Emerging infectious diseases: vulnerabilities, contributing factors and approaches

Predicting spatio-temporal population patterns of Borrelia burgdorferi, the Lyme disease pathogen

The causative bacterium of Lyme disease, Borrelia burgdorferi, expanded from an undetected human pathogen into the etiologic agent of the most common vector-borne disease in the United States over the last several decades. Systematic field collections of the tick vector reveal increases in the geographic range and prevalence of B. burgdorferi-infected ticks that coincided with increases in human Lyme disease incidence across New York State.We investigate the impact of environmental features on the population dynamics of B. burgdorferi. Analytical models developed using field collections of nearly 19,000 nymphal Ixodes scapularis and spatially and temporally explicit environmental features accurately explained the variation in the nymphal infection prevalence of B. burgdorferi across space and time.Importantly, the model identified environmental features reflecting landscape ecology, vertebrate hosts, climatic metrics, climate anomalies and surveillance efforts that can be used to predict the biogeographical patterns of B. burgdorferi-infected ticks into future years and in previously unsampled areas.Forecasting the distribution and prevalence of a pathogen at fine geographic scales offers a powerful strategy to mitigate a serious public health threat. Synthesis and applications. A decade of environmental and tick data was collected to create a model that accurately predicts the infection prevalence of Borrelia burgdorferi over space and time. This predictive model can be extrapolated to create a high-resolution risk map of the Lyme disease pathogen for future years that offers an inexpensive approach to improve both ecological management and public health strategies to mitigate disease risk.

SARS-COV-2/COVID-19: scenario, epidemiology, adaptive mutations, and environmental factors

The coronavirus pandemic of 2019 has already exerted an enormous impact. For over a year, the worldwide pandemic has ravaged the whole globe, with approximately 250 million verified human infection cases and a mortality rate surpassing 4 million. While the genetic makeup of the related pathogen (SARS-CoV-2) was identified, many unknown facets remain a mystery, comprising the virus's origin and evolutionary trend. There were many rumors that SARS-CoV-2 was human-borne and its evolution was predicted many years ago, but scientific investigation proved them wrong and concluded that bats might be the origin of SARS-CoV-2 and pangolins act as intermediary species to transmit the virus from bats to humans. Airborne droplets were found to be the leading cause of human-to-human transmission of this virus, but later studies showed that contaminated surfaces and other environmental factors are also involved in its transmission. The evolution of different SARS-CoV-2 variants worsens the condition and has become a challenge to overcome this pandemic. The emergence of COVID-19 is still a mystery, and scientists are unable to explain the exact origin of SARS-CoV-2. This review sheds light on the possible origin of SARS-CoV-2, its transmission, and the key factors that worsen the situation.

Ganoderma lucidum: Unutilized natural medicine and promising future solution to emerging diseases in Africa

Ganoderma lucidum is a well-known medicinal mushroom that has been used for the prevention and treatment of different ailments to enhance longevity and health specifically in China, Japan, and Korea. It was known as “God’s herb” in ancient China as it was believed to prolong life, enhance the youthful spirit and sustain/preserve vitality. G. lucidum is seldom collected from nature and is substantially cultivated on wood logs and sawdust in plastic bags or bottles to meet the international market demand. Both in vitro and in vivo studies on the copious metabolic activities of G. lucidum have been carried out. Varied groups of chemical compounds including triterpenoids, polysaccharides, proteins, amino acids, nucleosides, alkaloids, steroids, lactones, lectins, fatty acids, and enzymes with potent pharmacological activities have been isolated from the mycelia and fruiting bodies of G. lucidum. Several researchers have reported the abundance and diversification of its biological actions triggered by these chemical compounds. Triterpenoids and polysaccharides of G. lucidum have been reported to possess cytotoxic, hepatoprotective, antihypertensive, hypocholesterolemic, antihistaminic effects, antioxidant, antimicrobial, anti-inflammatory, hypoglycemic antiallergic, neuroprotective, antitumor, immunomodulatory and antiangiogenic activities. Various formulations have been developed, patented, and utilized as nutraceuticals, cosmeceuticals, and pharmaceuticals from G. lucidum extracts and active compounds. Thus, this review presents current updates on emerging infectious diseases and highlights the scope, dynamics, and advances in infectious disease management with a particular focus on Ganoderma lucidum, an unutilized natural medicine as a promising future solution to emerging diseases in Africa. However, details such as the chemical compound and mode of action of each bioactive against different emerging diseases were not discussed in this study.

Spatio-temporal evolution and trend prediction of the incidence of Class B notifiable infectious diseases in China: a sample of statistical data from 2007 to 2020

BACKGROUND

With the accelerated global integration and the impact of climatic, ecological and social environmental changes, China will continue to face the challenge of the outbreak and spread of emerging infectious diseases and traditional ones. This study aims to explore the spatial and temporal evolutionary characteristics of the incidence of Class B notifiable infectious diseases in China from 2007 to 2020, and to forecast the trend of it as well. Hopefully, it will provide a reference for the formulation of infectious disease prevention and control strategies.

METHODS

Data on the incidence rates of Class B notifiable infectious diseases in 31 provinces, municipalities and autonomous regions of China from 2007 to 2020 were collected for the prediction of the spatio-temporal evolution and spatial correlation as well as the incidence of Class B notifiable infectious diseases in China based on global spatial autocorrelation and Autoregressive Integrated Moving Average (ARIMA).

RESULTS

From 2007 to 2020, the national incidence rate of Class B notifiable infectious diseases (from 272.37 per 100,000 in 2007 to 190.35 per 100,000 in 2020) decreases year by year, and the spatial distribution shows an "east-central-west" stepwise increase. From 2007 to 2020, the spatial clustering of the incidence of Class B notifiable infectious diseases is significant and increasing year by year (Moran's I index values range from 0.189 to 0.332, p < 0.05). The forecasted incidence rates of Class B notifiable infectious diseases nationwide from 2021 to 2024 (205.26/100,000, 199.95/100,000, 194.74/100,000 and 189.62/100,000) as well as the forecasted values for most regions show a downward trend, with only some regions (Guangdong, Hunan, Hainan, Tibet, Guangxi and Guizhou) showing an increasing trend year by year.

CONCLUSIONS

The current study found that since there were significant regional disparities in the prevention and control of infectious diseases in China between 2007 and 2020, the reduction of the incidence of Class B notifiable infectious diseases requires the joint efforts of the surrounding provinces. Besides, special attention should be paid to provinces with an increasing trend in the incidence of Class B notifiable infectious diseases to prevent the re-emergence of certain traditional infectious diseases in a particular province or even the whole country, as well as the outbreak and spread of emerging infectious diseases.

Emerging and Re-emerging Vector-Borne Infectious Diseases and the Challenges for Control: A Review

Vector-borne emerging and re-emerging diseases pose considerable public health problem worldwide. Some of these diseases are emerging and/or re-emerging at increasing rates and appeared in new regions in the past two decades. Studies emphasized that the interactions among pathogens, hosts, and the environment play a key role for the emergence or re-emergence of these diseases. Furthermore, social and demographic factors such as human population growth, urbanization, globalization, trade exchange and travel and close interactions with livestock have significantly been linked with the emergence and/or re-emergence of vector-borne diseases. Other studies emphasize the ongoing evolution of pathogens, proliferation of reservoir populations, and antimicrobial drug use to be the principal exacerbating forces for emergence and re-emergence of vector-borne infectious diseases. Still other studies equivocally claim that climate change has been associated with appearance and resurgence of vector-borne infectious diseases. Despite the fact that many important emerging and re-emerging vector-borne infectious diseases are becoming better controlled, our success in stopping the many new appearing and resurging vector-borne infectious diseases that may happen in the future seems to be uncertain. Hence, this paper reviews and synthesizes the existing literature to explore global patterns of emerging and re-emerging vector-borne infections and the challenges for their control. It also attempts to give insights to the epidemiological profile of major vector-borne diseases including Zika fever, dengue, West Nile fever, Crimean-Congo hemorrhagic fever, Chikungunya, Yellow fever, and Rift Valley fever.

Exploratory study on the spatial relationship between emerging infectious diseases and urban characteristics: Cases from Korea

In the modern global context of interconnected populations, the recent emergence of infectious diseases involves complex interactions. The purpose of this study is to investigate the spatial correlations between urban characteristics, taking into account the socio-ecological aspects, and the emergence of infectious diseases. Using exploratory spatial data analysis and spatial regression between the infectious disease emergence data and 14 urban characteristics, we analyzed 225 spatial units in South Korea, where there was a re-emergence of measles and a 2015 outbreak of Middle East Respiratory Syndrome. As results of exploratory spatial data analysis, the emerging infectious diseases had spatial dependence and showed spatial clusters. Spatial regression models showed that urban characteristic factors had different effects according to the type of infectious disease. Common factors were characteristics related to low socioeconomic status in water or food-borne diseases and manageable infectious diseases. Intermittent infections disease epidemics are related to high-quality residential environments and the response capacity of the local government. New infectious diseases are different than other infectious diseases, which are related to the ecological environment. This study suggests spatial policies for preventing infectious diseases considering the spatial relationships between urban characteristics and infectious diseases as well as the management of public health.

Spatio-temporal variation in environmental features predicts the distribution and abundance of Ixodes scapularis

Many species have experienced dramatic changes in both geographic range and population sizes in recent history. Increases in the geographic range or population size of disease vectors have public health relevance as these increases often precipitate the emergence of infectious diseases in human populations. Accurately identifying environmental factors affecting the biogeographic patterns of vector species is a long-standing analytical challenge, stemming from a paucity of data capturing periods of rapid changes in vector demographics. We systematically investigated the occurrence and abundance of nymphal Ixodes scapularis ticks at 532 sampling locations throughout New York State (NY), USA, between 2008 and 2018, a time frame that encompasses the emergence of diseases vectored by these ticks. Analyses of these field-collected data demonstrated a range expansion into northern and western NY during the last decade. Nymphal abundances increased in newly colonised areas, while remaining stable in areas with long-standing populations over the last decade. These trends in the geographic range and abundance of nymphs correspond to both the geographic expansion of human Lyme disease cases and increases in incidence rates. Analytic models fitted to these data incorporating time, space, and environmental factors, accurately identified drivers of the observed changes in nymphal occurrence and abundance. These models accounted for the spatial and temporal variation in the occurrence and abundance of nymphs and can accurately predict nymphal population patterns in future years. Forecasting disease risk at fine spatial scales prior to the transmission season can influence both public health mitigation strategies and individual behaviours, potentially impacting tick-borne disease risk and subsequently human disease incidence.

An overview of chitosan and its application in infectious diseases

Infectious diseases, such as the coronavirus disease-19, SARS virus, Ebola virus, and AIDS, threaten the health of human beings globally. New viruses, drug-resistant bacteria, and fungi continue to challenge the human efficacious drug bank. Researchers have developed a variety of new antiviral and antibacterial drugs in response to the infectious disease crisis. Meanwhile, the development of functional materials has also improved therapeutic outcomes. As a natural material, chitosan possesses good biocompatibility, bioactivity, and biosafety. It has been proven that the cooperation between chitosan and traditional medicine greatly improves the ability of anti-infection. This review summarized the application and design considerations of chitosan-composed systems for the treatment of infectious diseases, looking forward to providing the idea of infectious disease therapy.

Cryptococcus deuterogattii VGIIa Infection Associated with Travel to the Pacific Northwest Outbreak Region in an Anti-Granulocyte-Macrophage Colony-Stimulating Factor Autoantibody-Positive Patient in the United States

Mortality rates associated with C. gattii infections are estimated to be between 13% and 33%, depending on an individual’s predisposition, and C. gattii has caused at least 39 deaths in the PNW region. There have been four other international travel cases reported in patients from Europe and Asia with travel history to the PNW, but this report describes the first North American traveler who acquired C. deuterogattii infection presenting within the United States and the first case of a C. deuterogattii outbreak infection associated with anti-GM-CSF autoantibodies. Early and accurate diagnoses are important for disease prevention and treatment and for control of infectious diseases. Continual reporting of C. deuterogattii infections is necessary to raise awareness of the ongoing outbreak in the PNW and to alert travelers and physicians to the areas of endemicity with potential risks.

The region encompassing the Pacific Northwest (PNW), Vancouver Island, Oregon, and Washington has been the location of an ongoing Cryptococcus gattii outbreak since the 1990s, and there is evidence that the outbreak is expanding along the West Coast into California. Here we report a clinical case of a 69-year-old, HIV-negative man from North Carolina who was diagnosed with a fungal brain mass by magnetic resonance imaging (MRI) and pathology. He had traveled to Seattle and Vancouver 3 years earlier and to Costa Rica 4 months prior to presentation. Phenotypic evidence showed that the fungal mass isolated from the patient’s brain represented C. gattii. In agreement with the phenotypic results, multilocus sequence typing (MLST) provided genotypic evidence that assigned the infecting organism within the C. gattii species complex and to the C. deuterogattii VGIIa clade. Whole-genome sequencing revealed >99.99% identity with the C. deuterogattii reference strain R265, indicating that the infecting strain is derived from the highly clonal outbreak strains in the PNW. We conclude that the patient acquired the C. gattii infection during his travel to the region 3 years prior and that the infection was dormant for an extended period of time before causing disease. The patient tested positive for anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies, supporting earlier reports that implicate these autoantibodies as a risk factor associated with C. gattii infection.

A Pilot Trial of Online Simulation Training for Ebola Response Education

This article describes a pilot trial of an internet-distributable online software package that provides course materials and built-in evaluation tools to train healthcare workers in high-risk infectious disease response. It includes (1) an online self-study component, (2) a "hands-on" simulation workshop, and (3) a data-driven performance assessment toolset to support debriefing and course reporting. This study describes a pilot trial of the software package using a course designed to provide education in Ebola response to prepare healthcare workers to safely function as a measurable, high-reliability team in an Ebola simulated environment. Eighteen adult volunteer healthcare workers, including 9 novices and 9 experienced participants, completed an online curriculum with pre- and posttest, 13 programmed simulation training scenarios with a companion assessment tool, and a confidence survey. Both groups increased their knowledge test scores after completing the online curriculum. Simulation scenario outcomes were similar between groups. The confidence survey revealed participants had a high degree of confidence after the course, with a median confidence level of 4.5 out of 5.0 (IQR = 0.5). This study demonstrated the feasibility of using the online software package for the creation and application of an Ebola response course. Future studies could advance knowledge gained from this pilot trial by assessing timely distribution and multi-site effectiveness with standard education.

Global spatial assessment of Aedes aegypti and Culex quinquefasciatus: a scenario of Zika virus exposure

Zika virus (ZIKV) is an arbovirus transmitted mainly by Aedes aegypti mosquitoes. Recent scientific evidence on Culex quinquefasciatus has suggested its potential as a vector for ZIKV, which may change the current risk zones. We aimed to quantify the world population potentially exposed to ZIKV in a spatially explicit way, considering the primary vector (A. aegypti) and the potential vector (C. quinquefasciatus). Our model combined species distribution modelling of mosquito species with spatially explicit human population data to estimate ZIKV exposure risk. We estimated the potential global distribution of C. quinquefasciatus and estimated its potential interaction zones with A. aegypti. Then we evaluated the risk zones for ZIKV considering both vectors. Finally, we quantified and compared the people under risk associated with each vector by risk level, country and continent. We found that C. quinquefasciatus had a more temperate distribution until 42° in both hemispheres, while the risk involving A. aegypti is concentrated mainly in tropical latitudes until 35° in both hemispheres. Globally, 4.2 billion people are under risk associated with ZIKV. Around 2.6 billon people are under very high risk associated with C. quinquefasciatus and 1 billion people associated with A. aegypti. Several countries could be exposed to ZIKV, which emphasises the need to clarify the competence of C. quinquefasciatus as a potential vector as soon as possible. The models presented here represent a tool for risk management, public health planning, mosquito control and preventive actions, especially to focus efforts on the most affected areas.

Syndromic Surveillance System for Korea-US Joint Biosurveillance Portal: Design and Lessons Learned

Driven by the growing importance of situational awareness of bioterrorism threats, the Republic of Korea (ROK) and the United States have constructed a joint military capability, called the Biosurveillance Portal (BSP), to enhance biosecurity. As one component of the BSP, we developed the Military Active Real-time Syndromic Surveillance (MARSS) system to detect and track natural and deliberate disease outbreaks. This article describes the ROK military health data infrastructure and explains how syndromic data are derived and made available to epidemiologists. Queries corresponding to 8 syndromes, based on published clinical effects of weaponized pathogens, were used to classify military hospital patient records to form aggregated daily syndromic counts. A set of ICD-10 codes for each syndrome was defined through literature review and expert panel discussion. A study set of time series of national daily counts for each syndrome was extracted from the Defense Medical Statistical Information System between January 1, 2011, and May 31, 2014. A stratified, adjusted cumulative summation algorithm was implemented for each syndrome group to signal alerts prompting investigation. The algorithm was developed by calculating sensitivity to sets of 1,000 artificial outbreak signals randomly injected in the dataset, with each signal injected in a separate trial. Queries and visualizations were adapted from the Suite for Automated Global bioSurveillance. Findings indicated that early warning of outbreaks affecting fewer than 50 patients will require analysis at subnational levels, especially for common syndrome groups. Developing MARSS to improve sensitivity will require modification of underlying syndromic diagnosis codes, engineering to coordinate alerts among subdivisions, and enhanced algorithms. The bioterrorist threat in the Korean peninsula mandates these efforts.

Emerging and Neglected Infectious Diseases: Insights, Advances, and Challenges

Infectious diseases are a significant burden on public health and economic stability of societies all over the world. They have for centuries been among the leading causes of death and disability and presented growing challenges to health security and human progress. The threat posed by infectious diseases is further deepened by the continued emergence of new, unrecognized, and old infectious disease epidemics of global impact. Over the past three and half decades at least 30 new infectious agents affecting humans have emerged, most of which are zoonotic and their origins have been shown to correlate significantly with socioeconomic, environmental, and ecological factors. As these factors continue to increase, putting people in increased contact with the disease causing pathogens, there is concern that infectious diseases may continue to present a formidable challenge. Constant awareness and pursuance of effective strategies for controlling infectious diseases and disease emergence thus remain crucial. This review presents current updates on emerging and neglected infectious diseases and highlights the scope, dynamics, and advances in infectious disease management with particular focus on WHO top priority emerging infectious diseases (EIDs) and neglected tropical infectious diseases.

Chagas' disease: an emergent urban zoonosis. The caracas valley (Venezuela) as an epidemiological model

The unprecedented emergence of important public health and veterinary zoonoses is usually a result of exponential population growth and globalization of human activities. I characterized Chagas’ disease as an emergent zoonosis in the Caracas Valley (Venezuela) due to the following findings: the presence of reservoirs (Didelphis marsupialis, Rattus rattus) and vectors (Panstrongylus geniculatus, Panstrongylus rufotuberculatus) infected with Trypanosoma cruzi in urbanized or marginalized areas; the elevated contact between P. geniculatus and human beings detected by parasitological and molecular examinations of triatomine feces demonstrated the possibility of transmission risks; a study of outbreaks of urban Chagas’ disease reported the first proven case of oral transmission of T. cruzi to human beings; the risk of transmission of glandular metacyclic stages from marsupials by experimental ocular and oral instillation; mice genitalia infected with T. cruzi contaminated blood resulted in the formation of amastigotes very close to the lumen suggesting that there may be a possibility of infection via their release into the urine and thence to the exterior; the ubiquitous histotropism and histopathology of T. cruzi was demonstrated using a mouse model; the presence of experimental T. cruzi pseudocysts in adipose, bone-cartilage, and eye tissue indicated a potential risk for transplants. Socio-sanitary programs that include improvements in housing, vector control, and access to medical treatment, as well as strategies aimed at combating social inequalities, poverty, and underdevelopment should be undertaken in those areas where zoonoses are most prevalent. Disciplines, such as Ecology, Epidemiology, Medical Entomology, Human and Veterinary Medicine, Environmental Studies, Public Health, Social and Political Studies, Immunology, Microbiology, and Pharmacology could all provide important contributions that aim to reduce the occurrence of factors governing the spread of emergent diseases.

Emerging and reemerging neglected tropical diseases: a review of key characteristics, risk factors, and the policy and innovation environment

In global health, critical challenges have arisen from infectious diseases, including the emergence and reemergence of old and new infectious diseases. Emergence and reemergence are accelerated by rapid human development, including numerous changes in demographics, populations, and the environment. This has also led to zoonoses in the changing human-animal ecosystem, which are impacted by a growing globalized society where pathogens do not recognize geopolitical borders. Within this context, neglected tropical infectious diseases have historically lacked adequate attention in international public health efforts, leading to insufficient prevention and treatment options. This subset of 17 infectious tropical diseases disproportionately impacts the world's poorest, represents a significant and underappreciated global disease burden, and is a major barrier to development efforts to alleviate poverty and improve human health. Neglected tropical diseases that are also categorized as emerging or reemerging infectious diseases are an even more serious threat and have not been adequately examined or discussed in terms of their unique risk characteristics. This review sets out to identify emerging and reemerging neglected tropical diseases and explore the policy and innovation environment that could hamper or enable control efforts. Through this examination, we hope to raise awareness and guide potential approaches to addressing this global health concern.

A quantitative prioritisation of human and domestic animal pathogens in Europe

Disease or pathogen risk prioritisations aid understanding of infectious agent impact within surveillance or mitigation and biosecurity work, but take significant development. Previous work has shown the H-(Hirsch-)index as an alternative proxy. We present a weighted risk analysis describing infectious pathogen impact for human health (human pathogens) and well-being (domestic animal pathogens) using an objective, evidence-based, repeatable approach; the H-index. This study established the highest H-index European pathogens. Commonalities amongst pathogens not included in previous surveillance or risk analyses were examined. Differences between host types (humans/animals/zoonotic) in pathogen H-indices were explored as a One Health impact indicator. Finally, the acceptability of the H-index proxy for animal pathogen impact was examined by comparison with other measures. 57 pathogens appeared solely in the top 100 highest H-indices (1) human or (2) animal pathogens list, and 43 occurred in both. Of human pathogens, 66 were zoonotic and 67 were emerging, compared to 67 and 57 for animals. There were statistically significant differences between H-indices for host types (humans, animal, zoonotic), and there was limited evidence that H-indices are a reasonable proxy for animal pathogen impact. This work addresses measures outlined by the European Commission to strengthen climate change resilience and biosecurity for infectious diseases. The results include a quantitative evaluation of infectious pathogen impact, and suggest greater impacts of human-only compared to zoonotic pathogens or scientific under-representation of zoonoses. The outputs separate high and low impact pathogens, and should be combined with other risk assessment methods relying on expert opinion or qualitative data for priority setting, or could be used to prioritise diseases for which formal risk assessments are not possible because of data gaps.

Investigations on the interactions of λphage-derived peptides against the SrtA mechanism in Bacillus anthracis

Bacillus anthracis is a well-known bioweapon pathogen, which coordinates the expression of its virulence factors in response to a specific environmental signal by its protein architecture. Absences of sortase signal functioning may fail to assemble the surface linked proteins and so B. anthracis cannot sustain an infection with host cells. Targeting the signaling mechanism of B. anthracis can be achieved by inhibition of SrtA enzyme through λphage-derived plyG. The lysin enzyme plyG is experimentally proven as bacteriolytic agent, specifically kill's B. anthracis by inhibiting the SrtA. Here, we have screened the peptides from λphage lysin, and these peptides are having the ability as LPXTG competitive inhibitors. In comparison to the activator peptide LPXTG binding motif, λphage lysin based inhibitor peptides are having much supremacy towards binding of SrtA. Finally, peptide structures extracted from PlyG are free from toxic, allergic abilities and also have the ability to terminate the signal transduction mechanism in B. anthracis.

Threats from emerging and re-emerging neglected tropical diseases (NTDs)

Background

Neglected tropical diseases impact over 1 billion of the world's poorest populations and require special attention. However, within the NTDs recognized by the World Health Organization, some are also dually categorized as emerging and re-emerging infectious diseases requiring more detailed examination on potential global health risks.

Methods

We reviewed the 17 NTDs classified by the WHO to determine if those NTDs were also categorized by the US Centers for Disease Control and Prevention as emerging and re-emerging infectious diseases (‘‘EReNTDs’’). We then identified common characteristics and risks associated with EReNTDs.

Results

Identified EReNTDs of dengue, rabies, Chagas Disease, and cysticercosis disproportionately impact resource-poor settings with poor social determinants of health, spread through globalization, are impacted by vector control, lack available treatments, and threaten global health security. This traditionally neglected subset of diseases requires urgent attention and unique incentive structures to encourage investment in innovation and coordination.

Discussion

Multi-sectorial efforts and targeted public–private partnerships would spur needed R&D for effective and accessible EReNTD treatments, improvement of social determinants of health, crucial low-income country development, and health system strengthening efforts. Utilization of One Health principles is essential for enhancing knowledge to efficaciously address public health aspects of these EReNTDs globally.

Carbohydrate-based label-free detection of Escherichia coli ORN 178 using electrochemical impedance spectroscopy

A label-free biosensor for Escherichia coli (E. coli) ORN 178 based on faradaic electrochemical impedance spectroscopy (EIS) was developed. α-Mannoside or β-galactoside was immobilized on a gold disk electrode using a self-assembled monolayer (SAM) via a spacer terminated in a thiol functionality. Impedance measurements (Nyquist plot) showed shifts due to the binding of E. coli ORN 178, which is specific for α-mannoside. No significant change in impedance was observed for E. coli ORN 208, which does not bind to α-mannoside. With increasing concentrations of E. coli ORN 178, electron-transfer resistance (R(et)) increases before the sensor is saturated. After the Nyquist plot of E. coli/mixed SAM/gold electrode was modeled, a linear relationship between normalized R(et) and the logarithmic value of E. coli concentrations was found in a range of bacterial concentration from 10(2) to 10(3) CFU/mL. The combination of robust carbohydrate ligands with EIS provides a label-free, sensitive, specific, user-friendly, robust, and portable biosensing system that could potentially be used in a point-of-care or continuous environmental monitoring setting.

Global Challenges of Infectious Disease Epidemiology

As we have seen in the last chapter, infectious and parasitic diseases are major causes of morbidity and mortality worldwide, particularly in developing countries. Approximately 26% of global deaths and 26% of global burden of disease were attributed to infectious diseases in 2001 (Lopez et al.2006 see Chapter 1). One in two deaths that are mostly preventable occurs in developing countries (Kim-Farley 2004 Folch et al.2003. Looking to the remaining 21st century, we could imagine a decline in major infectious diseases like malaria and AIDS as a result of an adoption of effective prevention strategies and treatments or, like in the case of hepatitis B, as a consequence of worldwide vaccination programs in children. In addition, new vaccines, new treatment technologies, as well as an improvement in infrastructures can contribute to win the “battle against infectious diseases.”

Evaluation of a multiplexed PCR assay for detection of respiratory viral pathogens in a public health laboratory setting

There are numerous viral and bacterial causes of respiratory disease. To enable rapid and sensitive detection of even the most prevalent causes, there is a need for more-simplified testing systems that enable researchers and clinicians to perform multiplexed molecular diagnostics quickly and easily. To this end, a new multiplexed molecular test called the MultiCode-PLx respiratory virus panel (PLx-RVP) was developed and then implemented in a public health laboratory setting. A total of 687 respiratory samples were analyzed for the presence of 17 viruses that commonly cause respiratory disease. As a comparator, the samples were also tested using a standard testing algorithm that included the use of a real-time influenza virus A and B reverse transcription-PCR test and routine viral culture identification. The standard testing algorithm identified 503 (73%) samples as positive and 184 as negative. Analyzing the same 687 samples, the PLx-RVP assay detected one or more targets in 528 (77%) samples and found 159 samples negative for all targets. There were 25 discordant results between the two systems; 14 samples were positive for viruses not routinely tested for by the Wisconsin State Laboratory of Hygiene, and 13 of these were confirmed by real-time PCR. When the results of the standard testing algorithm were considered "true positives," the PLx-RVP assay showed an overall sensitivity of 99% and an overall specificity of 87%. In total, the PLx-RVP assay detected an additional 40 viral infections, of which 11 were mixed infections.

Population dynamics of Bordetella pertussis in Finland and Sweden, neighbouring countries with different vaccination histories

Pertussis is an infectious disease of the respiratory tract in humans caused by Bordetella pertussis. Despite extensive vaccinations, pertussis has remained endemic and re-emerged. In Finland, a whole-cell pertussis vaccine has been used since 1952 with high coverage. In Sweden, whole-cell vaccinations were introduced in 1953 but ceased in 1979, and pertussis vaccinations with acellular vaccines were introduced in 1996. Two epidemic peaks occurred in Sweden in 1999 and 2002 and in Finland in 1999 and 2003. We compared Finnish (N=193) and Swedish (N=455) B. pertussis isolates circulating in 1998-2003 together with vaccine strains used in these neighbouring countries with different vaccination histories. The isolates were analysed by serotyping, genotyping of pertussis toxin S1 subunit and pertactin, and pulsed-field gel electrophoresis. The results suggest that the sequential epidemics were caused by clonal expansion of a certain B. pertussis strain possibly transmitted from Sweden to Finland. The roles of antigenic variation in immunity-driven evolution of B. pertussis in both countries are discussed.

Transmission and Epidemiology of HIV/AIDS: a Global View

Since the first recognition of the condition that is now called AIDS, much has been learned. We now know that AIDS results from infection with HIV types 1 and 2. Advancements in approaches to treatment, in the form of new types of medications, have changed the trajectory of illness by slowing progression and decreasing the incidence of HIV-associated opportunistic infections in the millions of people living with HIV infection, particularly in developed countries. In less developed areas of the world, HIV infection looks different, in part because of the differential availability of medications and health care. This article focuses on epidemiology of HIV infection and AIDS in the United States and worldwide, and on transmission, including susceptibility factors.

All Hands on Deck: Transdisciplinary Approaches to Emerging Infectious Disease

The increasing burden of emerging infectious diseases worldwide confronts us with numerous challenges, including the imperative to design research and responses that are commensurate to understanding the complex social and ecological contexts in which infectious diseases occur. A diverse group of scientists met in Hawaii in March 2005 to discuss the linked social and ecological contexts in which infectious diseases emerge. A subset of the meeting was a group that focused on “transdisciplinary approaches” to integrating knowledge across and beyond academic disciplines in order to improve prevention and control of emerging infections. This article is based on the discussions of that group. Here, we outline the epidemiological legacy that has dominated infectious disease research and control up until now, and introduce the role of new, transdisciplinary and systems-based approaches to emerging infectious diseases. We describe four cases of transboundary health issues and use them to discuss the potential benefits, as well as the inherent difficulties, in understanding the social–ecological contexts in which infectious diseases occur and of using transdisciplinary approaches to deal with them.