dedication of the staff.
While Hong Kong has been successful in the control of TB and other infectious diseases, lessons have been learnt from the past. New challenges arise as a result of emergence of new infectious diseases such as HIV/AIDS, avian influenza (H5N1), and SARS. Changes in lifestyle and behaviour have added many socially related health problems. The SARS epidemic has also highlighted the problems of communication, collaboration and coordination between Hong Kong and Mainland China and among government departments in Hong Kong.
In order to be better prepared for the future, there must be continuous commitment from the government to develop an effective health care system, to give greater emphasis to health promotion and disease prevention, and to strengthen partnerships at regional and international levels, particularly in the Pearl River Delta Region, in a global effort to stop TB and other infectious diseases.     

HIV-1/AIDS and the control of other infectious diseases in Africa

The effect of HIV-1 on other infectious diseases in Africa is an increasing public health concern. In this review, we describe the role that three major infectious diseases--malaria, sexually transmitted diseases (STDs), and tuberculosis--have had in the HIV-1 epidemic. The high prevalence of untreated STD infections has been a major factor facilitating the spread of HIV-1 in Africa; with the synergistic interaction between HIV-1 transmission and genital herpes being of special concern for control of both diseases. Increased susceptibility to tuberculosis after infection with HIV-1 has led to a rising incidence and threat of increased transmission of tuberculosis. Clinical malaria occurs with an increased frequency and severity in HIV-1-infected individuals, especially during pregnancy. As with tuberculosis, STDs, and other communicable HIV-1-associated diseases, the net effect of HIV-1 might include increased rates of malaria transmission across communities. In addition to enhancing access to HIV-1 prevention and care, public health surveillance and control programmes should be greatly intensified to cope with the new realities of infectious disease control in Africa.     

Research experimental platforms to study microgrids issues

Microgrid (MG) concept is becoming increasingly mature. It allows integrating better distributed generation, and especially renewable energy sources, in the grid. However, many issues have still to be resolved before implementing this concept in the real power system extensively. This paper presents first a review of the main issues associated to microgrids dealt with in the scientific literature. The different issues are classified and some examples of carried out studies are given for each issue. Then, a short review of existing experimental microgrids is done. They are classified in small-size and real-size experimental MGs. After that, the EneR-GEA experimental MG or platform of ESTIA Engineering School is presented, describing its different components. Then, some carried out experiments are explained. To finish, the main planned projects at short and medium term related to this platform are given.     

The basic reproductive rate of infection and the course of HIV epidemics

The basic reproductive rate is a measure of the potential for growth of an infectious disease epidemic and depends on the pattern of infectious contacts within the host population, the likelihood of infection being transmitted during a contact, and the duration of infectiousness. These three variables are reviewed along with the surveillance data that records the progress of the epidemic, with an emphasis on the HIV-1 epidemic in heterosexual populations in developing countries. The problems with sentinel surveillance data for HIV infection mean that our knowledge of HIV incidence is poor. However, what is clear is that HIV has spread widely in heterosexual populations in sub-Saharan Africa. The scale of the demographic impact seen here will depend on the local AIDS incubation period with a shorter period generating a more acute demographic impact. Heterogeneity in sexual behaviour is vital to generate a high sexual activity "core group" within which HIV spreads rapidly. How far out of this core group the virus will spread depends on the patterns of mixing within populations. Interventions to reduce the incidence of HIV work through reducing the reproductive rate of the virus. To be efficient, these interventions have to be targeted at those most likely to spread the virus.     

Influenza and Other Respiratory Viruses: Knowledge brokering on infectious diseases for public health

The National Collaborating Centres (NCCs) for Public Health (NCCPH) were established in 2005 as part of the federal government’s commitment to renew and strengthen public health following the severe acute respiratory syndrome (SARS) epidemic. They were set up to support knowledge translation for more timely use of scientific research and other knowledges in public health practice, programs and policies in Canada. Six centres comprise the NCCPH, including the National Collaborating Centre for Infectious Diseases (NCCID). The NCCID works with public health practitioners to find, understand and use research and evidence on infectious diseases and related determinants of health. The NCCID has a mandate to forge connections between those who generate and those who use infectious diseases knowledge.As the first article in a series on the NCCPH, we describe our role in knowledge brokering and the numerous methods and products that we have developed. In addition, we illustrate how NCCID has been able to work with public health to generate and share knowledge during the coronavirus disease 2019 (COVID-19) pandemic.     

Non-communicable health risks during mass gatherings

Mass gatherings (MGs) have been associated with high rates of morbidity and mortality from non-communicable diseases, accidents, and terrorist attacks, thus posing complex public health challenges. We assessed the health risks and public health responses to MGs to identify an evidence-based framework for public health interventions. Human stampedes and heat-related illnesses are the leading causes of mortality. Minor traumatic injuries and medical complaints are the main contributors to morbidity and, particularly, the need for on-site medical care. Infrastructure, crowd density and mood, weather, age, and sex determine the risks to health. Many predictive models for deployment of medical resources are proposed, but none have been validated. We identified the risks for mortality and morbidity during MGs, most efficient public health interventions, and need for robust research into health risks for non-communicable diseases during MGs.     

Role of a sentinel surveillance system in the context of global surveillance of infectious diseases

In some nation states, sustained integrated global epidemiological surveillance has been weakened as a result of political unrest, disinterest, and a poorly developed infrastructure due to rapidly increasing global inequality. The emergence of severe acute respiratory syndrome has shown vividly the importance of sensitive worldwide surveillance. The Agency for Cooperation in International Health, a Japanese non-governmental organisation, has developed on a voluntary basis a sentinel surveillance system for selected target infectious diseases, covering South America, Africa, and Asia. The system has uncovered unreported infectious diseases of international importance including cholera, plague, and influenza; current trends of acute flaccid paralysis surveillance in polio eradication; and prevalence of HIV, syphilis, hepatitis B, and hepatitis C in individual areas covered by the sentinels. Despite a limited geographical coverage, the system seems to supplement disease information being obtained by global surveillance. Further development of this sentinel surveillance system would be desirable to contribute to current global surveillance efforts, for which, needless to say, national surveillance and alert system takes principal responsibility.     

The SARS epidemic in mainland China: bringing together all epidemiological data

Objective  To document and verify the number of cases of severe acute respiratory syndrome (SARS) during the 2002–2003 epidemic in mainland China.
Method  All existing Chinese SARS data sources were integrated in one final database. This involved removing non-probable and duplicate cases, adding cases at the final stage of the outbreak, and collecting missing information.
Results  The resulting database contains a total of 5327 probable SARS cases, of whom 343 died, giving a case fatality ratio (CFR) of 6.4%. While the total number of cases happens to be equal to the original official reports, there are 5 cases overall which did not result in death. When compared with Hong Kong Special Administrative Region of China, China Taiwan, and Singapore, the SARS epidemic in mainland China resulted in a considerably lower CFR, involved relatively younger cases and included fewer health care workers.
Conclusions  To optimise future data collection during large-scale outbreaks of emerging or re-emerging infectious disease, China must further improve the infectious diseases reporting system, enhance collaboration between all levels of disease control, health departments, hospitals and institutes nationally and globally, and train specialized staff working at county centres of disease control.