Rickettsia felis in Ctenocephalides felis from Guatemala and Costa Rica.
ABSTRACT Rickettsia felis is an emerging human pathogen associated primarily with the cat flea Ctenocephalides felis. In this study, we investigated the presence of Rickettsia felis in C. felis from Guatemala and Costa Rica. Ctenocephalides felis were collected directly from dogs and cats, and analyzed by polymerase chain reaction for Rickettsia-specific fragments of 17-kDa protein, OmpA, and citrate synthase genes. Rickettsia DNA was detected in 64% (55 of 86) and 58% (47 of 81) of flea pools in Guatemala and Costa Rica, respectively. Sequencing of gltA fragments identified R. felis genotype URRWXCal(2) in samples from both countries, and genotype Rf2125 in Costa Rica. This is the first report of R. felis in Guatemala and of genotype Rf2125 in Costa Rica. The extensive presence of this pathogen in countries of Central America stresses the need for increased awareness and diagnosis.
- SourceAvailable from: sove.org[show abstract] [hide abstract]
ABSTRACT: Species in the genera Bartonella and Rickettsia are vector-borne pathogens of humans and domestic animals. The natural reservoirs and enzootic transmission cycles of these bacteria are poorly known in South Carolina. Thirteen species of lice and fleas were collected from urban animals and screened for the presence of Bartonella and Rickettsia by PCR amplification using genus-specific primers. Bartonella henselae was present in cat fleas (Ctenocephalides felis) from Virginia opossums (Didelphis virginiana) and a novel genotype of Bartonella was detected in Orchopeas howardi from an eastern gray squirrel (Sciurus carolinensis). We detected R. typhi and three novel genotypes Rickettsia in other species of fleas and lice. Rickettsia typhi, the causative agent of murine typhus, was detected in two pools of lice (Enderleinellus marmotae) from the woodchuck (Marmota monax). Cat fleas harbored one of two novel genotypes of Rickettsia. A third novel Rickettsia was detected in Orchopeas howardi from an eastern gray squirrel.Journal of Vector Ecology 01/2006; 30(2):310-5. · 1.23 Impact Factor
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ABSTRACT: To determine the cause of acute febrile illnesses other than malaria in the North Eastern Province, Kenya, we investigated rickettsial infection among patients from Garissa Provincial Hospital for 23 months during 2006-2008. Nucleic acid preparations of serum from 6 (3.7%) of 163 patients were positive for rickettsial DNA as determined by a genus-specific quantitative real-time PCR and were subsequently confirmed by molecular sequencing to be positive for Rickettsia felis. The 6 febrile patients' symptoms included headache; nausea; and muscle, back, and joint pain. None of the patients had a skin rash.Emerging Infectious Diseases 07/2010; 16(7):1081-6. · 6.79 Impact Factor
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ABSTRACT: Rickettsia felis infection usually is a mild-to-moderate illness characterized by general signs and symptoms. Generally, patients do not require hospitalization. However, we detected 2 severe infections with R. felis. Our findings support the importance of R. felis infection as a potentially severe illness in humans.International journal of medical microbiology: IJMM 06/2009; 299(7):529-33. · 4.54 Impact Factor
Am. J. Trop. Med. Hyg., 86(6), 2012, pp. 1054–1056
Copyright © 2012 by The American Society of Tropical Medicine and Hygiene
Short Report: Rickettsia felis in Ctenocephalides felis from Guatemala and Costa Rica
Adriana Troyo,* Danilo A´lvarez, Lizeth Taylor, Gabriela Abdalla, O´lger Caldero ´n-Arguedas, Maria L. Zambrano,
Gregory A. Dasch, Kim Lindblade, Laya Hun, Marina E. Eremeeva, and Alejandra Este ´vez
Departamento de Parasitologı ´a, Centro de Investigacio ´n en Enfermedades Tropicales, Facultad de Microbiologı ´a, Universidad de Costa Rica,
San Jose ´, Costa Rica; Centro de Estudios en Salud, Instituto de Investigaciones, Universidad del Valle de Guatemala, Ciudad de Guatemala,
Guatemala; Departamento de Microbiologı ´a e Inmunologı ´a, Centro de Investigacio ´n en Enfermedades Tropicales, Facultad de Microbiologı ´a,
Universidad de Costa Rica, San Jose ´, Costa Rica; Rickettsial Zoonoses Branch, National Center for Emerging and Zoonotic Infectious Diseases,
Centers for Disease Control and Prevention, Atlanta, Georgia; International Emerging Infectious Diseases Program,
Centers for Disease Control and Prevention, Atlanta, Georgia; Jiann-Ping Hsu College of Public Health,
Georgia Southern University, Statesboro, Georgia
In this study, we investigated the presence of Rickettsia felis in C. felis from Guatemala and Costa Rica. Ctenocephalides
felis were collected directly from dogs and cats, and analyzed by polymerase chain reaction for Rickettsia-specific
fragments of 17-kDa protein, OmpA, and citrate synthase genes. Rickettsia DNA was detected in 64% (55 of 86) and
58% (47 of 81) of flea pools in Guatemala and Costa Rica, respectively. Sequencing of gltA fragments identified R. felis
genotype URRWXCal2in samples from both countries, and genotype Rf2125 in Costa Rica. This is the first report of
R. felis in Guatemala and of genotype Rf2125 in Costa Rica. The extensive presence of this pathogen in countries of
Central America stresses the need for increased awareness and diagnosis.
Rickettsia felis is an emerging human pathogen associated primarily with the cat flea Ctenocephalides felis.
Rickettsia felis is an emerging pathogen, which was first
detected in the cat flea, Ctenocephalides felis. It was later
associated with human disease manifesting with fever, head-
aches, myalgia, and occasionally rash.1Even though R. felis
has also been detected in domestic and wild animals, their
susceptibility to this bacterium and their role as reservoirs
has not been well established.2
Rickettsia felis has a cosmopolitan distribution associated
with fleas. In the Americas, human disease caused by R. felis
has been described from the United States, Mexico, and
Brazil.2,3Furthermore, DNA of R. felis has also been detected
in fleas from Peru, Uruguay, Chile, Argentina, and more
recently in the West Indies, Panama ´, and Costa Rica.2–7There
is no evidence yet of human disease caused by R. felis in
Central America, although human exposure to pathogenic
spotted fever group rickettsiae different from R. rickettsii,
may occur in this region.8,9As part of an ongoing project to
characterize rickettsial diseases in Guatemala and Costa Rica,
we assessed the presence of R. felis in sites where cases of
rickettsioses have been previously reported.
Entomological surveys were carried out at several locations
in Guatemala and Costa Rica throughout 2009 and 2010,
including wet and dry seasons. Collection sites in Guatemala
were located in the Southeastern region, departments of
Santa Rosa (14°16¢N, 90°18¢W) and Jutiapa (14°16¢N,
89°53¢W), an area suspected of a spotted fever outbreak in
2007 (Eremeeva ME, unpublished data). In Costa Rica, collec-
tions were performed at sites from the Caribbean slope of
the country, where cases of Rocky Mountain spotted fever and
uncharacterized spotted fevers have been documented,10spe-
cifically in the districts of Turrialba (9°54¢N, 83°41¢W), La
Virgen (10°23¢N, 84°08¢W), Limo ´n (9°59¢N, 83°02¢W), Cahuita
(9°44¢N, 82°50¢W), Gua ´piles (10°13¢N, 83°47¢W), Gua ´cimo
(10°12¢N, 83°41¢W), and Jime ´nez (10°12¢N, 83°44¢W). Addi-
tional samples of C. felis from two locations in San Jose ´
(9°55¢N, 84°04¢W), obtained by the laboratory of Medical
Arthropodology (University of Costa Rica) through the gen-
eral public as part of inquiries and identification services, were
At collection locations (households, farms, etc.) fleas were
collected from household cats and dogs, and from opossums
captured using live animal traps. Ctenocephalides felis were
grouped into lots according to host species, collection site,
For the preliminary detection of DNA of Rickettsia spp.,
pools of 1–10 C. felis from each lot were analyzed using nested
and semi-nested polymerase chain reaction (PCR) assays
targeting specific fragments of the 17-kDa protein and OmpA
genes. Primers R17-122 and R17-500 were used for the pri-
mary PCR of Rickettsia-specific 17-kDa protein gene, and
nested PCRs were performed using primers TZ15 and TZ16
or RP2 and RPID, which detect fragments specific for Rickettsia
of the spotted fever group and typhus group, respec-
tively.11,12For ompA, primers Rr190-70 and Rr190-701 were
used in the first PCR, and Rr190-70 and Rr190-602 for the
semi-nested PCR.12Detection of positive samples was fur-
ther confirmed in samples from Guatemala using a TaqMan
assay for the citrate synthase (gltA) gene that is species
specific for detection of R. typhi and R. felis,13or by the
Rickettsia spp. wide-range gltA assay using primers CS-78
and CS-323 in samples from Costa Rica.14
Three-hundred thirty-three C. felis were collected from
two sites in Guatemala and grouped into 86 pools, including
73 flea pools from dogs and 13 from cats (Table 1). The DNA
of Rickettsia was detected in 55 pools (64%), 54 from Jutiapa
(78% collected from dogs and 22% from cats) and one pool
from Santa Rosa collected from a dog.
In Costa Rica, a total 439 C. felis was collected from the
Forty-seven pools (58%) contained Rickettsia DNA by positive
PCR for at least two of the three genes analyzed, and positivity
varied between sites. Forty-four of 74 pools from dogs (59%)
and 3 of 7 pools from cats (43%) were positive. No C. felis
was found on two Didelphis marsupialis and three Philander
opossum captured in Cahuita, Gua ´cimo, Limo ´n, and Turrialba.
*Address correspondence to Adriana Troyo, Centro de Investigacio ´n
en Enfermedades Tropicales, Facultad de Microbiologı ´a, Universidad
de Costa Rica, San Jose ´ 11501, Costa Rica. E-mail: adriana.troyo@
The DNA of R. typhi was not detected during this study.
The presence of R. felis DNA in C. felis from Guatemala
was confirmed by multiplex TaqMan gltA assay. Only one
genetic type of gltA was found by sequencing of the TaqMan
product, and it was the same as the URRWXCal2reference
strain of R. felis from California (CP000053). In contrast, two
genotypes were identified in fleas from Costa Rica after
sequencing gltA amplicons of 38 of 47 positive samples
(81%), Rf2125 (AF516333) and URRWXCal2 of R. felis
(Table 1). The gltA fragments were identical between the
three sequences of R. felis URRWXCal2 analyzed from
Costa Rica, and similarity was 99.25% (399 of 402) with the
sequence reported in GenBank (CP000053). The only Costa
Rican fleas containing R. felis URRWXCal2were from dogs
from the capital city, San Jose ´. Two different sequences were
detected in gltA fragments of R. felis Rf2125 from positive
samples of all other sites in Costa Rica, and they were both
99.25% (399 of 402) similar to the corresponding fragment of
the sequence reported in GenBank (AF516333). GenBank
accession nos. for fragments of R. felis gltA obtained in this
study are JF523341 (Guatemala) and JN982948-JN982950
To our knowledge, we describe the first detection of R. felis
in C. felis from Guatemala. This common and widespread
occurrence of R. felis in fleas in Costa Rica and Guatemala is
similar to findings previously reported from other countries
in Latin America.15–17For example, in a study that analyzed
pools of C. felis from Iquitos, Peru, 71 of 74 pools contained
In both countries, R. felis was detected in C. felis from both
dogs and cats, although more dogs were sampled. Further-
more, R. felis was detected frequently on fleas from dogs,
suggesting this may be a relevant host in maintaining C. felis
and possibly R. felis in the areas studied. Considering the
close relationship with pet owners, dogs may indirectly pose
a risk for human infection, because they may promote expo-
sure by transporting the infected fleas to the resident envi-
ronment. Although Didelphis virginiana opossums have been
associated with a life cycle of R. felis in wild-caught C. felis in
Texas and California,18C. felis were not found on the few
opossums captured during this study. Therefore, additional
trapping of opossums is needed to elucidate their role in cir-
culation of R. felis in Costa Rica and Guatemala.
Human infection with R. felis has not been documented in
Central America, although R. felis was reported recently in
Panama ´ and Costa Rica.5–7There are previous reports of
R. felis Rf2125 in Latin America and other countries, but as
no human disease has yet been associated with this genotype,
its pathogenic potential warrants further evaluation.19,20More-
over, this study shows the presence of at least two different
genotypes of R. felis, including the pathogenic URRWXCal2
strain, in regions of Central America. Whether either of these
genetic types has an adaptive advantage in infecting fleas has
not yet been evaluated.
Because C. felis was frequently found on cats and dogs in
this study, and substantial numbers of fleas tested were
infected with R. felis, humans may have a high probability of
exposure to this pathogenic Rickettsia. Clinical signs and
symptoms of R. felis infection are very similar to those of
other rickettsioses and resemble other more commonly diag-
nosed tropical diseases, such as dengue and malaria.3,21,22
Therefore, it is likely that infections caused by this pathogen
are underestimated and misdiagnosed by the medical commu-
nity throughout Central America. Because R. felis may cause
severe illness in some individuals,3,23proper physician educa-
tion, disease awareness, and adequate diagnosis are essential.
Received November 28, 2011. Accepted for publication March 4, 2012.
Acknowledgments: Wethank DavidMora ´n, LuisEscobar, and Ramo ´n
Medrano from Guatemala, and Adrian Avendan ˜o, Ivan Coronado,
Luis Vargas, Greivin Rodriguez, Julio Rojas, and Gilberth Alvarado
from Costa Rica, for technical support during entomological surveys.
Jusara Ortiz, Carlos Mata, and Carlos Vargas are also acknowledged
for technical support during PCR analyses in Costa Rica. We also
thank Marcelo B. Labruna for confirmation of Rickettsia genotypes
from Costa Rica, and Michael L. Levin and Marcelo Labruna for
their helpful guidance and suggestions.
Financial support: This research was supported byNeTropica 9-N-2008,
Universidad de Costa Rica 803-A8-127, and Cooperative Agreement
No. UO1 GH000028 from the U.S. Centers for Disease Control and
Disclaimer: The findings and conclusions in this report are those of
the authors and do not necessarily represent the official views of the
Centers for Disease Control and Prevention or the Department of
Health and Human Services of the United States, or the institutions
with which the authors are affiliated.
Authors’ addresses: Adriana Troyo, Lizeth Taylor, O´lger Caldero ´n-
Arguedas, and Laya Hun, Centro de Investigacio ´n en Enfermedades
Tropicales, Facultad de Microbiologı ´a, Universidad de Costa Rica,
San Jose ´, Costa Rica, E-mails: email@example.com, mayra.taylor@
ucr.ac.cr, firstname.lastname@example.org, and email@example.com. Danilo
A´lvarez, Gabriela Abdalla, and Alejandra Este ´vez, Centro de Estudios
Rickettsia felis frequency and gltA genotypes in Ctenocephalides felis pools from different areas of Guatemala and Costa Rica
Country SiteC. felis collected
Positive pools (%)
Samples sequenced R. felis genotype Dogs CatsTotal
Costa Rica Cahuita
Gua ´piles/Jime ´nez/Gua ´cimo
San Jose ´
RICKETTSIA FELIS IN GUATEMALA AND COSTA RICA
en Salud, Universidad del Valle de Guatemala, Ciudad de Guatemala,
Guatemala, E-mails: firstname.lastname@example.org, email@example.com,
and firstname.lastname@example.org. Kim Lindblade, CDC Regional Office for
Central America and Panama, Universidad del Valle de Guatemala,
Ciudad de Guatemala, Guatemala, E-mail: email@example.com. Maria L.
Zambrano, and Gregory A. Dasch, Rickettsial Zoonoses Branch,
National Center for Emerging and Zoonotic Infectious Diseases,
Centers for Disease Control and Prevention, Atlanta, GA, E-mails:
firstname.lastname@example.org and email@example.com. Marina E. Eremeeva,
Jiann-Ping Hsu College of Public Health, Georgia Southern Univer-
sity, Statesboro, GA, E-mail: firstname.lastname@example.org.
Reprint requests: Adriana Troyo, Centro de Investigacio ´n en
Enfermedades Tropicales, Facultad de Microbiologı ´a, Universidad
de Costa Rica, San Jose ´ 11501, Costa Rica, Tel: (506) 2511-5430,
Fax: (506) 2511 4360, E-mail: email@example.com.
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Rickettsia felis in
TROYO AND OTHERS