Unexplained Fever In Infectious Diseases: Section 2: Commonly Encountered Aerobic, Facultative Anaerobic, And Strict Anaerobic Bacteria, Spirochetes, And Parasites
Benedict Isaac, Serge Kernbaum, Michael Burke in Unexplained Fever, 2019
Tularemia is a rare infection caused by a Gram-negative coccobacillus, Francisella tularensis. It is characterized by high fever and severe constitutional symptoms that may persist for weeks to several months, if not treated appropriately. There are four clinical types: the most frequent, ulceroglandular, comprises over 80% of cases; the remainder being the glandular, oculoglandular and typhoidal forms. Problems of unexplained fever may arise in the typhoidal and ulceroglandular forms: the former, because the disease may be manifested only by fever without a primary lesion; the latter, because the primary lesion at the site of infection (papule, ulceration of the skin or mucous membrane) may be overlooked. In these two forms, the clinical and the differential diagnosis may be very difficult. The onset occurs suddenly 3 to 7 days after the infective contact, with high fever, chills, headache, nausea, vomiting, drenching sweats, severe prostration, regional lymph nodes, and splenomegaly.
Gentamicin
M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson in Kucers’ The Use of Antibiotics, 2017
Gentamicin, often with co-administration of other agents, is effective in the treatment of tularemia, plague, and brucellosis (Barza and Scheife, 1977). The drug alone is effective in the treatment of tularemia (Mason et al., 1980; Enderlin et al., 1994; Cross et al., 1995), but streptomycin is an equally effective alternative (Capellan and Fong, 1993). Gentamicin and streptomycin are considered the drugs of choice for the treatment of tularemia (Bossi et al., 2004). Even once-daily administration of gentamicin at 5.0 mg/kg is efficacious (Hassoun et al., 2006). For therapy of human plague, gentamicin alone or in combination with doxycycline is as efficacious as streptomycin (Boulanger et al., 2004). In another trial, gentamicin was as effective as doxycycline alone in the treatment of plague in both adults and children (Mwengee et al., 2006). A recent systematic review and meta-analysis of randomized controlled trials for the treatment of brucellosis showed that the preferred treatment should be with dual- or triple-drug regimens including an aminoglycoside, such as gentamicin or streptomycin (Shalsky et al., 2008). A specific comparative trial of doxycycline with gentamicin at 5.0 mg/kg daily or with streptomycin at 1.0 g daily as treatment for brucellosis in humans exhibited equivalent efficacy (Hasanjani Roushan et al., 2006).
Ticks
Gail Miriam Moraru, Jerome Goddard in The Goddard Guide to Arthropods of Medical Importance, Seventh Edition, 2019
Tularemia, sometimes called rabbit fever or deer fly fever, is a bacterial zoonosis that occurs throughout temperate climates of the Northern Hemisphere. Historically, approximately 150 to 300 cases occur in the United States each year, with most cases usually occurring in Arkansas, Missouri, and Oklahoma (Figure 30.8).73,74 There were 314 cases reported to the CDC during 2015, a 74% increase from 2014.18 The causative organism, Francisella tularensis, is a small, Gram-negative, nonmotile coccobacillus named after Sir Edward Francis (who did the classical early studies on the organism) and Tulare, CA (where it was first isolated). The disease may be contracted in a variety of ways: food, water, mud, articles of clothing, and (particularly) arthropod bites. Arthropods involved in transmission of tularemia include ticks, biting flies, and possibly even mosquitoes. Ticks account for a high percentage of human cases; one study of 78 clinical cases in Missouri with a known exposure source showed that 72% were associated with tick bite.73 Tularemia may present as several different clinical syndromes, including glandular, ulceroglandular, oculoglandular, oropharangeal, pneumonic, and typhoidal. In general, the clinical course is characterized by an influenza-like attack with severe initial fever, temporary remission, and a subsequent febrile period of at least 2 weeks. Later, a local lesion with or without glandular involvement may occur. Additional symptoms vary depending on the method of transmission and form of the disease (see the following discussion). Untreated, the mortality rate for tularemia is about 8%; early diagnosis and treatment can reduce that to 1 to 2%.
Gold nanoparticles for preparation of antibodies and vaccines against infectious diseases
Published in Expert Review of Vaccines, 2020
Conjugates of 15-nm GNPs with two isolated Francisella tularensis antigens, a protective antigenic complex and a glycosylated protein complex, were used to obtain antitularemia sera and vaccinate animals [140]. Subcutaneous immunization of mice with GNPs decorated with a glycosylated protein complex was more effective than was immunization with an unconjugated antigen. This greater effectiveness was manifested as an increase in the protection ability and titers of antibodies. The conjugation of GNPs to both antigens in the immunization of rabbits afforded sera with a high titer of specific antibodies in a relatively short period and with minimal consumption of the antigen. The use in ELISA of the immunoglobulins isolated from the sera allowed detection of F. tularensis cells of different subspecies, enabling their further use in the manufacture of diagnostic agents for tularemia.
Emerging and threatening vector-borne zoonoses in the world and in Europe: a brief update
Published in Pathogens and Global Health, 2019
Tularemia is caused by the gram-negative bacteria Francisella tularensis, which is one of the most virulent microorganisms currently known [93]. The lifecycle of F. tularensis takes place through terrestrial or aquatic environment. In terrestrial lifecycle, lagomorphs, rodents, and ticks are the main source of human infection and tularemia incidence is related to changes in rodent dynamics and to the expanding zone of ticks [94]. In aquatic lifecycle, the source is the water contaminated by carcasses and excrements of infected animals [94]. Tularemia outbreaks related to the aquatic lifecycle are more frequent [94]. Tularemia is highly infectious, can be easily transmitted by aerosol droplets, has a high mortality rate (up to 30%), remains in the environment for a long period of time and there is no vaccine available [93,95]. These alarming characteristics led to the consideration of tularemia as a potential bio-warfare weapon and it is currently classified as the most dangerous, category A infectious agent [81] F. tularensis was used for manufacturing of biological weapons during World War 2, although its use has never been reported [94]. Recently, tularemia has been detected in an increasing number of wild animal species, including lagomorphs, rodents, carnivores, fish and invertebrate arthropods [93]. The incidence of human tularemia is steeply increasing in Balkan countries and in Turkey [96]. In the rest of Europe, human incidence has declined, probably because of a more urban life style, decreasing number of people working outside in the countryside and a low exposition to infected wild animals [78]. However, it can represent a real threat to forest and field workers or to people living at the edge of society, such as homeless people; the transmission can be very fast and easy between them and they may comprise a center of infection outbreaks [78].
Related Knowledge Centers
- Bacteria
- Fever
- Francisella Tularensis
- Pneumonia
- Tick
- Ulcer
- Lymphadenopathy
- Infection
- Microbiological Culture
- Insect Repellent