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Biomedical subjects

Ariel Hourvitz

Publications and source records attributed to Ariel Hourvitz.

25 records · Page 2Linked to original sources

[Anthrax--an overview at 2002].

BACKGROUND: Bacillus anthracis, the causative agent of anthrax, is well known in human history as a major cause of disease in domestic and wild animals and as a rare condition in humans. For the last seventy years, anthrax was developed and occasionally stored as an agent of biological weapon arsenal in numerous countries. The incubation period in humans is 1-6 days and the disease may be present as three distinct clinical syndromes: cutaneous, inhalational, and gastrointestinal disease. The major concern in regard of biological warfare is the inhalational form of anthrax, which starts as a febrile flu-like disease. The development of malaise, fatigue, cough and mild chest discomfort is followed by severe respiratory distress with dyspnea, diaphoresis, stridor, and cyanosis. Shock and death occur within 24-36 hours after onset of severe symptoms. Physical findings are non-specific, but a widened mediastinum is usually seen on chest x-ray. A positive blood culture, immunohistochemical methods and the use of the polymerase chain reaction method confirm the diagnosis. Although effectiveness may be limited after severe symptoms are present, a high dose of antibiotic treatment should be administered and aggressive supportive therapy may be necessary. In the situation of an anthrax attack, as was recently seen in the United States, penicillin is no longer recommended as an acceptable first line therapy. In this case, ciprofloxacin or doxycycline is the recommended drug of choice since penicillin-resistant strains may be used, as well as the possibility of the emergence of an inducible beta-lactamase positive bacterium. Since a high infecting dose may exacerbate the clinical course of the disease, a combination antibiotic regimen should be considered. The disease is not contagious and standard precautions are sufficient. Pre-exposure prophylaxis is based on a vaccine administration, while post-exposure prophylaxis is feasible by the initial use of oral ciprofloxacin or doxycycline. In this article we reviewed the literature with emphasis on the recent medical reports from the United States analyzing the eleven cases of inhalational anthrax as well as the new guidelines for diagnosis and treatment that resulted from the bioterrorism attack in October 2001. Although physical findings were non-specific, abnormal findings on chest x-rays were present in all the eleven cases. A positive blood culture, immunohistochemical methods and the use of the polymerase chain reaction method were highly valuable in revealing and confirming the diagnosis of anthrax. In the case of an attack with anthrax spores, the likelihood of exposure to a large infective dose of high quality spores, may require a prolonged period of treatment as well as prolonged post-exposure therapy.

Animals↗

[Botulism disease].

Botulism is caused by a neurotoxin produced from the anaerobic, spore forming bacteria--clostridium botulinum. The disease is usually caused by toxins type A, B and E. Since the disease was first recognized in the beginning of the nineteenth century as food poisoning, different forms of intoxication were described. Infantile botulism, wound botulism, infectious botulism and inadvertent botulism are all clinical syndromes caused by the same toxin. The attempt to use the botulinum toxin as biological warfare agent is well known. Recently the potential terrorist use of botulinum toxin has become a real concern. Botulism is characterized by its classic triad: 1) symmetric descending flaccid paralysis with prominent bulbar palsies 2) afebrile patient 3) clear sensorium. The paralysis usually begins in the cranial nerves where blurred vision, dysarthia and dysphagia are the initial complaints. Diagnosis is based on clinical findings, history of suspicious exposure and supportive ancillary testing to rule out other causes of neurologic dysfunction that mimic botulism such as the Guillain-Barre syndrome, Myasthenia Gravis or cerebrovascular stroke. Laboratory confirmation of suspected cases is usually delayed and treatment should begin before confirmation is completed. The treatment includes supportive care, and the administration of antitoxin which reduces mortality if given early. Since community and emergency room physicians may be the first to treat patients with any type of botulinum intoxication, they must know how to diagnose and treat this rare but potentially lethal disease.

Bioterrorism↗

[Tularemia as a biological weapon].

Tularemia is a zoonosis, caused by the Gram-negative bacterium, Francisella tularensis. The organism penetrates the human body through interrupted skin or mucous membranes, via animal contact or bites from ticks, deer-flies and mosquitoes. Contaminated aerosol and water are alternative modes of transmitting the germ through the respiratory and alimentary tracks. In light of its high infectivity in aerosol and its offensive occupation in the past, tularemia may appear in a biological warfare context. After an incubation period of 3-5 days, the disease begins with systemic symptoms, which abate, leaving a clinical picture, dominated by one of the listed patterns: ulceroglandular, typhoidal, glandular, occuloglandular, pharyngeal or pneumonic. Diagnosis and identification of the bacterium is difficult and even hazardous. Most diagnoses are established by serology which is positive in 50-70% of the patients after 2 weeks of illness, and in most of them by 4-8 weeks. The treatment of choice is streptomycin intra-muscular, or gentamicin intra-venous for 10-14 days. Prophylaxis may be achieved by tetracycline treatment, beginning up to 24 hours from exposure, for 2 weeks, or by a live attenuated, investigational vaccine. Nevertheless, post-exposure, or even better so, pre-exposure intervention is the most effective way of preventing the devastating results of the attack.

Animals↗

[Glanders--a potential disease for biological warfare in humans and animals].

Infection with Burkholderia mallei (formerly Pseudomonas mallei) can cause a subcutaneous infection known as "farcy" or can disseminate to condition known as Glanders. It is primarily a disease affecting horses, donkeys and mules. In humans, Glanders can produce four types of disease: localized form, pulmonary form, septicemia, and chronic form. Necrosis of the tracheobronchial tree and pustular skin lesions characterize acute infection with B. mallei. Other symptoms include febrile pneumonia, if the organism was inhaled, or signs of sepsis and multiple abscesses, if the skin was the port of entry. Glanders is endemic in Africa, Asia, the Middle East, and Central and South America. Glanders has low contiguous potential, but because of the efficacy of aerosolized dissemination and the lethal nature of the disease, B. mallei was considered a candidate for biological warfare. During World War I, Glanders was believed to have been spread to infect large numbers of Russian horses and mules on the Eastern front. The Japanese infected horses, civilians and prisoners of war during World War II. The USA and the Soviet Union have shown interest in B. mallei in their biological warfare program. The treatment is empiric and includes mono or poly-therapy with Ceftazidime, Sulfadiazine, Trimethoprim + Sulfamethoxazol, Gentamicin, Imipenem etc. Aggressive control measures essentially eliminated Glanders from the west. However, with the resurgent concern about biological warfare, B. mallei is now being studied in a few laboratories worldwide. This review provides an overview of the disease and presents the only case reported in the western world since 1949.

Animals↗

Should diagnostic hysteroscopy be a routine procedure during diagnostic laparoscopy in women with normal hysterosalpingography?

The advantage of hysteroscopy (HSC) over hysterosalpingography (HSG) in the accuracy of the diagnosis of uterine cavity abnormalities that may cause or contribute to infertility has been shown by numerous studies. The aim of this study was to analyse the results obtained from diagnostic HSC performed routinely during diagnostic laparoscopy in the investigation of the infertile women, to evaluate the effectiveness of the procedure in the diagnosis of uterine causes of female infertility. Ninety-three infertile patients with normal uterine cavity as demonstrated in HSG underwent diagnostic laparoscopy and hysteroscopy in this infertility unit. The hysteroscopy showed a normal cavity in 80 cases (88%), giving a false-negative rate of 12% for HSG. The pathologies found included small adhesions (two cases), an arcuate fundus (two cases), an endometrial polyp (three cases), and endometrial hyperplasia was diagnosed in four cases. In the absence of a positive history or a radiographical suggestion of endometrial abnormalities, or both, HSC made little diagnostic contribution towards elucidating the cause of female infertility or to finding a pathology that could affect the chances of achieving a normal pregnancy. However, in view of the low complication rates, minimal time requirement, and a negligible effect on the post-operative course, HSC could be performed on all infertile patients undergoing diagnostic laparoscopy.

Female↗

Lessons learned from cross-border medical response to the terrorist bombings in Tabba and Ras-el-Satan, Egypt, on 07 October 2004.

INTRODUCTION: Large-scale, terrorist attacks can happen in peripheral areas, which are located close to a country's borders and far from its main medical facilities and involve multi-national casualties and responders. The objective of this study was to analyze the terrorist suicide bombings that occurred on 07 October 2004, near the Israeli-Egyptian border, as representative of such a complex scenario. METHODS: Data from formal debriefings after the event were processed in order to learn about victim outcomes, resource utilization, critical events, and time course of the emergency response. RESULTS: A total of 185 injured survivors were repatriated: four were severely wounded, 13 were moderately injured, and 168 were mildly injured. Thirty-eight people died. A forward medical team landed at the border town's airport, which provided reinforcement in the field and in the local hospital. Israeli and Egyptian search and rescue teams collaborated at the destruction site. One-hundred sixty-eight injured patients arrived at the small border hospital that rapidly organized itself for the mass-casualty incident, operating as an evacuation "staging hospital". Twenty-three casualties secondarily were distributed to two major trauma centers in the south and the center of Israel, respectively, either by ambulance or by helicopter. CONCLUSION: Large-scale, terrorist attacks at a peripheral border zone can be handled by international collaboration, reinforcement of medical teams at the site itself and at the peripheral neighboring hospital, rapid rearrangement of an "evacuation hospital", and efficient transport to trauma centers by ambulances, helicopters, and other aircraft.

Blast Injuries↗

Validity of self-assessment of skin reaction after smallpox vaccination.

OBJECTIVE: Smallpox vaccinees should be evaluated for the presence of a major skin reaction ("take") one week after vaccination, but this could prove to be logistically infeasible in the context of an emergency mass-vaccination campaign. We validated a tool for self-evaluation of the vaccination site for presence of take. METHODS: We conducted a prospective, double-blinded, paired-measurement validation study of 174 non-naive adult vaccinees and their physician evaluators. Subjects provided paired, blinded, independent assessments of take 7-9 days after vaccination. RESULTS: Overall, vaccinees and evaluators agreed on 157 of 174 (90.2%) take assessments. Sensitivity of the tool was 99.1%, and specificity was 75%. The positive predictive value of self-assessment was 87.2% and the negative predictive value was 98%. Specificity of the tool and measures of agreement were significantly modified by age, education, and occupation. When adjusted for the expected take rate among a population including naive vaccinees, positive predictive value and overall agreement increased significantly. CONCLUSIONS: Self-assessment may be a feasible option for evaluation of take in the event of mass smallpox vaccination. The predictive values and overall agreement of the tool are satisfactory, and can be expected to increase when used in a largely naive population.

Adult↗