| rocky mountain spotted fever is still the most lethal tick-vectored illness in the United States. We examine the dilemmas facing the clinician who is evaluating the patient with possible rocky mountain spotted fever, with particular attention to the following 8 pitfalls in diagnosis and treatment: (1) waiting for a petechial rash to develop before diagnosis; (2) misdiagnosing as gastroenteritis; (3) discounting a diagnosis when there is no history of a tick bite; (4) using an inappropriate geographic exclusion; (5) using an inappropriate seasonal exclusion; (6) failing to treat on clinical suspicion; (7) failing to elicit an appropriate history; and (8) failing to treat with doxycycline. early diagnosis and proper treatment save lives. ( info) |
12/73. Spotted fever rickettsiosis in Coronel Fabriciano, Minas Gerais State. We report cases of spotted fever rickettsiosis in Coronel Fabriciano Municipality of Minas Gerais State, brazil. The cases occurred in May and June of 2000. During this period there were two deaths among children from an area named Pedreira in a periurban area of this municipality. In a boy who died with clinical manifestations of Brazilian spotted fever, a necropsy revealed the presence of a spotted fever group Rickettsia. The serological results confirm the difficulty in the differential diagnosis of patients with symptoms of rickettsial diseases. ( info) |
13/73. Implications of presumptive fatal rocky mountain spotted fever in two dogs and their owner. A dog was examined because of petechiation, an inability to stand, pale mucous membranes, a possible seizure, and thrombocytopenia. Tick-borne illness was suspected, but despite treatment, the dog died. Eight days later, a second dog owned by the same individual also died. The dog was not examined by a veterinarian, but rocky mountain spotted fever (RMSF) was suspected on the basis of clinical signs. Two weeks after the second dog died, the owner was examined because of severe headache, fever, nausea, vomiting, decreased appetite, lethargy, and a fine rash on the body, face, and trunk. Despite intensive treatment for possible RMSF, the owner died. Although results of an assay for antibodies to rickettsia rickettsii were negative, results of polymerase chain reaction assays of liver, spleen, and kidney samples collected at autopsy were positive for spotted fever group Rickettsia spp. These cases illustrate how dogs may serve as sentinels for RMSF in humans and point out the need for better communication between physicians and veterinarians when cases of potentially zoonotic diseases are seen. ( info) |
| An 86-year-old woman with a history of tick bites in the previous months developed subnormal visual acuity in both eyes, keratic precipitates, anterior chamber and vitreous cells, optic disc edema, retinal hemorrhages, and retinal arteriolar sheathing. She had no fever or skin rash. Three weeks later, binocular macular star figures appeared. brain imaging was negative; cerebrospinal fluid disclosed a lymphocytic pleocytosis and elevated protein. The serum rickettsia rickettsii antibody test was markedly positive, establishing a diagnosis of rocky mountain spotted fever (RMSF) as the cause of the ophthalmic findings. Despite treatment with oral doxycycline, these findings improved only modestly. Although neuroretinitis has been previously described in RMSF, macular star has not been documented. ( info) |
15/73. Rickettsia parkeri: a newly recognized cause of spotted fever rickettsiosis in the United States. ticks, including many that bite humans, are hosts to several obligate intracellular bacteria in the spotted fever group (SFG) of the genus Rickettsia. Only rickettsia rickettsii, the agent of rocky mountain spotted fever, has been definitively associated with disease in humans in the United States. Herein we describe disease in a human caused by Rickettsia parkeri, an SFG rickettsia first identified >60 years ago in Gulf Coast ticks (Amblyomma maculatum) collected from the southern United States. Confirmation of the infection was accomplished using serological testing, immunohistochemical staining, cell culture isolation, and molecular methods. Application of specific laboratory assays to clinical specimens obtained from patients with febrile, eschar-associated illnesses following a tick bite may identify additional cases of R. parkeri rickettsiosis and possibly other novel SFG rickettsioses in the United States. ( info) |
| rocky mountain spotted fever (RMSF), a tickborne infection caused by rickettsia rickettsii and characterized by a rash, has a case-fatality rate as high as 30% in certain untreated patients. Even with treatment, hospitalization rates of 72% and case-fatality rates of 4% have been reported. This report summarizes the clinical course of three fatal cases of RMSF in children and related illness in family members during the summer of 2003. These cases underscore the importance of 1) prompt diagnosis and appropriate antimicrobial therapy in patients with RMSF to prevent deaths and 2) consideration of RMSF as a diagnosis in family members and contacts who have febrile illness and share environmental exposures with the patient. ( info) |
17/73. Rocky Mountain "spotless" and "almost spotless" fever: a wolf in sheep's clothing. In 10 (10.8%) of 93 laboratory-confirmed or probable cases of rocky mountain spotted fever seen at Duke University Medical Center from 1969 to 1991, illness without rash or fleeting or atypical skin eruptions were noted. Data from these 10 cases and 33 similar previously reported cases of Rocky Mountain "spotless" or "almost spotless" fever support the premise that human rickettsia rickettsii infection has a broader spectrum than that indicated by its classic description. Sixty-one percent of patients with Rocky Mountain spotless or almost spotless fever have been men. Two-thirds have been black. Although in some cases the absence of rash may be due to the prompt institution of therapy with chloramphenicol or tetracycline, in others long delays in recognition of the disease and treatment occurred, resulting in the deaths of 53% of patients. On the basis of outcome in the cases reviewed, empirical administration of chloramphenicol or a tetracycline to selected patients is justifiable (including those patients with severe organ dysfunction), even if they have no rash, a transient rash, or a rash of unusual distribution. Indeed, without such therapy, patients with spotless or almost spotless fever may die. Recognizing such atypical cases is analogous to seeing a wolf in sheep's clothing--intuition, experience, knowledge, and a high index of suspicion are required. ( info) |
| The first fatal rickettsia rickettsii infection was diagnosed in the southwest of mexico. The patient had fever, erythematous rash, abdominal pain, and severe central nervous system involvement with convulsive crisis. The diagnosis of R. rickettsii infection was established by immunohistochemistry and specific polymerase chain reaction. ( info) |
| rocky mountain spotted fever (RMSF), caused by Rickettia rickettsii, is a serious tickborne illness that is endemic in the southeastern united states. Although it is most commonly known as a cause of fever and rash, it can have systemic manifestations. The myocardium may rarely be involved, with symptoms that can mimic those of acute coronary syndromes. This report describes a case of serologically proven RMSF causing symptomatic myocarditis, manifested by chest pain, elevated cardiac enzyme levels, and decrease myocardial function. After treatment with antibiotics, the myocarditis resolved. Thus, although unusual, the clinician should be aware of myocardial disease in patients with appropriate exposure histories or other clinical signs of RMSF. Close monitoring and an aggressive approach are essential to reduce mortality rates. ( info) |
20/73. A rickettsial mixed infection in a dermacentor variabilis tick from ohio. We present the first report of superinfection in a dermacentor variabilis tick from nature. The single tick, collected in ohio, was found infected with Rickettsia belli, R. nontanensis, and R. rickettsii. ( info) |