[Viral hemorrhagic fevers--epidemiology and clinical picture]

The article presents current knowledge about viral hemorrhagic fevers (VHF), their epidemiology, etiological factors, pathogenesis, symptoms and clinical management. Since none of the diseases appear endemically in Poland, special attention was given to spatial distribution of VHF for the purpose to facilitate undertaking clinical suspicions on the basis of the patient's recent travels. Determining the etiological agent should lead to selection of appropriate management options.

Viral hemorrhagic fevers including hantavirus pulmonary syndrome in the Americas

The term viral hemorrhagic fever refers to an acute systemic illness with a propensity for bleeding and shock. The viral hemorrhagic fevers endemic in the Americas include yellow fever, dengue hemorrhagic fever, the South American hemorrhagic fevers, hantavirus pulmonary syndrome, and hemorrhagic fever with renal syndrome. Because these diseases are primarily zoonotic, the distribution of any given virus is generally restricted by the distribution of its natural reservoir or arthropod vector. A high index of suspicion, detailed investigation of the travel and exposure history of the patient, and a basic understanding of the incubation periods and distributions of the various reservoirs of hemorrhagic fever viruses are imperative, as are prompt notification and laboratory confirmation. Clinical management is largely supportive, with a special emphasis on safe nursing practices to prevent nosocomial transmission.

[How to treat a patient with indications for an infectious viral hemorrhagic fever]

Lassa, Ebola, Marburg and Crimean-Congo haemorrhagic fever viruses are the most important causes of viral haemorrhagic fever which is transmitted from person to person through contact with blood or excreta. A non-specific fever may be the initial symptom of viral haemorrhagic fever. By means of carefully noting where the patient has travelled, possible exposure to ill persons, vectors or an animal reservoir, and the incubation period (< or = 21 days versus longer), it is possible to estimate the risk of infection with one of these viruses. Using this approach it is possible to diagnose high-risk patients in good time and to take appropriate measures.

Defending against viruses in biowarfare. How to respond to smallpox, encephalitides, hemorrhagic fevers

The threat of bioterrorism with use of viruses is increasing. Smallpox, encephalitis, and hemorrhagic fevers are the most likely diseases to result from viral deployment. It is critical that all healthcare professionals become familiar with the clinical presentation, diagnosis, management, and prevention of these diseases. Awareness and preparedness are instrumental in reducing viral transmission and improving survival of the victims.

Threats in bioterrorism. I: CDC category A agents

Although once considered unlikely, bioterrorism is now a reality in the United States since the anthrax cases began appearing in the fall of 2001. Intelligence sources indicate there are many countries and terrorist organizations that either possess biological weapons or are attempting to procure them. In the future it is likely that we will experience additional acts of bioterrorism. The CDC category A agents represent our greatest challenge because they have the potential to cause grave harm to the medical and public health systems of a given population. Thus, it is imperative that plans be developed now to deal with the consequences of an intentional release of any one or more of these pathogens.

Biological and chemical agents: a brief synopsis

The objective of this article is to provide a concise overview of the most likely biological and chemical agents that could be used as biochemical weapons. The diagnosis, pathology, prevention, decontamination, treatment, and disposition of these biological and chemical agents are presented in a tabular format for quick reference purposes. The information provided outlines the bare essentials needed to deal with any emergency or catastrophic event involving these agents.

The model of response to viral haemorrhagic fevers of the National Institute for Infectious Diseases "Lazzaro Spallanzani"

Viral haemorrhagic fevers (VHF) are severe and life-threatening diseases caused by a range of viruses. However, only four agents of VHF are known to be readily capable of person-to-person spread: Lassa virus, Crimean/Congo haemorrhagic fever virus, Ebola and Marburg viruses. Diseases caused by these viruses are endemic only in few areas in the world, most notably Africa and some rural parts of the Middle East and Eastern Europe. Nonetheless, the increasing volume of international travel presents a greater likelihood for the importation of these infections or of suspected cases in non endemic countries. Four conditions can lead to the importation and to the subsequent recognition of VHF within Europe: 1) patients arriving as a result of a planned medical evacuation; 2) persons who became sick on route to their destination; 3) persons discovered ill when entering a country, for example during routine clinical examination at the airport; 4) persons becoming sick after their arrival. Public health implications and the risk of secondary spread of pathogens in the above reported circumstances are very different. Similarly, preparedness and response should vary. This paper summarizes the present knowledge on the four VHF capable of person-to-person spread, describes the high isolation area constructed at the Italian National Institute for Infectious Diseases Lazzaro Spallanzani in Rome to respond to the occurrence of VHF. A brief overview of procedures and equipment adopted is provided.

Rodent-borne emerging viral zoonosis. Hemorrhagic fevers and hantavirus infections in South America

Hantaviruses and arenaviruses are naturally occurring viruses of rodents. Four South American hemorrhagic fevers caused by arenaviruses have emerged in the last 5 decades. All have similar clinical manifestations, with a case-fatality rate as high as 15% to 30%. Hantavirus infections have been increasingly recognized in South America since the description in 1993 of Hantavirus pulmonary syndrome. Given the diversity of rodent species in the region, it can be foreseen that many other viruses will be discovered, and some of them will be causing human illnesses of high public health impact.

[Is MBSL-level ward needed for the treatment of viral hemorrhagic diseases and pest?]

The recently revised Japanese Law on Infectious Diseases designates pest, Lassa, Marburg, Ebola and Crimean-Congo hemorrhagic diseases should be treated in an MBSL-level ward and that it should be constructed in each prefecture. However, pest can be treated with several antibiotics easily in an ordinary infectious disease ward. Lassa, Marburg and Ebola virus diseases are endemic in tropical Africa and only Lassa fever was imported into Japan in 1987. The probability of its importation to each prefecture is calculated on an assumption that a Lassa fever patient may be imported into Japan once in 10 years. Its incidence was calculated in comparison with the incidence of imported malaria from the African continent. Its probability P is calculated as follows. Corrected number of imported malaria patients from the African continent per year for each prefecture CN is divided by 445. 445 is the number of imported malaria patients from the African continent in ten years. Finally 445/CN is the number of years needed for each prefecture to import one case of Lassa fever. The results indicate that it takes 37 years for Metropolitan Tokyo where the largest number of malaria patients are imported annually. Other prefectures need more than 100 to 10,000 years, with an average of 1,017 years, for importation of one patient of Lassa fever. It is concluded that construction of an MBSL-level ward in each prefecture is unnecessary. The reports that the above mentioned viral hemorrhagic diseases can be treated safely in the ordinary infectious disease ward should be carefully reviewed.

Exotic virus infections of military significance. Hemorrhagic fever viruses and pox virus infections

Military personnel are frequently deployed to distant locations around the world under conditions of great stress, which involve potential exposure to hazardous viruses that are not commonly seen in the developed world. This article will provide an overview of two clinical presentations of viral infections of potential military significance: hemorrhagic fever and poxvirus infections. The three viral hemorrhagic fever viruses described--dengue, hemorrhagic fever with renal syndrome, and Congo-Crimean hemorrhagic fever--represent the diversity of potential hemorrhagic fever viruses that military forces may be exposed. Human poxvirus infections are currently uncommon but knowledge of these agents, will again become important should a terrorist threat of the use of smallpox become real and widespread use of vaccinia be considered to protect the military force.

Venezuelan hemorrhagic fever: clinical and epidemiological studies of 165 cases

Epidemiological and clinical data are presented on 165 cases of Venezuelan hemorrhagic fever (VHF), a newly emerging viral zoonosis caused by Guanarito virus (of the family Arenaviridae). The disease is endemic in a relatively circumscribed area of central Venezuela. Since its first recognition in 1989, the incidence of VHF has peaked each year between November and January, during the period of major agricultural activity in the region of endemicity. The majority of cases have involved male agricultural workers. Principal symptoms among the patients with VHF included fever, malaise, headache, arthralgia, sore throat, vomiting, abdominal pain, diarrhea, convulsions, and a variety of hemorrhagic manifestations. The majority of patients also had leukopenia and thrombocytopenia. The overall fatality rate among the 165 cases was 33.3%, despite hospitalization and vigorous supportive care.

Filoviral haemorrhagic fevers

Sensationalised accounts of wards of dying patients have fueled intense public fascination with filoviruses and highlighted the global threat of emerging and re-emerging infectious diseases. Filoviruses are the prototypical emerging pathogens: they cause a haemorrhagic disease of high case-fatality associated with explosive outbreaks due to person-to-person transmission, have no known treatment, occur unpredictably, and have an unknown reservoir. In truth, since their initial discovery in 1967, only a handful of filoviral outbreaks have occurred, mostly in remote locations. However, the documented occurrence of secondary cases in locations far from endemic areas validates the concern that filoviruses have the potential to cause unprecedented outbreaks in the future.