Christian Ehrenborg

Subacute bartonella infection in Swedish orienteers succumbing to sudden unexpected cardiac death or having malignant arrhythmias.

During the period 1979-92, an increasing number of sudden unexpected cardiac deaths (SUCD) occurred in young, Swedish, male elite orienteers. Myocarditis was the most common diagnosis in the 16 victims, and in 4 cases was also associated with fatty infiltration mimicking arrhythmogenic right ventricular cardiomyopathy (ARVC). Tissues from autopsies of 5 orienteers were tested for Bartonella by PCR targeting the gltA (citrate-synthase) gene. The products were then sequenced. Antibodies to B. henselae, B. quintana and B. elizabethae were measured by indirect fluorescence antibody assay. Bartonella spp. DNA was detected in the hearts of 4 deceased orienteers, and in the lung of a fifth deceased case. The sequences were close to B. quintana in 2 cases and identical to B. henselae in 3. Four of these 5 cases, as well as 2 additional cases of elite orienteers with ARVC, indicated antibodies to Bartonella. It is suggested that Bartonella-induced silent subacute myocarditis, eventually leading to electric instability, caused the increased SUCD rate among the Swedish orienteers. It is further suggested that Bartonella infection may be a major pathogenetic factor in the development of ARVC-like disease. Although the mode of transmission is unknown, both zoonotic/vector-borne and parenteral person-to-person transmission may be involved.During the period 1979-92, an increasing number of sudden unexpected cardiac deaths (SUCD) occurred in young, Swedish, male elite orienteers. Myocarditis was the most common diagnosis in the 16 victims, and in 4 cases was also associated with fatty infiltration mimicking arrhythmogenic right ventricular cardiomyopathy (ARVC). Tissues from autopsies of 5 orienteers were tested for Bartonella by PCR targeting the gltA (citrate-synthase) gene. The products were then sequenced. Antibodies to B. henselae, B. quintana and B. elizabethae were measured by indirect fluorescence antibody assay. Bartonella spp. DNA was detected in the hearts of 4 deceased orienteers, and in the lung of a fifth deceased case. The sequences were close to B. quintana in 2 cases and identical to B. henselae in 3. Four of these 5 cases, as well as 2 additional cases of elite orienteers with ARVC, indicated antibodies to Bartonella. It is suggested that Bartonella-induced silent subacute myocarditis, eventually leading to electric instability, caused the increased SUCD rate among the Swedish orienteers. It is further suggested that Bartonella infection may be a major pathogenetic factor in the development of ARVC-like disease. Although the mode of transmission is unknown, both zoonotic/vector-borne and parenteral person-to-person transmission may be involved.

Migratory Birds, Ticks, and Crimean- Congo Hemorrhagic Fever Virus

TO THE EDITOR:In a recently published study, Estrada-Pena et al. reported the finding of Crimean-Congo hemorrhagic fever virus (CCHFV) in adult Hyalomma lusitanicum ticks from red deer (Cervus elap ...

High Bartonella spp. seroprevalence in a Swedish homeless population but no evidence of trench fever

Blood samples and epidemiological data were collected from 50 homeless patients in central Stockholm, Sweden. Sera were analysed for antibodies to B. henselae, B. quintana, B. elizabethae and B. grahamii. Whole blood was cultured and used as substrate for a newly developed quantitative real time polymerase chain reaction (QPCR) specifically targeting Bartonella spp. DNA. 61 matched blood donor sera were used as controls. Homeless patients were significantly more often seropositive to Bartonella spp. than controls (OR 7.58 (3.30–17.39), p<0.05). Reactivity to the B. elizabethae antigen was dominating, although the difference between patients and controls was most significant in seroreactivity to the B. henselae antigen. There was no evidence of an ongoing B. quintana epidemic. The absence of louse infestation could explain the lack of B. quintana bacteraemia and the failure to amplify Bartonella DNA.

Migratory birds, ticks, and Bartonella

Bartonella spp. infections are considered to be vector-borne zoonoses; ticks are suspected vectors of bartonellae. Migratory birds can disperse ticks infected with zoonotic pathogens such as Rickettsia and tick-borne encephalitis virus and possibly also Bartonella. Thus, in the present study 386 tick specimens collected in spring 2009 from migratory birds on the Mediterranean islands Capri and Antikythera were screened for Bartonella spp. RNA. One or more ticks were found on 2.7% of the birds. Most ticks were Hyalomma rufipes nymphs and larvae with mean infestation rates of 1.7 nymphs and 0.6 larvae per infested bird. Bartonella spp. RNA was not detected in any of the tick specimens.

First known case of Bartonella quintana endocarditis in Sweden

In this report, we present the first known case of Bartonella endocarditis in Sweden. IgG antibody titres to Bartonella spp. were elevated but blood cultures remained negative. Sequencing of a gltA fragment from DNA extracted from heart valve tissue specimens revealed sequence homology with B. quintana.

On the potential roles of ticks and migrating birds in the ecology of West Nile virus.

Background Mosquitoes are the primary vectors of West Nile virus (WNV). Ticks have, however, been suggested to be potential reservoirs of WNV. To investigate their role in the spread of the virus, ticks, which had been collected from birds migrating northward from Africa to Europe, were analyzed for the potential presence of WNV RNA. Methods On the Mediterranean islands of Capri and Antikythira, a total of 14,824 birds were captured and investigated from which 747 ticks were collected. Results and conclusion Most of the identified ticks (93%) were nymphs and larvae of Hyalomma marginatum sensu lato (s.l.), most of which were or appear to be Hyalomma rufipes. Of these ticks, 729 were individually screened for WNV RNA. None of the ticks was found to be WNV positive. Thus, there was no evidence that H. marginatum s.l. ticks play a role in the spread of WNV from Africa to Europe.