key: cord-0036605-tw3w4pjz authors: Negut, Marian title: Risk Assessment in Smallpox Bioterrorist Aggression date: 2007 journal: Risk Assessment and Risk Communication Strategies in Bioterrorism Preparedness DOI: 10.1007/978-1-4020-5808-0_16 sha: 5771495d598deb5f76ebaacbb2b580145e726225 doc_id: 36605 cord_uid: tw3w4pjz nan 1. At present, there is a high and global receptivity to variola virus. After eradication and more than 30 years no vaccination was performed and average protection postvaccination is about 5-7 years. A stock of 200 million doses of prepared vaccine was saved for use in case of accidental outbreak. In the last 5 years many countries prepared necessary stockpile of vaccine against smallpox. But WHO does not recommend vaccination of individuals before the smallpox epidemic occurs because of side effects. Vaccinia immune globulin recommended for the treatment of serious side effects is in very limited quantity so that stockpiles of this globulin were suggested to be made 2. Contagiousness of smallpox is higher than 80%. The first generation of cases would rapidly spread in highly susceptible population, expanding each generation of cases, by a factor of 10 times or more during winter or spring [9] . As was recently demonstrated by pandemic spreading of severe acute respiratory syndrome (SARS), this rapid extension of smallpox could be a global disaster. Long-distance traveling of undetected human sources could represent the major way of pandemic spreading of smallpox also. 3. Clinical picture of smallpox has always had strong psychological impact in "civilian population", so this impact is expected to happen. Because of lack of immunoprotection a high proportion of severe clinical pictures involving long hospitalization is estimated. Unpredictable medical difficulties will be arised by the incapacity of medical authorities to cover these huge requirements. Mild cases will be homeisolated increasing epidemic risk and spreading [14, 15] . 196 M. NEGUT laboratories in the world were required to destroy their remaining variola virus stocks. In 1996, WHO General Assembly decided to destroy the virus stocks exist officially [16] . Immense stockpiles of variola virus along with smallpox vaccine [6] . 4. There is no specific antiviral treatment for smallpox. Thiosemicarbazones and rifampicin previously reported having therapeutic benefits proved to be ineffective [9] . Cidofivir, a nucleotide analog of DNA polymerase inhibitor, experimented in cytomegalovirus infection treatment suggested to be used in postexposure treatment rather for treatment of the diagnosed smallpox [9, 11] . 5. The reported mortality of the smallpox was higher than 30%. Hemorrhagic and malignant forms are uniformly fatal [9, 14] . 6. A violent psychosocial reaction is likely to appear at the beginning of the epidemic "smallpox fear." This psychological impact is more stronger in the population than in some other severe transmissible diseases. Medical (clinical) impressive aspects, antiepidemic restrictive measures, current difficulties, and social perturbances could determine a psychosocial crisis followed by a real civilian panic [13] . The main areas of risk in smallpox bioaggression are presented in Figure 1 . All these areas are influencing in between them in realizing very strong psychosocial perturbances that could degenerate in a strong panic of civilian population. It is well known that one of the main targets of bioterrorist attack is to produce impressive psychosocial effects followed by socioeconomic perturbances and social disorganization. This psychosocial impact influences in many aspects of clinical and Clinical risk assessment is considered to be important. During the progression of the disease it has to take into account the following gravity factors in risk evaluation [5, 9, 14] . Smallpox is an exclusively human disease and nowadays any case is an alleged manipulation of variola virus. The illness is expected to be very severe in the majority of cases as the population under 40 years has no variola, "immunologic specific memory" (the vaccination was stopped in many countries before 1977). There is no etiologic treatment in smallpox. So the hospitalization will be of long duration overcoming hospital capacities in an epidemic situation. Severe malignant and hemorrhagic forms are fatal always so mortality is overcoming 30% in smallpox. Immunodeficient patients, pregnancy, and chronic cardiac diseases are predisposing conditions to severe forms. Clinical recognition of the illness is difficult in the first stage in the absence of epidemic information/suspicion. First cases will have high epidemic potential. Laboratory confirmation is also late in the first cases because routine laboratory investigation does not include such a potential etiology. Figure 2 shows the risk during the progression of disease. Starting from the 10th day after contamination, the patient represents an important source of infection by respiratory droplets and later by the content of vesicles and pustules and at the end by scabs. The hospitalization in smallpox is compulsory in all the period of contagiousness that means minimum 3-4 weeks. In epidemic situation hospital capacities are overcome. As the febrile onset is not specific, clinical presumption is late, when characteristic vesicles and pustules develop. In malignant forms, the diagnostic confusion is more frequent so first cases in absence of epidemic suspicion are "sacrificed patients" [9] . Laboratory identification of the virus in oropharyngeal exudate is possible by modern techniques (electron microscopy, immunoenzymatic detection, and molecular techniques) in less than 24 hours. Routine laboratory investigation does not include variola virus detection without any particular requirement. The confirmation of the first cases is late when virus detection is recommended from vesicles content (5-7 days of the progression of the disease) [3, 15] . No antiviral treatment is efficient in smallpox. The progression of the disease depends on the capacity of response of the patient. The estimated severity of the disease determines important vital risk. The historical known mortality of 30% is expected to be higher in absence of immune specific background [9] . Clinical factor will contribute substantially to increase associated psychosocial risk. Socioeconomic perturbances will increase psychosocial impact leading to "psychological mass reaction." Risk assessment of psychosocial reaction is as well important as medical risk. Epidemic risk assessment is dominated by the high capacity of spreading of the disease in modern opportunities of dissemination and lack of any immune protection [2, 10] . The interdependence of the particular epidemic factors in smallpox is presented schematically in Figure 3 . As global extension of SARS demonstrated recently, long-distance traveling nowadays represents a major risk activation of rapid spreading of high-risk respiratory diseases. Air-conditioning plane systems activate the spreading of virus by respiratory route. Virus dispersion in the modern huge "crowded" plains is very "efficient" in contaminating hundreds of people at once. Potential sources (unknown contaminated persons) play a huge spreading risk. Starting from a "first contaminated person" all the contacts incubating the smallpox become "secondary bioterrorists." Assuming a transmission rate of 20 cases by the "secondary bioterrorists" and a rate of 50 by the active, initial bioterrorist, a total of 1,000 cases would be prevalent before the earliest possible identification of the first wave of disease. Assuming that the first wave were misdiagnosed or diagnosed late the next wave would see 20,000 such cases, followed by 400,000 cases, 8 million cases, and so on [3] . Few physicians have enough experience, essential to establish a quick and accurate clinical diagnosis. But the high rapid detection and isolation of the first cases is crucial in limiting the risk of second-generation cases and in this context the professional training in urgent required today [3, 8, 12] . Preventing smallpox by vaccination is a long-debated decision. Wellknown reverse reaction mentioned in Figure 3 is a major limiting risk factor in a mass vaccination campaign in the present situation. As WHO specialists recommended important stockpiles of specific globulin have to be prepared for the moment when the vaccination will be considered necessary [4, 15] . Biosafety biosecurity risk. Maximum security measures are recommended for special designated hospitals for isolation and quarantine for protection of personnel and environment. Negative air pressure, fully isolating equipment for personnel, and continuing disinfection measures are recommended for limiting the risk of contamination (Figure 4 ). Laundry and waste is sterilized and strictly surveyed for safety transportation before incineration [11] . Sample transportation and laboratories manipulating variola virus require maximum containment (BL4 biosafety) [3, 11] . Smallpox became a symbol of the victory of the humanity against infectious diseases. Risk assessment of smallpox estimated by many specialists after 2001 is an alarming scenario to prevent a global catastrophe, because epidemic extension of very aggressive diseases has no borders [1, 3, 14] . New York: Random House Smallpox: a disease and a weapon Topley and Wilson's Microbiology and Microbial Infections Smallpox -preparing for the emergency Progrese in controlul si prevenirea virozelor cu potential bioterorist Virusologie medicala Bioterrorism: guidelines for medical and public health management Planning for smallpox: outbreak Bioterrorism: guidelines for medical and References public health management Smallpox biosecurity: preventing the unthinkable Intravenous cidofivir for peripheral cytomegalovirus retinitis in patients with AIDS a randomized, controlled trial Principle and practice of infectious diseases Preventing is better than postfactum intervention in bioerrorism Boli infectioase, arme biologice, bioterorism. Bucuresti Manual of clinical microbiology, 7th edn World Health Organization. The global eradication of smallpox. Final report of the Global commission for the certification of smallpox eradication