El comodín de la historia universal: las enfermedades infecciosas / The wild card of world history: infectious diseases

La migración de las poblaciones, a través de las diferentes etapas de la historia y su incursión en diversos ecosistemas del planeta, ha permitido irremediablemente una interacción dinámica con animales, plantas, insectos y con el mundo microbiológico. En esta trayectoria algunos microorganismos establecieron relaciones simbióticas con los seres humanos mediante la negociación de compromisos celulares y moleculares, eventualmente esculpiendo al genoma humano. Sin embargo, en muchas otras instancias, ciertos microorganismos han actuado como agentes de selección natural, ocasionando enfermedad y muerte. De esta forma, el establecimiento de las sociedades actuales se debe en gran medida al impacto que las enfermedades infecciosas tuvieron en la conformación de las poblaciones a través de los milenios. Las epidemias ocasionadas por esas enfermedades han influenciado aspectos políticos, económicos y sociales al menos por cuatro transiciones epidemiológicas: el Neolítico con la aparición de los primeros asentamientos humanos, la Edad Media -particularmente con el impacto de la plaga bubónica en Europa y Asia-, la época de exploración y colonialismo europeo y la actual era de globalización. La historia de la humanidad estaría inexorablemente ligada a la coexistencia con los agentes infecciosos

Throughout the history of mankind, population migration has played an important role in determining a dynamic interplay of humans with other animals, plants, insects, and microbial agents in different ecological niches. In this journey, some microbes have negotiated symbiotic relationships with humans by achieving molecular and cellular compromises, ultimately sculpting the human genome. In other cases, many microbial agents have acted as pathogens and therefore becoming forces of natural selection throughout different human societies by leading to morbidity, dysfunction, or death. In this manner, the establishment of modern societies is in many ways the result of the burden of disease associated with infectious pathogens throughout millennia. Throughout the history of mankind, epidemics of infectious diseases have influenced political, economic and social aspects of human societies at least through the occurrence of four epidemiologic transitions: a) the Neolithic period with the establishment of the first human villages with enough population density enabling the spread of infectious agents; b) the middle-ages with the spread of bubonic plague causing important demographic changes; c) the worldwide exploration of European with colonization in new territories; and d) the current era of globalization. In summary, there is an inextricable link between humanity's journey and microorganisms resulting in either beneficial or antagonistic interactions

La Lepra: una enfermedad vigente / Leprosy: an ongoing disease

El libro resalta que la lepra continúa siendo una enfermedad presente en Colombia y que aún constituye un problema de salud pública importante por los costos sociales, económicos y de sufrimiento humano que conlleva. Sabiendo que la literatura sobre el tema es escasa en nuestro medio, este libro surge como una herramienta de consulta creada para médicos y otros profesionales de salud, con la certeza de que es preciso mejorar la oportunidad del diagnóstico. Siendo fundamental que, durante su proceso formativo, todos los profesionales de la salud adquieran conocimientos sobre dicha enfermedad, que cada día se hace más visible por sus secuelas y diagnóstico tardío.

The book highlights the fact that leprosy continues to be a disease present in Colombia and that it is still a major public health problem due to the social, economic and human suffering costs it entails. Knowing that the literature on the subject is scarce in our country, this book is intended as a reference tool for doctors and other health professionals, in the knowledge that it is necessary to improve the timeliness of diagnosis. It is essential that, during their training process, all health professionals acquire knowledge about this disease, which is becoming more and more visible every day due to its sequelae and late diagnosis.

Aerobic actinomycetes that masquerade as pulmonary tuberculosis

Background: There is an increasing recognition of organisms in the order Actinomycetales including Nocardia sp. causing lung infections that mimic pulmonary tuberculosis or fungal pneumonias. Methods: We retrospectively evaluated a cohort of patients in the southeastern United States in whom a presumptive diagnosis of pulmonary tuberculosis was initially entertained but who eventually were found to have infection caused by Rhodococcus sp. or Tsukamurella sp. Results: Among a cohort of 52 individuals diagnosed as case suspects for pulmonary tuberculosis, we identified six patients who were infected with either Rhodococcus sp. or Tsukamurella sp. Of these six patients, two had co-infection with Mycobacterium tuberculosis. Conclusions: Infection with aerobic actinomycetes may mimic pulmonary tuberculosis or may cause concomitant disease in patients with pulmonary tuberculosis.

The global burden of neglected tropical diseases

The neglected tropical diseases (NTDs) consist of a group of chronic, debilitating, and poverty-promoting parasitic, bacterial, and viral and fungal infections that are widespread among people in poor rural or peri-urban communities living in tropical or subtropical areas. However, due to population mobility, diseases such as Chagas disease can be diagnosed anywhere on the globe. The NTDs are disabling, disfiguring and deadly diseases impacting more than one billion people worldwide. They also impair physical and cognitive development, cause adverse pregnancy outcomes, and limit adult productivity in the workforce. The global burden of disease associated with the NTDs is comparable to other infectious diseases such as that of malaria or tuberculosis. Controlling or eliminating NTDs represents an affordable opportunity to improve the health of poor communities, which may ultimately promote social development.

Achievements and challenges in controlling Chagas disease

American trypanosomiasis or Chagas disease continues to endanger the lives of many million people in Latin America, and through travel and population migration there is a risk of congenital cases in nonendemic settings. Substantial improvements in the transmission of the disease have been achieved through vector control and blood-bank screening. However, vector-borne transmission remains the main mode of acquisition of infection in many settings coupled with congenital transmission and food-borne and accidental exposure through transplantation or laboratory exposure. The main sites of affection include the heart and gastrointestinal tract. Antiparasitic treatment of indeterminate forms is successful in many cases by delaying the risk of progression of cardiomyopathy, but treatment of chronic chagasic cardiomyopathy remains mainly supportive. The BENEFIT trial that will be completed by late 2011 or early 2012 will provide evidence for or against treating chronic symptomatic forms. Control or eliminating Chagas disease transmission coupled with decreasing the associated burden of disease in Latin America will promote better health and social and economic development among the most impoverished populations in the region.

Leprosy: a modern assessment of an ancient neglected disease

Leprosy or Hansen's disease is a chronic mycobacterial infectious disease caused by Mycobacterium leprae and affects mainly peripheral nerves and skin as well as upper respiratory mucosae. This infection is a conjoined bacteriological and immunological disease. Target cells of infection are macrophages, histiocytes in the skin, and the nonmyelinating and myelinating Schwann cells in the peripheral nerves leading to axonal dysfunction and demyelination leading to functional impairment and deformity. Leprosy reactions represent the most important determinant of nerve impairment if untreated and unrecognized. Control of leprosy transmission remains a challenge despite substantial improvements through the use of multidrug therapy in many settings. Most importantly, although many patients have been microbiologically cured through the efforts of the World Health Organization, many are left with significant disability that has recently been estimated to be ~20% of those treated (~15 million individuals) in the last decades. Further efforts are needed to elucidate the epidemiology and risk factors for disability among those with multibacillary forms.

Are leprosy reactions autoinflammatory diseases?

There are two types of leprosy reactions: reversal reactions or type 1 and erythema nodosum leprosum or type 2. Deformity and disability associated with leprosy are frequently the result of uncontrolled or untreated reactions. Although there is current availability of glucocorticoids as the mainstay of therapy, much needs to be learned about the etiology, risk factors, and pathogenesis of leprosy reactions. There is some evidence that leprosy reactions may represent, particularly, erythema nodosum leprosum autoinflammatory disease due to the aberrant activation of the innate immune system. The role for herpesviruses influencing autophagy in macrophages needs to be evaluated in the pathogenesis of leprosy reactions.

Inmunizaciones y equidad en el Plan Regional del Sistema Mesoamericano de Salud Pública / Immunization and equity in the Regional Initiative of the Mesoamerican Health Initiative

Las cifras nacionales de inmunización indican altas coberturas de vacunación en Mesoamérica, sin embargo, hay evidencia creciente de que los grupos más vulnerables no son alcanzados por los programas de vacunación. La planeación de este proyecto se llevó a cabo entre junio y diciembre de 2009. La ejecución del proyecto se llevará a cabo en la población objetivo seleccionada a partir de junio de 2011. Está integrada por niños menores de cinco años y mujeres en edad fértil de las poblaciones más vulnerables en los países de Mesoamérica, identificadas geográficamente por un bajo índice de desarrollo humano o por la alta prevalencia de pobreza en el ámbito municipal, o a través del uso de métodos participativos para definir pobreza y vulnerabilidad en contextos locales. El Grupo de Trabajo ha definido tres líneas de acción para las intervenciones de enfermedades prevenibles por vacunación, para lograr una mejor cobertura efectiva en poblaciones vulnerables: 1) estudios piloto de coberturas para vacíos de conocimiento, 2) fortalecimiento de las políticas de vacunación, 3) ejecución de prácticas basadas en evidencia. El fortalecimiento de los sistemas de salud bajo la óptica de equidad en salud es el objetivo regional central del Grupo de Trabajo en inmunizaciones enfocado en un aumento de la cobertura efectiva.

National immunization rates indicate high vaccine coverage in Mesoamerica, but there is growing evidence that the most vulnerable groups are not being reached by immunization programs. Therefore, there is likely low effective vaccine coverage in the region, leading to persistent and growing health inequity. The planning phase of this project was from June to December 2009. The project will be conducted in the target populations which includes children under five, pregnant women, and women of child-bearing age from the most vulnerable populations within countries of the Mesoamerican region, as indicated geographically by a low human development index (HDI) and/or high prevalence of poverty at the municipal level and through the use of participatory methods to define poverty and vulnerability in local contexts. We defined three lines of action for vaccine-preventable disease interventions: 1) pilot projects to fill gaps in knowledge; 2) strengthening immunization policy; and 3) implementation of evidence-based practices. Health system strengthening through health equity is the central regional objective of the immunization workgroup. We hope to have a transformational impact on health systems so as to improve effective coverage, including vaccine and other integrated primary healthcare services.

Prevalence of untreated schistosomiasis among Sudanese refugees: "The Lost Boys of Sudan" in the United States

Background. The increase in global travelling also brings infections from endemic to non-endemic regions where diagnosis and treatment may be delayed. Methods. From 2005 to 2008, 104 Sudanese refugees were evaluated to determine the prevalence of untreated schistosomiasis at the Tropical Medicine Clinic at Emory University in Atlanta, GA. Sera from 87 patients were screened using FAST-ELISA and antigen-specific immunoblots. Results. Of the 87 patients screened, 44.8% were positive for schistosomiasis antibodies, including Schistosoma mansoni and S. haematobium. Conclusion. Our study emphasizes the need for single-dose presumptive treatment of praziquantel among sub-Saharan refugees and long-term travelers.

El virus del Oeste del Nilo: una realidad en México / West Nile virus: a reality in Mexico

El virus del Oeste del Nilo (VON) es un virus ARN perteneciente a la familia Flaviviridae del género Flavivirus que causa infección en aves, equinos y humanos. La infección por VON es transmitida por el mosquito Culex sp. El ciclo de vida del virus incluye a los mosquitos como vectores y a las aves como huéspedes naturales. El virus mantiene un ciclo de transmisión mosquito–ave-mosquito. Los seres humanos son huéspedes accidentales. Se han reportado epidemias en Rumania, Nueva York e Israel. Mediante el programa de vigilancia epidemiológica en nuestro país, se han reportado 90 muestras positivas en 1,223 casos estudiados en aves hasta el 15 de Septiembre del 2005. La enfermedad por el VON se presenta con fiebre, malestar general, anorexia, nausea, vómito, cefalea, mialgia, erupción cutánea y linfadenopatía. La principal entidad clínica descrita es la encefalitis y la parálisis flácida. A mayor edad, es mayor el riesgo de enfermedad neurológica y muerte. Los métodos diagnósticos incluyen determinación de anticuerpos IgM e IgG en suero y/o liquido cerebroespinal. No existe tratamiento antiviral para la infección por VON. Algunas terapias que se han utilizado incluyen interferón α2b e inmunoglobulina específica contra VON. La prevención juega un papel crucial.

West Nile virus (WNV) is a RNA virus of the Flaviridae, genus flavivirus family. It is a neuropathogenic virus causing disease in birds, horses and humans. WNVis transmitted by the vector mosquito Culex sp. The virus life 's cycle includes mosquitoes as vectors and birds as natural hosts. Humans are accidental hosts. Since the introduction of the Epidemiological Surveillance Program at the Ministry ofHealth. we have documented 90 positive test results among birds out of 1,223 cases studied in Mexico as of September IS. 2005. The incubation period in humans after a mosquito bite ranges from 3 to 14 days. Disease is characterized by early onset fever, general malaise, decreased appetite, nausea, vomiting, headaches, myalgias, enlarged lymph nodes andrash. Neurological manifestations include encephalitis andflaccid paralysis, which are present in less than 1% of subjects infected with WNV. Older patients display more adverse outcomes including death. The diagnosis is made by the determination of specific IgM and JgG antibodies in serum and/or cerebrospinal fluid. There is no antiviral treatment to date against WNV but interferon ?2b, and WNVspec4ic-immunoglobulin have been used Prevention is therefore the key to control the infection.

Agentes del bioterrorismo: preparándose para lo impensable / Bioterrorism agents: getting ready for the unthinkable

The September 11, 2001 terrorist attacks in the USA demonstrated our vulnerability to terrorist raids. Furthermore, in the same year inhalational anthrax cases in humans caused by the international release of Bacillus anthracis spores via the USA postal system inflicted a lot of panic and terror over the civilian population. The succeeding terrorist events scattered in several other countries are continous reminders of our failness and of the risk that terrorists attempts in the future may be implemented by means of deliberate evil release of biological agents. These events may be perpetrated by either the release of an infectious agent or any of its products in order to spread death or sickness in humans, animals, or plants with the obnoxius purpose of scaring governments and societies for the profit of particular ideological causes. In the current article, we present a review of the main bioterrorism agents, as well as a historical and clinical aspects and their significance for public health preparedness and response.

Los eventos terroristas del 11 de septiembre del 2001 en Estados Unidos de América (EUA) cambiaron para siempre nuestra percepción de la vulnerabilidad a los ataques terroristas. Aunado a esto, los primeros casos de ántrax en humanos ocasionados por la liberación intencional de esporas de Bacillus anthracis a través del sistema postal de EUA infligieron pánico y terror en la población general. Los subsecuentes eventos de terrorismo ocurridos en diversos países son recordatorios continuos de nuestra fragilidad y del riesgo que futuros ataques terroristas pudieran organizarse a través de liberación intencional de agentes biológicos. El bioterrorismo consiste en el uso intencional o amenaza de utilizar agentes biológicos; ya sea el propio agente infeccioso o sus productos para causar la muerte o enfermedad en humanos, animales o plantas con el objetivo de intimidar a gobiernos y sociedades en beneficio de causas ideológicas particulares. En el presente artículo se hace una revisión de los principales agentes del bioterrorismo, aspectos históricos, clínicos y terapéuticos, así como su prevención e importancia para la salud pública mundial.

Enfermedad por meningococo, Neisseria meningitidis: perspectiva epidemiológica, clínica y preventiva / Meningococcal disease caused by Neisseria meningitidis: epidemiological, clinical, and preventive perspectives

La meningitis bacteriana continúa siendo uno de los grandes problemas de la salud pública mundial. En particular, la infección por Neisseria meningitidis afecta tanto a países desarrollados como subdesarrollados, y se presenta en formas endémicas y epidémicas. La enfermedad meningocóccica se puede manifestar clínicamente no sólo como meningitis, sino con cuadros fulminantes de meningococcemia. La persistencia de N. meningitidis se debe al gran porcentaje de portadores y a la dinámica de transmisión de la bacteria. Aproximadamente 500 millones de personas en el mundo son portadoras de N. meningitidis en la nasofaringe. Los factores de transmisiblidad identificados han sido el tabaquismo activo o pasivo, la presencia de infecciones virales del tracto respiratorio superior, épocas de sequía, y el hacinamiento. Por lo anterior, se han descrito brotes de enfermedad meningocóccica en cuarteles militares, escuelas, cárceles y dormitorios. Algunos determinantes que permiten la invasión sistémica incluyen daños en la mucosa nasofaríngea de portadores, cepas virulentas con formación de cápsula, ausencia de anticuerpos bactericidas y deficiencias del sistema del complemento. El control de la enfermedad meningocóccica en circunstancias endémicas y epidémicas se logra por el tratamiento de casos con antibióticos adecuados (penicilina, ceftriaxona o cloranfenicol), la quimioprofilaxis de contactos cercanos (ciprofloxacina, rifampicina o ceftriaxona), y la vigilancia clínica de éstos. Sin embargo, es fundamental subrayar que la clave para el control efectivo de la enfermedad meningocóccica es la inmunoprofilaxis. Las vacunas disponibles incluyen las de polisacáridos monovalentes o bivalentes (serogrupos A y C), tetravalentes (A, C, Y, W-135), la conjugada (C) o la combinada de proteínas de membrana celular y polisacárido (B y C). Recientemente nos hemos visto forzados a establecer planes nacionales de respuesta que incluyen la disponibilidad de vacuna y de medicamentos para quimioprofilaxis, debido a que se ha documentado un incremento de casos de enfermedad por N. meningitidis, serogrupo C, en el país. Es por lo anterior que esta revisión está dirigida a proporcionar al personal de salud un recordatorio de los aspectos relevantes de la epidemiología, y de los clínicos y preventivos de la enfermedad meningocóccica.

Perspectiva histórica de la viruela en México: aparición, eliminación y riesgo de reaparición por bioterrorismo / Historical Perspective of Smallpox in Mexico: Emergence, Elimination, and Risk of Reemergence due to Bioterrorism

Desde la certificación de la erradicación de la viruela en 1980, ésta enfermedad había tenido únicamente un carácter histórico. Sin embargo, debido a los acontecimientos terroristas del 2001 en Estado Unidos de Norte América con la liberación intencional de esporas de Bacillus anthracis y a la actual situación política, el bioterrorismo ha escalado a los primeros peldaños de la salud pública mundial. La posibilidad de la utilización del virus Variola, como arma biológica, obliga a una revisión del impacto histórico de la viruela en nuestro país y evaluación del riesgo de su reintroducción. La entrada de la viruela en el continente Americano en el siglo XVL ocasionó epidemias catastróficas que contribuyeron al colapso de Imperio Azteca. En 1804, Francisco Xavier Balmis, realiza la expedición filantrópica desde España al Continente Americano para introducir la vacuna anti-variola, que representa la primera campaña mundial de erradicación contra una enfermedad inmunoprevenible . México logra eliminar la viruela en 1951. La era posterradicación ofrece un riesgo mínimo pero real de la posible liberación intencional del virus.. México, ha desarrollado planes de respuesta... Sin duda alguna, el enfrentar una nueva epidemia de viruela seria desastroso desde un punto de vista histórico y de salud pública.

Smallpox has been considered a disease of historical interest. However, given the 2001 terrorist events in the U.S. with intentional release of spores of Bacillus anthracis; and the current political worldwide agenda, the risk of bioterrorism has become a global public health concern. The risk of an intentional release of Variola virus as a biological weapon mandates a critical review of the historical impact of the disease in our country and the possible risk of its intentional reemergence. Smallpox was introduced into susceptible Indian populations in the Americas in the 16th century, contributing to the collapse of the Aztec Empire. Francisco Xavier Balmis start a vaccination campaign in the New World, and his efforts are considered the first eradication campaign of vaccine preventable diseases. Due to his efforts, smallpox was eliminated in Mexico in 1951. In the posteradication era, there is small but finite risk of intentional release of Variola virus. In response to this risk, Mexico has developed a comprehensive National preparedness plan. The impact of a new epidemic of smallpox will be considered a catastrophic event from both a historical and public health perspectives.