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PubMedDate not supplied

Ehrlichiosis.

A case of human ehrlichiosis is presented. This case review emphasizes the need for a thorough history and physical examination in all patients who present with relatively non-specific complaints such as headaches, chills, myalgias, and arthralgias. These complaints should elicit the question of recent tick exposure from the clinician, particularly if the area is endemic for various rickettsial diseases. Laboratory findings such as leukopenia, thrombocytopenia, and increased hepatic enzymes should strongly suggest the disease.

Adult↗

PubMed1997

Retinal manifestations of acute murine typhus.

PURPOSE: To report the ocular manifestations of acute serologically confirmed murine typhus. METHODS: A retrospective analysis of the clinical history, photography and fluorescein angiography of two patients with acute murine typhus with ocular involvement was conducted. RESULTS: A 38 year old male and a 49 year old female were included in the study. Both complained of fever, headache, rash, night sweats and pulmonary symptoms. They had noted the recent onset of diminished visual acuity and floaters. Examination of the posterior pole revealed mild optic nerve head edema (in one patient), intraretinal hemorrhages and small localized areas of retinal whitening. The history confirmed that both patients had been exposed to fleas and the serologic testing was positive for Rickettsia typhi. The systemic and ocular findings resolved after the use of systemic antibiotics. CONCLUSION: Rickettsial diseases such as murine typhus should be included in the differential diagnosis of otherwise healthy individuals who present with an acute systemic febrile illness and retinitis or neuroretinitis. SUMMARY STATEMENT: The clinical features of two patients with serologically proven acute murine typhus with ocular involvement are presented. Both patients presented with a retinal whitening that resolved after treatment.

Acute Disease↗

PubMed1996

Perpetuation of the agent of human granulocytic ehrlichiosis in a deer tick-rodent cycle.

A human-derived strain of the agent of human granulocytic ehrlichiosis, a recently described emerging rickettsial disease, has been established by serial blood passage in mouse hosts. Larval deer ticks acquired infection by feeding upon such mice and efficiently transmitted the ehrlichiae after molting to nymphs, thereby demonstrating vector competence. The agent was detected by demonstrating Feulgen-positive inclusions in the salivary glands of the experimentally infected ticks and from field-derived adult deer ticks. White-footed mice from a field site infected laboratory-reared ticks with the agent of human granulocytic ehrlichiosis, suggesting that these rodents serve as reservoirs for ehrlichiae as well as for Lyme disease spirochetes and the piroplasm that causes human babesiosis. About 10% of host-seeking deer ticks were infected with ehrlichiae, and of these, 20% also contained spirochetes. Cotransmission of diverse pathogens by the aggressively human-biting deer tick may have a unique impact on public health in certain endemic sites.

Animals↗

PubMed1990

Present and future possibilities for the control of cowdriosis and anaplasmosis.

Cowdriosis and anaplasmosis are most important tick-borne rickettsial diseases of ruminants. After a short introduction, in particular of their aetiology, epidemiology and diagnosis, present methods and future prospects for their control are briefly reviewed. The value and disadvantages of the four possible approaches, chemotherapy, tick control, the utilisation of inverse age-resistance in order to attain endemic stability, and artificial immunisation, are reviewed. Promising future developments in the field of immunisation are indicated.

Anaplasmosis↗

PubMed2001

Clarithromycin versus azithromycin in the treatment of Mediterranean spotted fever in children: a randomized controlled trial.

We conducted an open-label randomized controlled trial to compare the efficacy and safety of clarithromycin (15/mg/kg/day in 2 divided doses for 7 days) with those of azithromycin (10 mg/kg/day in 1 dose for 3 days) in the treatment of children with Mediterranean spotted fever. Until now, there has not been a gold-standard therapy for this rickettsial disease in children. Eighty-seven children were randomized to receive 1 of the 2 drugs. The mean time to defervescence (+/- standard deviation) was 46.2+/-36.4 h in the clarithromycin group and 39.3+/-31.3 h in the azithromycin group. These differences were not statistically significant and both drugs were equally well-tolerated. Clarithromycin and azithromycin could be acceptable therapeutic alternatives to chloramphenicol and tetracyclines for children aged < or =8 years with Mediterranean spotted fever. Azithromycin, because it has a long half-life, offers the advantages of administration in a single daily dose and a shorter duration of therapy, which could increase compliance in children.

Adolescent↗

PubMed2003

In search of encephalitis etiologies: diagnostic challenges in the California Encephalitis Project, 1998-2000.

The California Encephalitis Project was initiated in June 1998 to identify the causes and characterize the clinical and epidemiologic features of encephalitis in California. Testing for >or=13 agents, including herpesviruses, enteroviruses, arboviruses, Bartonella species, Chlamydia species, and Mycoplasma pneumoniae, was performed at the Viral and Rickettsial Disease Laboratory (Richmond, California). Epidemiologic and clinical information collected for each case guided further testing. From June 1998 through December 2000, 334 patients who met our case definition of encephalitis were enrolled. A confirmed or probable viral agent of encephalitis was found in 31 cases (9%), a bacterial agent was found in 9 cases (3%), and a parasitic agent was found in 2 cases (1%). A possible etiology was identified in 41 cases (12%). A noninfectious etiology was identified in 32 cases (10%), and a nonencephalitis infection was identified in 11 (3%). Despite extensive testing and evaluation, the etiology of 208 cases (62%) remained unexplained.

California↗

PubMed1987

Pilot study of the prevalence of head lice infestation in a population of Saudi Arabian children.

The prevalence of infestation with the head louse, Pediculus capitis, was assessed among the child population, from birth to 10 years old inclusive, of the rapidly expanding Saudi Arabian city of Jeddah. Over a period of two months, 300 consecutive children attending the general practitioner for any reason were examined specifically to identify those infested with head lice: 37 cases of active infestation were found, which is an overall prevalence of 12%. An interesting distribution, however, was noted in respect of age, ranging from less than 2% in the first year of life, rising rapidly to around 30% in ages six to eight years, thereafter declining steadily to about 16% by age 10 years. The distribution of infestation among males and females was broadly similar. These results show a high head lice infestation, particularly in the early school years, where presumably interpersonal contacts are most frequent, facilitating contagious spread. As the head lice is known to spread several viral and rickettsial diseases, such as relapsing fever and typhus, greater efforts should be made towards patient education in hygiene, and towards identifying and treating the disease when found.

Child↗

PubMed2000

Q fever 1985-1998. Clinical and epidemiologic features of 1,383 infections.

In order to describe the clinical features and the epidemiologic findings of 1,383 patients hospitalized in France for acute or chronic Q fever, we conducted a retrospective analysis based on 74,702 sera tested in our diagnostic center, National Reference Center and World Health Organization Collaborative Center for Rickettsial Diseases. The physicians in charge of all patients with evidence of acute Q fever (seroconversion and/or presence of IgM) or chronic Q fever (prolonged disease and/or IgG antibody titer to phase I of Coxiella burnetii > or = 800) were asked to complete a questionnaire, which was computerized. A total of 1,070 cases of acute Q fever was recorded. Males were more frequently diagnosed, and most cases were identified in the spring. Cases were observed more frequently in patients between the ages of 30 and 69 years. We classified patients according to the different clinical forms of acute Q fever, hepatitis (40%), pneumonia and hepatitis (20%), pneumonia (17%), isolated fever (17%), meningoencephalitis (1%), myocarditis (1%), pericarditis (1%), and meningitis (0.7%). We showed for the first time, to our knowledge, that different clinical forms of acute Q fever are associated with significantly different patient status. Hepatitis occurred in younger patients, pneumonia in older and more immunocompromised patients, and isolated fever was more common in female patients. Risk factors were not specifically associated with a clinical form except meningoencephalitis and contact with animals. The prognosis was usually good except for those with myocarditis or meningoencephalitis as 13 patients died who were significantly older than others. For chronic Q fever, antibody titers to C. burnetii phase I above 800 and IgA above 50 were predictive in 94% of cases. Among 313 patients with chronic Q fever, 259 had endocarditis, mainly patients with previous valvulopathy; 25 had an infection of vascular aneurysm or prosthesis. Patients with endocarditis or vascular infection were more frequently immunocompromised and older than those with acute Q fever. Fifteen women were infected during pregnancy; they were significantly more exposed to animals and gave birth to only 5 babies, only 2 with a normal birth weight. More rare manifestations observed were chronic hepatitis (8 cases), osteoarticular infection (7 cases), and chronic pericarditis (3 cases). Nineteen patients were observed who experienced first a documented acute infection, then, due to underlying conditions, a chronic infection. To our knowledge, we report the largest series of Q fever to date. Our results indicate that Q fever is a protean disease, grossly underestimated, with some of the clinical manifestations being only recently reported, such as Q fever during pregnancy, chronic vascular infection, osteomyelitis, pericarditis, and myocarditis. Our data confirm that chronic Q fever is mainly determined by host factors and demonstrate for the first time that host factors may also play a role in the clinical expression of acute Q fever.

Age Distribution↗

PubMed1982

Roentgenographic abnormalities in Rocky Mountain Spotted Fever.

Rock Mountain spotted fever (RMSF) is a tick-borne rickettsial disease which produces a widespread vasculitis. A mortality of 7% to 13% has been reported in the United States which is due at least in part to delay in diagnosis and appropriate treatment. The classic features of this disease include a history of tick bite with the clinical presentation of skin rash and fever in association with thrombocytopenia. Few reports have emphasized the radiologic chest abnormalities in this disease or their relationship to thrombocytopenia. We review 70 cases of RMSF with abnormal roentgenographic features and their pathologic correlation.

Adult↗

PubMed1990

Neurologic abnormalities in a patient with human ehrlichiosis.

Human ehrlichiosis is a tick-borne rickettsial disease characterized by fever, headache, myalgias, anorexia, and occasionally rash. In our patient, changes in mental status, upper motor neuron signs, cerebrospinal fluid pleocytosis, and increased serum protein levels were found in association with serologically confirmed ehrlichiosis and were most likely due to vasculitis involving the central nervous system. Intraleukocytic inclusions, although observed in our case, have been infrequently found in other reported cases of ehrlichiosis.

Adult↗

PubMed2005

Blood culture-negative endocarditis in a reference center: etiologic diagnosis of 348 cases.

To identify the current etiologies of blood culture-negative infective endocarditis and to describe the epidemiologic, clinical, laboratory, and echocardiographic characteristics associated with each etiology, as well as with unexplained cases, we tested samples from 348 patients suspected of having blood culture-negative infective endocarditis in our diagnostic center, the French National Reference Center for Rickettsial Diseases, between 1983 and 2001. Serology tests for Coxiella burnettii, Bartonella species, Chlamydia species, Legionella species, and Aspergillus species; blood culture on shell vial; and, when available, analysis of valve specimens through culture, microscopic examination, and direct PCR amplification were performed. Physicians were asked to complete a questionnaire, which was computerized. Only cases of definite infective endocarditis, as defined by the modified Duke criteria, were included. A total of 348 cases were recorded-to our knowledge, the largest series reported to date. Of those, 167 cases (48%) were associated with C. burnetii, 99 (28%) with Bartonella species, and 5 (1%) with rare, fastidious bacterial agents of endocarditis (Tropheryma whipplei, Abiotrophia elegans, Mycoplasma hominis, Legionella pneumophila). Among 73 cases without etiology, 58 received antibiotic drugs before the blood cultures. Six cases were right-sided endocarditis and 4 occurred in patients who had a permanent pacemaker. Finally, no explanatory factor was found for 5 remaining cases (1%), despite all investigations.Q fever endocarditis affected males in 75% of cases, between 40 and 70 years of age. Ninety-one percent of patients had a previous valvulopathy, 32% were immunocompromised, and 70% had been exposed to animals. Our study confirms the improved clinical presentation and prognosis of the disease observed during the last decades. Such an evolution could be related to earlier diagnosis due to better physician awareness and more sensitive diagnostic techniques. As for Bartonella species, B. quintana was recorded more frequently than B. henselae (53 vs 17 cases). For 18 patients with Bartonella endocarditis, the responsible species was not identified. Species determination was achieved through culture and/or PCR in 49 cases and through Western immunoblotting in 22. Comparison of B. quintana and B. henselae endocarditis revealed distinct epidemiologic patterns. The 2 cases due to T. whipplei reflect the emerging role of this agent as a cause of infective endocarditis. Because identification of the bacterium was possible only through analysis of excised valves by histologic examination, PCR, and culture on shell vial, the prevalence of the disease might be underestimated. Among patients who received antibiotic drugs before blood cultures, 4 cases (7%) were found to be associated with Streptococcus species (2 S. bovis and 2 S. mutans) through 16S rDNA gene amplification directly from the valve, which shows the usefulness of this technique in overcoming the limitations of previous antibiotic treatment. Right-sided endocarditis occurred classically in young patients (mean age, 36 yr), intravenous drug users in 50% of cases, and suffering more often from embolic complications. Finally, 5 cases without etiology or explaining factors were all immunocompetent male patients with previous aortic valvular lesions, and 3 of the 5 presented with an aortic abscess. Further investigations should be focused on this group to identify new agents of infective endocarditis.

Adolescent↗

PubMed1999

The effects of Ehrlichia (Cytoecetes) phagocytophila on the clinical chemistry of sheep and goats.

Tick-borne fever (TBF) is a rickettsial disease of domestic and wild ruminants in temperate climates where the hard tick Ixodes ricinus is present. The disease is characterized by a high temperature and severe leukopenia. In the present study, the effects of TBF on the activity of serum alkaline phosphatase (ALP), and on the concentrations of plasma zinc, iron, total bilirubin, urea, creatinine and albumin were investigated by inoculating one group of eight sheep and one group of eight goats with the Old Sourhope (OS) strain of Ehrlichia (Cytoecetes) phagocytophila. All goats and sheep experimentally infected with E. phagocytophila reacted with fever, rickettsiaemia and leukopenia. The leukopenia was due to an acute lymphocytopenia and prolonged neutropenia. In both groups of animals. TBF was characterized by significant reductions in the activities of serum ALP and concentrations of plasma zinc, iron and albumin. However, there were significant increases in the concentrations of plasma total bilirubin, urea and creatinine in both species of animals. The reductions in ALP and iron were significantly more pronounced in sheep than in goats.

Alkaline Phosphatase↗

PubMed1999

Differential haematological effects of tick-borne fever in sheep and goats.

Tick-borne fever (TBF) is a rickettsial disease of domestic and wild ruminants in temperate climates. It is characterized by high fever and severe leukopenia. In the present study, the possible difference in the severity of disease in sheep and goats was investigated by inoculating one group of eight goats and one group of eight sheep with the Old Sourhope (OS) strain of Ehrlichia (Cytoecetes) phagocytophila. All sheep and goats experimentally infected with E. phagocytophila reacted with fever and rickettsiaemia, but there were significant differences between goats and sheep in the severity of clinical disease, the duration and magnitude of fever, the magnitude of rickettsiaemia and the patterns of reduction in the number of total leucocytes. Sheep reacted with fever significantly earlier than goats and the febrile period lasted for a significantly longer period. In contrast, the magnitude of rickettsiaemia was significantly higher in goats than in sheep. Infection with TBF was characterized by a transient increase in the number of neutrophils, which was quickly followed by an acute reduction in the number of lymphocytes and a prolonged reduction in the number of neutrophils in both sheep and goats. In both groups of animals, infection with TBF was also characterized by significant reductions in the total number of red blood cells (RBCs), thrombocytes and packed cell volume (PCV) and the concentration of haemoglobin (Hb). However, the mean corpuscular volume (MCV) and mean corpuscular Hb (MCH) were significantly increased in sheep only.

Animals↗

PubMed2004

Q fever: a new cause of 'doughnut' granulomatous lobular panniculitis.

Q fever is an uncommon zoonotic rickettsial disease with no exanthem or specific cutaneous lesions. Only nonspecific cutaneous involvement has been reported to date. A 69-year-old Spanish woman with chronic myelogenous leukaemia developed fever and two subcutaneous nodules. The patient complained of extreme pain. Biopsy revealed a granulomatous lobular panniculitis with a characteristic 'fibrin ring' or 'doughnut' appearance: fibrin and inflammatory cells arranged around a central clear space. Changes of membranous lipodystrophy were also found. Q fever serological studies were positive. Our patient had panniculitis with singular histopathological features. These histopathological changes have been described in liver and bone marrow of patients with Q fever. To the best of our knowledge, this cutaneous involvement due to Q fever has not previously been described in the literature.

Aged↗

PubMed1991

Shell-vial assay: evaluation of a new technique for determining antibiotic susceptibility, tested in 13 isolates of Coxiella burnetii.

Coxiella burnetii is a strictly intracellular bacterium. Bacteriostatic effects have been described previously on a few isolates in embryonated eggs (A. J. Spicer, M. G. Peacock, and J. C. Williams, p. 375-383, in W. Burgdorfer and R. L. Anacker, ed., Rickettsiae and rickettsial diseases, 1981). We used the shell-vial technique (D. Raoult, G. Vestris, and M. Enea, J. Clin. Microbiol. 28:2482-2484, 1990) to determine the susceptibility of C. burnetii to amoxicillin, amikacin, erythromycin, co-trimoxazole, pefloxacin, ofloxacin, ciprofloxacin, chloramphenicol, tetracycline, doxycycline, minocycline, and rifampin antibiotics at a single dilution. Human embryonic lung fibroblast monolayers in shell vials were seeded with 13 different C. burnetii isolates, including 3 reference strains (Nine Mile, Q212, and Priscilla) and 10 new isolates, in order to obtain 30% infected cells 6 days later. After inoculation, antibiotics were added, shell vials were incubated for 7 days, and immunofluorescence was revealed and compared with that of the positive controls. Strain Nine Mile was more susceptible than strains Q212 and Priscilla were. The heterogeneity of susceptibility to fluoroquinolones, chloramphenicol, and erythromycin was noted among the strains; all were resistant to amoxicillin and amikacin, and all were susceptible to rifampin, co-trimoxazole, tetracycline, and tetracycline analogs.

Anti-Bacterial Agents↗

PubMed1992

In vitro antibiotic susceptibility of the newly recognized agent of ehrlichiosis in humans, Ehrlichia chaffeensis.

Ehrlichiosis in humans, a rickettsial disease recently discovered in the United States, is generally treated successfully with tetracyclines; however treatment with these agents is usually avoided with children and pregnant women. The in vitro susceptibility of Ehrlichia chaffeensis, the agent of human ehrlichiosis in the United States, was assessed by a quantitative evaluation of infected DH82 cells cultivated in 96-well microtiter plates in the presence of different concentrations of selected antibiotics. Extracellular MICs and MBCs were evaluated after 72 h of exposure to the antibiotics. Doxycycline and rifampin were found to exert rapidly bactericidal effects, with MBCs in the extracellular culture medium of less than 0.5 and 0.125 microgram/ml, respectively. E. chaffeensis was resistant to chloramphenicol, ciprofloxacin, erythromycin, co-trimoxazole, penicillin, and gentamicin, which had MICs greater than 16, 4, 8, 4, 40, and 32 micrograms/ml, respectively. These observations are consistent with the finding that human ehrlichiosis appears to respond to tetracycline therapy, which has been the therapy of first choice. Further clinical investigations are necessary to evaluate the role of rifampin in the treatment of human ehrlichiosis, especially in children.

Anti-Bacterial Agents↗

PubMed1995

In vitro and in vivo antibiotic susceptibilities of ELB rickettsiae.

The activities of doxycycline, rifampin, chloramphenicol, and erythromycin against ELB rickettsiae (Rickettsia azadi) were determined by dye uptake and plaque assays. Plaque formation in Vero cells was inhibited by 0.12 microgram of doxycycline per ml. The data presented demonstrate the susceptibility of ELB rickettsiae to commonly used antibiotics for the treatment of rickettsial diseases.

Animals↗

PubMed1998

In vitro susceptibilities of 27 rickettsiae to 13 antimicrobials.

The MICs of 13 antibiotics (doxycycline, thiamphenicol, rifampin, amoxicillin, gentamicin, co-trimoxazole, ciprofloxacin, pefloxacin, ofloxacin, erythromycin, josamycin, clarithromycin, and pristinamycin) were determined for 27 available rickettsial species or strains. We used two in vitro cell culture methods described previously: the plaque assay and the microplaque colorimetric assay. Our results confirm the susceptibilities of rickettsiae to doxycycline, thiamphenicol, and fluoroquinolones. Beta-lactams, aminoglycosides, and cotrimoxazole were not active. Typhus group rickettsiae were susceptible to all macrolides tested, whereas the spotted fever group rickettsiae, R. bellii, and R. canada were more resistant, with josamycin, a safe alternative for the treatment of Mediterranean spotted fever, being the most effective compound. Strain Bar 29, R. massiliae, R. montana, R. aeschlimannii, and R. rhipicephali, which are members of the same phylogenetic subgroup, were more resistant to rifampin than the other rickettsiae tested. Heterogeneity in susceptibility to rifampin, which we report for the first time, may explain in vivo discrepancies in the effectiveness of this antibiotic for the treatment of rickettsial diseases. We hypothesize that rifampin resistance and erythromycin susceptibility may reflect a divergence during the evolution of rickettsiae.

Animals↗