Case reportImported rickettsioses in Italy
Introduction
New rickettsial species have been identified over the past few years as a consequence of the use of cell culture systems and sequence-based molecular identification technique.1, 2 Recent studies suggest that 2% of fever in ill travellers returned from the developing world is caused by rickettsioses.3, 4 Rickettsioses observed most frequently are African tick bite fever (ATBF) and Mediterranean spotted fever (MSF).2, 5
Few cases of tick-borne spotted fever group (SFG) rickettsioses have been reported in travellers returning to Italy from endemic areas, probably due to non-specific clinical signs and limited availability of diagnostic tests.6, 7 The diagnosis of tick-borne SFG rickettsioses in Italy is confirmed by non-specific serologic assay (indirect immunofluorescence reaction, ELISA, Weil Felix) with issues of cross-reactivity. It is therefore likely that within the autochthonous MSF cases reported each year some are caused by other species.8
The purpose of this Italian Rickettsioses Surveillance Study (IRiSS) was to investigate some epidemiological and clinical features of tick-borne SFG rickettsioses acquired abroad or in Italy.
Section snippets
Materials and methods
The cases were collected prospectively within the Gruppo di Interesse e Studio delle Patologie di Importazione (GISPI), a network of Institutes for Infectious and Tropical Diseases in Northern Italy. Diagnosis of tick-borne SFG rickettsioses was suspected when three or more symptoms and/or signs were presents: fever (T ≥ 38 °C), rash, eschar, headache, alopecia, lymphangitis, and satellite lymphadenopathy.
Two categories were defined: imported rickettsioses, when the symptoms and/or signs were
Results
From September 2005 to September 2009 a total of 26 suspected cases of tick-borne SFG rickettsioses were observed (20 imported and 6 autochthonous).
Eight tick-borne SFG rickettsioses (30.8%) were confirmed by serology. Only one patient (1/4, 25.0%) had acute-phase serum sample positive whereas eight patients (8/8, 100%) had convalescent-phase serum samples positive (Table 1). After the Western blot and cross absorption assays, a total of six cases were confirmed as R. africae infections and one
Discussion
Out of 26 clinically suspected patients, 8 (30.8%) were documented as having tick-borne SFG rickettsioses.
All patients were travellers returning from Africa. Six cases were caused by R. africae.
These observations are similar to other published findings, suggesting that a high proportion of imported tick-borne SFG rickettsioses diagnosed in travellers are acquired in southern Africa and that R. africae is the most commonly rickettsia acquired.4, 5, 6, 13, 14
Seven patients (88%) had an initial
Conflict of interest
None declared.
Acknowledgements
None.
References (18)
- et al.
Rickettsia parkeri rickettsiosis and its clinical distinction from Rocky Mountain spotted fever
Clin Infect Dis
(2008) - et al.
Tick borne rickettsioses around the world: emerging diseases challenging old concepts
Clin Microbiol Rev
(2005) - et al.
Fever in returned travelers: results from the GeoSentinel Surveillance Network
Clin Infect Dis
(2007) - et al.
Multicenter GeoSentinel analysis of rickettsial diseases in international travelers, 1996–2008
Emerg Infect Dis
(2009) - et al.
Rickettsioses and the international traveler
Clin Infect Dis
(2004) - et al.
Outbreak of African tick-bite fever in six Italian tourists returning from South Africa
Eur J Clin Microbiol Infect Dis
(2002) - et al.
Prospective observational study of fever in hospitalized returning travelers and migrants from tropical areas, 1997–2001
J Travel Med
(2004) - et al.
Current knowledge of rickettsial diseases in Italy
Ann N Y Acad Sci
(2006) - et al.
Kinetics of antibody responses in Rickettsia africae and Rickettsia conorii infections
Clin Diagn Lab Immunol
(2002)
Cited by (10)
Imported rickettsial infections to the United Kingdom, 2015–2020
2023, Journal of InfectionIdentification of rickettsial immunoreactive proteins using a proximity ligation assay Western blotting and the traditional immunoproteomic approach
2018, Comparative Immunology, Microbiology and Infectious DiseasesCitation Excerpt :Both R. africae and R. conorii were detected in ticks removed from humans in Turkey [18], also in ticks from Kenya [19] and should be considered as potential pathogens [20]. However, the cases with R. africae in Europe are all imported by travelers from endemic zones [21–23,7]. ATBF is usually a benign disease, but perhaps more severe for the elderly population [24].
Rickettsia diversity in southern Africa: A small mammal perspective
2018, Ticks and Tick-borne DiseasesCitation Excerpt :In addition, recent studies described R. massiliae in ticks from tortoises (Halajian et al., 2016) and R. felis in ticks from dogs (Kolo et al., 2016). R. africae has often been implicated in ATBF in travelers returning from South Africa and Swaziland (Jensenius et al., 1999; Raoult et al., 2001; Pretorius et al., 2004; Parola et al., 2005; Büchau et al., 2006; Roch et al., 2008; Tappe et al., 2009; Althaus et al., 2010; Wieten et al., 2011; Beltrame et al., 2012; Schleenvoigt et al., 2012; Socolovschi et al., 2012). Also, R. sibirica mongolitimonae was confirmed in a patient suffering from lymphangitis, headache, and fever in South Africa (Parola, 2006).
Rickettsioses imported by travellers and migrants to Spain attended in the +Redivi network, 2009-2020
2023, Journal of Travel MedicineFatal complicated infection by Rickettsia conorii: Role of cerebral involvement, antiphospholipid antibodies, and multiple comorbidities
2023, Recenti Progressi in MedicinaRickettsiosis with Pleural Effusion: A Systematic Review with a Focus on Rickettsiosis in Italy
2022, Tropical Medicine and Infectious Disease