Disease-A-Month RSS feed: Current Issue. Designed for primary care physicians, each issue of Disease-a-Month presents an in-depth review of a single topic. In this way, the publication can cover all aspects of the topic-pathophysiology, clinical features of the disease or condition, diagnostic techniques, therapeutic approaches, and prognosis. http://www.diseaseamonth.com/?rss=yesElsevier Inc.en © 2012 Published by Elsevier Inc. All rights reserved. Disease-A-Month0011-5029586June 2012 © 2012 Published by Elsevier Inc. All rights reserved. healthpermissions@elsevier.comhttp://www.diseaseamonth.com/article/PIIS0011502912000776/abstract?rss=yesEditorial Board10.1016/S0011-5029(12)00077-6Disease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6IFCIFChttp://www.diseaseamonth.com/article/PIIS0011502912000788/abstract?rss=yesTitle Page10.1016/S0011-5029(12)00078-8Disease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6321321http://www.diseaseamonth.com/article/PIIS001150291200079X/abstract?rss=yesInformation for Readers10.1016/S0011-5029(12)00079-XDisease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6322322http://www.diseaseamonth.com/article/PIIS0011502912000806/abstract?rss=yesTable of Contents10.1016/S0011-5029(12)00080-6Disease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6323325http://www.diseaseamonth.com/article/PIIS0011502912000430/abstract?rss=yesAs outdoor activities increase during the warm-weather months, physicians must be aware of the variety and constellation of symptoms caused by ticks. Certainly, the multisymptom involvement of this exposure can make the diagnosis very difficult. Environmental investigations and public health involvement often need to be considered in order to identify the underlying cause and guide remediation efforts to prevent re-exposure to ticks. Dr. Catherine F. Decker and colleagues at Walter Reed National Military Medical Center in Bethesda, MD give a comprehensive and detailed overview of this challenging topic.ForewordJerrold B. Leikin10.1016/j.disamonth.2012.03.002Disease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6326326http://www.diseaseamonth.com/article/PIIS0011502912000442/abstract?rss=yesOver the past several decades, tick-borne illnesses have become more widespread throughout the US because of such factors as climate change, increasing numbers of animal reservoirs and tick vectors, suburban development, and participation in outdoor recreational activities. Despite the availability of low-cost and effective antibiotics, these infections continue to cause severe illness in adults and children. Tick-borne illnesses in the USA are clinically similar, but epidemiologically and etiologically distinct, illnesses. The more commonly encountered infections include Lyme disease, human anaplasmosis (human granulocytic anaplasmosis), human ehrlichiosis (human monocytic ehrlichiosis), babesiosis, and Rocky Mountain spotted fever. The infecting organisms are maintained in natural cycles involving mammals and predominately hard-bodied ticks. Although tick-borne illnesses have been reported year-round, over 90% of reported cases occur April to September, coincident with peak levels of tick feeding activity on humans. Ticks are excellent vectors for disease transmission. Generally, 24 to 48 hours of attachment to the host is required for infection to occur, so regular skin examination for ticks and early removal can help prevent disease. To optimize the attachment, most ticks secrete anticoagulants and analgesics. However, most tick bites do not result in transmission of infection. For example, in the case of Lyme disease, only about 2% to 3% of all persons bitten by Ixodes scapularis in an endemic area will develop Lyme disease.Tick-Borne Illnesses: An OverviewCatherine F. Decker10.1016/j.disamonth.2012.03.003Disease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6327329http://www.diseaseamonth.com/article/PIIS0011502912000454/abstract?rss=yesWhen a patient develops a febrile illness, particularly during the summer months, the index of suspicion for tick-borne illness should always be high in those who live in or travel (within 2 weeks) to areas where tick-borne diseases are endemic, such as the microfoci of the Northeastern US, Western Wisconsin, and Nantucket. In addition to travel, other important clinical history includes recent tick exposure, specific recreational or occupational exposures to tick-infested habitats, or similar illness in family members or coworkers, all of which may be critical information in the diagnosis of tick-borne illnesses.When to Suspect Tick-Borne IllnessCatherine F. Decker10.1016/j.disamonth.2012.03.004Disease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6330334http://www.diseaseamonth.com/article/PIIS0011502912000466/abstract?rss=yesLyme disease is the most common vector-borne illness in the USA. It was originally described in 1976 after an unusual cluster of juvenile rheumatoid arthritis cases in Lyme, CT. The causative agent of Lyme disease is the tick-borne spirochete Borrelia burgdorferi, which is transmitted through the bite of the tick species, Ixodes scapularis, in the northeastern and north central USA and Ixodes pacificus in the Western USA. Lyme disease is a multisystem illness with variable clinical presentations and most often involves the skin, joints, nervous system, and heart. After infection, some patients may have disease localized to the skin, whereas others may only present with later illness, such as arthritis. Early cutaneous findings of erythema migrans (EM) in the right clinical setting are usually sufficient for diagnosis; however, for extracutaneous manifestations of Lyme disease, diagnostic testing must be performed.Lyme DiseaseOmolara R. Alao, Catherine F. Decker10.1016/j.disamonth.2012.03.005Disease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6335345http://www.diseaseamonth.com/article/PIIS0011502912000478/abstract?rss=yesHuman ehrlichiosis and anaplasmosis are acute febrile tick-borne rickettsial diseases caused by organisms of the closely related genera Ehrlichia and Anaplasma. Over the past 20 years, Ehrlicha has become increasingly recognized as an emerging zoonotic infection since it was first found to cause human disease in 1986. The most common agents of human tick-borne ehrlichiosis include Anaplasma phagocytophlium, Ehrlichia chaffenenis, and Ehrlichia ewingii. The more commonly recognized infections include anaplasmosis (human granulocytic anaplasmosis [HGA]) and human ehrlichiosis (human monocytic ehrlichiosis [HME]). The causative agents of HME and HGA are small, Gram-negative, obligate intracellular bacteria that have tropism for specific leukocytes. HME has an affinity for monocytes and HGA preferentially infects granulocytes. Ehrlichieae replicate within vacuoles in these leukocytes forming microcolonies called morulae, derived from Latin word “Morus” for mulberry, which allows the organisms to avoid phagocytosis to facilitate their survival. Morulae can be visualized by light microscopy of Giemsa- or Wright-stained peripheral smears.Ehrlichioses: Anaplasmosis and Human EhrlichiosisKristina St. Clair, Catherine F. Decker10.1016/j.disamonth.2012.03.006Disease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6346354http://www.diseaseamonth.com/article/PIIS001150291200048X/abstract?rss=yesBabesiosis is a tick-borne illness caused by the protozoa Babesia, an obligate parasite of red blood cells that produces a malaria-like illness. It is transmitted by the tick, Ixodes scapularis, which is also the vector of Lyme disease and anaplasmosis. Over the past 50 years, Babesia sp increasingly has been identified as a cause of human infection. The first cases of babesiosis were reported in Europe in 1956 and in the US in 1966. Most cases of human babesiosis occur during the summer months and are endemic in the northeastern US, including Massachusetts, Rhode Island, Connecticut, and New York. Outbreaks have also occurred in Wisconsin, Minnesota, California, and Washington. In the US, most clinically apparent disease occurs primarily in those patients with advanced age or those with underlying immunosuppression.BabesiosisMichael J. Kavanaugh, Catherine F. Decker10.1016/j.disamonth.2012.03.007Disease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6355360http://www.diseaseamonth.com/article/PIIS0011502912000491/abstract?rss=yesRocky Mountain spotted fever (RMSF) is both the most serious and the most commonly reported rickettsial infection in the USA. The causative organism is Rickettsia rickettsii, which is a member of the spotted fever group. R. rickettsii are small, aerobic, obligate intracellular, Gram-negative coccobacilli. The disease name is derived from its origins in the Rocky Mountains. Initially known as “black measles,” RMSF was first recognized in the Snake River Valley of Idaho and the Bitterroot Valley of western Montana in the late 1890s. In 1906, a medical team led by Howard Taylor Ricketts determined the role of ticks in disease transmission. Today, most cases in the USA occur in the mid-Atlantic and southern states (). RMSF also has been found in Canada and in Central and South America. RMSF is a systemic small-vessel vasculitis. Clinical presentations range from benign to life threatening. Early recognition and prompt treatment are keys to reduce mortality from this intriguing illness.Rocky Mountain Spotted FeverLeyi Lin, Catherine F. Decker10.1016/j.disamonth.2012.03.008Disease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6361369http://www.diseaseamonth.com/article/PIIS001150291200051X/abstract?rss=yesTularemia, caused by the small, aerobic Gram-negative coccobacillus Francisella tularensis, is a zoonotic disease found largely in the Northern Hemisphere. It has also been referred to by many other names, including deerfly fever, rabbit fever, hare fever, meat-cutter's disease, and market man's disease. The organism can be transmitted by inhalation or tick or biting fly vectors. Most cases of tularemia are associated with inhalation of the organism via direct exposure (direct inoculation) to infected animals' carcasses or animal products (especially rabbits) during hunting or food processing; however, cases do occur via bite of a tick or fly. It is one of the most infectious pathogens known; less than 10 organisms may cause disease. Its high degree of infectivity and the ability of this organism to be aerosolized have caused concern for its use as a powerful bioterrorism weapon.Other Tick-Borne Illnesses: Tularemia, Colorado Tick Fever, Tick ParalysisKerry E. Meagher, Catherine F. Decker10.1016/j.disamonth.2012.03.010Disease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6370376http://www.diseaseamonth.com/article/PIIS0011502912000508/abstract?rss=yesLyme disease and other tick-borne illnesses have become increasingly common in the US. Suburban development, adventurous habits, and increased recognition are likely all responsible for these trends. In 2010, nearly 30,000 cases of Lyme disease were reported to the Centers for Disease Control and Prevention (CDC). Clinicians seeking to advise patients regarding the prevention of Lyme and the other tick-borne illnesses are challenged by a complex field at the intersection of vector biology, microbiology, and infectious disease.Prevention of Tick-Borne IllnessRamiro L. Gutiérrez, Catherine F. Decker10.1016/j.disamonth.2012.03.009Disease-A-Month 58, 6 (2012)2012-06-01Disease-A-Month2012-06-01586S0011-5029(11)X0019-6377387