Abstract

Background

Epidemiologic features of tick typhus among German travelers has not been surveyed recently.

Methods

Clinical features, travel and medical histories in 78 patients with tick typhus who presented to a German outpatient clinic for Infectious and Tropical Diseases were investigated, in order to identify common epidemiological factors and potential strategies of prevention. Diagnosis was confirmed by serological detection of IgG‐ and IgM‐antibodies to Rickettsia conorii by indirect immunofluorescence.

Results

The majority of patients (71.8%) had visited southern Africa prior to presentation. All patients presented with fever as the main symptom. An eschar was still present in 68 patients (87.2%) with regional lymphadenitis in 19.2%. However, only a minority of patients (17.9%) remembered a tick bite at the location of the eschar.

Conclusion

Efforts to reduce the incidence of tick typhus in travelers should focus on preventive measures targeting behavioral changes. Avoiding tick bites during travel to endemic areas appears to be the single most important prophylactic action. Taking this into consideration, it should be possible to decrease the number of travelers returning with tick typhus significantly by adequate pretravel counseling.

References

1
Raeber
P
Winteler
S
Paget
J
.
Fever in the returned traveller: remember rickettsial diseases
.
Lancet
 
1994
;
344
:
331
. (PubMed) 7914272
2
Brouqui
P
Harle
J
Delmont
J
et al.
African tick‐bite fever. An imported spotless rickettsiosis
.
Arch Intern Med
 
1997
;
157
:
119
124
. (PubMed) 8996049
3
Kelly
P
Beati
L
Mason
P
et al.
Rickettsia africae sp. nov., the etiological agent of African tick bite fever
.
Int J Syst Bacteriol
 
1996
;
46
:
611
614
. 8934912
4
Walker
T
.
Rickettsial interactions with human endothelial cells in vitro: adherence and entry
.
Infect Immun
 
1984
;
44
:
205
210
. (PubMed) 6425214
5
Helmick
C
Bernard
K
D'Angelo
L
.
Rocky Mountain spotted fever: clinical, laboratory, and epidemiological features of 262 cases
.
J Infect Dis
 
1984
;
150
:
480
488
. (PubMed) 6491365
6
Cascio
A
Dones
P
Romano
A
Titone
L
.
Clinical and laboratory findings of boutonneuse fever in Sicilian children
.
Eur J Pediatr
 
1998
;
157
:
482
486
. (PubMed) 9667405
7
Kemper
C
Spivack
A
Deresinski
S
.
Atypical papulovesicular rash due to infection with Rickettsia conorii
.
Clin Infect Dis
 
1992
;
15
:
591
594
. 1420671
8
Senneville
E
Ajana
F
Lecocq
P
et al.
Rickettsia conorii isolated from ticks introduced to northern France by a dog
.
Lancet
 
1991
;
337
:
676
. AMBIGUOUS 1672016,1672015,1672014
9
Marschang
A
Nothdurft
H
Kumlien
S
von Sonnenburg
F
.
Imported rickettsioses in German travellers
.
Infection
 
1995
;
23
:
94
97
. (PubMed) 7622271
10
McCarron
B
Clelland
S
Kennedy
D
Pithie
A
.
Visual loss in a returning traveller with tick typhus
.
Scott Med J
 
1998
;
43
:
116
117
. (PubMed) 9757503
11
Fournier
P
Roux
V
Caumes
E
et al.
Outbreak of Rickettsia africae infections in participants of an adventure race in South Africa
.
Clin Infect Dis
 
1998
;
27
:
316
323
. 9709882
12
African tick‐bite fever among international travelers—Oregon 1988
.
MMWR Morb Mortal Wkly Rep
 
1998
;
47
:
950
952
Anonymous. (PubMed) 9832471
13
Broadhurst
L
Kelly
D
Chan
C
et al.
Laboratory evaluation of a dot‐blot enzyme immunoassay for serologic confirmation of illness due to Rickettsia conorii
.
Am J Trop Med Hyg
 
1998
;
58
:
786
789
. 9660464