Trombiculid mites (Acari: Trombiculidae) are distributed worldwide ectoparasites of a wide range of vertebrates. More than 50 species are known to bite humans, and about 20 have medical importance. The larval stages (chiggers) of the genus Leptotrombidium are vectors of Orientia tsutsugamushi, causative agent of scrub typhus. This life-threatening disease is widely endemic in Asian Pacific regions where more than one billion people are at risk of acquiring the infection and around one million new cases are estimated to occur annually. In addition, although underreported and often misdiagnosed, trombiculiasis, defined as a dermatitis caused by the salivary secretion of biting chiggers, is present in America and Europe.
Part of the book: An Overview of Tropical Diseases
Proton nuclear magnetic resonance (1H NMR) is a spectroscopic technique usually used for structural determination of molecules. In recent years, this technique has been employed for easy and quick recognition of microorganisms, in antimicrobial susceptibility tests and even for the diagnosis of different infectious conditions. Though 1H NMR shows great potential for expanded applications in microbiological studies, to date applications of proton NMR to microbiological research are not totally standardized. In this chapter, we summarize the state of knowledge about 1H NMR and its current and potential applications in this field.
Tropheryma whipplei mainly known as the causative agent of classical Whipple’s disease, also produces acute, sub-acute and chronic localized forms of infection such as endocarditis. The development of molecular tools has allowed increasing the number of cases of endocarditis due to blood culture use to be negative in T. whipplei endocarditis and most of the cases are confirmed post-surgery when molecular analyses of heart valves are performed. Although, T. whipplei endocarditis is an uncommon condition with an atypical presentation it must be considered in the diagnosis of blood culture negative endocarditis and in patients with heart failure in which valve affectation is present. Other clinical features such as long lasting arthralgia can be present in a high percentage of the patients. It is important to know that few cases are diagnosed in the context of the classical Whipple’s disease. The prognosis is very good when an appropriate surgical management and antimicrobial-specific treatment is given. This chapter describes the epidemiological, clinical characteristics, diagnosis and treatments for T. whipplei endocarditis.
Part of the book: Advanced Concepts in Endocarditis