Logo: to the web site of Uppsala University

Sweden is an area potentially endemic for spotted fever rickettsioses. Rickettsia helvetica has been isolated from its tick vector Ixodes Ricinus, and in a handful of cases linked to human disease. This study demonstrates for the first time in Sweden the transmission of rickettsial infection after a tick bite and the attack rate in an endemic area. We present three cases of documented rickettsial infection and a prospective serological study of Swedish recruits who were trained in the area where the patients lived and showed seroconversion to spotted fever rickettsiae. All patients showed a four-fold increas in antibody titer to the spotted fever rickettsia, R. helvetica, and immunohistochemical examination revealed rickettsia-like organisms in the walls of skin capillaries and veins. Electron microscopy showed organisms resembling R. helvetica and immunogold labeling with two anti-rickettsial antibodies demonstrated specific labeling of the rickettsial organisms in the skin biopsy specimens. Eight of the thirty-five recruits showed a four-fold increase in IgG titer reflecting a high rate of exposure. The results of this study demonstrate that spotted fever rickettsioses should be taken into consideration in the diagnosis of tick-transmitted infections in Sweden.

Infection with Bartonella, an emerging bacterial pathogen which often affects immunodeficient patients, has been reported in Sweden over the past few years, with a high seroprevalence of B. elizabethae. A high prevalence of antibodies against B. elizabethae has also been found in urban intravenous drug users in the USA. Using immunofluorescence, we retrospectively examined serum samples taken at autopsy from 59 Swedish intravenous drug addicts from the Stockholm area for evidence of antibodies against 6 pathogenic strains of Bartonella. The 59 addicts died following heroin injection during the years 1987–1992 and include 24 individuals (41%) who were additionally HIV-positive. An overall seropositivity rate for Bartonella spp. of 39% (23/59) was found with the following antigenic reactivities: B. elizabethae, 39% (23/59); B. grahamii, 3% (2/59); B. henselae (Houston-1), 14% (8/59); and B. quintana, 3% (2/59). There were no positive reactions for B. henselae (Marseille) or B. vinsonii subsp. vinsonii. The Bartonella-seropositive cases included 11/23 (48%) individuals who were HIV-positive. Subacute to chronic myocarditis was seen in 2/11 microscopically investigated Bartonella-seropositive cases that were HIV-negative and in 1/14 seronegative cases. No cases of endocarditis or other common manifestations of Bartonella infection were found. An overall Bartonella seropositivity of 21% (9/44) was observed in control forensic autopsy samples.

Several trace elements are essential nutrients for an optimal functioning of organs and tissues, including the immune system and the heart. The pathogenesis of some heart diseases has been associated with changes in the balance of certain trace elements. The etiology of nonrheumatic aortic valve sclerosis is unknown, however. A prospective study was performed on trace element changes in the sclerotic valves of 46 patients undergoing surgical aortic valve replacement because of aortic stenosis. Valves from 15 individual forensic cases without known cardiac disease served as controls. The contents of 15 trace elements (Al, As, Cd, Ca, Co, Cu, Fe, Pb, Mg, Mn, Hg, Se, Ag, V, and Zn) were measured by inductively coupled plasma - mass spectrometry (ICP-MS) of aortic valve tissue from both patients and forensic autopsy controls. Some trace elements showed similar concentrations in sclerotic and control valves (Al, Ag, Hg, Mn), whereas a few were moderately changed in the sclerotic as compared with the control valves, including an increase in Cd by 52% (p < 0.05) and decreases in Se by 14% (p < 0.05), in V by 42% (p < 0,001), and in Cu by 45% (p < 0.001). However, there were pronounced increases (p < 0.001) in the concentrations of As (5-fold), Ca (70-fold), Co(10-fold), Fe (20-fold), Pb (8-fold), Mg (20-fold), and Zn (10-fold) in the sclerotic valves. Thus, sclerotic aortic valve disease is associated with a pronounced imbalance in several trace elements of well-known importance for cardiovascular and immune function as well as in trace elements with hitherto unknown significance.