Bioterrorism--preparing to fight the next war

Aerosol-to-Hydrosol Sampling and Simultaneous Enrichment of Airborne Bacteria For Rapid Biosensing

Rapid monitoring of biological particulate matter (Bio-PM, bioaerosols) requires an enrichment technique for concentrating the Bio-PM dispersed in the air into a small volume of liquid. In this study, an electrostatic air sampler is employed to capture aerosolized test bacteria in a carrier liquid (aerosol-to-hydrosol (ATH) enrichment). Simultaneously, the captured bacteria are carried into a fluid channel for hydrosol-to-hydrosol (HTH) enrichment with Concanavalin A coated magnetic particles (CMPs). The ATH enrichment capacity of the air sampler was evaluated with an aerosol particle counter for the following test bacteria: Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Acinetobacter baumannii. Then, the HTH enrichment capacity for the ATH-collected sample was evaluated using the colony-counting method, scanning electron microscopy based image analysis, fluorescence microscopy, electrical current measurements, and real-time quantitative polymerase chain reaction (qPCR). The ATH and HTH enrichment capacities for the given operation conditions were up to 80 000 and 14.9, respectively, resulting in a total enrichment capacity of up to 1.192 × 10⁶. Given that air-to-liquid enrichment required to prepare detectable bacterial samples for real-time qPCR in field environments is of the order of at least 10⁶, our method can be used to prepare a detectable sample from low-concentration airborne bacteria in the field and significantly reduce the time required for Bio-PM monitoring because of its enrichment capacity.

Biowarfare and bioterrorism

Bioterrorism is not only a reality of the times in which we live but bioweapons have been used for centuries. Critical care physicians play a major role in the recognition of and response to a bioterrorism attack. Critical care clinicians must be familiar with the diagnosis and management of the most likely bioterrorism agents, and also be adequately prepared to manage a mass casualty situation. This article reviews the epidemiology, diagnosis, and treatment of the most likely agents of biowarfare and bioterrorism.

Detection of viruses in used ventilation filters from two large public buildings

BACKGROUND

Viral and bacterial pathogens may be present in the air after being released from infected individuals and animals. Filters are installed in the heating, ventilation, and air-conditioning (HVAC) systems of buildings to protect ventilation equipment and maintain healthy indoor air quality. These filters process enormous volumes of air. This study was undertaken to determine the utility of sampling used ventilation filters to assess the types and concentrations of virus aerosols present in buildings.

METHODS

The HVAC filters from 2 large public buildings in Minneapolis and Seattle were sampled to determine the presence of human respiratory viruses and viruses with bioterrorism potential. Four air-handling units were selected from each building, and a total of 64 prefilters and final filters were tested for the presence of influenza A, influenza B, respiratory syncytial, corona, parainfluenza 1-3, adeno, orthopox, entero, Ebola, Marburg, Lassa fever, Machupo, eastern equine encephalitis, western equine encephalitis, and Venezuelan equine encephalitis viruses. Representative pieces of each filter were cut and eluted with a buffer solution.

RESULTS

Attempts were made to detect viruses by inoculation of these eluates in cell cultures (Vero, MDCK, and RK-13) and specific pathogen-free embryonated chicken eggs. Two passages of eluates in cell cultures or these eggs did not reveal the presence of any live virus. The eluates were also examined by polymerase chain reaction or reverse-transcription polymerase chain reaction to detect the presence of viral DNA or RNA, respectively. Nine of the 64 filters tested were positive for influenza A virus, 2 filters were positive for influenza B virus, and 1 filter was positive for parainfluenza virus 1.

CONCLUSION

These findings indicate that existing building HVAC filters may be used as a method of detection for airborne viruses. As integrated long-term bioaerosol sampling devices, they may yield valuable information on the epidemiology and aerobiology of viruses in air that can inform the development of methods to prevent airborne transmission of viruses and possible deterrents against the spread of bioterrorism agents.

Influenza virus-like particle can accommodate multiple subtypes of hemagglutinin and protect from multiple influenza types and subtypes

Despite existing vaccines and specific therapies, epidemics of seasonal influenza annually claim 200,000-500,000 lives worldwide. Pandemic influenza represents an even greater threat, with numerous potentially pandemic viruses circulating in nature. Development of multi-specific vaccines against multiple pandemic or seasonal strains is important for human health and the global economy. Here we report a novel virus-like particle (VLP) platform that contains three hemagglutinin (HA) subtypes. This recombinant vaccine design resulted in the expression of three HA subtypes co-localized within a VLP. Experimental triple-HA VLPs containing HA proteins derived from H5N1, H7N2, and H2N3 viruses were immunogenic and protected ferrets from challenge from all three potentially pandemic viruses. Similarly, VLPs containing HA subtypes derived from seasonal H1N1, H3N2, and type B influenza viruses protected ferrets from three seasonal influenza viruses. We conclude that this technology may represent a novel strategy for rapid development of trivalent seasonal and pandemic vaccines.

Microbial threat lists: obstacles in the quest for biosecurity?

The Select Agents and Toxins List was created by the US Government to limit the possession of and access to particular microorganisms and toxins. Casadevall and Relman argue that this list, and others like it, could have the paradoxical effect of increasing our vulnerability to biological attack and natural epidemics.

Anxiety about threats from the microbial world and about the deliberate misuse of microorganisms has led to efforts to define and control these dangers using lists and regulations. One list with tremendous legal implications and a potentially huge impact on research is the Select Agents and Toxins List, which was created by the US Government to limit the possession of and access to particular microorganisms and toxins. In this article, in addition to highlighting general problems with taxonomy-based, microorganism-centric lists, we discuss our view that such lists may have the paradoxical effect of increasing the societal vulnerability to biological attack and natural epidemics by interfering with the sharing of microbial samples and hindering research on vaccines and therapeutics.

Responsible conduct by life scientists in an age of terrorism

The potential for dual use of research in the life sciences to be misused for harm raises a range of problems for the scientific community and policy makers. Various legal and ethical strategies are being implemented to reduce the threat of the misuse of research and knowledge in the life sciences by establishing a culture of responsible conduct.

Bioterrorism

Bioterrorism is defined as the deliberate and malicious deployment of microbial agents or their toxins as weapons in a non-combat setting, represents perhaps the most overt example of human behavior impacting epidemic infectious diseases. There is historical precedent for the use of biological agents against both military and civilian populations. The use of biological (and chemical) agents as weapons of war has been well documented. The German biological warfare program during World War I included covert infections of Allied livestock with anthrax and glanders. The Japanese army began conducting experiments on the effects of bacterial agents of biowarfare on Chinese prisoners in occupied Manchuria in 1932 at their infamous Unit 731. The United States began its own offensive biological weapons program in 1942 and, during its 28-year official existence, weaponized and stockpiled lethal biological agents, such as anthrax, as well as incapacitating agents, such as the etiologic agent of Q fever. There are some recent examples of bioterrorism, though not necessarily resulting in attacks causing morbidity or mortality, may serve as harbingers of future events. Saddam Hussein's regime in Iraq developed and deployed anthrax and botulinum-laden warheads in the years leading up to the Gulf War. The reasons that these weapons were never used in an actual attack probably had more to do with the implicit threat of overwhelming US retaliation and Iraqi technological deficiencies rather than the regime's reluctance to violate any moral principles. Biological agents have also been used to forward political ideologies: in 1984 a religious cult, intent on influencing voter turnout during a local election, contaminated restaurant salad bars in The Dalles, Oregon.

Biodefense countermeasures: the impact of Title IV of the US Pandemic and All-Hazards Preparedness Act

The 2006 US Pandemic and All-Hazards Preparedness Act gave the Department of Health and Human Services (HHS) new authority to fund the development and procurement of medical countermeasures against chemical, biological, radiological, and nuclear (CBRN) threats. The legislation builds on the authority the HHS gained in 2004 under Project BioShield, which established a fund to procure medical countermeasures. This article reviews the new HHS authorities and the improvements on BioShield, and it describes some of the challenges HHS will face in exercising the new authorities to fund the development and procurement of medical countermeasures against CBRN threats.

Q fever in Logroño: an attack scenario

Bioterrorism has emerged as an important infectious disease and public health challenge in the 21st century, and issues of preparedness and response are now prominent. The development of attack scenarios for assessing this problem contributes to the organization of response systems and identifies aspects that may need to be improved. The authors present an attack scenario involving Q fever in a specific area, the city of Logroño, Spain. The evolution of the outbreak is described and the attempts at diagnosis and implementation of public health measures are outlined. Knowledge of the pathogen in the specific scenario and the ability to directly diagnose the disease it causes may be of help to facilitate a fast response that will contain public unrest and the eventual outcome in terms of morbidity and mortality.

Economic stress and misaligned incentives in critical care medicine in the United States

OBJECTIVES

This review will provide an overview of issues with economic ramifications intrinsic to the management of intensive care resources and identify some of the external pressures that ultimately influence the provision of intensive care services.

DESIGN

A review of the current literature was performed.

RESULTS

Economic stress is a reality of the management of intensive care resources. The nature of critical care medicine as a technologically heavy, labor intensive, high-cost, limited resource, combined with a projected increase in demand in an era of cost containment, presents an array of challenges.

CONCLUSIONS

It is in the best interest of the care of our patients that critical care providers increase awareness of the many factors influencing our practice economically. It is through such understanding that challenges can be met, solutions can be found, and the quality of intensive care can be improved in a financially sustainable environment.