China
Africa
Explore chapters and articles related to this topic
Infectious Optic Neuropathies
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Imran Rizvi, Ravindra Kumar Garg
Bartonella henselae is a gram-negative bacteria, which is known to cause the zoonotic cat-scratch disease.42 The Bartonella henselae organism is transmitted by the infected cats, through bites, licks or abrasions.42 The cat-scratch disease usually manifests with a flu-like syndrome along with tender lymphadenitis.43 Ocular involvement is described in 5 to 10% of patients.44 The ocular involvement in cat-scratch disease is common. There is a gap of about 4 weeks between inoculation and development of ocular complications. Neuroretinitis is the most common and most characteristic ocular complication.45 Patients can have vision loss, RAPD, color desaturation and visual field abnormalities. The fundus examination shows optic disc edema along with macular star formation. In majority of patients, vision recovers following treatment.46,47 The indirect fluorescent antibody test, enzyme-linked immunoassay (ELISA), Western blot and polymerase chain reaction (PCR)-based assays are used for the laboratory diagnosis.42,43 The treatment guidelines are not clear. Usually patients are treated with doxycycline.48 Alternatively, rifampicin, gentamycin, ciprofloxacin and trimethoprim-sulfamethoxazole have also been used.49
Fleas
Published in Gail Miriam Moraru, Jerome Goddard, The Goddard Guide to Arthropods of Medical Importance, Seventh Edition, 2019
Gail Miriam Moraru, Jerome Goddard
Fleas are small, laterally flattened, wingless insects (see box) that are of great importance as vectors of disease in many parts of the world.1,2 Because fleas are not very host specific (as compared to other insects such as lice), there is significant potential for zoonotic disease transmission. Public health workers are most concerned with fleas that carry the agents of bubonic plague and murine typhus from rats to people and fleas that transmit plague among wild rodents and secondarily to humans; however, there are other fleaborne diseases. The bacterium, Rickettsia felis, has been found worldwide in cat fleas. Its ability to cause disease in humans has been controversial,3 but apparently it can infect humans, producing a murine typhuslike illness.4–6 Certain rodent fleas are efficient vectors of Bartonella organisms.7 Also, fleas may serve as intermediate hosts for helminths such as the dog tapeworm (Figure 18.1). Despite these disease threats, for many people (especially the lay public), the insidious attacks by fleas on people and domestic animals causing irritation, blood loss, and severe discomfort are equal in importance to disease transmission. Included here are discussions of a few of the more common species, comments as to their medical importance, and notes on their biologies.
Infective endocarditis in older adults
Published in Wilbert S. Aronow, Jerome L. Fleg, Michael W. Rich, Tresch and Aronow’s Cardiovascular Disease in the Elderly, 2019
The most likely causes of culture-negative IE include Coxiella burnetii, Bartonella spp., and Tropheryma whipplei. C. burnetii, the causative agent of Q fever, is associated with animal contact. Patients with endocarditis often present with a flu-like illness. Bartonella spp. have been implicated as a cause of culture-negative endocarditis for several decades, primarily affecting younger adults, particularly the homeless, because the major Bartonella spp. that causes IE, B. quintana, is louse-borne. Other Bartonella spp. are carried by fleas/other vectors or can be transmitted by cat scratches/bites and have also been reported as a cause of IE (28). Recent reports of IE due to Bartonella spp. have emerged in older patients with prosthetic valves and in device-associated IE (28,29). T. whipplei, the causative agent of Whipple’s disease, is well recognized as a cause of culture-negative endocarditis, and in a recent study of such patients the organism was the fourth most common pathogen identified by PCR of surgical valve material (causing 6% of cases). Of the 16 patients in that series, the aortic valve was affected in 13, the mitral valve in 3. Also, 12 patients were age 60 years and older; 6 were older than age 70, and only 2 had gastrointestinal symptoms. Thus, T. whipplei may be a relatively common cause of culture-negative IE in seniors and appears to rarely present with classic signs of Whipple’s disease.
Clinical Features and Multimodal Imaging in Atypical Posterior Uveitis Secondary to Bartonella Henselae Infection
Published in Ocular Immunology and Inflammation, 2022
Zachary A. Koretz, Anna Apostolopoulou, Edwin Chen, Oliver Beale, Peter Veldkamp, John Alex Viehman, José-Alain Sahel, Jay Chhablani, Kunal K. Dansingani, Marie-Hélène Errera, Gabrielle R. Bonhomme
On swept-source OCT imaging, many of the peripheral choroidal lesions appeared to have the same characteristic appearance as the choroidal granulomas described in cases of tuberculosis and sarcoidosis.12,13 There were round, homogenously hyporeflective lesions within the inner choroid that allowed for a cone of increased transmission of the OCT signal through the underlying structures consistent with other descriptions of choroidal granulomas.12,14,15 Additionally, on swept-source OCT some of the larger lesions appeared to be compressing choroidal vessels (Figure 1b), which could account for the hypofluorescence observed on ICGA (Figure 2) as well as the flow voids on OCT angiography (Figure 3).16 On ICGA, these lesions remained hypofluorescent in late phase images, which could be explained by focal non-perfusion or by a space-occupying lesion. On follow up OCT angiography there appeared to be complete normalization of the choroidal flow signal in these areas. Bartonella infection has been reported to cause granulomatous inflammation, including granulomatous conjunctivitis, optic nerve head granuloma, and solitary choroidal granuloma, as well as cutaneous granulomas and granulomatous hepatitis.2,17–20 Although we do not have histopathology of this patient’s choroidal lesions, the multimodal imaging findings for many of these lesions appear consistent with descriptions of choroidal granulomas in tuberculosis, sarcoidosis, and Vogt-Koyanagi-Harada disease.12,14,15
Cat at home? Cat scratch disease with atypical presentations and aggressive radiological findings mimicking sarcoma, a potential diagnostic pitfall
Published in Acta Orthopaedica, 2021
Florian Amerstorfer, Jasminka Igrec, Thomas Valentin, Andreas Leithner, Lukas Leitner, Mathias Glehr, Jörg Friesenbichler, Iva Brcic, Marko Bergovec
Due to inconclusive findings and suspicion of malignancy, core-needle, incision, or excision biopsies were performed in 6 cases. Histological examination showed numerous granulomas composed of central necrotic areas admixed with neutrophils surrounded by the palisading histiocytes (Figure 2); occasionally giant cells were also found. In 4 cases, granulomas were found only in the soft tissue and in 2 patients, soft tissues and the lymph nodes were affected. In 1 of the latter cases with soft tissue swelling in the left axilla (case number 9), a core-needle and incision biopsy was performed first, and CSD was diagnosed. However, due to findings suspicious of malignancy and after multidisciplinary discussion, an excision biopsy was performed. Histology revealed granulomatous inflammation in the soft tissue and the adjacent lymph node. A concomitant malignant melanoma composed of diffusely and atypical melanocytes arranged in clusters, with high mitotic activity and necrosis, was found in the same lymph node (Figure 5). The diagnosis was confirmed immunohistochemically by strong positive reaction of the tumor cells to S100, SOX10, HMB-45, and Melan A. To confirm the presence of Bartonella organisms, PCR analysis was performed in 6 cases and was positive. In addition, in 5 cases serologic testing for the presence of antibodies to B. henselae was positive. Moreover, in 5 patients, microbiological cultures were performed and all came back negative.
A review of current treatment strategies for infective endocarditis
Published in Expert Review of Anti-infective Therapy, 2021
David Luque Paz, Ines Lakbar, Pierre Tattevin
According to European guidelines, treatment of Bartonella endocarditis relies on doxycycline (during 4 weeks), associated with one of the few antibiotic bactericidal on Bartonella in vitro, gentamicin, during the first two weeks [3]. Treatment of C. burnetii endocarditis relies on a prolonged combination of doxycycline and hydroxychloroquine during at least 12 months, with systematic monitoring of doxycline and hydroxychloroquine plasma concentrations, as well as anti-phase I Ig titers. For T. whipplei endocarditis, prolonged treatment with trimethoprim/sulfamethoxazole, or the same doxycycline-hydroxychloroquine combination as for C. burnettii have been proposed, with discrepancies between experts, and very limited robust data [3,89].