China
Africa
Explore chapters and articles related to this topic
Tick Typhus
Published in James H. S. Gear, CRC Handbook of Viral and Rickettsial Hemorrhagic Fevers, 2019
The characteristics of the rickettsias have been described in detail in Chapters 2 and 3 need not be considered further now, except to note that Rickettsia conorii, like the other rickettsias, is an obligate intracellular parasite to some extent dependent on the enzyme systems of the host cells for its metabolism and multiplication. The rickettsias of tick typhus are not massed together in the cytoplasm of the infected cells, as in infections due to Rickettsia prowazeki and Rickettsia mooseri, but occur evenly scattered in the cytoplasm of the endothelial and mononuclear cells. In addition to forming a characteristic pattern of infection in the cytoplasm, Rickettsia conorii also invades the nucleus of the host cells, occurring singly or in small clumps.
Ticks
Published in Gail Miriam Moraru, Jerome Goddard, The Goddard Guide to Arthropods of Medical Importance, Seventh Edition, 2019
Gail Miriam Moraru, Jerome Goddard
Boutonneuse fever (BF), or Mediterranean spotted fever, caused by Rickettsia conorii, is widely distributed in Africa, areas surrounding the Mediterranean, southern Europe, and India. The name is derived from the manifestation of a papular rather than a macular rash. Typically, there is also development of an inoculation eschar at the tick bite site. BF often resembles a mild form of RMSF, characterized by mild to moderately severe fever, headache, and a rash usually involving the palms and soles; however, a few cases of severe illness have been associated with BF. Several tick species serve as vectors of the agent to humans, but especially Rhipicephalus sanguineus, R. appendiculatus, and Amblyomma hebraeum.
Case 98: Headache at the Cattle Farm
Published in Layne Kerry, Janice Rymer, 100 Diagnostic Dilemmas in Clinical Medicine, 2017
The infectious diseases team reviewed the patient and commenced doxycycline therapy for possible Borrelia meningitis or rickettsial (spotted fever) meningitis. Over the next 2–3 days, the patient became more alert and was able to protect his airway. He was extubated and transferred to a medical ward. Serological testing subsequently came back positive for Rickettsia conorii.
Spotted fever diagnosis: Experience from a South Indian center
Published in Pathogens and Global Health, 2021
Elangovan D, Perumalla S, Gunasekaran K, Rose W, Verghese V p, Abhilash K Pp, Prakash Jaj, Dumler Js
Whole EDTA-anticoagulated blood for buffy coat preparations and blood for serum were collected from all patients after informed consent. Scrub typhus (ST) ELISA to detect IgM antibodies to Orientia tsutsugamushi (Scrub Typhus Detect IgM ELISA System, InBios International, Inc., Seattle, WA, USA) and spotted fever (SF) ELISA for rickettsia (Rickettsia conorii IgM ELISA, Vircell, Granada, Spain) were performed on the serum samples. IgM antibodies were considered positive if the OD was ≥1.0 at a serum dilution of 1:100 for scrub typhus [20] and for spotted fever based on our in-house studies (Prakash JA, personal communication). While IgM testing of the initial serum sample has great limitations when applied to all AFIs largely owing to low specificity [14], our prior validation demonstrated 95% specificity when 173 non-rickettsial sera were tested (data not shown). Since the study excluded the major known causes of AFI in our region as described, and our prior work demonstrated that the prevalence of spotted fever rickettsiosis in a population that excludes the most common causes of AFI increases to at least 59% [11], we estimate that the positive predictive value of acute phase IgM under these circumstances is approximately 97%.
Typical Kawasaki disease with atypical pneumonia: a paediatric case report
Published in Scandinavian Journal of Rheumatology, 2021
MC Maggio, R Cimaz, MC Failla, P Dones, G Corsello
A chest radiograph revealed consolidation in the right middle lobe and pulmonary hilum opacity with pleural effusion, confirmed by computed tomography (CT) (Figure1). There were no respiratory symptoms or signs, and the respiratory rate, lung auscultation, and oxygen saturation were normal. He was treated with various antibiotics, including clarithromycin, ceftriaxone, chloramphenicol, imipenem, and teicoplanin. Specific immunoglobulin M (IgM) and IgG antibodies against Mycoplasma pneumoniae, Chlamydia, Rickettsia conorii, Epstein–Barr virus, and cytomegalovirus, as well as quantiferon testing, bronchoalveolar lavage with culture, and polymerase chain reaction, were negative, excluding an infectious agent as the origin of the pneumonia (5–9). CRP levels persisted elevated at 6.75 mg/dL, the white blood cell count was 11.23 × 103 cells/µL, and the platelet count was 803 × 103 cells/µL.
Emerging and threatening vector-borne zoonoses in the world and in Europe: a brief update
Published in Pathogens and Global Health, 2019
Bacterial order Rickettsiales causes wide range of related diseases spread by ticks, fleas, chiggers and lice. Spreading abilities, morbidity and mortality rates of Rickettsiales are high. Typhus fever caused by Rickettsia prowazekii was classified as the category B on the list of bioterrorism agents [81]. The most common rickettsiosis in Europe is Mediterranean spotted fever caused by Rickettsia conorii. Even though the disease had been endemic to Southern Italy for many years [82], it has been spreading recently [83]. This infection may represent a severe threat, as its mortality rate is about 32% [84]. Anaplasmosis caused by Anaplasma phagophytophila has also a strongly increasing and widespread occurrence in Europe [85,86]. Recently, new human rickettsial infections have been recognized in Europe [82,87]. In general, rickettsioses occurrence increases in northern countries, which had been traditionally Rickettsia free [88]. It is supposed that this increasing occurrence is associated with the rise of temperature and decreasing number of frosty days [83,89,90]. Several rickettsial vaccines were developed; however, they were difficult, expensive and very hazardous to produce [91]. There is still no approved vaccine available yet [92].