Tags: Brucellosis

Leishmania

Leishmania & Trypanosoma The genera Leishmania and Trypanosoma are members of the family Trypanosomatidae. These protozoans cause diseases with widely varied clinical presentations as well as geographic distributions, including leishmaniasis, American trypanosomiasis (Chagas’ disease), and African trypanosomiasis (sleeping sickness). For example, the endemic zones for African and American trypanosomiasis do not overlap, the diseases are transmitted by different vectors, they involve distinct mechanisms of pathogenesis, and they follow different clinical courses. Nonetheless, the causative agents share important biological features. Each is a hemoflagellate with a kinetoplast containing its own chromosomal DNA with highly conserved and repeated elements, each forms a single flagellum at some point during its life cycle, and each …

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Bartonella

Essentials of Diagnosis Key signs and symptoms include dermal lesion (bacillary angiomatosis and chronic phase of Bartonella bacilliformis infection); papule at inoculation site followed by proximal lymphadenopathy (cat scratch disease); fever, bacteremia, acute hemolytic anemia (acute phase of B bacilliformis infection); persistent or relapsing fever (fever and bacteremia/endocarditis). Predisposing factors include louse exposure, low income, and homelessness (Bartonella quintana-associated bacillary angiomatosis, fever, and bacteremia/endocarditis); cat exposure (cat scratch disease and Bartonella henselae-associated bacillary angiomatosis, fever and bacteremia/endocarditis); sandfly exposure in endemic areas of South American Andes (B bacilliformis infection). History of HIV or immunocompromise (bacillary angiomatosis). Key laboratory findings include small, curved, pleomorphic weakly gram-negative bacilli, best visualized with Warthin-Starry silver …

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Brucella, Francisella, Pasteurella, Yersinia, & Hacek

BRUCELLOSIS Essentials of Diagnosis • Suspected in patients with chronic fever of unknown etiology who have a history of occupational exposure or come from a high prevalence area. • Leukopenia. • Blood culture or bone marrow cultures on appropriate media. • Serum antibody titer = 1:160. • Polymerase chain reaction. General Considerations Brucellosis (also called undulant fever, Mediterranean fever, Malta fever) is an infection that causes abortion in domestic animals. It is caused by one of six species of Brucella coccobacilli. It may occasionally be transmitted to humans, in whom the disease could be acute or chronic with ongoing fever and constitutional symptoms without localized findings. A. Epidemiology. Brucellosis is transmitted …

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Tularemia

Essentials of Diagnosis • Suspected in patients with fever, lymphadenopathy, and skin lesions who have a history of animal exposure (including to wild animals, ticks, or deerflies) or are coming from a high prevalence area or in laboratory personnel who work with Francisella spp. • Blood culture or other biologic specimen cultures on appropriate culture media. • Serum antibody titer = 1:160 or a fourfold increase or decrease in titer. General Considerations Francisella tularensis is the causative agent of tularemia (also called rabbit fever or deerfly fever), an infectious disease that occurs primarily in animals. It may occasionally cause human disease, which most often manifests itself by one or more skin …

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Brucellosis

Description of Medical Condition Systemic bacterial infection caused by Brucella species in infected animal products, or vaccine. Incubation period usually 5-60 days, but highly variable and may be several months. Characterized by intermittent or irregular fevers, with symptoms ranging from subclinical disease to infection of almost any organ system. Bone and joint involvement common. May be chronic or recurrent. Case fatality untreated less than 2%. System(s) affected: Endocrine/Metabolic, Gastrointestinal, Renal/Urologic, Pulmonary, Nervous, Skin/Exocrine, Musculoskeletal, Cardiovascular Genetics: None; some evidence for intrauterine transmission Incidence/Prevalence in USA: • About 100/year (105 cases in 1992; 0.34/100,000), but probably underreported • Common in developing countries; consider in immigrants • Highest rates in Hispanic population, along …

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Tissue Protozoa

Leishmaniasis Prevalence, Epidemiology, and Life Cycle Leishmania has caused major epidemics in eastern India, Bangladesh, and East Africa. Urban outbreaks have been reported in the cities of northeastern Brazil. A small number of American military personnel contracted leishmaniasis during the Persian Gulf War in 1991 and in Afghanistan more recently. Indigenous cases have been reported occasionally in the United States, but most U.S. cases result from travel to a tropical country. Leishmaniasis has emerged as an opportunistic infection in patients with HIV or an organ transplant. The Leishmania parasite is transmitted by the female phlebotomine sandfly. Sandflies breed in cracks in the walls of dwellings, in rubbish, and in rodent burrows. …

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Anti-Infective Therapy

Despite dire warnings that we are approaching the end of the antibiotic era, the incidence of antibiotic-resistant bacteria continues to rise. The proportions of penicillin-resistant Streptococcus pneumoniae, hospital-acquired methicillin-resistant Staphylococcus aureus, and vancomycin-resistant Enterococcus strains continue to increase. Community-acquired methicillin-resistant Staphylococcus aureus is now common throughout the world. Multiresistant Acinetobacter and Pseudomonas are everyday realities in many of our hospitals. The press is now warning the lay public of the existence of “dirty hospitals.” As never before, it is critical that health care providers understand the principles of proper anti-infective therapy and use anti-infective agents judiciously. These agents need to be reserved for treatable infections — not used to calm the …

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Specific Anti-Infective Agents

Antibiotics Before prescribing a specific antibiotic, clinicians should be able to answer these questions: •  How does the antibiotic kill or inhibit bacterial growth? •  What are the antibiotic’s toxicities and how should they be monitored? •  How is the drug metabolized, and what are the dosing recommendations? Does the dosing schedule need to be modified in patients with renal dysfunction? •  What are the indications for using each specific antibiotic? •  How broad is the antibiotic’s antimicrobial spectrum? •  How much does the antibiotic cost? Clinicians should be familiar with the general classes of antibiotics, their mechanisms of action, and their major toxicities. The differences between the specific antibiotics in …

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Infectious disorders

Infectious diseases comprise those illnesses that are caused by microorganisms or their products. Clinical manifestations of infection occur only when sufficient tissue injury has been inflicted directly by microbial products (e.g., endotoxins and exotoxins), or indirectly by host responses (e.g., cytokines and hydrolytic enzymes released by polymorphonuclear leukocytes). Despite the extraordinary recent advances that have occurred in therapeutics for infectious diseases, a number of basic principles should be followed to prescribe antimicrobials and vaccines is an optimal manner. This chapter addresses the broader issues of treating infectious diseases and provides a number of practical clinical examples to demonstrate rational therapeutics. A rational therapeutic strategy in the management of proved or suspected …

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Rifampin: Dosage and Administration

• Reconstitution and Administration Rifampin usually is administered orally. When oral therapy is not feasible, the drug may be given by IV infusion. Rifampin should not be administered IM or subcutaneously since local irritation and inflammation can occur. • Oral Administration Rifampin should be given orally either 1 hour before or 2 hours after a meal with a full glass of water to ensure maximum absorption. The fixed-combination preparation containing isoniazid and rifampin (Rifamate®) and the fixed-combination preparation containing isoniazid, rifampin, and pyrazinamide (Rifater®) also should be given either 1 hour before or 2 hours after a meal; the manufacturer states that Rifater® should be given with a full glass of …

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