Case reportSepticaemia with Rickettsia helvetica in a patient with acute febrile illness, rash and myasthenia
Introduction
The spotted fever rickettsia, Rickettsia helvetica, has been described in several European countries as well as Japan, but recently also reported in Thailand and Laos.1, 2 The tick Ixodes ricinus represents a potential vector and natural reservoir of R. helvetica, but in Japan the organism has also been isolated in other ticks.1 The pathogenic role of R. helvetica is debated and remains a matter of controversy. But R. helvetica has been implicated in acute perimyocarditis, unexplained febrile illness, sarcoidosis and fever following an Ixodes holocyclus bite.1, 3, 4, 5 In Denmark, a serosurvey of 168 Danish patients seropositive for borreliosis, demonstrated that a total of 12.5% (21/168) tick-bitten patients were seropositive for R. helvetica, and four cases of seroconversion were identified.6 Recently, eight patients from France, Italy and Thailand were reported, with serological evidence of infection associated with mild fever, myalgia and no cutaneous rash.1 In another study from Laos, serological analysis identified R. helvetica as the cause of fever in 2.6% of adults admitted to hospital, and in Sweden, a recent study shows that between 3 and 4.4% of patients with symptoms of infectious disease appearing after a tick bite had significant titres of antibodies to Rickettsia spp.2, 7 Most reported patients have presented a flu-like self-limiting mild febrile disease, sometimes with prolonged fever and less frequently with a rash.1 Relevant studies using culture or PCR to confirm the causative role of R. helvetica in acute febrile illness are lacking, but in the present case, the presence of R. helvetica in the blood was verified by PCR together with serological evidence of infection. All other reported cases of SFG rickettsiosis, possibly caused by R. helvetica, have been diagnosed using serological criteria including MIF, Western blotting and cross-absorption methods, and the causative role of R. helvetica has not previously been verified by isolation or, as in the present case, by PCR during the phase of active illness. The patient studied here also presented a different clinical picture, with fever and muscular symptoms that were found to be more severe and intense than previously described for this agent, together with a rash and a slow and delayed recovery.
Section snippets
Case report
A 57-year-old, healthy and immunocompetent man, living on the eastern coast of Sweden, a tick-endemic area, was admitted to the Department of Infectious Diseases in Falun, Sweden, on May 17, 2003, with septicaemic fever, myalgias, arthralgias, severe headache and photophobia of unknown aetiology. A prominent neck muscle myalgia with subjective neck stiffness was one reason for initial suspicion of meningitis. The fever had begun on May 11 and 1–2 days after onset of illness, a 1–2-mm macular
Discussion
In addition to high fever, the patient had severe headache, subjective neck stiffness, photophobia and a macular rash involving the arms and legs, a clinical picture that differs from previous observations of R. helvetica. Owing to the prominent neck muscle myalgia, meningitis or meningoencephalitis was suspected, but could be ruled out. Notably, in African tick bite fever and Rocky Mountain spotted fever (RMSF), neck myalgia is thought to indicate a central nervous system affection. However,
Conclusion
The present case indicates that R. helvetica may also present a more acute febrile illness with rash and long-lasting muscular symptoms, and it is therefore important that this agent be taken into consideration in cases of FUO or symptoms of infection appearing after a tick bite. PCR may be a tool that makes early diagnosis possible.
Acknowledgement
This study was supported by grants from the Dalarna Research Foundation (project no. 99285) and the Center for Clinical Research Dalarna (project no. 420016).
References (15)
- et al.
Association of Rickettsia helvetica with chronic perimyocarditis in sudden cardiac death
Lancet
(1999) - et al.
Tick-borne rickettsioses around the world: emerging diseases challenging old concepts
Clin Microbiol Rev
(2005) - et al.
Rickettsial infections and fever, Vientiane, Laos
Emerging Infect Dis
(2006) - et al.
Ticks and tickborne bacterial diseases in humans: an emerging infectious threat
Clin Infect Dis
(2001) - et al.
Presence of Rickettsia helvetica in granulomatous tissue from patients with sarcoidosis
J Infect Dis
(2002) - et al.
Serological and molecular evidence of Rickettsia helvetica in Denmark
Scand J Infect Dis
(2004) - et al.
Seroprevalence of Rickettsia spp. infection among tick-bitten patients and blood-donors in Sweden
Scand J Infect Dis
(2008)
Cited by (62)
Rickettsiosis in Denmark: A nation-wide survey
2023, Ticks and Tick-borne DiseasesTick-borne diseases under the radar in the North Sea Region
2023, Ticks and Tick-borne DiseasesEmerging tick-borne spotted fever group rickettsioses in the Balkans
2023, Infection, Genetics and EvolutionCitation Excerpt :In contrast to the high prevalence of R. helvetica infection in ticks (Andersson et al., 2018; Szekeres et al., 2016) and frequent human exposure in endemic areas (Lindblom et al., 2016; Wolfel et al., 2017), the reports of clinical infection caused by this TBP in Europe are scarce. Rickettsia helvetica was reported as single causative agent in patients with acute febrile illness (Fournier et al., 2000), rash, myasthenia (Nilsson, 2009) and meningitis (Nilsson et al., 2010). Rickettsia helvetica infection in the tick feeding on human is found to be strongly associated with development of facial paralysis (Azagi et al., 2022).
Prevalence of zoonotic and non-zoonotic Rickettsia in horses: A systematic review and meta-analysis
2023, New Microbes and New InfectionsEmerging tick-borne pathogens in the Nordic countries: A clinical and laboratory follow-up study of high-risk tick-bitten individuals
2020, Ticks and Tick-borne DiseasesCitation Excerpt :Moreover, studies have detected Bartonella henselae DNA in field-collected I. ricinus ticks but, thus far, no convincing clinical cases of cat-scratch disease, following a tick-bite, have been reported and the viability of ticks as vectors for this bacterium remains controversial (Telford and Wormser, 2010). All of the aforementioned microorganisms have been associated with infections in humans (Fehr et al., 2010; Nilsson, 2009; Nilsson et al., 2011, 2010; Uhnoo et al., 1992; von Loewenich et al., 2010). Despite this, with the exception of Bbsl and TBE virus, little is known about their pathogenic potential in a northern European setting and the clinical features of patients seeking medical care due to these infections remain to be fully elucidated.
Rickettsioses in Denmark: A retrospective survey of clinical features and travel history
2018, Ticks and Tick-borne DiseasesCitation Excerpt :This low number of possible endemic rickettsioses in the hospital cohort is in line with several other studies, reporting asymptomatic seroconversion or mild, self-limiting disease during infection with R. helvetica, likely perceived as too mild for hospital referral by many primary care physicians (Fournier et al., 2004, 2000; Lindblom et al., 2016; Phongmany et al., 2006). Serious infections with R. helvetica have been described by a Swedish research group (Nilsson, 2009; Nilsson et al., 2011, 2010, 1999b). However, such reports are scarce and have, so far, not described cases in other geographical locations, outside of Sweden, where R. helvetica is also endemic in ticks.