Contribuição para o diagnóstico de peste

Apesar de sua fundamentação clínico-epidemiológica, numerosos casos suspeitos de peste nos focos brasileiros têm sido descartados por serem negativos pelo teste de hemaglutinação para detecção de anticorpos contra o antígeno F1 da Yersinia pestis. A transcendência da peste justifica estudar se tais resultados decorrem da falta de resposta ao F1, e se outras proteínas da Yersinia pestis poderiam ser reconhecidas nos soros suspeitos, sendo desta forma candidatas como alvo diagnóstico alternativo ao F1. Assim sendo, cepas de Yersinia pestis e de Yersinia pseudotuberculosis, uma proteína YopH recombinante e a F1 foram utilizadas para analisar soros de pacientes e soros imunes de coelhos. A F1 e a YopH não foram reconhecidas pelos soros humanos HA- e nenhuma proteína majoritária, comum a todos os soros humanos e coelhos, foi identificada, o que permite concluir que os casos suspeitos devem ser submetidos a uma avaliação clínico-laboratorial mais rigorosa, aprofundando a investigação epidemiológica em busca de outras etiologias.

[Methods of diagnostics and differentiation of the plague agent: intraspecies differentiation of Yersinia pestis. Part II]

State Research Institute for Plague Control, Rostov-on-Don In the second part of the review aspects of intraspecies differentiation of the plague agent are discussed. Special emphasis is placed on the necessity of more precise definition of taxonomic position of plague agent isolates considering genotypical characteristics, data on their selective virulence, and evolutionary origin of the genus Yersinia.

[Indication of extremely dangerous infectious pathogens using immunochromatography and digital video analysis]

The use of immunochromatographic indicatory elements based on antibody conjugates and colloidal gold was suggested to detect cells and the antigens of extremely dangerous infectious pathogens. The specificity and specific activity (sensitivity) of the mentioned elements were studied on vaccinal strains of plague, anthrax, and tularemia pathogens. The researchers studied a possibility to increase the sensitivity of immunochromatographic analysis using computed scanning and Reflecom, a specialized digital video recorder of immunochromatogramms. The study demonstrated that the use of electronic devices to record immunochromatogramms increased the sensitivity to microbial cells and antigens 1.5 to 2 times vs. visual registration and simplified documentation of the results.

Prompt laboratory diagnosis in timely containment of a plague outbreak in India

A focal outbreak of pneumonic plague occurred in a hamlet of village Hatkoti, district Shimla, Himachal Pradesh in the first fortnight of February, 2002. A total of 16 cases with 4 deaths were reported. Diagnosis of plague was confirmed by the laboratory in 10 (63%) cases. Y. pestis was isolated from clinical samples of 3 cases and confirmed by bacteriophage lysis. Molecular tests confirmed the presence of Y. pestis specific pla and F1 genes in 4 cases; DNA fingerprinting had identity with the known sequence of plague bacilli. Paired samples from 5 cases showed more than 4 fold rise and 1 case showed more than 4 fold fall in antibodies against F1 antigen of Y. pestis. The present communication emphasises that timely and systematic laboratory investigations give confirmatory diagnosis in shortest possible time which forms the backbone of the outbreak control in a timely fashion and prevents confusion and controversy.

The science of surge: detection and situational awareness

As part of the broader "science of surge" consensus initiative sponsored by Academic Emergency Medicine, this report addresses the issues of detection and situational awareness as they relate to surge in the practice of emergency medicine. The purpose of this report, and the breakout group that contributed to its content, was to provide emergency physicians and other stakeholders in the emergency medicine community a sense of direction as they plan, prepare for, and respond to surge in their practice.

Bioterrorism: management of major biological agents

Bioterrorism is defined by the intentional or threatened of microorganisms or toxins derived from living organisms to cause death or diseases in humans, animals or plants on which we depend. The other major point is to generate fear in the population. More than 180 pathogens have been reported to be potential agents for bioterrorism. The following is an overview of several agents that could be involved in a biological attack.

Human plague--four states, 2006

Plague is a zoonotic disease caused by the bacterium Yersinia pestis. In 2006, a total of 13 human plague cases have been reported among residents of four states: New Mexico (seven cases), Colorado (three cases), California (two cases), and Texas (one case). This is the largest number of cases reported in a single year in the United States since 1994. Dates of illness onset ranged from February 16 to August 14; two (15%) cases were fatal. The median age of patients was 43 years (range: 13-79 years); eight (62%) patients were female. Five (38%) patients had primary septicemic plague, and the remaining eight (62%) had bubonic plague. Two (15%) patients developed secondary plague pneumonia, leading to administration of antibiotic prophylaxis to their health-care providers. This report summarizes six of the 13 cases, highlighting the severity and diverse clinical presentations of plague and underscoring the need for prompt diagnosis and treatment when plague is suspected.

[Rochus, patron saint of physicians and hospitals--a teledermatologic quiz]

The painting "St. Rochus with an angel" by Quinten Massys in the Alte Pinakothek in Munich was utilized for a teledermatological quiz. First, only a detail of the plague bubo on the thigh was sent electronically to all physicians in our department. The answers were correct descriptions, but the interpretations quite heterogeneous. In a second set, the full painting together with the hint- Pinakothek - was given. Now the number of descriptively correct diagnoses was high; one resident knew the name of the featured individual and his diagnosis. This example demonstrates one problem with teledermatology - when viewing a clinical picture, relevant additional information is frequently essential in order to make a correct diagnosis. In addition, this presentation of saint physicians and hospitals, the holy Rochus, better known to those who are under his protection.

Surat plague of 1994 re-examined

A plague episode in Surat in 1994, and its spread to other cities in India, lasted only a little over 2 weeks, but it created an unprecedented panic that had global repercussions. At first, the Surat hospital doctors could not diagnose the disease, but when they did, immediate intervention, in the form of preventation and treatment (administration of antibodies) prevented the disease from spreading beyond Surat, Delhi, Calcutta, Bombay and their vicinities. Fewer than 1,200 people were diagnosed with plague. A DNA-based study in 2000 decisively concluded that the Surat episode was a plague, but the Indian isolates were genetically more heterogeneous compared to others in the world.

Pneumonic plague cluster, Uganda, 2004

The public and clinicians have long-held beliefs that pneumonic plague is highly contagious; inappropriate alarm and panic have occurred during outbreaks. We investigated communicability in a naturally occurring pneumonic plague cluster. We defined a probable pneumonic plague case as an acute-onset respiratory illness with bloody sputum during December 2004 in Kango Subcounty, Uganda. A definite case was a probable case with laboratory evidence of Yersinia pestis infection. The cluster (1 definite and 3 probable cases) consisted of 2 concurrent index patient-caregiver pairs. Direct fluorescent antibody microscopy and polymerase chain reaction testing on the only surviving patient's sputum verified plague infection. Both index patients transmitted pneumonic plague to only 1 caregiver each, despite 23 additional untreated close contacts (attack rate 8%). Person-to-person transmission was compatible with transmission by respiratory droplets, rather than aerosols, and only a few close contacts, all within droplet range, became ill.

A 12-case outbreak of pharyngeal plague following the consumption of camel meat, in north-eastern Jordan

Between late January and early February 1997, an outbreak of plague, associated with cervical lymphadenopathy and fever, occurred in the Jordanian village of Azraq ad-Druze, which lies about 50 km west of the border with Saudi Arabia. The 12 cases who presented at hospital were initially assumed to have tularaemia, and all were successfully treated with gentamicin. When, however, their sera were tested for evidence of Yersinia pestis or Francisella tularensis infection (using haemagglutination, enzyme immuno-assays for specific IgM or the F1 antigen of Y. pestis, and micro-agglutination tests), all 12 were found to have anti-Y. pestis IgM. Three dogs shot near the Saudi Arabian border were also found seropositive for antibodies against Y. pestis. Eleven of the 12 patients reported that, 2-4 days before their symptoms appeared, they had eaten the meat cut from the carcass of the same camel, either raw (10 cases) or cooked (one case). All 12 patients were diagnosed as cases of pharyngeal plague (the first cases of plague reported in Jordan for more than 80 years), caused by Y. pestis that most had acquired when they ate raw meat from a camel that was infected with the pathogen.

Cutaneous reactions in nuclear, biological and chemical warfare

Nuclear, biological and chemical warfare have in recent times been responsible for an increasing number of otherwise rare dermatoses. Many nations are now maintaining overt and clandestine stockpiles of such arsenal. With increasing terrorist threats, these agents of mass destruction pose a risk to the civilian population. Nuclear and chemical attacks manifest immediately while biological attacks manifest later. Chemical and biological attacks pose a significant risk to the attending medical personnel. The large scale of anticipated casualties in the event of such an occurrence would need the expertise of all physicians, including dermatologists, both military and civilian. Dermatologists are uniquely qualified in this respect. This article aims at presenting a review of the cutaneous manifestations in nuclear, chemical and biological warfare and their management.

Pulmonary Disease from Biological Agents: Anthrax, Plague, Q Fever, and Tularemia

Anthrax, plague, Q fever, and tularemia are all potential inhalational bioterrorism agents. The pulmonary manifestations of these agents can be readily confused with each other as well as other more common diseases such as influenza and atypical pneumonia. This article reviews the threat potential, microbiology, pathogenesis, clinical features, diagnosis, and treatment of each of these agents and highlights the similarities and differences between their pulmonary presentations.

Ability of Physicians to Diagnose and Manage Illness Due to Category A Bioterrorism Agents

BACKGROUND

Early recognition of a terrorist attack with biologic agents will rely on physician diagnosis. Physicians' ability to diagnose and care for patients presenting after a bioterror event is unknown. The role of online case-based didactics to measure and improve knowledge in the diagnosis and treatment of these patients is unknown.

METHODS

A multicenter online educational intervention was completed by 631 physicians at 30 internal medicine residency programs in 16 states and Washington, DC, between July 1, 2003, and June 10, 2004. Participants completed a pretest, assessing ability to diagnose and manage potential cases of smallpox, anthrax, botulism, and plague. A didactic module reviewing diagnosis and management of these diseases was then completed, followed by a posttest. Pretest performance measured baseline knowledge. Posttest performance compared with pretest performance measured effectiveness of the educational intervention. Results were compared based on year of training and geographic location of the residency program.

RESULTS

Correct diagnoses of diseases due to bioterrorism agents were as follows: smallpox, 50.7%; anthrax, 70.5%; botulism, 49.6%; and plague, 16.3% (average, 46.8%). Correct diagnosis averaged 79.0% after completing the didactic module (P<.001). Correct management of smallpox was 14.6%; anthrax, 17.0%; botulism, 60.2%; and plague, 9.7% (average, 25.4%). Correct management averaged 79.1% after completing the didactic module (P<.001). Performance did not differ based on year of training (P = .54) or geographic location (P = .64). Attending physicians performed better than residents (P<.001).

CONCLUSIONS

Physician diagnosis and management of diseases caused by bioterrorism agents is poor. An online didactic module may improve diagnosis and management of diseases caused by these agents.

Histopathology and immunohistochemistry in the diagnosis of bioterrorism agents

From October to November 2001, the inhalational and cutaneous anthrax cases that occurred in the U.S. underscored the importance of recognizing the clinical and pathological features of infectious agents that can be used in acts of terrorism. Early confirmation of bio-terrorist acts can only be performed by making organism-specific diagnosis of cases with clinical and pathologic syndromes that could be caused by possible bioterrorism weapons. Recognition and diagnosis of these cases is central to establish adequate responses. This review will examine the events that occurred during the anthrax bio-terrorist attack with specific emphasis on the role of pathology and immunohistochemistry and will describe the histopathologic features of category A bioterrorism agents (anthrax, plague, tularemia, botulism, smallpox, and viral hemorrhagic fevers).

[New diagnostic methods for bacterial infections after the introduction of increased bioterrorism preparedness]

Bacillus anthracis, Francicella tularensis, Yersinia pestis, Burkholderia pseudomallei and Brucella melitensis are the bacteria most often mentioned in connection with possible biological terrorist acts. It is known that these microorganisms can be cultured and weaponised for such a purpose. This survey provides examples of the use of diagnostic methods for those microorganisms, further detailed in relation to establishing a national center for biological preparedness in Denmark.

[Study on an epidemic of human lung plaque in Nangqian county, Qinghai province]

OBJECTIVE

To study an epidemic of human lung plague fulminant from September to October, 2004 in Nangqian county, Qinghai province.

METHODS

Cases were diagnosed through data from epidemiological, clinical, bacteriological, serological and autopsy studies.

RESULTS

14 patients were identified, ending up with 6 deaths and 8 cured. The first case was diagnosed as primary pesticemia late progressed to lung plague. 4 cases were transformed from pesticemia out of 13, leaving the 9 cases as primary lung plague. Situation was under complete control through routinely handling the plague focus.

CONCLUSION

The first case was bitten by the infected fleas which parasitized the marmota preyed on a dog but later these fleas were brought into the tent by the dog. The others cases were infected through droplets or dust. Programs on monitoring and controling the amount of marmotas and fleas should to be strengthened to prevent the epidemics of plague in the area.

[Primary characterization of the properties and diagnostic value of the antigenic complex "fraction V" in a plague microbe]

The experimentally obtained antigenic complex isolated by extraction in the gradient surfactants from live and acetone-dried bacteria of the capsule-free vaccine strain EV76 of a plague microbe that had lost its ability to synthesize the diagnostic species-specific capsular antigen F1 was investigated. The antigenic complex fraction V (FV) was obtained after the fifth stage of extraction at a concentration of 1.28% of surfactants and after additional purification. The thermostable FV was found to consist mainly of protein. The protein having a molecular mass of about 43 kD predominates in the fraction. The latter is nontoxic for albino mice and antigenic. It forms a precipitate with commercial antiplague serum antibodies. FV antigenic sensitization of tanned sheep red blood cells gave rise to a diagnostic agent that specifically reacted with an antiplague serum rather than with heterologous sera against enterobacteria. The sera immunized with FV specifically reacted in the JDJFR with all the strains of the pathogen of plague irrespective of the temperature of their cultivation, including "fraction-free", which did not interact with a diagnosticum on F1. The animal sera immunized with capsule-free plague microbial strain reacted only with a FV-erythrocytic diagnosticum and they did not interact with F1 antigen-sensitized red blood cells. The erythrocytic FV diagnosticum was tested in ABNR with 130 typical and atypical plague microbial strains and with 133 strains of heterologous bacteria of different species of the family Enterobacteriaceae. The FV diagnosticum identified all the variants of a plague microbe, while the F1 diagnosticum revealed only its capsular variants. Among the heterologous bacteria, some strains of the closely related pathogen of pseudotuberculosis in those who were in the R form, rather than S form, positively reacted. The use of FV identified 2 groups of hybridomas obtained after immunization of albino mice with the capsule-free variant of a plague microbe. Some hybridomas reacted only with plague bacteria while others did with two above pathogens. The authors substantiate the expediency of using FV, its components, and obtained monoclonal plague pathogen antibodies to improve antiplague diagnosticums with an activity spectrum that exceeds that of the existing commercial F1 antigen-based diagnosticums. They also discuss the lines of further studies.