Contours of risk: spatializing human behaviors to understand disease dynamics in changing landscapes

We echo viewpoints presented in recent publications from EcoHealth and other journals arguing for the need to understand linkages between human health, disease ecology, and landscape change. We underscore the importance of incorporating spatialities of human behaviors and perceptions in such analyses to further understandings of socio-ecological interactions mediating human health. We use Buruli ulcer, an emerging necrotizing skin infection and serious health concern in central Ghana, to illustrate our argument.

The use of expert opinion to assess the risk of emergence or re-emergence of infectious diseases in Canada associated with climate change

Global climate change is predicted to lead to an increase in infectious disease outbreaks. Reliable surveillance for diseases that are most likely to emerge is required, and given limited resources, policy decision makers need rational methods with which to prioritise pathogen threats. Here expert opinion was collected to determine what criteria could be used to prioritise diseases according to the likelihood of emergence in response to climate change and according to their impact. We identified a total of 40 criteria that might be used for this purpose in the Canadian context. The opinion of 64 experts from academic, government and independent backgrounds was collected to determine the importance of the criteria. A weight was calculated for each criterion based on the expert opinion. The five that were considered most influential on disease emergence or impact were: potential economic impact, severity of disease in the general human population, human case fatality rate, the type of climate that the pathogen can tolerate and the current climatic conditions in Canada. There was effective consensus about the influence of some criteria among participants, while for others there was considerable variation. The specific climate criteria that were most likely to influence disease emergence were: an annual increase in temperature, an increase in summer temperature, an increase in summer precipitation and to a lesser extent an increase in winter temperature. These climate variables were considered to be most influential on vector-borne diseases and on food and water-borne diseases. Opinion about the influence of climate on air-borne diseases and diseases spread by direct/indirect contact were more variable. The impact of emerging diseases on the human population was deemed more important than the impact on animal populations.

Re-emergence of brucellosis in cattle in France and risk for human health

A case of human brucellosis was diagnosed in France in January 2012. The investigation demonstrated that the case had been contaminated by raw milk cheese from a neighbouring dairy farm. As France has been officially free of bovine brucellosis since 2005, veterinary investigations are being conducted to determine the origin of the infection and avoid its spread among other herds. Hypotheses about the source of this infection are discussed.

Invasive non-typhoidal salmonella disease: an emerging and neglected tropical disease in Africa

Invasive strains of non-typhoidal salmonellae have emerged as a prominent cause of bloodstream infection in African adults and children, with an associated case fatality of 20-25%. The clinical presentation of invasive non-typhoidal salmonella disease in Africa is diverse: fever, hepatosplenomegaly, and respiratory symptoms are common, and features of enterocolitis are often absent. The most important risk factors are HIV infection in adults, and malaria, HIV, and malnutrition in children. A distinct genotype of Salmonella enterica var Typhimurium, ST313, has emerged as a new pathogenic clade in sub-Saharan Africa, and might have adapted to cause invasive disease in human beings. Multidrug-resistant ST313 has caused epidemics in several African countries, and has driven the use of expensive antimicrobial drugs in the poorest health services in the world. Studies of systemic cellular and humoral immune responses in adults infected with HIV have revealed key host immune defects contributing to invasive non-typhoidal salmonella disease. This emerging pathogen might therefore have adapted to occupy an ecological and immunological niche provided by HIV, malaria, and malnutrition in Africa. A good understanding of the epidemiology of this neglected disease will open new avenues for development and implementation of vaccine and public health strategies to prevent infections and interrupt transmission.

Pseudomonas aeruginosa, an emerging pathogen among burn patients in Kurdistan Province, Iran

This study was conducted to determine the incidence of Pseudomonas aeruginosa infections among burn patients at Tohid Hospital, Iran. A total of 176 clinical specimens were obtained from 145 burn patients admitted to the burn unit of Tohid Hospital to detect the presence of P. aeruginosa. Antimicrobial susceptibility testing was conducted to detect extended spectrum beta-lactamase (ESBL) producing P. aeruginiosa using Clinical and Laboratory Standards Institute guidelines with the double disc synergy test (DDST). A polymerase chain reaction was used to detect PER-1 and OXA-10 among the isolates. The mean age, total body surface area and length of hospital stay among patients were 29 years, 37.7%, and 10 days, respectively. Kerosene was the commonest cause of burn (60%), followed by gas (30%). During the study, P. aeruginosa was detected in 100 isolates. The antibiotics they were most commonly resistant to were cefotaxime, ceftriaxone and ciprofloxacin. Of the 100 P. aeroginusa isolates, 28% were positive for ESBL production with the DDST, 48% and 52% were PER-1 and OXA-10 producers, respectively. The high frequency of PER-1 and OXA-10 producers at this hospital is of concern considering their potential spread among burn patients.

A flu by any other name: why the World Health Organization should adopt the World Meteorological Association's storm naming system as a model for naming emerging infectious diseases

This article explores the factors that contributed to the use of different names for H1N1 by diverse actors in the early stages of the pandemic of 2009 and discusses the implications of inconsistent naming practices for the public's understanding of the virus and the credibility of scientists and health authorities. The authors propose a naming protocol for novel variants modeled after the World Meteorological Association's practice for naming weather events, a model that would enable accurate transmission of technical information among experts and provide a stable name for public use, even in the context of incomplete or changing scientific understanding of the nature of the pathogen.

Swine flu. Mexico's handling of A/H1N1 in comparative perspective

Emerging infectious diseases (EIDs) pose international security threats because of their potential to inflict harm upon humans, crops, livestock, health infrastructure, and economies. Despite the scale of this threat, there are inherent limitations in preventing and controlling EIDs, including the scope of current disease surveillance efforts. All of this leads to the following questions in the context of Mexico's recent swine flu experience: What were the cultural, political, and economic challenges to Influenza A/H1N1 virus response in Mexico? By way of comparison, what can we learn from the U.S. experience in 1976 with A/New Jersey/76 (Hsw1N1), later referred to as H1N1? This article explores the comparative political economy of Mexico's handling of influenza virus A/H1N1 outbreak in 2009. Research provides notable observations-based on the strengths and weaknesses of each country's response--that can be used as a starting point of discussion for the design of effective EIDs surveillance programs in developing and middle-income countries. In the U.S., the speed and efficiency of the 1976 U.S. mobilization against H1N1 was laudable. Although the U.S. response to the outbreak is seldom praised, the unity of the scientific and political communities demonstrated the national ability to respond to the situation. Mexico's strongest characteristics were its transparency, as well as the cooperation the country exhibited with other nations, particularly the U.S. and Canada. While Mexico showed savvy in its effective management of public and media relations, as the article details, political, economic, and cultural problems persisted.

Public health, global surveillance, and the "emerging disease" worldview: a postcolonial appraisal of PEPFAR

Drawing upon a postcolonial lens, this project looks at how meanings of HIV/AIDS are discursively constructed within the U.S. President's Emergency Plan for AIDS Relief (PEPFAR), which was launched in 2003 under the presidency of George W. Bush and has been heralded as the largest global public health intervention program in history. Building on existing literature that theorizes the interrelationships of public health and national security, global surveillance, and transnational hegemony, the postcolonial theoretical standpoint interrogates how such meanings are constructed within PEPFAR. A postcolonial deconstruction of the 2009 PEPFAR report to the Congress revealed three meanings of HIV/AIDS that were discursively constructed in such policy documents: (a) the "Third World" as a site of intervention, (b) U.S. altruism as "lifting" the burden of the soul, and (c) AIDS, economics, and security. The themes put forth the linkages among the symbolic representations in neocolonial configurations and the politics of material disparities across the globe, thus issuing a call for the creation of participatory and dialogic spaces for engaging subaltern voices that are typically treated as targets of policy and intervention discourses.

Phylogeny, life history, and ecology contribute to differences in amphibian susceptibility to ranaviruses

Research that identifies the potential host range of generalist pathogens as well as variation in host susceptibility is critical for understanding and predicting the dynamics of infectious diseases within ecological communities. Ranaviruses have been linked to amphibian die-off events worldwide with the greatest number of reported mortality events occurring in the United States. While reports of ranavirus-associated mortality events continue to accumulate, few data exist comparing the relative susceptibility of different species. Using a series of laboratory exposure experiments and comparative phylogenetics, we compared the susceptibilities of 19 amphibian species from two salamander families and five anurans families for two ranavirus isolates: frog virus 3 (FV3) and an FV3-like isolate from an American bullfrog culture facility. We discovered that ranaviruses were capable of infecting 17 of the 19 larval amphibian species tested with mortality ranging from 0 to 100%. Phylogenetic comparative methods demonstrated that species within the anuran family Ranidae were generally more susceptible to ranavirus infection compared to species from the other five families. We also found that susceptibility to infection was associated with species that breed in semi-permanent ponds, develop rapidly as larvae, and have limited range sizes. Collectively, these results suggest that phylogeny, life history characteristics, and habitat associations of amphibians have the potential to impact susceptibility to ranaviruses.

Uncertainties in the governance of animal disease: an interdisciplinary framework for analysis

Uncertainty is an inherent feature of strategies to contain animal disease. In this paper, an interdisciplinary framework for representing strategies of containment, and analysing how uncertainties are embedded and propagated through them, is developed and illustrated. Analysis centres on persistent, periodic and emerging disease threats, with a particular focus on cryptosporidiosis, foot and mouth disease and avian influenza. Uncertainty is shown to be produced at strategic, tactical and operational levels of containment, and across the different arenas of disease prevention, anticipation and alleviation. The paper argues for more critically reflexive assessments of uncertainty in containment policy and practice. An interdisciplinary approach has an important contribution to make, but is absent from current real-world containment policy.

Strengthening infectious disease surveillance in a Dutch-German crossborder area using a real-time information exchange system

International outbreaks are occurring much faster than before and require rapid trans-national detection and response. Never before has there been a more urgent need for improved crossborder collaboration on harmonisation of surveillance and response systems despite varying legislations. In the Euregion Maas Rhine, the Public Health Services of South Limburg in the Netherlands and Aachen in Germany agreed to join forces to work on a collaborative tool for sharing real-time infectious disease data. Both units had already implemented an adapted version of HPZone (a web-based software suite for managing infectious diseases at the local level). The collaborative work was realised through finding solutions to five key challenges. First, Euregional disease protocols were agreed commensurate with national guidelines. Secondly, a minimal dataset for infectious disease exchange information was negotiated taking into consideration international health regulations and differences in legislation. Thirdly, a mature risk assessment model for infectious disease was augmented to account for transborder spread and Euregional impact. Fourthly, protocol alert rules were negotiated on triggers for early warning. Finally, a crossborder dashboard, as a component of HPVista and encapsulating the four previous deliverables into a secure web-based system, was developed. HPVista is the parent application to HPZone and enables wider incident command and control regionally, nationally and internationally. The dashboard has facilities for displaying what, when, where and how cases, contacts and outbreaks happen in the crossborder area. It also provides secure communications for further discussion and exchange of other key information not currently shared electronically. The collaborative work embedded in the modified HPZone and HPVista versions with real-time surveillance and geographical information system mapping readily facilitates the systematic analysis of crossborder health incidents in a continuously changing environment and will result in improved public health emergency management.

Emergence of dengue virus serotype 3 on Mayotte Island, Indian Ocean

A serosurvey carried out in 2006 in Mayotte, a French overseas collectivity in the Indian Ocean, confirmed previous circulation of dengue virus (DENV) on the island, but since the set up of a laboratory-based surveillance of dengue-like illness in 2007, no case of DENV has been confirmed. In response to an outbreak of DENV-3 on Comoros Islands in March 2010 surveillance of dengue-like illness in Mayotte was enhanced. By September 15, 76 confirmed and 31 probable cases of DENV have been identified in Mayotte. In urban and periurban settings on the island, Aedes albopictus is the predominant Aedes species, but Ae. aegyptii remains the most common species in rural areas. Given the epidemic potential of dengue virus in Mayotte, adequate monitoring including early detection of cases, timely investigation and sustained mosquito control actions remain essential.

Prevalence of Lyme disease agents and several emerging pathogens in questing ticks from the German Baltic coast

In summer 2008, a total of 512 Ixodes ricinus (Acari: Ixodidae) ticks was collected from vegetation in four areas at the Baltic coast of Germany and tested for the presence of Lyme disease spirochetes. Among them, 293 ticks from three areas were screened for Anaplasma phagocytophilum (Rickettsiales: Anaplasmataceae), rickettsiae of the spotted fever group (Rickettsiales: Rickettsiaceae), and Babesia spp. (Piroplasmida: Babesiidae), respectively. Borrelia burgdorferi sensu lato genospecies (Spirochaetales: Spirochaetaceae) were detected in 3.1% of the tick samples. The prevalence ofA. phagocytophilum was 1.0%, rickettsiae were present in 8.5%, and pathogenic Babesia spp. in 8.9% of analyzed ticks. Coinfections occurred in five ticks. With this study we report first data on the coexistence of established and emerging pathogens in questing ticks from recreational areas of northeastern Germany, indicating the need of further studies for a reliable risk assessment.

Evolution and population genetics of exotic and re-emerging pathogens: novel tools and approaches

Given human population growth and accelerated global trade, the rate of emergence of exotic plant pathogens is bound to increase. Understanding the processes that lead to the emergence of new pathogens can help manage emerging epidemics. Novel tools for analyzing population genetic variation can be used to infer the evolutionary history of populations or species, allowing for the unprecedented reconstruction of the demographic history of pathogens. Specifically, recent advances in the application of coalescent, maximum likelihood (ML), and Bayesian methods to population genetic data combined with increasing availability of affordable sequencing and parallel computing have created the opportunity to apply these methods to a broad range of questions regarding the evolution of emerging pathogens. These approaches are particularly powerful when used to test multiple competing hypotheses. We provide several examples illustrating how coalescent analysis provides critical insights into understanding migration pathways as well as processes of divergence, speciation, and recombination.

Distribution and risk factors for spread of amphibian chytrid fungus Batrachochytrium dendrobatidis in the Tasmanian Wilderness World Heritage Area, Australia

Chytridiomycosis is an emerging infectious disease caused by the pathogen Batrachochytrium dendrobatidis (Bd) and is the cause of the decline and extinction of amphibian species throughout the world. We surveyed the distribution of Bd within and around the Tasmanian Wilderness World Heritage Area (TWWHA), a 1.38 million ha area of significant fauna conservation value, which provides the majority of habitat for Tasmania's 3 endemic frog species (Litoria burrowsae, Bryobatrachus nimbus and Crinia tasmaniensis). Bd was detected at only 1 (3%) of the 33 sites surveyed within the TWWHA and at 15 (52%) of the 29 sites surveyed surrounding the TWWHA. The relatively low incidence of the disease within the TWWHA suggests that the majority of the TWWHA is currently free of the pathogen despite the fact that the region provides what appears to be optimal conditions for the persistence of Bd. For all survey sites within and around the TWWHA, the presence of Bd was strongly associated with the presence of gravel roads, forest and < 1000 m altitude--factors that in this study were associated with human-disturbed landscapes around the TWWHA. Conversely, the presence of walking tracks was strongly associated with the absence of Bd, suggesting an association of absence with relatively remote locations. The wide distribution of Bd in areas of Tasmania with high levels of human disturbance and its very limited occurrence in remote wilderness areas suggests that anthropogenic activities may facilitate the dissemination of the pathogen on a landscape scale in Tasmania. Because the majority of the TWWHA is not readily accessible and appears to be largely free of Bd, and because Tasmanian frogs reproduce in ponds rather than streams, it may be feasible to control the spread of the disease in the TWWHA.

Tracking the emergence of pandemic Influenza A/H1N1/2009 and its interaction with seasonal influenza viruses in Singapore

INTRODUCTION

Since the emergence of the pandemic influenza A/H1N1/2009 virus in April 2009, diagnostic testing in many countries has revealed the rapid displacement and then replacement of circulating seasonal influenza viruses by this novel virus.

MATERIALS AND METHODS

In-house seasonal and pandemic influenza-specific polymerase chain reaction assays were introduced and/or developed at the Molecular Diagnosis Centre (MDC) at the National University Hospital (NUH), Singapore. These assays have been used to test all samples received from in-patients, out-patients, staff and visitors for suspected pandemic influenza A/H1N1/2009 infection.

RESULTS

Prior to the arrival of the pandemic A/H1N1/2009 virus in Singapore at the end of May 2009, seasonal influenza A/H3N2 predominated in this population, with very little seasonal influenza A/H1N1 and B viruses detected. Within about 1 month of its arrival in Singapore (mainly during June to July 2009), this pandemic virus rapidly displaced seasonal influenza A/H3N2 to become the predominant strain in the Singaporean population served by MDC/NUH.

CONCLUSIONS

Realtime molecular techniques have allowed the prompt detection of different influenza subtypes during this current pandemic, which has revealed the displacement/replacement of previously circulating seasonal subtypes with A/H1N1/2009. Although some of this may be explained by immunological cross-reactivity between influenza subtypes, more studies are required.

Leishmaniasis emergence in Europe

Leishmaniasis emergence in Europe is reviewed, based on a search of literature up to and including 2009. Topics covered are the disease, its relevance, transmission and epidemiology, diagnostic methods, treatment, prevention, current geographical distribution, potential factors triggering changes in distribution, and risk prediction. Potential factors triggering distribution changes include vectorial competence, importation or dispersal of vectors and reservoir hosts, travel, and climatic/environmental change. The risk of introducing leishmaniasis into the European Union (EU) and its spread among Member States was assessed for the short (2-3 years) and long term (15-20 years). There is only a low risk of introducing exotic Leishmania species because of the absence of proven vectors and/or reservoir hosts. The main threat comes from the spread of the two parasites endemic in the EU, namely Leishmania infantum, which causes zoonotic visceral and cutaneous leishmaniasis in humans and the domestic dog (the reservoir host), and L. tropica, which causes anthroponotic cutaneous leishmaniasis. The natural vector of L. tropica occurs in southern Europe, but periodic disease outbreaks in Greece (and potentially elsewhere) should be easily contained by surveillance and prompt treatment, unless dogs or other synanthropic mammals prove to be reservoir hosts. The northward spread of L. infantum from the Mediterranean region will depend on whether climate and land cover permit the vectors to establish seasonal biting rates that match those of southern Europe. Increasing dog travel poses a significant risk of introducing L. infantum into northern Europe, and the threat posed by non-vectorial dog-to-dog transmission should be investigated.

[Tick bite fever in West Africa: difficulties in diagnosis of an emerging disease]

West African tick bite fever is a prevalent emerging zoonosis from the coast of Senegal to Chad. It is characterized by recurrent fever in association with a deteriorating clinical state. It is now the second most common vector-borne disease in Senegal. The purpose of this report is to describe one case and to review the main clinical and epidemiological features of this disease.

[Melioidosis: an emerging tropical disease]

Melioidosis is an infection affecting both human and animal health. The causative agent is Burkholderia pseudomallei, a Gram-negative soil bacterium. Melioidosis is endemic in tropical areas of Southeast Asia and Northern Australia, and sporadic in many other countries. Clinical presentation is variable ranging from acute septicemia, isolated pulmonary infection, or chronic granulomatous lesions to asymptomatic forms with positive serology. There is no vaccine and treatment is difficult because B. pseudomallei is resistant to a wide range of antibiotics. Relapses are common. B. pseudomallei is listed as a biological risk class 3 and considered as a potential bioterrorism agent due to its high virulence by inhalation, to the difficulty of treatment, and to the lack of vaccine.

International Health Regulations: a major paradigm shift from 1969 to 2005

The International Health Regulations (IHR 1969), replaced by IHR 2005 had been adopted by the World Health Assembly on 23 May 2005 and came into force on 15 June 2007. IHR 2005 are a legally binding agreement among World Health Organisation (WHO) member states and other states that have agreed to be bound by them. New revision was necessitated by concerns about increasing global health threats and the need to respond with more effective surveillance and control practices. The limitations of IHR 1969, which led to their revision, related to their narrow scope, their dependence on official country notifications, and their lack of a formal internationally coordinated mechanism to contain international disease spread. The IHR 2005, which is firmly based on practical experiences, has broaden the scope of IHR 1969 to cover existing, new and re-emerging diseases, including emergencies caused by non-infectious disease agents.

[Buruli ulcer re-emergent infection]

Nowadays, Buruli ulcer caused by Mycobacterium ulcerans remains a highly stigmatizing emerging disease in tropical countries, currently being the third mycobacterian infection in immunocompetent individuals. The purpose of this paper is to gather a number of information (epidemiological, clinical, laboratory and related to current treatment) in order to make the "aura of mysterious disease" fade away. Our work insists on the fact that prevention of Buruli ulcer and its complications is based on a better awareness of the dynamics and evolution of ecosystems as well as on socio-economic factors in tropical countries. Besides prophylactic measures, efficient methods for diagnosis and treatment are emphasized.

[Evolution of pathogenic micro-organisms as a challenge for medicine]

Successful parasitic micro-organisms are able to adapt to the circumstances of the host's organ system, and it is usually not expedient for them to kill their host. Under selection pressure, the evolution of micro-organisms is vastly quicker that that of man. The selection pressure brought about by rapid ecological changes and alterations associated with human action provides for the development of new, dangerous pathogens and transformation of familiar pathogens to become more dangerous. Progress in molecular biology has thus far not yielded as many new tools for the treatment of infectious diseases as the hopes were in the early 2000's.

Emerging and re-emerging tick-transmitted rickettsial and ehrlichial infections

Recently in the field of rickettsiology, an explosion of new isolates of pathogens have received species designation and new disease names, all of which have been relatively neglected by primary care and infectious disease physicians. A broad group of other tick-associated rickettsial and ehrlichial agents of unknown pathogenicity exist (eg, R amblyommii) that may cause confusion in interpreting serologic surveys or a single elevated antibody titer. Rickettsial and ehrlichial diseases are remarkable for their uniform susceptibility to doxycycline but are clinically difficult to distinguish from many viral infections and each another, and therefore misdiagnosis and failure to treat have unfortunate and sometimes tragic outcomes. Globally, many of these bacteria have been named but the genetic differences among them are often small, and many of their clinical manifestations may not be distinguishable diagnostically.

Evolutionary dynamics and emergence of panzootic H5N1 influenza viruses

The highly pathogenic avian influenza (HPAI) H5N1 virus lineage has undergone extensive genetic reassortment with viruses from different sources to produce numerous H5N1 genotypes, and also developed into multiple genetically distinct sublineages in China. From there, the virus has spread to over 60 countries. The ecological success of this virus in diverse species of both poultry and wild birds with frequent introduction to humans suggests that it is a likely source of the next human pandemic. Therefore, the evolutionary and ecological characteristics of its emergence from wild birds into poultry are of considerable interest. Here, we apply the latest analytical techniques to infer the early evolutionary dynamics of H5N1 virus in the population from which it emerged (wild birds and domestic poultry). By estimating the time of most recent common ancestors of each gene segment, we show that the H5N1 prototype virus was likely introduced from wild birds into poultry as a non-reassortant low pathogenic avian influenza H5N1 virus and was not generated by reassortment in poultry. In contrast, more recent H5N1 genotypes were generated locally in aquatic poultry after the prototype virus (A/goose/Guangdong/1/96) introduction occurred, i.e., they were not a result of additional emergence from wild birds. We show that the H5N1 virus was introduced into Indonesia and Vietnam 3–6 months prior to detection of the first outbreaks in those countries. Population dynamics analyses revealed a rapid increase in the genetic diversity of A/goose/Guangdong/1/96 lineage viruses from mid-1999 to early 2000. Our results suggest that the transmission of reassortant viruses through the mixed poultry population in farms and markets in China has selected HPAI H5N1 viruses that are well adapted to multiple hosts and reduced the interspecies transmission barrier of those viruses.

H5N1 influenza virus has been responsible for poultry outbreaks over the last 12 years—the longest recorded example of highly pathogenic avian influenza (HPAI) circulation in poultry. The ecological success of this virus in diverse species of both poultry and wild birds with sporadic introduction to humans suggests that it is a likely source of the next human pandemic. Genome sequences of H5N1 viruses reveal extensive genetic reassortment (mixing) with other influenza subtypes to produce many H5N1 genotypes that have developed into multiple genetically distinct clades, some of which have spread to affect over 60 countries. Here, we analyze all available sequence data of avian influenza viruses from Eurasia and show that the original HPAI H5N1 virus (referred to as A/goose/Guangdong/1/96) was likely introduced directly into poultry as an intact virus particle from wild aquatic birds. In contrast, H5N1 genotypes were generated in aquatic poultry populations after the introduction of A/goose/Guangdong/1/96 virus. Our results suggest that the transmission of reassortant viruses through the diverse poultry populations in farms and markets in China has selected H5N1 viruses that are well-adapted to multiple hosts and reduced the interspecies transmission barrier of those viruses.

Questions on Mediterranean spotted fever a century after its discovery

Mediterranean spotted fever (MSF) was first described in 1910. Twenty years later, it was recognized as a rickettsial disease transmitted by the brown dog tick. In contrast to Rocky Mountain spotted fever (RMSF), MSF was thought to be a benign disease; however, the first severe case that resulted in death was reported in France in the 1980s. We have noted important changes in the epidemiology of MSF in the last 10 years, with emergence and reemergence of MSF in several countries. Advanced molecular tools have allowed Rickettsia conorii conorii to be classified as a subspecies of R. conorii. New clinical features, such as multiple eschars, have been recently reported. Moreover, MSF has become more severe than RMSF; the mortality rate was as high as 32% in Portugal in 1997. Whether Rhipicephalus sanguineus is the only vector and reservoir for R. conorii conorii is a question not yet answered.

An emerging infectious disease triggering large-scale hyperpredation

Hyperpredation refers to an enhanced predation pressure on a secondary prey due to either an increase in the abundance of a predator population or a sudden drop in the abundance of the main prey. This scarcely documented mechanism has been previously studied in scenarios in which the introduction of a feral prey caused overexploitation of native prey. Here we provide evidence of a previously unreported link between Emergent Infectious Diseases (EIDs) and hyperpredation on a predator-prey community. We show how a viral outbreak caused the population collapse of a host prey at a large spatial scale, which subsequently promoted higher-than-normal predation intensity on a second prey from shared predators. Thus, the disease left a population dynamic fingerprint both in the primary host prey, through direct mortality from the disease, and indirectly in the secondary prey, through hyperpredation. This resulted in synchronized prey population dynamics at a large spatio-temporal scale. We therefore provide evidence for a novel mechanism by which EIDs can disrupt a predator-prey interaction from the individual behavior to the population dynamics. This mechanism can pose a further threat to biodiversity through the human-aided disruption of ecological interactions at large spatial and temporal scales.

Description of Lyme disease-like syndrome in Brazil. Is it a new tick borne disease or Lyme disease variation?

An emerging clinical entity that reproduces clinical manifestations similar to those observed in Lyme disease (LD) has been recently under discussion in Brazil. Due to etiological and laboratory particularities it is named LD-like syndrome or LD imitator syndrome. The condition is considered to be a zoonosis transmitted by ticks of the genus Amblyomma, possibly caused by interaction of multiple fastidious microorganisms originating a protean clinical picture, including neurological, osteoarticular and erythema migrans-like lesions. When peripheral blood of patients with LD-like syndrome is viewed under a dark-field microscope, mobile uncultivable spirochete-like bacteria are observed. PCR carried out with specific or conservative primers to recognize Borrelia burgdorferi sensu stricto or the genus Borrelia has been negative in ticks and in biological samples. Two different procedures, respectively involving hematoxylin and eosin staining of cerebrospinal fluid and electron microscopy analysis of blood, have revealed spirochetes not belonging to the genera Borrelia, Leptospira or Treponema. Surprisingly, co-infection with microorganisms resembling Mycoplasma and Chlamydia was observed on one occasion by electron microscopy analysis. We discuss here the possible existence of a new tick-borne disease in Brazil imitating LD, except for a higher frequency of recurrence episodes observed along prolonged clinical follow-up.

The future of health care in the United States

The U.S. government is involved in health care in various ways that include (1) providing services to veterans, (2) paying for care received by Medicare and Medicaid beneficiaries, (3) assuring quality through regulatory activity, (4) financing the discovery of medical breakthroughs, and (5) training members of the health workforce and assuring that the nation has an adequate supply of them. With the aging of the population, the role of the government in these endeavors will increase. This essay considers ways in which the health care of tomorrow will be affected by the intermingling of factors such as demography, epidemiology, economics, technology, globalization, and individual health behavior.

Rudolf Virchow and the recognition of alveolar echinococcosis, 1850s

Virchow proved that the disease “alveolar colloid” was caused by an Echinococcus sp.

Alveolar echinococcosis, which is caused by the larval stage of the fox tapeworm Echinococcus multilocularis, is one of the most dangerous parasitic diseases. It is endemic in many parts of the Northern Hemisphere and an emerging health problem in the People’s Republic of China. In Europe and North America, human cases are rare, but concomitant with an increase in the population of the final host, the red fox, an increase of human infections is expected. Rudolf Virchow, the father of the concept of cellular pathology, determined in the 1850s that an Echinococcus sp. was the causative agent of this enigmatic emerging disease. In his famous publication in 1855, he described the clinical course of the disease, its macroscopic aspects, and histopathologic findings in detail. He also identified the disease formerly known as alveolar colloid of the liver to be an infection with the larval stage of an Echinococcus sp.

Chikungunya virus in US travelers returning from India, 2006

Chikungunya virus (CHIKV), a mosquitoborne alphavirus; is endemic in Africa and Asia. In 2005–2006, CHIKV epidemics were reported in islands in the Indian Ocean and in southern India. We present data on laboratory-confirmed CHIKV infections among travelers returning from India to the United States during 2006.

The need for public-health veterinarians as seen by future employers

Future employers of veterinarians working in public health see a fast-growing demand. Emerging zoonotic diseases, bio-security threats, and food-safety problems all require the expertise of veterinarians with a focus on complex, global problems that span both human and animal health. The Public Health Task Force of the Association of American Veterinary Medical Colleges convened a group of stakeholders representing various branches of the US federal government, state and local governments, and professional societies to discuss their needs for public-health veterinarians. This article discusses those needs, the broader societal needs that require veterinarians with public-health expertise, and the implications of these for educational programs to train DVMs in public-health issues.